DOC AIRBUS | AMM A320FFLIGHT MANAGEMENT SYSTEM (FMS) - DESCRIPTION AND OPERATION
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1. General
The Flight Management System (FMS) gives various functions to help the crew in the management of the flight. These functions are all constructed from a lateral and a vertical flight plan. The pilot can select this flight plan from a data base stored in the system and he can modify it at any time.
In the lateral plan, the FMS gives:
In the vertical plan, it computes:
Then it computes predictions along the flight plan based on these speeds and weight. It performs vertical guidance referenced to these predictions.
The crew can insert different data or can select function modes through two Multipurpose Control and Display Units (MCDU) linked to two Flight Management and Guidance Computers (FMGC).
The FMS also uses the two MCDUs, both Navigation Display (ND), and, for some parameters, the Primary Flight Display (PFD), to display data related to the above mentioned functions.
** ON A/C NOT FOR ALL The Flight Management System (FMS) gives various functions to help the crew in the management of the flight. These functions are all constructed from a lateral and a vertical flight plan. The pilot can select this flight plan from a data base stored in the system and he can modify it at any time.
In the lateral plan, the FMS gives:
- navigation computation (aircraft position),
- radio navigation aids selection (automatically or by pilot selection),
- lateral guidance to keep the aircraft along the flight plan from the take-off to the approach.
In the vertical plan, it computes:
- an optimum speed at each point,
- other characteristic speeds,
- the aircraft predicted weight and center of gravity,
- predicted wind at each point.
Then it computes predictions along the flight plan based on these speeds and weight. It performs vertical guidance referenced to these predictions.
The crew can insert different data or can select function modes through two Multipurpose Control and Display Units (MCDU) linked to two Flight Management and Guidance Computers (FMGC).
The FMS also uses the two MCDUs, both Navigation Display (ND), and, for some parameters, the Primary Flight Display (PFD), to display data related to the above mentioned functions.
2. Component Location
** ON A/C NOT FOR ALL | FIN | FUNCTIONAL DESIGNATION | PANEL | ZONE | ACCESS DOOR | ATA REF |
|---|---|---|---|---|---|
| ** ON A/C ALL | |||||
| 1CA1 | FMGC-1 | 824 | 127 | 22-83-34 | |
| 1CA2 | FMGC-2 | 84VU | 128 | 22-83-34 | |
3. System Description
The FMS general architecture which shows the two FM portions incorporated in the FMGCs, with the two MCDUs and the Display Management Computers (DMC) for display is given in the following figure:
** ON A/C NOT FOR ALL The FMS general architecture which shows the two FM portions incorporated in the FMGCs, with the two MCDUs and the Display Management Computers (DMC) for display is given in the following figure:
4. Power Supply
The 28VDC power supplies:
In addition to the 28VDC power supply, the following signals supply the FMGCs:
In electrical emergency configuration, only the FMGC1 is supplied.
** ON A/C NOT FOR ALL The 28VDC power supplies:
- FMGC1 through 28VDC ESS SHED BUS 8PP
- FMGC2 through 28VDC BUS2 2PP
In addition to the 28VDC power supply, the following signals supply the FMGCs:
- chassis ground,
- side 1 signals (C and M) wired to the ground on the FMGC1 only (priority).
In electrical emergency configuration, only the FMGC1 is supplied.
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6. Component Description
A. Overview of the Flight Management Function (FMF) Software
It is composed of:
Hardware Performance:
It is composed of:
- Flight Management Processor (FMP) applicative software,
- Input/Output Data Processor (IDP) applicative software,
- FMP/IDP basic software.
Hardware Performance:
- two microprocessors (6o Mhz, 32 bits),
- 16 Mega bytes RAM,
- 7 Mega bytes Navigation Data Base (NBD) capacity.
B. Reset Management
Robustness versus resets is improved:
Reset cockpit impacts are lowered:
Robustness versus resets is improved:
- deactivation/reset of specific functions is implemented in order to limit the functional consequences of multiple reset (avoid loss of flight plan),
- the following functions are concerned: predictions (Active, TMPY, and SEC F-PLN), MCDU, AOC/ATC, and Printer.
Reset cockpit impacts are lowered:
- no AP/ATHR cut-off upon reset, but a reversion to selected guidance mode (V/S, HDG),
- no reconfiguration of DMC upon reset, so it is no longer necessary to switch the display mode to get the ND back to normal display, instead of MAP NOT AVAIL message configuration.
7. Operation/Control and Indicating
This chapter describes the following functions:
This chapter describes the following functions:
- Navigation function,
- Lateral function,
- Vertical function.
- Navigation function,
- Lateral function,
- Vertical function.
A. Navigation Function
The navigation function of the FMS gives to the system the following indications:
This function also performs the management of the radio Navigation Aids (navaids) VHF Omnidirectional Range (VOR), Distance Measuring Equipment (DME), Global Positioning System (GPS), Instrument Landing System (ILS), Microwave Landing System (MLS if installed) and Automatic Direction Finder (ADF) for the position computation, for the display and the take-off/approach guidance.
The navigation function of the FMS gives to the system the following indications:
This function also performs the management of the radio Navigation Aids (navaids) VHF Omnidirectional Range (VOR), Distance Measuring Equipment (DME), Global Positioning System (GPS), Instrument Landing System (ILS), GNSS Landing System (GLS if installed), Microwave Landing System (MLS if installed) and Automatic Direction Finder (ADF) for the position computation, for the display and the take-off/approach guidance.
The position computation algorithms take into account polar navigation.
For the case of a Biased DME, the frequency is not used for the position computation but only for the display.
The navigation function of the FMS gives to the system the following indications:
- present aircraft position,
- altitude,
- wind,
- true airspeed,
- ground speed,
- true and magnetic heading,
- true track angle.
This function also performs the management of the radio Navigation Aids (navaids) VHF Omnidirectional Range (VOR), Distance Measuring Equipment (DME), Global Positioning System (GPS), Instrument Landing System (ILS), Microwave Landing System (MLS if installed) and Automatic Direction Finder (ADF) for the position computation, for the display and the take-off/approach guidance.
The navigation function of the FMS gives to the system the following indications:
- present aircraft position,
- altitude,
- wind,
- true airspeed,
- ground speed,
- true and magnetic heading,
- true track angle.
This function also performs the management of the radio Navigation Aids (navaids) VHF Omnidirectional Range (VOR), Distance Measuring Equipment (DME), Global Positioning System (GPS), Instrument Landing System (ILS), GNSS Landing System (GLS if installed), Microwave Landing System (MLS if installed) and Automatic Direction Finder (ADF) for the position computation, for the display and the take-off/approach guidance.
The position computation algorithms take into account polar navigation.
For the case of a Biased DME, the frequency is not used for the position computation but only for the display.
B. Navigation Function- Aircraft Position Computation
The inertial position and the speed of each Inertial Reference System (IRS) is the basis for an aircraft position computation.
If an IRS position is available, one of the navigation modes, as described below, is used. Otherwise, no navigation computation is provided.
The navigation function uses Kalman filter techniques to integrate inertial, radio, and hybrid/autonomous GPS data to:
The inertial position and the speed of each Inertial Reference System (IRS) is the basis for an aircraft position computation.
If an IRS position is available, one of the navigation modes, as described below, is used. Otherwise, no navigation computation is provided.
The navigation function uses Kalman filter techniques to integrate inertial, radio, and hybrid/autonomous GPS data to:
- produce a solution of an optimal aircraft navigation related to a specific navigation mode and,
- estimate its corresponding precision.
(1) Modes of navigation selection
When GPS is installed, GPS/INERTIAL is the basic navigation mode, so long as the GPS data are available with the required precision and integrity. Otherwise, a navigation mode with the least errors is chosen based upon the best position available.
In case of navigation mode transition, the current FM position reaches smoothly the best estimated position (slew limiting rate depending on the flight area).
The basic modes of navigation given by order of precision and importance, are the following:
Navigation Mode Selection Logic ** ON A/C NOT FOR ALL
Navigation Mode Selection Logic ** ON A/C NOT FOR ALL
When GPS is installed, GPS/INERTIAL is the basic navigation mode, so long as the GPS data are available with the required precision and integrity. Otherwise, a navigation mode with the least errors is chosen based upon the best position available.
In case of navigation mode transition, the current FM position reaches smoothly the best estimated position (slew limiting rate depending on the flight area).
The basic modes of navigation given by order of precision and importance, are the following:
Navigation Mode Selection Logic ** ON A/C NOT FOR ALL Navigation Mode Selection Logic ** ON A/C NOT FOR ALL (2) Modes of navigation selection - GPS/INERTIAL
- For hybrid GPS architecture:
if a valid and reasonable hybrid GPS/IRS position is available from one of the ADIRU, the GPS/INERTIAL mode is chosen. - For GPS autonomous architecture:
if a valid and reasonable autonomous GPS position is available from one of the GPS, the GPS/INERTIAL mode is chosen.
(3) Modes of navigation selection - DME/DME/INERTIAL
This mode can be selected only if the GPS/INERTIAL position mode is not available and if a valid and reasonable radio combination allows the computation of a DME/DME position.
This mode can be inhibited throught the selection of Radionav Deselect prompt on SELECTED NAVAIDS page.
This mode can be selected only if the GPS/INERTIAL position mode is not available and if a valid and reasonable radio combination allows the computation of a DME/DME position.
This mode can be inhibited throught the selection of Radionav Deselect prompt on SELECTED NAVAIDS page.
(4) Modes of navigation selection - GPS/INERTIAL
- For hybrid GPS architecture:
If a valid and reasonable hybrid GP/IRS position is available from one of the IRS's and if it provides the best accuracy solution than any other sensor (based on sensor EPE), the GPS/INERTIAL mode is chosen. - For GPS autonomous architecture:
If a valid and reasonable autonomous GPS position is available from one of the GPS's and if it provides the best accuracy solution than any other sensor (based on sensor EPE), the GPS/INERTIAL mode is chosen.
(5) Modes of navigation selection - DME/DME/INERTIAL
This mode can be selected only if the GPS/INERTIAL position mode is not available and if a valid and reasonable radio combination allows the computation of a DME/DME position, or if it provides the best accuracy solution than any other sensor (based on sensor EPE).
This mode can be inhibited throught the selection of Radionav Deselect prompt on SELECTED NAVAIDS page.
This mode can be selected only if the GPS/INERTIAL position mode is not available and if a valid and reasonable radio combination allows the computation of a DME/DME position, or if it provides the best accuracy solution than any other sensor (based on sensor EPE).
This mode can be inhibited throught the selection of Radionav Deselect prompt on SELECTED NAVAIDS page.
(6) Modes of navigation selection - DME/VOR/INERTIAL
This mode can be selected only if the GPS/INERTIAL and DME/DME/INERTIAL position modes are not available and if it gives a better accurate position than any other sensor.
This mode can be selected only if the GPS/INERTIAL and DME/DME/INERTIAL position modes are not available and if it gives a better accurate position than any other sensor.
(7) Modes of navigation selection - INERTIAL ONLY
This mode of navigation is used if VOR/DME/INERTIAL, DME/DME/INERTIAL or GPS/INERTIAL modes are not available and at least one IRS is valid. If three IRS are available, the inertial position is an optimal mixed position based on the three IRS positions and speeds.
This mode of navigation is used if VOR/DME/INERTIAL, DME/DME/INERTIAL or GPS/INERTIAL modes are not available and at least one IRS is valid. If three IRS are available, the inertial position is an optimal mixed position based on the three IRS positions and speeds.
(8) Modes of navigation selection - DME/VOR/INERTIAL
This mode can be selected only if the GPS/INERTIAL and DME/DME/INERTIAL position modes are not available and if it gives a better accurate position than any other sensor.
This mode can be inhibited throught the selection of Radionav Deselect prompt on SELECTED NAVAIDS page.
This mode can be selected only if the GPS/INERTIAL and DME/DME/INERTIAL position modes are not available and if it gives a better accurate position than any other sensor.
This mode can be inhibited throught the selection of Radionav Deselect prompt on SELECTED NAVAIDS page.
(9) Modes of navigation selection - INERTIAL ONLY
This mode of navigation is used if VOR/DME/INERTIAL, DME/DME/INERTIAL or GPS/INERTIAL modes are not available and at least one IRS is valid. If three IRS are available, the inertial position is an optimal mixed position based on the three IRS positions and speeds.
This mode of navigation is used if VOR/DME/INERTIAL, DME/DME/INERTIAL or GPS/INERTIAL modes are not available and at least one IRS is valid. If three IRS are available, the inertial position is an optimal mixed position based on the three IRS positions and speeds.
(10) Class of navigation
Two classes of navigation are defined (HIGH or LOW). They reflect the fact that the system respects the current navigation accuracy requirement. The current class of navigation is determined by comparing the Estimated Position Uncertainty (EPU: value of the 95% of confidence on the computed system position) with the current Required Navigation Performance (RNP based on navigation area / manually entered / leg dependent). When EPU < RNP, the class of navigation is HIGH, otherwise it is LOW. The class of navigation is displayed continuously on the PROG page.
A level of confidence on the FMS position in GPS mode is determined as a function of the GP(IR)S position accuracy and integrity. The GPS confidence status is GPS PRIMARY when both accuracy and integrity requirements are met.
Two classes of navigation are defined (HIGH or LOW). They reflect the fact that the system respects the current navigation accuracy requirement. The current class of navigation is determined by comparing the Estimated Position Uncertainty (EPU: value of the 95% of confidence on the computed system position) with the current Required Navigation Performance (RNP based on navigation area / manually entered / leg dependent). When EPU < RNP, the class of navigation is HIGH, otherwise it is LOW. The class of navigation is displayed continuously on the PROG page.
A level of confidence on the FMS position in GPS mode is determined as a function of the GP(IR)S position accuracy and integrity. The GPS confidence status is GPS PRIMARY when both accuracy and integrity requirements are met.
| --------------------------------------- |
| ! GPS Reasonable ! GPS Unreasonable ! |
| ---------------------------------------------------------- |
| ! HIGH (EPU < RNP) ! GPS PRIMARY ! GPS PRIMARY LOST ! |
| ---------------------------------------------------------- |
| ! LOW (EPU > RNP) ! GPS PRIMARY LOST ! GPS PRIMARY LOST ! |
| ---------------------------------------------------------- |
(11) Class of navigation
Two classes of navigation are defined (HIGH or LOW). They reflect the fact that the system respects the current navigation accuracy requirement. The current class of navigation is determined by comparing the Estimated Position Uncertainty (EPU: value of the 95% of confidence on the computed system position) with the current Required Navigation Performance (RNP based on navigation area / manually entered / leg dependent). When EPU < RNP, the class of navigation is HIGH, otherwise it is LOW. The class of navigation is displayed continuously on the PROG page.
A level of confidence on the FMS position in GPS mode is determined as a function of the GP(IR)S position accuracy and integrity. The GPS confidence status is GPS PRIMARY when both accuracy and integrity requirements are met.
Two classes of navigation are defined (HIGH or LOW). They reflect the fact that the system respects the current navigation accuracy requirement. The current class of navigation is determined by comparing the Estimated Position Uncertainty (EPU: value of the 95% of confidence on the computed system position) with the current Required Navigation Performance (RNP based on navigation area / manually entered / leg dependent). When EPU < RNP, the class of navigation is HIGH, otherwise it is LOW. The class of navigation is displayed continuously on the PROG page.
A level of confidence on the FMS position in GPS mode is determined as a function of the GP(IR)S position accuracy and integrity. The GPS confidence status is GPS PRIMARY when both accuracy and integrity requirements are met.
| --------------------------------------- |
| ! GPS Reasonable ! GPS Unreasonable ! |
| ---------------------------------------------------------- |
| ! HIGH (EPU < RNP) ! GPS PRIMARY ! GPS PRIMARY LOST ! |
| ---------------------------------------------------------- |
| ! LOW (EPU > RNP) ! GPS PRIMARY LOST ! GPS PRIMARY LOST ! |
| ---------------------------------------------------------- |
(12) Class of navigation - RNP value
The RNP value depends of the navigation area (TERMINAL, ENROUTE, OCEANIC, APPROACH); concerning the logic for switching between the TERMINAL and ENROUTE navigation areas, the navigation area selection will be function of the aircraft altitude.
To pass from the TERMINAL navigation area to the APPROACH navigation area, the distance between the aircraft and the first approach waypoint can be less than 5 NM.
The RNP value depends of the navigation area (TERMINAL, ENROUTE, OCEANIC, APPROACH); concerning the logic for switching between the TERMINAL and ENROUTE navigation areas, the navigation area selection will be function of the aircraft altitude.
To pass from the TERMINAL navigation area to the APPROACH navigation area, the distance between the aircraft and the first approach waypoint can be less than 5 NM.
(13) Class of navigation - RNP value
If not manually entered or leg dependent (defined in the NDB), a RNP value depends of the navigation area (TERMINAL, ENROUTE, OCEANIC, APPROACH); concerning the logic for switching between the TERMINAL and ENROUTE navigation areas, the navigation area selection will be function of the aircraft altitude.
To pass from the TERMINAL navigation area to the APPROACH navigation area, the distance between the aircraft and the first approach waypoint can be less than 5 NM.
If not manually entered or leg dependent (defined in the NDB), a RNP value depends of the navigation area (TERMINAL, ENROUTE, OCEANIC, APPROACH); concerning the logic for switching between the TERMINAL and ENROUTE navigation areas, the navigation area selection will be function of the aircraft altitude.
To pass from the TERMINAL navigation area to the APPROACH navigation area, the distance between the aircraft and the first approach waypoint can be less than 5 NM.
C. Navigation Function - Radio Tuning
The navigation function automatically selects and tunes navaids:
The navigation function automatically selects and tunes navaids:
- for display and takeoff/approach guidance, with priority given to any manual tuning orders made by the crew,
- for navigation computations (on the basis of their availability and suitability).
- automatic tuning,
- manual tuning,
- Radio Management Panel (RMP) tuning.
(1) Automatic tuning
Provided that the RMP has no control on the navigation radios (RMP NAV CONTROL discrete not set to the open state), the FMGC tunes automatically VOR and DME for display, VOR/DME and DME for navigation computation, ILS (and MLS if installed) for navigation update and takeoff/approach guidance, NDB for display.
The tuning of the navigation radios follows hierarchically rules to facilitate the optimal combination based on the A/C position and on the radio NAV availability. Five frequencies are available for DME tuning, one for VOR tuning and another one for ILS.
Provided that the RMP has no control on the navigation radios (RMP NAV CONTROL discrete not set to the open state), the FMGC tunes automatically VOR and DME for display, VOR/DME and DME for navigation computation, ILS (and MLS if installed) for navigation update and takeoff/approach guidance, NDB for display.
The tuning of the navigation radios follows hierarchically rules to facilitate the optimal combination based on the A/C position and on the radio NAV availability. Five frequencies are available for DME tuning, one for VOR tuning and another one for ILS.
(2) Automatic tuning
Provided that the RMP has no control on the navigation radios (RMP NAV CONTROL discrete not set to the open state), the FMGC tunes automatically VOR and DME for display, VOR/DME and DME for navigation computation, ILS (MLS if installed and GLS if installed) for navigation update and takeoff/approach guidance, NDB for display.
The tuning of the navigation radios follows hierarchically rules to facilitate the optimal combination based on the A/C position and on the radio NAV availability. Five frequencies are available for DME tuning, one for VOR tuning and another one for ILS, MLS or GLS.
MLS if embedded is not associated to RUNWAY displayed in DEPARTURE page, so MLS is not automatically tuned for take off guidance (according to pilot selection on DEPARTURE page. However MLS is automatically tuned for approach guidance (according to pilot selection on ARRIVAL pages)
Provided that the RMP has no control on the navigation radios (RMP NAV CONTROL discrete not set to the open state), the FMGC tunes automatically VOR and DME for display, VOR/DME and DME for navigation computation, ILS (MLS if installed and GLS if installed) for navigation update and takeoff/approach guidance, NDB for display.
The tuning of the navigation radios follows hierarchically rules to facilitate the optimal combination based on the A/C position and on the radio NAV availability. Five frequencies are available for DME tuning, one for VOR tuning and another one for ILS, MLS or GLS.
MLS if embedded is not associated to RUNWAY displayed in DEPARTURE page, so MLS is not automatically tuned for take off guidance (according to pilot selection on DEPARTURE page. However MLS is automatically tuned for approach guidance (according to pilot selection on ARRIVAL pages)
(3) Automatic tuning - OPC option
The option No ADF on board (OPC option) allows to manage fully the navigation architecture with no ADF on board:
The option No ADF on board (OPC option) allows to manage fully the navigation architecture with no ADF on board:
- ADF tuning is desactivated,
- ADF informations/prompts are removed from RAD NAV pages,
- NDB approaches are inhibited.
(4) Manual tuning
The pilot can tune, through the RAD NAV page, VOR, ILS, NDB, MLS (if installed) for display. When a station is manually tuned, it cannot be overridden by an automatic tuning. When the system comes into the PREFLIGHT phase, all the previously selected navaids are deselected.
The pilot can tune, through the RAD NAV page, VOR, ILS, NDB, MLS (if installed) for display. When a station is manually tuned, it cannot be overridden by an automatic tuning. When the system comes into the PREFLIGHT phase, all the previously selected navaids are deselected.
(5) RMP tuning
The FMGC recognises the RMP tuning when the RMP NAV CONTROL discrete is set to the open state. When this occurs, neither the system nor the pilot can tune the radio frequencies on either side of the PROG page or RAD NAV pages of MCDU.
The FMGC recognises the RMP tuning when the RMP NAV CONTROL discrete is set to the open state. When this occurs, neither the system nor the pilot can tune the radio frequencies on either side of the PROG page or RAD NAV pages of MCDU.
(6) Manual tuning
The pilot can tune, through the RAD NAV page, VOR, ILS, NDB, MLS (if installed) , GLS (if installed) for guidance. When a station is manually tuned, it cannot be overridden by an automatic tuning. When the system comes into the PREFLIGHT phase, all the previously selected navaids are deselected.
When a VOR, an ILS or a MLS is manually tuned by frequency/channel on RAD NAV page, the associated DME frequency is systematically tuned to avoid partial tuning.
The pilot can tune, through the RAD NAV page, VOR, ILS, NDB, MLS (if installed) , GLS (if installed) for guidance. When a station is manually tuned, it cannot be overridden by an automatic tuning. When the system comes into the PREFLIGHT phase, all the previously selected navaids are deselected.
When a VOR, an ILS or a MLS is manually tuned by frequency/channel on RAD NAV page, the associated DME frequency is systematically tuned to avoid partial tuning.
(7) RMP tuning
The FMGC recognises the RMP tuning when the RMP NAV CONTROL discrete is set to the open state. When this occurs, neither the system nor the pilot can tune the radio frequencies on either side of the PROG page or RAD NAV pages of MCDU.
The FMGC recognises the RMP tuning when the RMP NAV CONTROL discrete is set to the open state. When this occurs, neither the system nor the pilot can tune the radio frequencies on either side of the PROG page or RAD NAV pages of MCDU.
D. Navigation Function - Messages and MCDU Display
(1) Navigation messages
The messages related to the navigation that can be displayed on the MCDU and/or the Electronic Flight Instrument System (EFIS) navigation display are:
The messages related to the navigation that can be displayed on the MCDU and/or the Electronic Flight Instrument System (EFIS) navigation display are:
- GPS messages,
- radio tuning messages,
- messages related to the IRS alignment,
- messages related to the IRS attitude mode,
- other navigation messages.
(2) MCDU display
The display related to the navigation available for the crew on the MCDU are the following:
The display related to the navigation available for the crew on the MCDU are the following:
- POSITION MONITOR page:
This page displays general navigation information which represent the A/C position (FMGC 1 and 2 positions, and its current navigation modes, radio position or GPS position, mixed IRS position, IRS deviations and modes). - PROGRESS page:
This page displays navigation information such as GPS confidence level, RNP threshold, EPU, class of navigation, information about the position entered by the crew to update the A/C position. - RADIO NAV page:
This page displays identifiers, frequencies and course for radio navaids for side 1 and side 2 receivers when no RMP is in Nav mode (if at least one RMP is in Nav mode, then all fields, except titles, are blank). The navaids selected by the crew are manually entered via the Radio Nav page. The navaids selected by the crew are displayed in large font. The automatically selected navaids are displayed in small font. - SELECTED NAVAIDS page:
This page displays all the radio navaids being tuned (identifiers and frequencies), and the associated class and tuning mode for each. It displays also a line select prompt next to each displayed radio navaid and a pilot deselected navaid. A GPS deselect/reselect prompt allows the crew to deselect or reselect the use of the GPS. When GPS is deselected by the crew, the FM will not use the GPS data. - GPS MONITOR page (only if GPS is installed):
This page displays GPS information from two GPS sensors. The information displayed includes for each GPS sensor: identifier, position, true track, altitude, ground speed, horizontal figure of merit (HFOM), mode, number of satellites currently being tracked. - PREDICTIVE GPS page:
This page displays information on GPS confidence level or status, at and near the time of arrival (predicted or specified by the crew ) at the destination airport specified in the flight plan, and, at and near the time of arrival (predicted or specified by the crew) at a reference waypoint specified by the crew. The display also includes provision for the crew to deselect up to 32 GPS satellites, but only four at a time. - IRS MONITOR page:
This page displays the following information for each of the three IRS: identifier, mode, mode dependent status message, time to go in the align mode before the nav mode can be initiated, average rate of the IRS drift. - IRSn page:
This page displays IRSn parameters and GPS/IRSn hybrid parameters: Identifier, IRS inertial position, true track, true heading, magnetic heading, ground speed, wind direction and speed, GPS/IRS hybrid position, GPS/IRS HFOM.
(3) Navigation messages
The messages related to the navigation that can be displayed on the MCDU and/or the Electronic Flight Instrument System (EFIS) navigation display are:
The messages related to the navigation that can be displayed on the MCDU and/or the Electronic Flight Instrument System (EFIS) navigation display are:
- GPS messages,
- radio tuning messages,
- messages related to the IRS alignment,
- messages related to the IRS attitude mode,
- other navigation messages.
(4) MCDU display
The display related to the navigation available for the crew on the MCDU are the following:
The display related to the navigation available for the crew on the MCDU are the following:
- POSITION MONITOR page:
This page displays general navigation information which represent the A/C position (FMGC 1 and 2 positions, and its current navigation modes, radio position or GPS position, mixed IRS position, IRS deviations and modes). - PROGRESS page:
This page displays navigation information such as GPS confidence level, RNP threshold, EPU, class of navigation, information about the position entered by the crew to update the A/C position. - RADIO NAV page:
This page displays identifiers, frequencies and course for radio navaids for side 1 and side 2 receivers when no RMP is in Nav mode (if at least one RMP is in Nav mode, then all fields, except titles, are blank). The navaids selected by the crew are manually entered via the Radio Nav page. The navaids selected by the crew are displayed in large font. The automatically selected navaids are displayed in small font.
When an ILS is tuned, the G/S deselect/select prompt exists if both FLS option activated and Mix LOC/VNAV option activated OPC options are activated. - SELECTED NAVAIDS page:
This page displays all the radio navaids being tuned (identifiers and frequencies), and the associated class and tuning mode for each. It displays also a line select prompt next to each displayed radio navaid and a pilot deselected navaid. A GPS deselect/reselect prompt allows the crew to deselect or reselect the use of the GPS. When GPS is deselected by the crew, the FM will not use the GPS data.
The 4L prompt should refer to ILS, MLS or GLS navaid. A Radionav deselect/select prompt provides the means to inhibit the use of radionavigation modes (IRS/DME/DME and IRS/VOR/DME). - GPS MONITOR page (only if GPS is installed):
This page displays GPS information from two GPS sensors. The information displayed includes for each GPS sensor: identifier, position, true track, altitude, ground speed, horizontal figure of merit (HFOM), mode, number of satellites currently being tracked. - PREDICTIVE GPS page:
This page displays information on GPS confidence level or status, at and near the time of arrival (predicted or specified by the crew ) at the destination airport specified in the flight plan, and, at and near the time of arrival (predicted or specified by the crew) at a reference waypoint specified by the crew. The display also includes provision for the crew to deselect up to 32 GPS satellites, but only four at a time. - IRS MONITOR page:
This page displays the following information for each of the three IRS: identifier, mode, mode dependent status message, time to go in the align mode before the nav mode can be initiated, average rate of the IRS drift. - IRSn page:
This page displays IRSn parameters and GPS/IRSn hybrid parameters: Identifier, IRS inertial position, true track, true heading, magnetic heading, ground speed, wind direction and speed, GPS/IRS hybrid position, GPS/IRS HFOM.
E. Navigation Function - IRS Alignment
Alignment of the IRS starts when the OFF/NAV/ATT selector switch of the Mode Select Unit (MSU) is in the Nav position. IRS ALIGNMENT calculations can only be done on ground before take-off, after the pilot entered the current A/C coordinates or after auto alignment by the IRS itself (auto-aligning IRS generation).
The entry results from a pilot action either (as basic procedure) on the MCDU INIT A page, or (as optional procedure) on the Inertial System Display Unit (ISDU). If the option of the automatic alignment on GPS position is activated (depending of IRS standards), no pilot action is required. The alignment is automatically done in relation with the GPS position.
The entry results from a pilot action either (as basic procedure) on the MCDU IRS INIT page
accessible from the INIT A page, or (as optional procedure) on the Inertial System Display Unit (ISDU). If the option of the automatic alignment on GPS position is activated (depending of IRS standards), no pilot action is required. The alignment is automatically done in relation with the GPS position.
The alignment is only available on the active Flight Plan and automatically performed on GPS position.
In case of bad IRS alignment (at least one of the three IRS has been aligned more than 5Nm away from the departure airport position), a CHECK IRS/AIRPORT POS message is displayed in the MCDU scratchpad to warn the crew of a discrepancy between origin departure and IRS alignment position before take-off.
The alignment is only available on the active Flight Plan and automatically performed on GPS position.
IRS INIT page displays for each IRS during or after alignment:
Alignment of the IRS starts when the OFF/NAV/ATT selector switch of the Mode Select Unit (MSU) is in the Nav position. IRS ALIGNMENT calculations can only be done on ground before take-off, after the pilot entered the current A/C coordinates or after auto alignment by the IRS itself (auto-aligning IRS generation).
The entry results from a pilot action either (as basic procedure) on the MCDU INIT A page, or (as optional procedure) on the Inertial System Display Unit (ISDU). If the option of the automatic alignment on GPS position is activated (depending of IRS standards), no pilot action is required. The alignment is automatically done in relation with the GPS position.
The entry results from a pilot action either (as basic procedure) on the MCDU IRS INIT page
accessible from the INIT A page, or (as optional procedure) on the Inertial System Display Unit (ISDU). If the option of the automatic alignment on GPS position is activated (depending of IRS standards), no pilot action is required. The alignment is automatically done in relation with the GPS position.
The alignment is only available on the active Flight Plan and automatically performed on GPS position.
In case of bad IRS alignment (at least one of the three IRS has been aligned more than 5Nm away from the departure airport position), a CHECK IRS/AIRPORT POS message is displayed in the MCDU scratchpad to warn the crew of a discrepancy between origin departure and IRS alignment position before take-off.
The alignment is only available on the active Flight Plan and automatically performed on GPS position.
IRS INIT page displays for each IRS during or after alignment:
- the IRS state : ALIGNING, ALIGNED, IN ATT or OFF
- the source of alignment if defined (GPS for automatic alignment, CDU or
- the alignment position if defined
The two first lines make it possible to define a reference position to be sent to the IRS for alignment (by default this position is the FROM position) and to cross-check alignment or reference position with the GPS one. When the alignment ends up these two lines are blank.
The alignment on REF is done by selecting ALIGN ON REF prompt which then changes to CONFIRM ALIGN ON REF * prompt.
In case of bad IRS alignment (at least one of the three IRS has been aligned or is aligning more than 5Nm away from the departure airport position), a CHECK IRS/AIRPORT POS message is displayed in the MCDU scratchpad to warn the crew of a discrepancy between origin departure and IRS alignment position before take-off.
If the IRS INIT page is not currently displayed and at least one of the ADIRU is waiting for an alignment position the ALIGN IRS message is displayed.
F. Navigation Function - IRS Heading Initialization
When any one of three IRS is set to the ATT mode, the pilot must initialize the appropriate IRS with a heading. This initialization can occur in flight or on ground, in case of failed IRS in NAV mode. The entry is done on the MCDU when the IRS/HDG initialization option is activated (via OPC software option) or on the ISDU (if an optional ISDU is installed).
When any one of three IRS is set to the ATT mode, the pilot must initialize the appropriate IRS with a heading. This initialization can occur in flight or on ground, in case of failed IRS in NAV mode. The entry is done on the MCDU when the IRS/HDG initialization option is activated (via OPC software option) or on the ISDU (if an optional ISDU is installed).
G. Navigation Function - Average Drift Computation
The FM computes on the ground at the end of the flight, an average drift for each IRS. This drift is then displayed on the IRS page.
The FM computes on the ground at the end of the flight, an average drift for each IRS. This drift is then displayed on the IRS page.
H. Lateral Flight Planning
The lateral functions for the FMS includes:
The lateral functions for the FMS includes:
- lateral flight planning such as initialization and lateral revisions,
- guidance such as lateral guidance mode selection.
The FMS can give up to three flight plans (F-PLN): - an ACTIVE F-PLN (the one currently used for the flight),
- a TEMPORARY F-PLN dedicated to tactical revisions,
- a SECONDARY F-PLN dedicated to strategical purpose.
I. Lateral Flight Planning - Initialization
Due to the type of the various functions that the system is performing during the flight, it is necessary for the crew to initialize the system by inserting some data via the MCDU. By selecting the INIT page, the pilot has the possibility to initialize the FMS.
Initialization is presented in the following paragraphs from a lateral and a vertical point of view.
The initialization consists of three main functions:
Due to the type of the various functions that the system is performing during the flight, it is necessary for the crew to initialize the system by inserting some data via the MCDU. By selecting the INIT page, the pilot has the possibility to initialize the FMS.
Initialization is presented in the following paragraphs from a lateral and a vertical point of view.
The initialization consists of three main functions:
- select a F-PLN which will be the real basis for all the computations and the displays done by the FMS,
- align the IRS by using the position of the airport stored in the FMS data base and called by selection of the F-PLN,
- enter the zero fuel weight (ZFW) and center of gravity for zero fuel weight (ZFWCG) which will be used for all the various performance computations.
J. Lateral Flight Planning - F-PLN Initialization
The default primary F-PLN (that means without flight plan initialization) is as follows:
PPOS
-- F-PLN DISCONTINUITY --
The major purpose of this function is to declare the flight plan origin and destination (FROM/TO) or to call up a pre-stored company route.
The default primary F-PLN (that means without flight plan initialization) is as follows:
PPOS
-- F-PLN DISCONTINUITY --
The major purpose of this function is to declare the flight plan origin and destination (FROM/TO) or to call up a pre-stored company route.
(1) INIT A/SEC INIT A pages
The initialization is done on the INIT A page for the active F-PLN and on the SEC INIT A page for the secondary F-PLN. For example, the initialization parameters are the following: company route (CO RTE), FROM/TO designation.
The SEC INIT A page has the same objective as the ACTIVE flight plan on the INIT A page.
The initialization is done on the INIT A page for the active F-PLN and on the SEC INIT A page for the secondary F-PLN. For example, the initialization parameters are the following: company route (CO RTE), FROM/TO designation.
The SEC INIT A page has the same objective as the ACTIVE flight plan on the INIT A page.
(2) Route selection page
The pilot can enter origin and destination airports on the INIT A page for the active F-PLN and on the SEC INIT A page for the secondary F-PLN. The skeleton of the F-PLN is strung with FROM/TO airports as follows:
ORIGIN AIRPORT
-- F-PLN DISCONTINUITY --
DESTINATION AIRPORT
If one or several routes match with this city pair in the NDB, then the ROUTE SELECTION pages are automatically proposed before inserting the desired route.
The company route, when inserted, designates all or any portion of the primary route. Access to these pages can also result in the designation of a list of alternate CO RTE, one of these being selected.
The pilot can enter origin and destination airports on the INIT A page for the active F-PLN and on the SEC INIT A page for the secondary F-PLN. The skeleton of the F-PLN is strung with FROM/TO airports as follows:
ORIGIN AIRPORT
-- F-PLN DISCONTINUITY --
DESTINATION AIRPORT
If one or several routes match with this city pair in the NDB, then the ROUTE SELECTION pages are automatically proposed before inserting the desired route.
The company route, when inserted, designates all or any portion of the primary route. Access to these pages can also result in the designation of a list of alternate CO RTE, one of these being selected.
(3) Passenger count
This function allows to enter pax number through the INIT A page and to send the passenger count value to the Cabin Pressure Control System (CPCS) in order to optimise cabin pressure.
This function allows to enter pax number through the INIT A page and to send the passenger count value to the Cabin Pressure Control System (CPCS) in order to optimise cabin pressure.
(4) Ground Temperature
In preflight phase, the pilot can enter or modify the Ground Temperature for take off in this field. The A/C SAT (while aircraft is on ground) should not be used for forecast and predicted temperature. It is used to define ISA deviation at airport for FMS temperature model used in take-off/climb phases.
In preflight phase, the pilot can enter or modify the Ground Temperature for take off in this field. The A/C SAT (while aircraft is on ground) should not be used for forecast and predicted temperature. It is used to define ISA deviation at airport for FMS temperature model used in take-off/climb phases.
K. Lateral Flight Planning - Fuel Initialization
The purpose of this function is to initialize weights and to display fuel predictions for the flight. On first access to the INIT B page, pilot has to insert the ZFW/ZFWCG, then enter a BLOCK FUEL. Pilot has two options:
The FMS will only accept ZFW, ZFWCG and BLOCK FUEL pilot inserted values if they are inside pre-defined input range (the ZFW input range can be refined and A/C customized if the Take-off securing OPC option is activated).
When Engine start occurs while the INIT B page is displayed, the FUEL PRED page is automatically displayed.
The pilot can also insert the ZFW/ZFWCG on this page which is displayed in 3R; a pilot entry on the GW/CG, displayed in 5R, is not allowed.
The scratchpad message REENTER ZFW/ZFWCG is issued when the connection (or 15 s initialization integrity check) between FMC and Fuel Quantity Indication Computer (FQIC) failed.
The scratchpad message INITIALIZE ZFW/ZFWCG is issued when the engines are started without having previously provided those data to the system.
After transition to TAKE-OFF, all the route reserve values are converted in EXTRA fuel, and pilot entry for RTE RSV/RTE RSV % is not allowed.
However the RTE RSV/RTE RSV % field remains displayed on FUEL PRED page to inform the crew that a zero value is used for both data in fuel predictions computation.
RTE RSV/RTE RSV % field remains displayed in flight even if the fuel policy specifies that route reserve cannot be computed in flight. In this latter case, the display is zero for both data and pilot entry is not allowed.
The ALTN fuel value is either a calculated value or a pilot entry.
Pilot entry for this data is possible on INIT B page and FUEL PRED page, where the ALTN/TIME field is added with the same format as on INIT B page.
When Engine start occurs while the INIT B page is displayed, the FUEL PRED page is automatically displayed.
The pilot can also insert the ZFW/ZFWCG on this page which is displayed in 3R; a pilot entry on the GW/CG, displayed in 5R, is not allowed.
The scratchpad message REENTER ZFW/ZFWCG is issued when the connection (or 15 s initialization integrity check) between FMC and Fuel Quantity Indication Computer (FQIC) failed.
The scratchpad message INITIALIZE ZFW/ZFWCG is issued when the engines are started without having previously provided those data to the system.
After transition to TAKE-OFF, all the route reserve values are converted in EXTRA fuel, and pilot entry for RTE RSV/RTE RSV % is not allowed.
However the RTE RSV/RTE RSV % field remains displayed on FUEL PRED page to inform the crew that a zero value is used for both data in fuel predictions computation.
RTE RSV/RTE RSV % field remains displayed in flight even if the fuel policy specifies that route reserve cannot be computed in flight. In this latter case, the display is zero for both data and pilot entry is not allowed.
The ALTN fuel value is either a calculated value or a pilot entry.
Pilot entry for this data is possible on INIT B page and FUEL PRED page, where the ALTN/TIME field is added with the same format as on INIT B page.
FINAL is the fuel weight burnt in a holding pattern that is assumed to be flown prior to final approach at either the primary or alternate destination. The FINAL fuel value is either a computed value or a pilot entry.
MIN DEST FOB is the minimum fuel weight at primary destination requested by the crew. It shall be either a default value or a pilot-entered value. The default value of MIN DEST FOB shall be equal to FINAL + ALTN fuel.
The scratchpad message CHECK MIN DEST FOB is issued when MIN DEST FOB is a pilot entry & MIN DEST FOB < ALTN + FINAL.
The purpose of this function is to initialize weights and to display fuel predictions for the flight. On first access to the INIT B page, pilot has to insert the ZFW/ZFWCG, then enter a BLOCK FUEL. Pilot has two options:
- enter a value through the BLOCK field.
- use the FUEL PLANNING function by pressing the associated prompt. It will compute and display the minimum fuel to satisfy the requirements of the flight plan.
The FMS will only accept ZFW, ZFWCG and BLOCK FUEL pilot inserted values if they are inside pre-defined input range (the ZFW input range can be refined and A/C customized if the Take-off securing OPC option is activated).
When Engine start occurs while the INIT B page is displayed, the FUEL PRED page is automatically displayed.
The pilot can also insert the ZFW/ZFWCG on this page which is displayed in 3R; a pilot entry on the GW/CG, displayed in 5R, is not allowed.
The scratchpad message REENTER ZFW/ZFWCG is issued when the connection (or 15 s initialization integrity check) between FMC and Fuel Quantity Indication Computer (FQIC) failed.
The scratchpad message INITIALIZE ZFW/ZFWCG is issued when the engines are started without having previously provided those data to the system.
After transition to TAKE-OFF, all the route reserve values are converted in EXTRA fuel, and pilot entry for RTE RSV/RTE RSV % is not allowed.
However the RTE RSV/RTE RSV % field remains displayed on FUEL PRED page to inform the crew that a zero value is used for both data in fuel predictions computation.
RTE RSV/RTE RSV % field remains displayed in flight even if the fuel policy specifies that route reserve cannot be computed in flight. In this latter case, the display is zero for both data and pilot entry is not allowed.
The ALTN fuel value is either a calculated value or a pilot entry.
Pilot entry for this data is possible on INIT B page and FUEL PRED page, where the ALTN/TIME field is added with the same format as on INIT B page.
When Engine start occurs while the INIT B page is displayed, the FUEL PRED page is automatically displayed.
The pilot can also insert the ZFW/ZFWCG on this page which is displayed in 3R; a pilot entry on the GW/CG, displayed in 5R, is not allowed.
The scratchpad message REENTER ZFW/ZFWCG is issued when the connection (or 15 s initialization integrity check) between FMC and Fuel Quantity Indication Computer (FQIC) failed.
The scratchpad message INITIALIZE ZFW/ZFWCG is issued when the engines are started without having previously provided those data to the system.
After transition to TAKE-OFF, all the route reserve values are converted in EXTRA fuel, and pilot entry for RTE RSV/RTE RSV % is not allowed.
However the RTE RSV/RTE RSV % field remains displayed on FUEL PRED page to inform the crew that a zero value is used for both data in fuel predictions computation.
RTE RSV/RTE RSV % field remains displayed in flight even if the fuel policy specifies that route reserve cannot be computed in flight. In this latter case, the display is zero for both data and pilot entry is not allowed.
The ALTN fuel value is either a calculated value or a pilot entry.
Pilot entry for this data is possible on INIT B page and FUEL PRED page, where the ALTN/TIME field is added with the same format as on INIT B page.
FINAL is the fuel weight burnt in a holding pattern that is assumed to be flown prior to final approach at either the primary or alternate destination. The FINAL fuel value is either a computed value or a pilot entry.
MIN DEST FOB is the minimum fuel weight at primary destination requested by the crew. It shall be either a default value or a pilot-entered value. The default value of MIN DEST FOB shall be equal to FINAL + ALTN fuel.
The scratchpad message CHECK MIN DEST FOB is issued when MIN DEST FOB is a pilot entry & MIN DEST FOB < ALTN + FINAL.
L. Lateral Flight Planning - Revisions
With regards to the active F-PLN (primary and/or alternate), the lateral revisions generate a temporary flight plan (TMPY F-PLN) allowing multiple revisions. Multiple revisions contains the possibility to link up several flight plan modifications, before inserting them. As many revisions as necessary can be taken into account in the TMPY F-PLN, provided that the F-PLN capacity is respected. The secondary F-PLN revisions are applied directly to the flight plan.
There are two types of lateral revisions:
The TMPY F-PLN (copy of the active F-PLN which has been changed according to a lateral or vertical action) also gives UNDO mechanisms: the last revision can be deleted by the UNDO prompt selection from TMPY F-PLN.
With regards to the active F-PLN (primary and/or alternate), the lateral revisions generate a temporary flight plan (TMPY F-PLN) allowing multiple revisions. Multiple revisions contains the possibility to link up several flight plan modifications, before inserting them. As many revisions as necessary can be taken into account in the TMPY F-PLN, provided that the F-PLN capacity is respected. The secondary F-PLN revisions are applied directly to the flight plan.
There are two types of lateral revisions:
- Revisions directly applied on Active/Temporary F-PLN or SEC F-PLN pages (Direct F-PLN revisions).
- Revisions through the following MCDU pages:
LAT REV page: insert or modify departure/arrival procedures, insert next waypoint/new destination, insert or modify or clear offset, insert or modify holding pattern, select or activate alternate F-PLN, insert airway, insert LAT/LONG crossing, insert radial/abeam fix info.
or
DIR TO page: go direct to with or without abeam, intercept inbound or outbound radial.
The TMPY F-PLN (copy of the active F-PLN which has been changed according to a lateral or vertical action) also gives UNDO mechanisms: the last revision can be deleted by the UNDO prompt selection from TMPY F-PLN.
(1) DEPARTURE procedure
This function is used to insert or modify a departure procedure which contains three optional elements:
A matching waypoint is searched between the procedure and the enroute. For an active F-PLN modification, the temporary F-PLN is updated as soon as a new element of the departure procedure is selected.
One prompt and two different pages are available to select a departure procedure:
This function is used to insert or modify a departure procedure which contains three optional elements:
- RWY (runway transition),
- SID (standard instrument departure),
- TRANS (SID enroute transition).
A matching waypoint is searched between the procedure and the enroute. For an active F-PLN modification, the temporary F-PLN is updated as soon as a new element of the departure procedure is selected.
One prompt and two different pages are available to select a departure procedure:
- the DEPARTURE prompt is only available on LAT REV page at origin airport,
- the DEPARTURE 1 page displays the available runways and means,
- the DEPARTURE 2 page displays the list of SID which are compatible with the selected runway and the enroute transitions compatible with the selected SID.
(2) DEPARTURE procedure - General information
NOTE: When the FMS flight plan contains a discontinuity as the first leg, the automatic arm of the FG NAV mode is inhibited on ground in order to improve performance of the radar vector departure procedures.
(3) ARRIVAL procedure
This function is used to insert or modify an arrival procedure which contains four optional elements:
One prompt and three different pages are available to select an arrival procedure:
This function is used to insert or modify an arrival procedure which contains four optional elements:
- APPR (final approach, including runway and missed approach),
- APPR VIA (approach transition),
- STAR (including STAR runway transition),
- TRANS (STAR enroute transition).
One prompt and three different pages are available to select an arrival procedure:
- the ARRIVAL prompt is only available on LAT REV page at destination airport,
- the ARRIVAL 1 page displays the available runways, final approaches and means,
- the ARRIVAL 2 page displays the lists of compatible STAR and TRANS,
- the APPR VIA page displays the list of approaches transition.
(4) Flight plan stringing logics for STAR/VIA/APPROACH are modified. The aim of the modification is to avoid waypoint stacking in the FMS flight plan and decrease the number of keystroke number in order to perform FMS flight plan modification.
(5) NEXT waypoint
This function is used to insert a waypoint into the flight plan, just after the revised waypoint. This function is accessible through the NEXT WAYPOINT field which is available on LAT REV page. The entered next waypoint (it must be a fixed waypoint but not a runway) is inserted following the revised point with a direct leg. If the inserted waypoint already exists downpath in the flight plan, all legs between the revised point and the identical waypoint are deleted. If the inserted waypoint does not exist downpath in the flight plan, a discontinuity is inserted after the inserted waypoint.
This function is used to insert a waypoint into the flight plan, just after the revised waypoint. This function is accessible through the NEXT WAYPOINT field which is available on LAT REV page. The entered next waypoint (it must be a fixed waypoint but not a runway) is inserted following the revised point with a direct leg. If the inserted waypoint already exists downpath in the flight plan, all legs between the revised point and the identical waypoint are deleted. If the inserted waypoint does not exist downpath in the flight plan, a discontinuity is inserted after the inserted waypoint.
(6) New destination
This function is used to designate a new primary destination (it must be an airport name), through the NEW DEST field which is available on LAT REV page. All waypoints in the flight plan following the revised point are deleted and a discontinuity is strung between the revised point and the new destination.
This function is used to designate a new primary destination (it must be an airport name), through the NEW DEST field which is available on LAT REV page. All waypoints in the flight plan following the revised point are deleted and a discontinuity is strung between the revised point and the new destination.
(7) HOLD (HX)
When HOLD page is accessed, a default hold is proposed by the system. When revised point is not PPOS and a database hold is defined for the point, the database hold is proposed as default.
A holding pattern (HM leg) can be inserted on a flight plan waypoint through a lateral revision at that waypoint, including the FROM waypoint (PPOS hold), or through extraction of a database procedure that has a holding pattern pre-coded at a waypoint. The lateral path function will generate a holding pattern based on the specified holding parameters: the inbound course (INB CRS), turn direction and leg time or distance.
When HOLD page is accessed, a default hold is proposed by the system. When revised point is not PPOS and a database hold is defined for the point, the database hold is proposed as default.
A holding pattern (HM leg) can be inserted on a flight plan waypoint through a lateral revision at that waypoint, including the FROM waypoint (PPOS hold), or through extraction of a database procedure that has a holding pattern pre-coded at a waypoint. The lateral path function will generate a holding pattern based on the specified holding parameters: the inbound course (INB CRS), turn direction and leg time or distance.
(8) HOLD (HX)
When HOLD page is accessed, a default hold is proposed by the system. When revised point is not PPOS and a database hold is defined for the point, stored in the Enroute Holding Pattern file, the database hold is proposed as default and for all other cases if it is possible the system proposes a COMPUTED hold.
A holding pattern (HM leg) can be inserted on a flight plan waypoint through a lateral revision at that waypoint, including the FROM waypoint (PPOS hold), or through extraction of a database procedure that has a holding pattern pre-coded at a waypoint. The lateral path function will generate a holding pattern based on the specified holding parameters: the inbound course (INB CRS), turn direction and leg time or distance.
When HOLD page is accessed, a default hold is proposed by the system. When revised point is not PPOS and a database hold is defined for the point, stored in the Enroute Holding Pattern file, the database hold is proposed as default and for all other cases if it is possible the system proposes a COMPUTED hold.
A holding pattern (HM leg) can be inserted on a flight plan waypoint through a lateral revision at that waypoint, including the FROM waypoint (PPOS hold), or through extraction of a database procedure that has a holding pattern pre-coded at a waypoint. The lateral path function will generate a holding pattern based on the specified holding parameters: the inbound course (INB CRS), turn direction and leg time or distance.
(9) Airways
This function is used, through the AIRWAYS page, to select a pre-stored airway segment with ending points for insertion into the flight plan after the revised point.
It is possible to select up to five airway segments on the AIRWAYS page.
This function is accessible from the AIRWAYS prompt which is available on LAT REV page. The airway segment is strung into the F-PLN at the revised point if its ending point has been defined.
Concerning the airways which includes some fixed Radius Transitions (FRT), the AIRWAYS page will display FIXED TURN RADIUS AWY for an airway (VIA) that is a fixed radius transition airway as defined in the navigation database.
This function is used, through the AIRWAYS page, to select a pre-stored airway segment with ending points for insertion into the flight plan after the revised point.
It is possible to select up to five airway segments on the AIRWAYS page.
This function is accessible from the AIRWAYS prompt which is available on LAT REV page. The airway segment is strung into the F-PLN at the revised point if its ending point has been defined.
Concerning the airways which includes some fixed Radius Transitions (FRT), the AIRWAYS page will display FIXED TURN RADIUS AWY for an airway (VIA) that is a fixed radius transition airway as defined in the navigation database.
(10) Alternate
This function is used, through the ALTERNATE page, to select an alternate destination for the F-PLN. This function is accessible from the ALTN prompt which is available on LAT REV page.
When an alternate destination or company route is selected, the alternate F-PLN is strung with the same stringing rules as for the primary F-PLN. ENABLE ALTN prompt on LAT REV page is used to activate the alternate portion of the F-PLN. The activation of the alternate F-PLN deletes all legs beyond the revised point and strings a discontinuity to the alternate origin waypoint.
This function is used, through the ALTERNATE page, to select an alternate destination for the F-PLN. This function is accessible from the ALTN prompt which is available on LAT REV page.
When an alternate destination or company route is selected, the alternate F-PLN is strung with the same stringing rules as for the primary F-PLN. ENABLE ALTN prompt on LAT REV page is used to activate the alternate portion of the F-PLN. The activation of the alternate F-PLN deletes all legs beyond the revised point and strings a discontinuity to the alternate origin waypoint.
(11) Alternate - Cost Index
When alternate flight plan is activated, the Cost Index (CI) shall be forced to zero for the active flight plan predictions in order to be consistent with alternate flight plan prediction. Additionally, the scratchpad message USING COST INDEX : 0 can be displayed.
When an alternate is defined and a temporary FPLN exists, the alternates idents are displayed in cyan. DEST will then be the last yellow ident.
When alternate flight plan is activated, the Cost Index (CI) shall be forced to zero for the active flight plan predictions in order to be consistent with alternate flight plan prediction. Additionally, the scratchpad message USING COST INDEX : 0 can be displayed.
When an alternate is defined and a temporary FPLN exists, the alternates idents are displayed in cyan. DEST will then be the last yellow ident.
(12) Direct To/Intercept/Abeam
The DIRECT-TO/INTERCEPT function is used to:
This function is accessible on the DIR TO page which is accessible by pressing the DIR key on the MCDU.
The DIRECT-TO/INTERCEPT function is used to:
- fly directly from the current A/C position to a selected database fix or geographically defined waypoint,
- project active F-PLN waypoints along the Direct To route, from the current A/C position to the specified Direct To fix (case 1),
- specify an intercept radial into a specified fix (case 3) or from a specified fix (case 2).
This function is accessible on the DIR TO page which is accessible by pressing the DIR key on the MCDU.
(13) Direct TO
If a DIRECT-TO is selected as part of the DIRECT-TO/INTERCEPT function, a DF leg is strung from the current A/C position to the selected waypoint. Moreover a Turn-Point (T-P) leg becomes the FROM waypoint and is followed by the TO fix of the DF leg. When the A/C is in heading mode, the NAV mode is engaged as soon as the DIR TO is inserted.
If a DIRECT-TO is selected as part of the DIRECT-TO/INTERCEPT function, a DF leg is strung from the current A/C position to the selected waypoint. Moreover a Turn-Point (T-P) leg becomes the FROM waypoint and is followed by the TO fix of the DF leg. When the A/C is in heading mode, the NAV mode is engaged as soon as the DIR TO is inserted.
(14) Intercept
The DIRECT-TO/INTERCEPT function gives a procedure to join a radial by specifying an origin waypoint. Such a radial can subsequently be captured and automatically flown by the A/C, either inbound into the specified point or outbound from the specified point.
A DIR TO INTERCEPT-RADIAL IN default value is now available when a FPLN waypoint is selected on the DIR TO page.
The DIRECT-TO/INTERCEPT function gives a procedure to join a radial by specifying an origin waypoint. Such a radial can subsequently be captured and automatically flown by the A/C, either inbound into the specified point or outbound from the specified point.
- If an INTERCEPT-TO is selected, a CF leg is strung along the specified radial into the selected waypoint. All F-PLN waypoints preceding the selected waypoint will be deleted. An IN-BND leg becomes the FROM waypoint and is followed by the TO fix of the selected waypoint.
- If an INTERCEPT-FROM is selected, a FM leg followed by a discontinuity is strung along the specified radial from the selected waypoint. All flight plan waypoints preceding the selected waypoint will be deleted. An OUT-BND leg becomes the FROM waypoint and is followed by the MANUAL termination of the FM leg.
A DIR TO INTERCEPT-RADIAL IN default value is now available when a FPLN waypoint is selected on the DIR TO page.
(15) Abeam
The abeam points operation projects existing active F-PLN waypoints between the A/C current position and the selected Direct-To point onto the Direct-To leg.
When a DIR TO with abeam is performed, the waypoint displayed on the top right of the ND is not an abeam waypoint but a fix waypoint as TO waypoint.
The abeam points operation projects existing active F-PLN waypoints between the A/C current position and the selected Direct-To point onto the Direct-To leg.
When a DIR TO with abeam is performed, the waypoint displayed on the top right of the ND is not an abeam waypoint but a fix waypoint as TO waypoint.
(16) Engine Out SID (EOSID)
The EOSID is a standard procedure to use if an engine fails just after a take-off. When an origin runway and an EOSID are defined in the active F-PLN, an EOSID diversion point is defined: it is the leg termination at which the EOSID diverges from the active F-PLN.
If the A/C is before the diversion point when the engine out is detected by the FMS, then:
The EOSID is a standard procedure to use if an engine fails just after a take-off. When an origin runway and an EOSID are defined in the active F-PLN, an EOSID diversion point is defined: it is the leg termination at which the EOSID diverges from the active F-PLN.
If the A/C is before the diversion point when the engine out is detected by the FMS, then:
- automatically, the EOSID is strung in the TMPY F-PLN with the EOSID diversion point,
- any part of the EOSID before the EOSID diversion point is ignored,
- a discontinuity is strung between the last waypoint of the EOSID and the remaining active F-PLN.
(17) Offset
The offset function is used, through the OFFSET page, to enable the A/C to fly:
The offset function is used, through the OFFSET page, to enable the A/C to fly:
- parallel to the parent path,
- laterally offset by a given distance,
- direction entered by the pilot.
(18) Radial Fix Info
The Radial Fix Info pages provides a means for creating Nav Display references based on a given database fix or a Pilot defined element. The references may be one or two radial bearings, one circle and one abeam. If the radial, circle or abeam intercepts the active or temporary flight plan, the intersection point can be converted to a waypoint and inserted into the flight plan.
The number of FIX INFO pages is extended to 4 pages and are identical. One reference fix is defined per each FIX INFO page.
It is accessible through the RADIAL FIX INFO prompt from a LAT REV page at any primary F-PLN waypoints (primary destination excluded).
The ABEAM function is not applicable to the secondary F-PLN.
The Radial Fix Info pages provides a means for creating Nav Display references based on a given database fix or a Pilot defined element. The references may be one or two radial bearings, one circle and one abeam. If the radial, circle or abeam intercepts the active or temporary flight plan, the intersection point can be converted to a waypoint and inserted into the flight plan.
The number of FIX INFO pages is extended to 4 pages and are identical. One reference fix is defined per each FIX INFO page.
It is accessible through the RADIAL FIX INFO prompt from a LAT REV page at any primary F-PLN waypoints (primary destination excluded).
The ABEAM function is not applicable to the secondary F-PLN.
(19) LAT / LONG crossing points
This function allows the creation of a point at the intersection of a specific LAT or LONG and the enroute part of the F/PLN. It also allows the creation of a series of crossing points at specified intervals of latitude or longitude. It is accessible through an entry field on the LAT REV page at any revised point between the origin and the last enroute waypoint.
This function allows the creation of a point at the intersection of a specific LAT or LONG and the enroute part of the F/PLN. It also allows the creation of a series of crossing points at specified intervals of latitude or longitude. It is accessible through an entry field on the LAT REV page at any revised point between the origin and the last enroute waypoint.
(20) Direct F-PLN revisions
The following lateral revisions are directly available on Active/Temporary F-PLN and SEC F-PLN pages:
The following lateral revisions are directly available on Active/Temporary F-PLN and SEC F-PLN pages:
- insert a new waypoint,
- clear a waypoint, a discontinuity or an holding pattern,
- insert an along track offset waypoint,
- insert a time marker.
(a) Insert a new waypoint
This function results from the direct entry of a new waypoint into the flight plan via the F-PLN page. The new waypoint is inserted at the position selected by the pilot (all markers are included). However, it cannot be inserted directly following FM or VM legs or at the FROM waypoint (except PPOS).
This function results from the direct entry of a new waypoint into the flight plan via the F-PLN page. The new waypoint is inserted at the position selected by the pilot (all markers are included). However, it cannot be inserted directly following FM or VM legs or at the FROM waypoint (except PPOS).
(b) Clear a waypoint or a discontinuity
This function is used by first pressing the CLR function key with the F-PLN or SEC F-PLN page displayed and the scratchpad empty.
Then the left line select key, next to the selected waypoint, is pressed.
The function performed depends on whether the waypoint is a downpath waypoint, the TO waypoint or the FROM waypoint.
If the function is performed on the active F-PLN, it results in the creation of a temporary F-PLN (or updating if it already exists). In both cases, the function has no effect on the active F-PLN until insertion of the temporary.
Clearing a downpath lateral waypoint or discontinuity deletes the selected leg from the flight plan.
This function is used by first pressing the CLR function key with the F-PLN or SEC F-PLN page displayed and the scratchpad empty.
Then the left line select key, next to the selected waypoint, is pressed.
The function performed depends on whether the waypoint is a downpath waypoint, the TO waypoint or the FROM waypoint.
If the function is performed on the active F-PLN, it results in the creation of a temporary F-PLN (or updating if it already exists). In both cases, the function has no effect on the active F-PLN until insertion of the temporary.
Clearing a downpath lateral waypoint or discontinuity deletes the selected leg from the flight plan.
(c) Along Track Offset (PLACE / DIST)
The Along Track Offset (ATO) waypoint is a pilot-defined waypoint that can be entered only on the F-PLN pages. However, a waypoint defined as an ATO is included as one of the twenty pilot-defined waypoints.
An ATO waypoint is inserted into the flight plan by entering a PLACE/DIST into the scratchpad and pressing the left LS key adjacent to the revised point.
The PLACE entry must be identical to the revised point. An ATO cannot be entered at the FROM waypoint.
The DIST entered to define the ATO cannot exceed the distance of the leg on which it is inserted. A distance can be entered up to 9999 NM as long as it satisfies the rules herein.
A positive DIST entry results in an ATO inserted on the leg following the revised point while a negative DIST entry results in an ATO inserted on the leg preceding the revised point. If "+" or "-" is not specified, a positive entry is assumed.
Once an ATO waypoint is inserted, the distance of the ATO from the revised point becomes the upper limit for the DIST entry for any other ATO in the same direction from that revised point.
The Along Track Offset (ATO) waypoint is a pilot-defined waypoint that can be entered only on the F-PLN pages. However, a waypoint defined as an ATO is included as one of the twenty pilot-defined waypoints.
An ATO waypoint is inserted into the flight plan by entering a PLACE/DIST into the scratchpad and pressing the left LS key adjacent to the revised point.
The PLACE entry must be identical to the revised point. An ATO cannot be entered at the FROM waypoint.
The DIST entered to define the ATO cannot exceed the distance of the leg on which it is inserted. A distance can be entered up to 9999 NM as long as it satisfies the rules herein.
A positive DIST entry results in an ATO inserted on the leg following the revised point while a negative DIST entry results in an ATO inserted on the leg preceding the revised point. If "+" or "-" is not specified, a positive entry is assumed.
Once an ATO waypoint is inserted, the distance of the ATO from the revised point becomes the upper limit for the DIST entry for any other ATO in the same direction from that revised point.
(d) Time Marker
This function allows to create a pseudo waypoint by entering a time into the scratchpad and then pressing any left LSK on the F-PLN A or B pages.
The pseudo waypoint is displayed on the MCDU and on the ND (green circle (HHMM)), located at the predicted position of the aircraft at the entered time.
This function allows to create a pseudo waypoint by entering a time into the scratchpad and then pressing any left LSK on the F-PLN A or B pages.
The pseudo waypoint is displayed on the MCDU and on the ND (green circle (HHMM)), located at the predicted position of the aircraft at the entered time.
(21) Direct F-PLN revisions
The following lateral revisions are directly available on Active/Temporary F-PLN and SEC F-PLN pages:
The following lateral revisions are directly available on Active/Temporary F-PLN and SEC F-PLN pages:
- insert a new waypoint,
- clear a waypoint, a discontinuity or an holding pattern,
- add or remove an overfly at waypoint,
- insert an along track offset waypoint,
- insert a time marker.
(a) Insert a new waypoint
This function results from the direct entry of a new waypoint into the flight plan via the Active/Temporary F-PLN or SEC F-PLN pages. The new waypoint is inserted at the position selected by the pilot, just before the selected waypoint, including the F-PLN DISCONTINUITY marker, the END OF F-PLN and END OF ALTN F-PLN marker.
This function results from the direct entry of a new waypoint into the flight plan via the Active/Temporary F-PLN or SEC F-PLN pages. The new waypoint is inserted at the position selected by the pilot, just before the selected waypoint, including the F-PLN DISCONTINUITY marker, the END OF F-PLN and END OF ALTN F-PLN marker.
(b) Clear a waypoint or a discontinuity
This function is called by pressing the CLR key on MCDU, on condition that the scratchpad is empty, when Active/Temporary F-PLN, or SEC F-PLN pages are displayed. Then the crew can press the left Line Select Key (LSK) corresponding to the waypoint or the discontinuity to be cleared.
The function, clear a waypoint, generates a discontinuity. Clearing a discontinuity is allowed and it is replaced with a direct leg strung from the termination which preceded the discontinuity to the initial fix which follows the discontinuity.
This function is called by pressing the CLR key on MCDU, on condition that the scratchpad is empty, when Active/Temporary F-PLN, or SEC F-PLN pages are displayed. Then the crew can press the left Line Select Key (LSK) corresponding to the waypoint or the discontinuity to be cleared.
The function, clear a waypoint, generates a discontinuity. Clearing a discontinuity is allowed and it is replaced with a direct leg strung from the termination which preceded the discontinuity to the initial fix which follows the discontinuity.
(c) Overfly waypoint
This function is used to add or remove an overfly at a specific waypoint. It is called by pressing the OVFY Delta (overfly) key on MCDU, on condition that the scratchpad is empty, when the Active/Temporary F-PLN or SEC F-PLN pages are displayed. Then the crew can press the left LSK corresponding to the waypoint to be revised.
This function is used to add or remove an overfly at a specific waypoint. It is called by pressing the OVFY Delta (overfly) key on MCDU, on condition that the scratchpad is empty, when the Active/Temporary F-PLN or SEC F-PLN pages are displayed. Then the crew can press the left LSK corresponding to the waypoint to be revised.
(d) Along Track Offset (PLACE / DIST)
An Along Track Offset (ATO) waypoint is a waypoint defined by the pilot that is directly entered on the Active/Temporary F-PLN or SEC F-PLN pages and also on STEP ALTS page. An ATO waypoint is inserted into the F-PLN by entering a PLACE/DIST into the scratchpad and pressing the left LSK adjacent to the revised point.
The entered PLACE must be identical to the revised point. A positive DIST entry results in an ATO inserted on the leg following the revised point. A negative DIST entry results in an ATO inserted on the leg preceding the revised point. If the A/C is in active leg and if an ATO waypoint with a negative DEST is inserted, then before insertion the crew must disengage NAV mode, insert and reengage NAV mode.
An Along Track Offset (ATO) waypoint is a waypoint defined by the pilot that is directly entered on the Active/Temporary F-PLN or SEC F-PLN pages and also on STEP ALTS page. An ATO waypoint is inserted into the F-PLN by entering a PLACE/DIST into the scratchpad and pressing the left LSK adjacent to the revised point.
The entered PLACE must be identical to the revised point. A positive DIST entry results in an ATO inserted on the leg following the revised point. A negative DIST entry results in an ATO inserted on the leg preceding the revised point. If the A/C is in active leg and if an ATO waypoint with a negative DEST is inserted, then before insertion the crew must disengage NAV mode, insert and reengage NAV mode.
(e) Time Marker
This function allows to create a pseudo waypoint by entering a time into the scratchpad and then pressing any left LSK on the F-PLN A or B pages.
The pseudo waypoint is displayed on the MCDU and on the ND (green circle (HHMM)), located at the predicted position of the aircraft at the entered time.
This function allows to create a pseudo waypoint by entering a time into the scratchpad and then pressing any left LSK on the F-PLN A or B pages.
The pseudo waypoint is displayed on the MCDU and on the ND (green circle (HHMM)), located at the predicted position of the aircraft at the entered time.
(22) Secondary flight plan
Initialization of the secondary F-PLN is done on the SEC INIT page which is accessible from the SEC INDEX page. The following revised function applies to the secondary F-PLN (via the SEC INDEX page):
Initialization of the secondary F-PLN is done on the SEC INIT page which is accessible from the SEC INDEX page. The following revised function applies to the secondary F-PLN (via the SEC INDEX page):
- Copy active:
This function copies elements from the active F-PLN into the secondary F-PLN and deletes the previously defined secondary F-PLN.
(23) Secondary flight plan - Access
Secondary INIT A / B pages are always accessible by the crew in order to enable modifications for secondary predictions.
Secondary INIT A / B pages are always accessible by the crew in order to enable modifications for secondary predictions.
(24) Secondary flight plan - Sequencing
The sequencing of the secondary F-PLN occurs only if the secondary F-PLN is copied from the active F-PLN and the active leg in the active F-PLN is identical to the active leg of the secondary F-PLN.
The sequencing of the secondary F-PLN occurs only if the secondary F-PLN is copied from the active F-PLN and the active leg in the active F-PLN is identical to the active leg of the secondary F-PLN.
- Activate sec:
This function activates the secondary F-PLN by copying parameters from the secondary F-PLN to the active F-PLN by deleting completely the previous active F-PLN.
- preparation of a second departure procedure before take-off when this one is defined late,
- preparation of the next flight while in flight,
- training.
M. Lateral Flight Planning - Closest Airport
The CLOSEST AIRPORT function allows to display the four closest airports from the present aircraft position in addition with a fifth airport defined by the crew. It is accessible through the CLOSEST AIRPORT prompt on the DATA INDEX A page. The bearing, distance, time to go to each airport are displayed on CLOSEST AIRPORT page 1. Associated Estimated Fuel on Board (EFOB) are displayed on CLOSEST AIRPORT page 2 through EFOB/WIND prompt.
Time and EFOB computation are based on the currently measured wind or effective wind vector to fly to the airport entered by the pilot on CLOSEST AIRPORT page 2.
The CLOSEST AIRPORT function allows to display the four closest airports from the present aircraft position in addition with a fifth airport defined by the crew. It is accessible through the CLOSEST AIRPORT prompt on the DATA INDEX A page. The bearing, distance, time to go to each airport are displayed on CLOSEST AIRPORT page 1. Associated Estimated Fuel on Board (EFOB) are displayed on CLOSEST AIRPORT page 2 through EFOB/WIND prompt.
Time and EFOB computation are based on the currently measured wind or effective wind vector to fly to the airport entered by the pilot on CLOSEST AIRPORT page 2.
N. Lateral Flight Planning - Guidance
With an active flight plan and a valid aircraft position, the FMS is able to perform lateral guidance along this flight plan coupled with auto pilot. This mode is the managed one. The selected mode is performed through direct pilot targets.
With an active flight plan and a valid aircraft position, the FMS is able to perform lateral guidance along this flight plan coupled with auto pilot. This mode is the managed one. The selected mode is performed through direct pilot targets.
(1) NAV guidance mode
(a) LAT AUTO CONTROL engagement conditions
Lateral autopilot modes selectable through the Flight Control Unit (FCU) in enroute or terminal area or in approach (except take-off and landing) are:
Lateral autopilot modes selectable through the Flight Control Unit (FCU) in enroute or terminal area or in approach (except take-off and landing) are:
- Auto control (NAV mode is engaged)
- Heading/Track control (heading mode or track mode is engaged).
1 Managed NAV mode
This mode is armed if the pilot pushes heading/track selector knob on the FCU. If NAV mode is armed on ground, and if a valid FM flight plan exists and active leg is not a discontinuity, then it is automatically engaged at 30 ft altitude after take-off. When automatic control is requested by the pilot, the activation depends upon whether the A/C is inside or outside a capture zone (at least 2 NM wide zone for fixed path legs). If the A/C is inside the capture zone, then the NAV engagement conditions are satisfied. Else, NAV engagement is still armed until the pilot selects an appropriate HDG/TRK to enter the capture zone. When NAV is engaged, the A/C follows the targets given by the system based on F-PLN structure.
This mode is armed if the pilot pushes heading/track selector knob on the FCU. If NAV mode is armed on ground, and if a valid FM flight plan exists and active leg is not a discontinuity, then it is automatically engaged at 30 ft altitude after take-off. When automatic control is requested by the pilot, the activation depends upon whether the A/C is inside or outside a capture zone (at least 2 NM wide zone for fixed path legs). If the A/C is inside the capture zone, then the NAV engagement conditions are satisfied. Else, NAV engagement is still armed until the pilot selects an appropriate HDG/TRK to enter the capture zone. When NAV is engaged, the A/C follows the targets given by the system based on F-PLN structure.
2 Selected mode
Heading/track is engaged if the pilot selects a FCU target and pulls the heading/track selector knob. In heading/track mode the F-PLN remains active without modification and leg sequencing remains automatic if the A/C is in a zone defined as 5 NM besides the waypoint or the sequencing waypoint defined in legs transition. NAV mode is automatically disengaged by the system upon sequencement of a discontinuity on F-PLN and below MDA/MDH (Minimum Descent Altitude / Minimum Descent Height) during non precision approach.
Heading/track is engaged if the pilot selects a FCU target and pulls the heading/track selector knob. In heading/track mode the F-PLN remains active without modification and leg sequencing remains automatic if the A/C is in a zone defined as 5 NM besides the waypoint or the sequencing waypoint defined in legs transition. NAV mode is automatically disengaged by the system upon sequencement of a discontinuity on F-PLN and below MDA/MDH (Minimum Descent Altitude / Minimum Descent Height) during non precision approach.
(2) NAV Guidance submodes
When the NAV mode is engaged, the FM guides the aircraft along the flight plan. The NAV mode is made up of three submodes: Heading (HDG), Track and Hpath. One submode is selected according to the type of the active leg except when the active leg is an IF, in that case the NAV mode is disengaged by the Flight Guidance (FG).
When the NAV mode is engaged, the FM guides the aircraft along the flight plan. The NAV mode is made up of three submodes: Heading (HDG), Track and Hpath. One submode is selected according to the type of the active leg except when the active leg is an IF, in that case the NAV mode is disengaged by the Flight Guidance (FG).
- The heading submode guides the aircraft along a magnetic heading (trajectory not fixed on ground). The heading submode is selected when the active leg is a heading leg (VX legs).
- The track submode guides the aircraft along a trajectory with a constant course. The track submode is selected when the active leg is a course leg (CX legs, except CF).
- The Hpath submode is selected to guide the aircraft along a trajectory fixed on ground (CF, FA, AF, FD, TF, DF legs).
(a) Roll command authority limitation when Hpath submode active
When NAV mode is engaged, the output of the roll command by the FM to the FG insures passengers comfort and smooth aircraft maneuvers. It is limited to 30 degrees bank angle when aircraft is not in engine out conditions. When engine out is detected, roll command output by the FM to the FG is limited in order to get safe manoeuvres.
When NAV mode is engaged, the output of the roll command by the FM to the FG insures passengers comfort and smooth aircraft maneuvers. It is limited to 30 degrees bank angle when aircraft is not in engine out conditions. When engine out is detected, roll command output by the FM to the FG is limited in order to get safe manoeuvres.
(b) Lateral targets computation
- Heading submode:
When the heading submode is selected and the NAV mode is engaged or the NAV mode engagement is requested, the FM requests to the FG the HDG submode engagement and computes the heading target. - Track submode:
When the track submode is selected and the NAV mode is engaged or the NAV mode engagement is requested, the FM requests to the FG the TRACK submode engagement and computes the course target. - Hpath submode:
Hpath submode computes a roll command and sends it to the FG. The roll bank angle depends on crosstrack error (XTK) and the track angle error (TKE).
(3) General Information
The design for computing the roll bank angle upon DIR TO has been improved in order to increase the bank angle value (within the 30° limitation).
The design for computing the roll bank angle upon DIR TO has been improved in order to increase the bank angle value (within the 30° limitation).
(4) Lateral path errors - Displayed parameters
(a) Definition of lateral path errors
The FMS computes a crosstrack error displayed on ND and a track angle error for control of the A/C in Hpath submode along the lateral path and for determination of lateral path capture and leg sequencing. Heading and Track submodes do not use lateral path errors computed by FMS.
The FMS computes a crosstrack error displayed on ND and a track angle error for control of the A/C in Hpath submode along the lateral path and for determination of lateral path capture and leg sequencing. Heading and Track submodes do not use lateral path errors computed by FMS.
1 Crosstrack error (XTK)
When the selected submode is Hpath, the XTK is computed as follows:
When the selected submode is Hpath, the XTK is computed as follows:
- If the active segment is a straight segment, the XTK is the distance from the current aircraft position to the point P defined as the perpendicular projection of the current aircraft position on the straight line defined by the active straight segment.
- If the active segment is a curved segment, the XTK is the distance from the current aircraft position to the point P defined as the perpendicular projection of the current aircraft position on the circle, if the point P belongs to the active curve segment. If the point P does not belong to the active curve segment, the XTK is the distance between the current aircraft position and the reference fix. The reference fix is the initial turn point (ITP) or final turn point (FTP), it is defined in order that the distance between the aircraft position and the reference fix is the minimum of the distances between the aircraft position and the ITP or the FTP. If the distances between the aircraft position and the ITP and the FTP are equal, the reference fix is the FTP.
2 Track angle error (TKE)
The absolute value of the track Angle Error is the desired true course minus the aircraft true track. The TKE (-179.99 to +180 degrees) is positive when the angle from the aircraft true track to the desired track turns clockwise.
The absolute value of the track Angle Error is the desired true course minus the aircraft true track. The TKE (-179.99 to +180 degrees) is positive when the angle from the aircraft true track to the desired track turns clockwise.
(b) Computation of specific display parameters
| ------------------------------------------------------------------------------- |
| ! Display parameters ! Defintion ! |
| !--------------------!--------------------------------------------------------! |
| ! BEARING TO GO ! Bearing to go from the current A/C position to the leg ! |
| ! ! termination point. ! |
| !--------------------!--------------------------------------------------------! |
| ! DISTANCE TO GO ! Direct distance to go from the current A/C position to ! |
| ! ! the leg termination point. ! |
| !--------------------!--------------------------------------------------------! |
| ! TIME TO GO ! Time to go from the current A/C position to the leg ! |
| ! ! termination point. ! |
| !--------------------!--------------------------------------------------------! |
| ! REQUIRED DISTANCE ! Minimum lateral distance required to pass from the ! |
| ! TO LAND ! current A/C energy state to the landing energy state ! |
| ! ! assuming a default descent profile from the current ! |
| ! ! A/C altitude to a destination airport elevation. ! |
| !--------------------!--------------------------------------------------------! |
| ! DIRECT DIST TO ! Distance along a great circle path connecting the A/C ! |
| ! DEST ! position to the LOC capture point and then to ! |
| ! ! destination runway. ! |
| !-----------------------------------------------------------------------------! |
| ! ALONG TRACK DIST ! Distance along the active leg from the point where ! |
| ! TO GO ! XTK ERROR is computed to the leg termination point ! |
| !--------------------!--------------------------------------------------------! |
| ! DIST TO DEST ! Sum of the lateral leg distances in the F-PLN ! |
| ! ! beginning with the active leg termination and the ! |
| ! ! ALONG TRACK DIST TO GO ! |
| ------------------------------------------------------------------------------- |
(5) Dual behaviour
(6) Dual behaviour
In DUAL mode, some events are Master imposed. Among them the synchronization of waypoint sequencing is Master imposed.
In DUAL mode, some events are Master imposed. Among them the synchronization of waypoint sequencing is Master imposed.
- Master is ahead the Slave. Sequencing on master side entails the final update and waypoint sequencing on slave side.
- Slave is ahead the Master. Sequencing on Slave side is allowed only after Master has sequenced the TO waypoint.
O. Lateral Flight Planning - Construction of the Lateral Path
The flight plan obeys regulation rules to allow an airplane to fly under airspace control. The flight plan is registered relative to an airport of departure and an airport of destination. Charts exists for each airport to define the procedures of departure (SID) and procedures of arrival (STAR) for each runways.
The airplane is under Air Traffic Management (ATM) control during all the climb and descent phases.
During cruise phase, the aircraft follows corridor areas defined for each airways, existing also in charts.
The FMS finds all these elements in a Navigation Data Base, including all airports, procedures, runways, waypoints, radio beacons, airways allowing the construction of a trajectory.
The construction of a trajectory is dependent on a succession of legs and waypoints. The FMS allows the pilot to construct the flight plan, to perform revisions, to insert or modify airport, runways, procedures, airways.
From all these information, the FMS constructs a trajectory and when the pilot chooses the managed mode (or NAV mode), the FMS sends all the targets to the auto pilot to enable the flight plan to be followed by the aircraft.
The flight plan obeys regulation rules to allow an airplane to fly under airspace control. The flight plan is registered relative to an airport of departure and an airport of destination. Charts exists for each airport to define the procedures of departure (SID) and procedures of arrival (STAR) for each runways.
The airplane is under Air Traffic Management (ATM) control during all the climb and descent phases.
During cruise phase, the aircraft follows corridor areas defined for each airways, existing also in charts.
The FMS finds all these elements in a Navigation Data Base, including all airports, procedures, runways, waypoints, radio beacons, airways allowing the construction of a trajectory.
The construction of a trajectory is dependent on a succession of legs and waypoints. The FMS allows the pilot to construct the flight plan, to perform revisions, to insert or modify airport, runways, procedures, airways.
From all these information, the FMS constructs a trajectory and when the pilot chooses the managed mode (or NAV mode), the FMS sends all the targets to the auto pilot to enable the flight plan to be followed by the aircraft.
P. Vertical Function
The main vertical function are the following:
The main vertical function are the following:
- define the flight phases and their transition rules,
- determine the elements which are the basis for the vertical F-PLN construction (cruise altitudes, constraints..),
- compute ECON and characteristic speeds,
- compute the predictions for characteristic parameters (speed, altitude, time, fuel on board, wind, temperature) based on current atmospheric conditions,
- guide the A/C along the vertical F-PLN.
Q. Vertical Function - Flight Phases
The flight plan is divided in several flight phases for which specific operations, prediction and guidance are defined. The PERF page reflects the main parameters of the different phases. These flight phases are:
The flight plan is divided in several flight phases for which specific operations, prediction and guidance are defined. The PERF page reflects the main parameters of the different phases. These flight phases are:
- preflight,
- take off (from origin to acceleration altitude,
- climb (from acceleration alt to Top of climb,
- cruise (from Top of climb to Top of descent),
- descent (from Top of descent to Deceleration point),
- approach (from Deceleration point to destination),
- go around (missed approach points) (no predictions),
- done.
R. Vertical Function - F-PLN Elements
The vertical F-PLN is defined as a set of operational limitations. These limitations mainly consist in three types of constraints that can be entered into the F-PLN affecting the vertical profile:
Speed limit can be also entered into the F-PLN. They are represented by a magenta full circle on the ND.
The vertical F-PLN is defined as a set of operational limitations. These limitations mainly consist in three types of constraints that can be entered into the F-PLN affecting the vertical profile:
- Altitude constraints,
- Speed constraints,
- Time constraints.
Speed limit can be also entered into the F-PLN. They are represented by a magenta full circle on the ND.
(1) Altitude constraints
It is an A/C altitude requirement to be met over a specified waypoint in the lateral flight plan.
It can be an AT, AT or BELOW, AT or ABOVE or altitude window constraint.
An altitude constraint can be defined in altitude or in flight level.
It is defined in altitude below the departure transition altitude (in climb) or the arrival transition altitude (in descent). On the contrary, it is defined in flight level.
An altitude constraint is predicted missed if the aircraft cannot satisfy the constraint. In that case, the difference between the predicted altitude at the constrained waypoint and the altitude constraint value is displayed on vertical revision page (if the difference is greater than 100 ft or as long as it remains greater than 50 ft). On flight plan page the star near the constraint is then in amber color.
There are two types of constraint: climb and descent constraints defined as follow:
It is an A/C altitude requirement to be met over a specified waypoint in the lateral flight plan.
It can be an AT, AT or BELOW, AT or ABOVE or altitude window constraint.
An altitude constraint can be defined in altitude or in flight level.
It is defined in altitude below the departure transition altitude (in climb) or the arrival transition altitude (in descent). On the contrary, it is defined in flight level.
An altitude constraint is predicted missed if the aircraft cannot satisfy the constraint. In that case, the difference between the predicted altitude at the constrained waypoint and the altitude constraint value is displayed on vertical revision page (if the difference is greater than 100 ft or as long as it remains greater than 50 ft). On flight plan page the star near the constraint is then in amber color.
There are two types of constraint: climb and descent constraints defined as follow:
- When the aircraft is not in CRUISE yet:
* If a constraint is set at a waypoint and prior to T/C (if it exists) or belonging to a SID or prior to a climb alt or speed constraint waypoint, then the constraint is a climb constraint.
* If a constraint is set at a waypoint and beyond T/D (if it exists) or belonging to a STAR or beyond a descent alt or speed constraint waypoint, then the constraint is a descent constraint. - When the aircraft is in CRZ, DES or APPR phase, if a constraint is set at any active primary waypoint, then it is a descent constraint.
- In other cases, the pilot has to choose the type upon entry of the constraint.
(2) Altitude constraints
An altitude constraint is an a/c altitude requirement to be met over a specified point or leg in the lateral F-PLN. It is related either to the Take-Off-Climb phases or to the Descent-Approach phases.
There are four requirements about altitude constraints: AT, AT or BELOW, AT or ABOVE and WINDOW.
An altitude constraint is either stored in the database and then inserted into the F-PLN via the terminal area procedures or entered manually by the pilot through the F-PLN A or VERT REV pages.
An altitude constraint is predicted as missed if the following condition is checked for Hs = 250ft:
An altitude constraint is an a/c altitude requirement to be met over a specified point or leg in the lateral F-PLN. It is related either to the Take-Off-Climb phases or to the Descent-Approach phases.
There are four requirements about altitude constraints: AT, AT or BELOW, AT or ABOVE and WINDOW.
An altitude constraint is either stored in the database and then inserted into the F-PLN via the terminal area procedures or entered manually by the pilot through the F-PLN A or VERT REV pages.
An altitude constraint is predicted as missed if the following condition is checked for Hs = 250ft:
- Delta h is > Hs for an AT or BELOW constraint where Hs is an altitude margin and Delta h is the difference between predicted altitude and constrained altitude,
- absolute value of Delta h > Hs for an AT constraint,
- Delta h < - Hs for an AT or ABOVE constraint.
(3) Speed constraints
A speed constraint is an AT or BELOW constraint and is related either to the take-off and climb phases or to the descent and approach phases. There are two types of speed constraints:
A speed constraint is an AT or BELOW constraint and is related either to the take-off and climb phases or to the descent and approach phases. There are two types of speed constraints:
- climb speed constraints which are to be respected from the origin up to the constrained waypoint,
- descent speed constraints which are to be respected from the constrained waypoint down to the destination.
(4) Time constraints (Requested Time of Arrival (RTA))
It is an aircraft time requirement to be met over a specified waypoint in lateral flight plan. It can be an AT, AT or BEFORE, AT or AFTER time constraint. It is predicted missed if the difference between the predicted time at constrained waypoint and time constraint value is greater than 30 seconds and as long as this difference is greater than 15 seconds.
There can be only one time constraint in the flight plan, if the pilot enters a new constraint, the previous one is automatically deleted. The time constraint can also be automatically deleted upon activation of the ENGINE OUT mode or, at transition from approach to GO AROUND or if alternate is enable or if the active leg is a manual holding pattern.
A time constraint is predicted as missed at WPT01 if the predicted time minus constraint time (Delta T) meets the following condition A applied to the time tolerance Delta T1. The time constraint remains missed at WPT01 until condition A, when applied to the time tolerance Delta T2, is not met.
Delta T1 and Delta T2 are functions of distance between A/C position and WPT01 location.
Condition A:
It is an aircraft time requirement to be met over a specified waypoint in lateral flight plan. It can be an AT, AT or BEFORE, AT or AFTER time constraint. It is predicted missed if the difference between the predicted time at constrained waypoint and time constraint value is greater than 30 seconds and as long as this difference is greater than 15 seconds.
There can be only one time constraint in the flight plan, if the pilot enters a new constraint, the previous one is automatically deleted. The time constraint can also be automatically deleted upon activation of the ENGINE OUT mode or, at transition from approach to GO AROUND or if alternate is enable or if the active leg is a manual holding pattern.
A time constraint is predicted as missed at WPT01 if the predicted time minus constraint time (Delta T) meets the following condition A applied to the time tolerance Delta T1. The time constraint remains missed at WPT01 until condition A, when applied to the time tolerance Delta T2, is not met.
Delta T1 and Delta T2 are functions of distance between A/C position and WPT01 location.
Condition A:
- Delta T > Time tolerance for an AT or BEFORE constraint,
- absolute value of Delta T > Time tolerance for an AT constraint,
- Delta T < - Time tolerance for an AT or AFTER constraint.
(5) Estimated Take-off Time (ETT)
The ETT is a time which is used as the time initialization factor for predictions. The ETT can be manually entered by the pilot on the RTA page or can be computed automatically by the system as a result of a time constraint entry (the entry is accepted if clock data is valid).
The ETT is a time which is used as the time initialization factor for predictions. The ETT can be manually entered by the pilot on the RTA page or can be computed automatically by the system as a result of a time constraint entry (the entry is accepted if clock data is valid).
(6) Equi-Time Point (ETP)
The ETP is a point along the lateral flight plan at which the time to reach two designated reference airports or waypoints is the same, taking distance and wind into account. The two designated reference waypoints are entered by the pilot on the Equi-Time Point page accessed via the Data index. Then the following data are displayed:
The ETP is a point along the lateral flight plan at which the time to reach two designated reference airports or waypoints is the same, taking distance and wind into account. The two designated reference waypoints are entered by the pilot on the Equi-Time Point page accessed via the Data index. Then the following data are displayed:
- Time, Distance and Bearing from A/C position and the designated reference waypoint,
- Time, Distance and Bearing from ETP and the designated reference waypoint,
- ETP location,
- Time and Distance from A/C position and ETP.
(7) Time constraints (Requested Time of Arrival (RTA))
A time constraint is an a/c time requirement to be met at a specified waypoint. It can only be entered manually by the pilot in the RTA page through the VERT REV page or uplinked by AOC.
The RTA function allows entry and display of a waypoint identifier with associated time constraint. The RTA page also displays the following data:
A time constraint is predicted as missed at WPT01 if the predicted time minus constraint time (Delta T) meets the following condition A applied to the time tolerance Delta T1. The time constraint remains missed at WPT01 until condition A, when applied to the time tolerance Delta T2, is not met.
Delta T1 and Delta T2 are functions of distance between A/C position and WPT01 location.
Condition A:
A time constraint is an a/c time requirement to be met at a specified waypoint. It can only be entered manually by the pilot in the RTA page through the VERT REV page or uplinked by AOC.
The RTA function allows entry and display of a waypoint identifier with associated time constraint. The RTA page also displays the following data:
- Entered or computed ETT
- Predicted ETA at the time constrained waypoint
- Performance adjusted speed target
- Time error
- Distance to time constrained waypoint
- Active speed mode
A time constraint is predicted as missed at WPT01 if the predicted time minus constraint time (Delta T) meets the following condition A applied to the time tolerance Delta T1. The time constraint remains missed at WPT01 until condition A, when applied to the time tolerance Delta T2, is not met.
Delta T1 and Delta T2 are functions of distance between A/C position and WPT01 location.
Condition A:
- Delta T > Time tolerance for an AT or BEFORE constraint,
- absolute value of Delta T > Time tolerance for an AT constraint,
- Delta T < - Time tolerance for an AT or AFTER constraint.
(8) Estimated Take-off Time (ETT)
The ETT is a time which is used as the time initialization factor for predictions. The ETT can be manually entered by the pilot on the RTA page or can be computed automatically by the system as a result of a time constraint entry (the entry is accepted if clock data is valid).
The ETT is a time which is used as the time initialization factor for predictions. The ETT can be manually entered by the pilot on the RTA page or can be computed automatically by the system as a result of a time constraint entry (the entry is accepted if clock data is valid).
(9) Equi-Time Point (ETP)
The ETP is a point along the lateral flight plan at which the time to reach two designated reference airports or waypoints is the same, taking distance and wind into account. The two designated reference waypoints are entered by the pilot on the Equi-Time Point page accessed via the Data index. Then the following data are displayed:
The ETP is a point along the lateral flight plan at which the time to reach two designated reference airports or waypoints is the same, taking distance and wind into account. The two designated reference waypoints are entered by the pilot on the Equi-Time Point page accessed via the Data index. Then the following data are displayed:
- Time, Distance and Bearing from A/C position and the designated reference waypoint,
- Time, Distance and Bearing from ETP and the designated reference waypoint,
- ETP location,
- Time and Distance from A/C position and ETP.
(10) Speed limit
The speed limit has a speed and altitude associated with it.
The speed must be a CAS. The altitude can be in altitude or flight level following the same logic as for altitude constraints.
Below the specified altitude, the aircraft is not allowed to exceed the specified speed (except in cruise phase).
This limit does not apply to a specific lateral path but rather to a specific altitude. There is a system default speed limit which is 250/10000, but it is possible not to use it by selection in the AMI file via speed limit requested information.
There can be only two speed limits: one in CLB and one in DES.
The speed limit has a speed and altitude associated with it.
The speed must be a CAS. The altitude can be in altitude or flight level following the same logic as for altitude constraints.
Below the specified altitude, the aircraft is not allowed to exceed the specified speed (except in cruise phase).
This limit does not apply to a specific lateral path but rather to a specific altitude. There is a system default speed limit which is 250/10000, but it is possible not to use it by selection in the AMI file via speed limit requested information.
There can be only two speed limits: one in CLB and one in DES.
(11) Speed limit
The speed limit is defined by a speed constraint and an associated altitude. There can not be more than one speed limit in CLB and one in DES. The speed value must not be exceeded below the associated altitude. In climb, cruise and descent flight phases, the speed limit is said to be exceeded when the A/C speed exceeds the speed limit by a tolerance of 10 kts when the A/C is below the speed limit altitude 150 ft. It remains exceeded until it stands above the speed limit + 5 kts.
The speed limit is defined by a speed constraint and an associated altitude. There can not be more than one speed limit in CLB and one in DES. The speed value must not be exceeded below the associated altitude. In climb, cruise and descent flight phases, the speed limit is said to be exceeded when the A/C speed exceeds the speed limit by a tolerance of 10 kts when the A/C is below the speed limit altitude 150 ft. It remains exceeded until it stands above the speed limit + 5 kts.
(12) Speed change indication
A speed change indication is displayed on the ND to precise the start of the speed change. The speed change for speed limit can be displayed whatever the clearance altitude is (altitude defined at the FCU).
A speed change indication is displayed on the ND to precise the start of the speed change. The speed change for speed limit can be displayed whatever the clearance altitude is (altitude defined at the FCU).
NOTE: The Speed limit cannot be cleared in the temporary F-PLN.
(13) Steps climb and steps descent
A step climb (step descent) in the flight plan occurs when the vertical profile changes from one cruise altitude to a higher (lower) cruise altitude.
A step can be automatically derived from data base if two cruise altitudes are defined for the selected stored route.
The pilot can define up to 4 steps at a time on step prediction page which is accessed through vertical revision page.
If below the present cruise altitude, a step descent is predicted and if above the present altitude, a step climb is predicted. There is only one step in the flight plan at any time. If a second step is inserted, the first one is deleted.
The STEP ALTS page allows entry and display of the geographic and optimum step points, with associated cost savings for the optimum step.
Up to three geographic steps can be allowed after an inserted optimum step.
Time and fuel saving are provided continously for an optimum step climb point that has not been inserted.
If no optimum step climb point exists or if it has been inserted, no savings are displayed.
A step climb (step descent) in the flight plan occurs when the vertical profile changes from one cruise altitude to a higher (lower) cruise altitude.
A step can be automatically derived from data base if two cruise altitudes are defined for the selected stored route.
The pilot can define up to 4 steps at a time on step prediction page which is accessed through vertical revision page.
If below the present cruise altitude, a step descent is predicted and if above the present altitude, a step climb is predicted. There is only one step in the flight plan at any time. If a second step is inserted, the first one is deleted.
The STEP ALTS page allows entry and display of the geographic and optimum step points, with associated cost savings for the optimum step.
Up to three geographic steps can be allowed after an inserted optimum step.
Time and fuel saving are provided continously for an optimum step climb point that has not been inserted.
If no optimum step climb point exists or if it has been inserted, no savings are displayed.
(14) Steps climb and steps descent
This function is applicable to all primary F-PLNs, in the Cruise flight phase only. A step in the F-PLN is where the vertical profile changes from one cruise altitude to another. It can be either to a higher (step climb) or lower (step descent) cruise altitude.
There are two types of steps:
In flight, the FM evaluates alternative step initiation points and provides the capability to select the optimal point (according to current CI) to the altitude based on the first geographical step altitude or entered altitude if no geographical step is defined.
Steps are defined in one of three ways:
This function is applicable to all primary F-PLNs, in the Cruise flight phase only. A step in the F-PLN is where the vertical profile changes from one cruise altitude to another. It can be either to a higher (step climb) or lower (step descent) cruise altitude.
There are two types of steps:
- step at PPOS through new FCU altitude selection,
- pre-planned step at geographical waypoint. or at optimal point.
In flight, the FM evaluates alternative step initiation points and provides the capability to select the optimal point (according to current CI) to the altitude based on the first geographical step altitude or entered altitude if no geographical step is defined.
Steps are defined in one of three ways:
- entry of flight plan waypoints and/or altitudes on the STEP ALTS page,
- entry of a step altitude constraint on a fixed flight plan waypoint via the F-PLN page,
- through flight planning operations where steps are obtained from company routes.
(15) Steps climb and steps descent
This function is applicable to all primary F-PLNs, in the Cruise flight phase only. A step in the F-PLN is where the vertical profile changes from one cruise altitude to another. It can be either to a higher (step climb) or lower (step descent) cruise altitude. The pilot can enter up to four geographical step points.
There are two types of steps:
In flight, the FM evaluates alternative step initiation points and provides the capability to select the optimal point (according to current CI) to the altitude based on the first geographical step altitude or entered altitude if no geographical step is defined. The optimum step function is accessible through the STEP ALTS page.
Steps are defined in one of three ways:
This function is applicable to all primary F-PLNs, in the Cruise flight phase only. A step in the F-PLN is where the vertical profile changes from one cruise altitude to another. It can be either to a higher (step climb) or lower (step descent) cruise altitude. The pilot can enter up to four geographical step points.
There are two types of steps:
- step at PPOS through new FCU altitude selection,
- pre-planned step at geographical waypoint. or at optimal point.
In flight, the FM evaluates alternative step initiation points and provides the capability to select the optimal point (according to current CI) to the altitude based on the first geographical step altitude or entered altitude if no geographical step is defined. The optimum step function is accessible through the STEP ALTS page.
Steps are defined in one of three ways:
- entry of flight plan waypoints and/or altitudes on the STEP ALTS page,
- entry of a step altitude constraint on a fixed flight plan waypoint via the F-PLN page,
- through flight planning operations where steps are obtained from company routes.
(16) Optimum altitude
The optimum altitude is the altitude where the cost function is minimized. The value of the computed optimum altitude is accessible on the PROG page:
The optimum altitude is the altitude where the cost function is minimized. The value of the computed optimum altitude is accessible on the PROG page:
- minimum altitude of computation is FL100,
- minimum optimum cruise duration is 5 minutes,
- optimum altitude value is frozen for the 5 last minutes of cruise phase.
(17) Cost Index (CI)
Each airline defines its own flight strategy regarding fuel consumption and flight time. This is one of FMS parameters to compute optimum speeds. It is defined as the ratio between the cost per flight time unit and the cost per fuel weight unit. A CI equal to 0 corresponds to the minimum fuel strategy, a CI equal to 999 corresponds to the minimum time strategy. CI can be entered via MCDU on INIT A page, or on PERF pages or automatically after insertion of a CO RTE.
Each airline defines its own flight strategy regarding fuel consumption and flight time. This is one of FMS parameters to compute optimum speeds. It is defined as the ratio between the cost per flight time unit and the cost per fuel weight unit. A CI equal to 0 corresponds to the minimum fuel strategy, a CI equal to 999 corresponds to the minimum time strategy. CI can be entered via MCDU on INIT A page, or on PERF pages or automatically after insertion of a CO RTE.
(18) Optimum altitude
The optimum altitude is the altitude where the cost function is minimized. The value of the computed optimum altitude is accessible on the PROG page and computed while satisfying the following requirements:
The optimum altitude is the altitude where the cost function is minimized. The value of the computed optimum altitude is accessible on the PROG page and computed while satisfying the following requirements:
- minimum altitude of computation is FL100,
- minimum optimum cruise duration is 5 minutes,
- optimum altitude value is frozen for the 5 last minutes of cruise phase.
(19) Cost Index (CI)
Each airline defines its own flight strategy regarding fuel consumption and flight time. This is one of FMS parameters to compute optimum speeds. It is defined as the ratio between the cost per flight time unit and the cost per fuel weight unit. A CI equal to 0 corresponds to the minimum fuel strategy, a CI equal to 999 corresponds to the minimum time strategy. CI can be entered via MCDU on INIT A page, or on PERF pages or automatically after insertion of a CO RTE. When alternate flight plan is activated, the CI shall be forced to zero for the active flight plan predictions in order to be consistent with alternate flight plan prediction.
Each airline defines its own flight strategy regarding fuel consumption and flight time. This is one of FMS parameters to compute optimum speeds. It is defined as the ratio between the cost per flight time unit and the cost per fuel weight unit. A CI equal to 0 corresponds to the minimum fuel strategy, a CI equal to 999 corresponds to the minimum time strategy. CI can be entered via MCDU on INIT A page, or on PERF pages or automatically after insertion of a CO RTE. When alternate flight plan is activated, the CI shall be forced to zero for the active flight plan predictions in order to be consistent with alternate flight plan prediction.
(20) Wind modelling
This model is defined by the vendor.
Cruise wind entries or modifications are only allowed on the CRZ ACTIVE (or SEC) F-PLN waypoints.
Wind data (Pilot or uplink) is entered through the CLB, CRZ and DES wind pages.
On INIT B page a TRIP WIND field allows the entry of a mean effective wind component for the trip from the primary origin to the primary destination, which becomes invalidated if a wind is entered along the climb, cruise or descent profiles.
Wind input data, after the global wind insertion, is used by the wind model to compute the forecast winds. Forecast winds are blended with actual wind for computation of the predicted winds that are displayed on the F-PLN B page. Winds are entered in direction/magnitude format, where the wind direction is the bearing that the wind is coming from.
This model is defined by the vendor.
Cruise wind entries or modifications are only allowed on the CRZ ACTIVE (or SEC) F-PLN waypoints.
Wind data (Pilot or uplink) is entered through the CLB, CRZ and DES wind pages.
On INIT B page a TRIP WIND field allows the entry of a mean effective wind component for the trip from the primary origin to the primary destination, which becomes invalidated if a wind is entered along the climb, cruise or descent profiles.
Wind input data, after the global wind insertion, is used by the wind model to compute the forecast winds. Forecast winds are blended with actual wind for computation of the predicted winds that are displayed on the F-PLN B page. Winds are entered in direction/magnitude format, where the wind direction is the bearing that the wind is coming from.
(21) Temperature modeling
This model is defined by the vendor.
Temperature modeling is based on the computation of an International Standard Atmosphere temperature deviation (ISA DEV) profile, based on the difference between an entered or measured Static Air Temperature (SAT) and a reference temperature profile at a given altitude. The reference temperature profile is either the ISA temperature profile or a pilot defined standard atmosphere temperature profile if a tropopause altitude has been entered by the pilot. The pilot defined standard atmosphere temperature profile is the ISA temperature profile affected by the pilot entered tropopause altitude.
Forecast ISA DEV profiles are constructed for three distinct segments:
This model is defined by the vendor.
Temperature modeling is based on the computation of an International Standard Atmosphere temperature deviation (ISA DEV) profile, based on the difference between an entered or measured Static Air Temperature (SAT) and a reference temperature profile at a given altitude. The reference temperature profile is either the ISA temperature profile or a pilot defined standard atmosphere temperature profile if a tropopause altitude has been entered by the pilot. The pilot defined standard atmosphere temperature profile is the ISA temperature profile affected by the pilot entered tropopause altitude.
Forecast ISA DEV profiles are constructed for three distinct segments:
- the climb segment, defined from the origin to the initial Top of Climb (T/C), using current A/C SAT and CRZ TEMP entered on the INIT A or FUEL PRED page,
- the cruise segment, defined from the initial T/C to the Top of Descent (T/D), using current A/C SAT and CRZ TEMP entered on the INIT A or FUEL PRED page,
- the descent segment, defined from the T/D to the destination, using the destination temperature entered on the APPR PERF page.
(22) Predicted winds and temperatures
This blending method is defined by the vendor.
FM predictions blend current A/C (or measured) wind and ISA DEV into the forecast wind and temperature model for use in the computation of parameters such as fuel burn, altitude at waypoints, time at waypoints, etc. Predicted winds and temperature are used for predictions.
This blending method is defined by the vendor.
FM predictions blend current A/C (or measured) wind and ISA DEV into the forecast wind and temperature model for use in the computation of parameters such as fuel burn, altitude at waypoints, time at waypoints, etc. Predicted winds and temperature are used for predictions.
(23) Temperature modeling
This model is defined by the vendor.
Temperature modeling is based on the computation of an International Standard Atmosphere temperature deviation (ISA DEV) profile, based on the difference between an entered or measured Static Air Temperature (SAT) and a reference temperature profile at a given altitude. The reference temperature profile is either the ISA temperature profile or a pilot defined standard atmosphere temperature profile if a tropopause altitude has been entered by the pilot. The pilot defined standard atmosphere temperature profile is the ISA temperature profile affected by the pilot entered tropopause altitude.
Forecast ISA DEV profiles are constructed for three distinct segments:
This model is defined by the vendor.
Temperature modeling is based on the computation of an International Standard Atmosphere temperature deviation (ISA DEV) profile, based on the difference between an entered or measured Static Air Temperature (SAT) and a reference temperature profile at a given altitude. The reference temperature profile is either the ISA temperature profile or a pilot defined standard atmosphere temperature profile if a tropopause altitude has been entered by the pilot. The pilot defined standard atmosphere temperature profile is the ISA temperature profile affected by the pilot entered tropopause altitude.
Forecast ISA DEV profiles are constructed for three distinct segments:
- the climb segment, defined from the origin to the initial Top of Climb (T/C), using current A/C SAT, GND TEMP entered on the INIT A page and CRZ TEMP entered on the INIT A or FUEL PRED page,
- the cruise segment, defined from the initial T/C to the Top of Descent (T/D), using current A/C SAT and CRZ TEMP entered on the INIT A or FUEL PRED page,
- the descent segment, defined from the T/D to the destination, using the destination temperature entered on the APPR PERF page.
(24) Predicted winds and temperatures
This blending method is defined by the vendor.
FM predictions blend current A/C (or measured) wind and ISA DEV into the forecast wind and temperature model for use in the computation of parameters such as fuel burn, altitude at waypoints, time at waypoints, etc. Predicted winds and temperature are used for predictions.
This blending method is defined by the vendor.
FM predictions blend current A/C (or measured) wind and ISA DEV into the forecast wind and temperature model for use in the computation of parameters such as fuel burn, altitude at waypoints, time at waypoints, etc. Predicted winds and temperature are used for predictions.
(25) GRID MORA (Minimum Off Route Altitude)
This function is enabled or disabled through the OPC file according to the GRID MORA ACTIVATED software option value.
It allows to determine and display on ND only one value corresponding to the highest of the Minimum Off Route Altitudes (MORA).
Each MORA is defined for a square whose dimensions are one degree of latitude by one degree of longitude. The data required is as follows: MORA.
This function is enabled or disabled through the OPC file according to the GRID MORA ACTIVATED software option value.
It allows to determine and display on ND only one value corresponding to the highest of the Minimum Off Route Altitudes (MORA).
Each MORA is defined for a square whose dimensions are one degree of latitude by one degree of longitude. The data required is as follows: MORA.
(26) GRID MORA (Minimum Off Route Altitude)
The GRID MORA function (OPC software option), consists in determining only one value corresponding to the highest of the Minimum Off Route Altitudes as stored within the Grid MORA record of the Nav Data Base, which are applicable within a circular area centered on present A/C position and bounded by 40 NM of radius limit.
The list of all coded MORA whose GRID region is intercepting this above defined circle constitutes a candidate list for this computation which is updated at time interval of about 30 s.
The highest MORA value resulting from this above shall be transmitted to EFIS with the following display conditions:
The GRID MORA function (OPC software option), consists in determining only one value corresponding to the highest of the Minimum Off Route Altitudes as stored within the Grid MORA record of the Nav Data Base, which are applicable within a circular area centered on present A/C position and bounded by 40 NM of radius limit.
The list of all coded MORA whose GRID region is intercepting this above defined circle constitutes a candidate list for this computation which is updated at time interval of about 30 s.
The highest MORA value resulting from this above shall be transmitted to EFIS with the following display conditions:
- MORA is valid (i.e. A/C position is valid and all Moras considering for the canditate list are specified on the NDB),
- On EFIS:
* control panel waypoint constraints option is selected,
* mode display is ARC, ROSE NAV or PLAN,
* range > 40 NM.
S. Vertical Function - Speed Generation
(1) FM computed speed - Take-off
Characteristic take-off speeds as, F, S and Green Dot take-off are computed in preflight and take-off phases using the performance model (V1, V2 and VR are entered by the pilot). They are computed with the Take-Off Weight (TOW) if it is available, else they are not computed.
Characteristic take-off speeds as, F, S and Green Dot take-off are computed in preflight and take-off phases using the performance model (V1, V2 and VR are entered by the pilot). They are computed with the Take-Off Weight (TOW) if it is available, else they are not computed.
(2) FM computed speed - Take-off
Characteristic take-off speeds as, F, S and Green Dot take-off are computed in preflight and take-off phases using the performance model (V1, V2 and VR are entered by the pilot, the FM only checks their consistency: V1 less than or equal Vr less than or equal V2 if activated by Take-off securing OPC option). They are computed with the Take-Off Weight (TOW) if it is available, else they are not computed.
Characteristic take-off speeds as, F, S and Green Dot take-off are computed in preflight and take-off phases using the performance model (V1, V2 and VR are entered by the pilot, the FM only checks their consistency: V1 less than or equal Vr less than or equal V2 if activated by Take-off securing OPC option). They are computed with the Take-Off Weight (TOW) if it is available, else they are not computed.
(3) FM computed speed - Take-off logic
Take-off speed check logic warn the pilot of a change of the existing runway; at the first runway insertion, the take-off speed check logic is not applied.
Take-off speed check logic warn the pilot of a change of the existing runway; at the first runway insertion, the take-off speed check logic is not applied.
(4) FM computed speeds - Approach and Go-Around
While not in approach flight phase, the approach speeds (VLS, default VAPP, Green Dot, S, and F) and the go-around reference speeds (F, S and Green Dot) are computed using the performance model with the predicted Landing Weight (LW) if available, with the current Gross Weight (GW) if not. At transition to approach phase, these speeds are computed with the current GW and current Center of Gravity (CG).
Takeoff, approach and go around speeds are displayed on the corresponding PERF pages.
While not in approach flight phase, the approach speeds (VLS, default VAPP, Green Dot, S, and F) and the go-around reference speeds (F, S and Green Dot) are computed using the performance model with the predicted Landing Weight (LW) if available, with the current Gross Weight (GW) if not. At transition to approach phase, these speeds are computed with the current GW and current Center of Gravity (CG).
Takeoff, approach and go around speeds are displayed on the corresponding PERF pages.
(5) Take-off speed - General information
NOTE: The minimum value that can be entered in Take-off speed fields (V1, V2, VR) is decreased from 100 kts to 80 kts.
(6) FM computed speed - Economy (ECON)
The ECON speeds are the optimum speeds for the given cost index which satisfy a time constraint (if one exists) and/or speed constraints (if they exist) and the speed envelope. If there is no time or speed constraint, the ECON speeds are the optimum speeds computed in the previous paragraph. They are displayed on the PERF page under the ECON prompt.
The ECON speeds are the optimum speeds for the given cost index which satisfy a time constraint (if one exists) and/or speed constraints (if they exist) and the speed envelope. If there is no time or speed constraint, the ECON speeds are the optimum speeds computed in the previous paragraph. They are displayed on the PERF page under the ECON prompt.
(7) FM computed speed - Optimum ECON
All speeds defined in this paragraph are computed inside the speed envelope of the managed speed mode.
Climb, cruise and descent optimum speeds are optimized on the basis of these values:
In Preflight phase, these speeds are computed using the TOW and the predicted weights at the various points of the F-PLN. If no TOW is available, no speed is computed. After transition to take-off phase, they are computed using the A/C GW and the predicted weights at the various points of the F-PLN. If no A/C GW is available, no speed is computed. If there is no CRZ FL or no CI, they default to Green Dot.
All speeds defined in this paragraph are computed inside the speed envelope of the managed speed mode.
Climb, cruise and descent optimum speeds are optimized on the basis of these values:
- Gross Weight (GW),
- Cost Index (CI),
- Cruise Flight Level (CRZ FL),
- Wind and temperature models,
- current Center of Gravity (CG).
In Preflight phase, these speeds are computed using the TOW and the predicted weights at the various points of the F-PLN. If no TOW is available, no speed is computed. After transition to take-off phase, they are computed using the A/C GW and the predicted weights at the various points of the F-PLN. If no A/C GW is available, no speed is computed. If there is no CRZ FL or no CI, they default to Green Dot.
(8) FM computed speed - Performance
In case a time constraint is inserted in the F-PLN, the FM computes performance speeds within the speed envelope so as to try to satisfy the constraint, taking into account all applicable speed limits and constraints. These speeds are used until the time constrained waypoint. FM computed performance speeds are computed as optimum speeds for a pseudo cost index value which satisfies the time constraint and the current flight conditions. In Descent or Approach flight phase, the performance speed adjustment process based on the performance cost index optimization is performed while current A/C altitude is above Max (DES SPD LIM altitude; FL100).
In case a time constraint is inserted in the F-PLN, the FM computes performance speeds within the speed envelope so as to try to satisfy the constraint, taking into account all applicable speed limits and constraints. These speeds are used until the time constrained waypoint. FM computed performance speeds are computed as optimum speeds for a pseudo cost index value which satisfies the time constraint and the current flight conditions. In Descent or Approach flight phase, the performance speed adjustment process based on the performance cost index optimization is performed while current A/C altitude is above Max (DES SPD LIM altitude; FL100).
(9) FM computed speed - Expedite
Expedite climb speed is defined as the maximum speed between VMAN and VLS. Expedite descent speeds is the maximum speed: EXP SPD = MIN(VMAX OPFAC; VMO - Delta V; MMO - Delta M).
Expedite climb speed is defined as the maximum speed between VMAN and VLS. Expedite descent speeds is the maximum speed: EXP SPD = MIN(VMAX OPFAC; VMO - Delta V; MMO - Delta M).
(10) FM computed speed - Holding pattern (HM)
The holding speed which must be used in the ECON speed profile computation within a HM is defined as the minimum of:
The holding speed which must be used in the ECON speed profile computation within a HM is defined as the minimum of:
- ICAO limits,
- max endurance speed given by PERF model,
- NDB holding pattern speed constraint (if one exists),
- any flight plan speed constraints or limits that apply to the hold.
(11) FM computed speed - Holding pattern (HM)
The holding pattern size is computed taking into account the speed at which the aircraft is supposed to fly the Hold (holding pattern speed in managed speed mode or selected speed in manual speed mode). The segment necessary to decelerate from current speed (ECON, AUTO or MAN) to the holding speed is limited to a maximal length of 20 NM. The holding speed which must be used in the ECON speed profile computation within a HM is defined as the minimum of:
If an altitude constraint was defined at the revise point, then this constraint is applied to both the hold entry fix and the hold exit fix to prevent A/C from descending below the Alt constraint.
The holding pattern size is computed taking into account the speed at which the aircraft is supposed to fly the Hold (holding pattern speed in managed speed mode or selected speed in manual speed mode). The segment necessary to decelerate from current speed (ECON, AUTO or MAN) to the holding speed is limited to a maximal length of 20 NM. The holding speed which must be used in the ECON speed profile computation within a HM is defined as the minimum of:
- ICAO limits,
- max endurance speed given by PERF model,
- NDB holding pattern speed constraint (if one exists),
- any flight plan speed constraints or limits that apply to the hold.
If an altitude constraint was defined at the revise point, then this constraint is applied to both the hold entry fix and the hold exit fix to prevent A/C from descending below the Alt constraint.
(12) Descent auto speed
The descent auto speed is a particular speed target, unlike the optimum DES speed which can be preselected by the pilot on the PERF descent page before transition to descent phase. The pilot can select a CAS or a Mach or both to replace the optimum descent speed. The descent auto speed is submitted to speed limitations within the descent phase.
The descent auto speed is a particular speed target, unlike the optimum DES speed which can be preselected by the pilot on the PERF descent page before transition to descent phase. The pilot can select a CAS or a Mach or both to replace the optimum descent speed. The descent auto speed is submitted to speed limitations within the descent phase.
(13) Manual speed (selected speed mode)
Pilot can preselect a manual speed through:
Pilot can preselect a manual speed through:
- the MCDU for future flight phase (Climb or Cruise) by entering a speed, either a CAS or a Mach, on the PERF page of this future phase. The selected speed is only limited by the flight envelope. This speed will be automatically used at transition to this phase as manual speed.
- the FCU.
(14) Descent auto speed
The descent auto speed is a particular speed target, unlike the optimum DES speed which can be preselected by the pilot on the PERF descent page as long as it can be accessed. The pilot can select a CAS or a Mach or both to replace the optimum descent speed. The descent auto speed is submitted to speed limitations within the descent phase.
The descent auto speed is a particular speed target, unlike the optimum DES speed which can be preselected by the pilot on the PERF descent page as long as it can be accessed. The pilot can select a CAS or a Mach or both to replace the optimum descent speed. The descent auto speed is submitted to speed limitations within the descent phase.
(15) Manual speed (selected speed mode)
Pilot can preselect a manual speed through:
Pilot can preselect a manual speed through:
- the MCDU for future flight phase (Climb or Cruise) by entering a speed, either a CAS or a Mach, on the PERF page of this future phase. The selected speed is only limited by the flight envelope. This speed will be automatically used at transition to this phase as manual speed.
- the FCU.
(16) Constant Mach Segment (CMS)
The crew can select on the MCDU a speed for the cruise or only on a specific segment in cruise phase. All the flight plan constraints will be taken into account.
In addition to this selection, the crew can preselect a speed or a Mach number on the MCDU for any further flight phase. This preselection will become active when the considered flight phase becomes active.
The crew can select on the MCDU a speed for the cruise or only on a specific segment in cruise phase. All the flight plan constraints will be taken into account.
In addition to this selection, the crew can preselect a speed or a Mach number on the MCDU for any further flight phase. This preselection will become active when the considered flight phase becomes active.
(17) Constant Mach
This function allows the crew to define a constant Mach Speed along a specified segment by entering a desired Mach value, a starting waypoint and an ending waypoint. These parameters are selectable manually in the Constant Mach page through the VERT REV page.
This function allows the crew to define a constant Mach Speed along a specified segment by entering a desired Mach value, a starting waypoint and an ending waypoint. These parameters are selectable manually in the Constant Mach page through the VERT REV page.
T. Vertical Function - Engine Out (EO)
(1) Activation
The system detects automatically an engine out situation from various signals received from the FADECs. When Engine Out mode is active, then the MCDU display reverts either to temporary F-PLN page in order to enable or erase the EOSID procedure (if the A/C is before the diversion point) or to present flight phase PERF page (if the A/C is after the diversion point). Any preselected speed on the MCDU PERF pages, any time constraint and any pre-planned step inserted in F-PLN are deleted and none can be inserted. When the Engine Out mode is active, the Engine Out maximum altitude is computed (EO MAX ALT) and displayed on the Progress page (in place of REC MAX ALT).
The system detects automatically an engine out situation from various signals received from the FADECs. When Engine Out mode is active, then the MCDU display reverts either to temporary F-PLN page in order to enable or erase the EOSID procedure (if the A/C is before the diversion point) or to present flight phase PERF page (if the A/C is after the diversion point). Any preselected speed on the MCDU PERF pages, any time constraint and any pre-planned step inserted in F-PLN are deleted and none can be inserted. When the Engine Out mode is active, the Engine Out maximum altitude is computed (EO MAX ALT) and displayed on the Progress page (in place of REC MAX ALT).
(2) De-activation
The first way to exit the ENGINE OUT mode is a manual selection of the EO CLR prompt on the active PERF page. The other way is an automatic one at full engine recovery detection.
The first way to exit the ENGINE OUT mode is a manual selection of the EO CLR prompt on the active PERF page. The other way is an automatic one at full engine recovery detection.
(3) Take-Off or Go-Around phase
(a) Predictions
F-PLN predictions are not computed. The predictions of speed, alt, time, fuel and wind at each WPT are dashed on F-PLN pages.
F-PLN predictions are not computed. The predictions of speed, alt, time, fuel and wind at each WPT are dashed on F-PLN pages.
(b) Guidance
Guidance is provided by FG.
Guidance is provided by FG.
(4) CLIMB or CRZ phase (and A/C below EO Max Alt)
(a) Predictions
All the F-PLN predictions are computed at each waypoint and down to the primary Destination assuming CRZ phase will be performed at min. (CRZ alt., LRC EO Max alt).
All the F-PLN predictions are computed at each waypoint and down to the primary Destination assuming CRZ phase will be performed at min. (CRZ alt., LRC EO Max alt).
(b) Guidance
The MCT message is displayed on PFD by the FG.
If A/C is in speed Management Control mode, the speed target is as follows:
In level off, the mode is basically ALT/SPD (under FG responsibility).
The MCT message is displayed on PFD by the FG.
If A/C is in speed Management Control mode, the speed target is as follows:
- A/C in ALT or ALT ACQ mode:
It is equal to EO CRZ SPD computed with the altitude of the level segment limited to EO MAX ALT. But if at engine out detection the A/C speed is above EO CRZ speed, the speed target is ramped down from current speed to EO CRZ speed at - 1 kt/sec ; this is to avoid a too hard thrust reduction. - A/C not in (ALT or ALT ACQ mode):
It is equal to GREENDOT limited to speed envelope. But if at engine out detection, A/C speed is above GREENDOT, the speed target is ramped down to GREENDOT with a rate equal to (Delta V/Delta t) = (- 1 kt/s).
In level off, the mode is basically ALT/SPD (under FG responsibility).
(5) CLB or CRZ phase (and A/C above LRC EO Max alt)
(a) Predictions
All the F-PLN predictions are computed till the primary destination, assuming CRZ alt is immediately reset down to LRC EO Max alt and a Drift Down Descent is performed to reach this new CRZ alt.
The Drift Down descent is performed with following conditions:
PERF CRZ Page in EO Condition ** ON A/C NOT FOR ALL
PERF CRZ Page in EO Condition ** ON A/C NOT FOR ALL
All the F-PLN predictions are computed till the primary destination, assuming CRZ alt is immediately reset down to LRC EO Max alt and a Drift Down Descent is performed to reach this new CRZ alt.
The Drift Down descent is performed with following conditions:
- MCT thrust target,
- Greendot speed target.
PERF CRZ Page in EO Condition ** ON A/C NOT FOR ALL PERF CRZ Page in EO Condition ** ON A/C NOT FOR ALL (b) Guidance
The MCT message is displayed on PFD by the FG.
If CLB or DES was the currently engaged mode at EO detection, the FG is automatically reverting to V/S mode using current A/C V/S as target.
In Speed Management mode the speed target is as follows:
The MCT message is displayed on PFD by the FG.
If CLB or DES was the currently engaged mode at EO detection, the FG is automatically reverting to V/S mode using current A/C V/S as target.
In Speed Management mode the speed target is as follows:
- A/C in ALT ACQ or ALT mode (above LRC EO Max Alt):
The current speed target at EO detection is kept unmodified (actually the A/C speed is going to decrease due to engine performance). - A/C is descending or climbing in any current guidance mode (Vert Man Control):
It is equal to GREENDOT speed after having been ramped if necessary.
(6) Descent or Approach phase
(a) Predictions
Predictions are computed with the same assumptions as for all-engine operations, except for alternate predictions which are invalid. When an Engine Out occurs, predictions are recomputed using the applicable cost index for engine out condition.
Predictions are computed with the same assumptions as for all-engine operations, except for alternate predictions which are invalid. When an Engine Out occurs, predictions are recomputed using the applicable cost index for engine out condition.
(b) Guidance
It is the same as in all engine case except that MCT is immediately requested on PFD by the FG.
The DES mode is using any relevant submode to follow the descent path as in all engine case.
It is the same as in all engine case except that MCT is immediately requested on PFD by the FG.
The DES mode is using any relevant submode to follow the descent path as in all engine case.
U. Vertical Function - F-PLN management (predictions/vertical guidance)
The vertical F-PLN management provided by the FM mainly consists of these two tasks:
The vertical F-PLN management provided by the FM mainly consists of these two tasks:
- Computations of predictions: F-PLN predictions attempt to predict the A/C performance from the primary origin (or A/C position) to the primary destination. The current A/C state is propagated along the lateral and vertical flight plan, on the basis of various assumptions concerning how a particular flight phase will be flown in given modes and sub-modes. The goal is to provide predictions of time, speed, altitude, distance, fuel on board and true wind for display at downpath waypoints and pseudo waypoints on the F-PLN A and B pages. It also provides the summary data of time, distance, and EFOB at the destination for display on the F-PLN, PERF, and FUEL PRED pages. Predictions can start as soon as a GW, a CRZ FL, a CI and a lateral flight plan are defined (pilot entries or FM computations).
- Vertical guidance: it provides mode and sub-mode requests and altitude, speed, and, in VPATH modes, thrust and pitch targets to the FG based on the current A/C state, the immediate vertical profile, the current flight phase, and the selected mode.
- Computations of predictions: F-PLN predictions attempt to predict the A/C performance from the primary origin (or A/C position) to the primary destination. The current A/C state is propagated along the lateral and vertical flight plan, on the basis of various assumptions concerning how a particular flight phase will be flown in given modes and sub-modes. The goal is to provide predictions of time, speed, altitude, distance, fuel on board and true wind for display at downpath waypoints and pseudo waypoints on the F-PLN A and B pages. It also provides the summary data of time, distance, and EFOB at the destination for display on the F-PLN, PERF, and FUEL PRED pages. Predictions can start as soon as a GW, a CRZ FL, a CI and a lateral flight plan are defined (pilot entries or FM computations).
- Vertical guidance: it provides mode and sub-mode requests and altitude, speed, and, in VPATH modes, thrust and pitch targets to the FG based on the current A/C state, the immediate vertical profile, the current flight phase, and the selected mode.
(1) Lateral, Vertical and Speed Auto Control (normal default mode) - Take-off
(a) Predictions
Below Thrust Reduction Altitude (TRA), F-PLN predictions are based upon take-off allowances provided by the performance data base. Altitude/distance, EFOB and time predictions at waypoints occurring before reaching TRA are linearly interpolated between the rotation point and the TRA. Predicted speed profile is fixed at V2+10 kts.
Upon reaching the TRA, the LVR CLB message is displayed on the FMA (on the PFD) to warn the pilot that he has to set the throttle to the CLB position, which corresponds to the climb. Above TRA, assuming that SPD/THR submode is active until the acceleration altitude, predictions are computed with A/C motion equations using the engine and aerodynamic model part of the performance data base. Predicted speed remains fixed at V2+10 kts.
Assuming ACC ALT > TRA, if an altitude constraint is below these 2 values then TRA and ACC ALT are automatically reassigned to the constrained altitude.
Below Thrust Reduction Altitude (TRA), F-PLN predictions are based upon take-off allowances provided by the performance data base. Altitude/distance, EFOB and time predictions at waypoints occurring before reaching TRA are linearly interpolated between the rotation point and the TRA. Predicted speed profile is fixed at V2+10 kts.
Upon reaching the TRA, the LVR CLB message is displayed on the FMA (on the PFD) to warn the pilot that he has to set the throttle to the CLB position, which corresponds to the climb. Above TRA, assuming that SPD/THR submode is active until the acceleration altitude, predictions are computed with A/C motion equations using the engine and aerodynamic model part of the performance data base. Predicted speed remains fixed at V2+10 kts.
Assuming ACC ALT > TRA, if an altitude constraint is below these 2 values then TRA and ACC ALT are automatically reassigned to the constrained altitude.
(b) Guidance
As there is no optimization on the whole take-off phase, the active SPD/THR mode is not under FM responsibility.
As there is no optimization on the whole take-off phase, the active SPD/THR mode is not under FM responsibility.
(2) Lateral, Vertical and Speed Auto Control (normal default mode) - Climb
(a) Predictions
From the acceleration altitude, predictions assume an acceleration to the initial ECON climb speed. The assumed climb sub-mode is SPD/THR. The trajectory considered optimum of the A/C is the one created from ECON speed control on the elevator and climb thrust. Predictions are computed taking all climb altitude and speed constraints into account. Above greendot until approach, predictions assume clean configuration.
The ECON climb speed at a specific point is defined as the minimum of the optimum climb speed and the downpath climb speed constraints and climb speed limits.
Upon reaching the waypoint associated with the restrictive speed constraint (or limit), predictions assume an acceleration to the next restrictive speed constraint or limit or to the optimum speed.
Predictions of altitudes are based on a climbing altitude profile determined from the acceleration altitude until the interception of the first CRZ FL or the theoretical descent profile. If the optimum trajectory is above an AT or BELOW constraint, an altitude hold is assumed until the constraint is passed. If this optimum trajectory is below such constraints, they are ignored.
No DES segment is authorised during climb phase.
From the acceleration altitude, predictions assume an acceleration to the initial ECON climb speed. The assumed climb sub-mode is SPD/THR. The trajectory considered optimum of the A/C is the one created from ECON speed control on the elevator and climb thrust. Predictions are computed taking all climb altitude and speed constraints into account. Above greendot until approach, predictions assume clean configuration.
The ECON climb speed at a specific point is defined as the minimum of the optimum climb speed and the downpath climb speed constraints and climb speed limits.
Upon reaching the waypoint associated with the restrictive speed constraint (or limit), predictions assume an acceleration to the next restrictive speed constraint or limit or to the optimum speed.
Predictions of altitudes are based on a climbing altitude profile determined from the acceleration altitude until the interception of the first CRZ FL or the theoretical descent profile. If the optimum trajectory is above an AT or BELOW constraint, an altitude hold is assumed until the constraint is passed. If this optimum trajectory is below such constraints, they are ignored.
No DES segment is authorised during climb phase.
(b) Guidance
If the climb mode is active, the FM LVL/CHG AUTO CONTROL SUBMODE REQUEST is set as follows:
If ALT ACQ or ALT mode is active, the speed target remains the ECON climb guidance speed target.
If the climb mode is active, the FM LVL/CHG AUTO CONTROL SUBMODE REQUEST is set as follows:
| ---------------------------------------------------- |
| ! Elevator target ! SPD Guidance Speed Auto Target ! |
| !-----------------!--------------------------------! |
| ! Thrust target ! THR Climb Thrust ! |
| ---------------------------------------------------- |
If ALT ACQ or ALT mode is active, the speed target remains the ECON climb guidance speed target.
(3) Lateral, Vertical and Speed Auto Control (normal default mode) - Take-off
(a) Predictions
Below Thrust Reduction Altitude (TRA), F-PLN predictions are based upon take-off allowances provided by the performance data base. Altitude/distance, EFOB and time predictions at waypoints occurring before reaching TRA are linearly interpolated between the rotation point and the TRA. Predicted speed profile is fixed at V2+10 kts.
Upon reaching the TRA, the LVR CLB message is displayed on the FMA (on the PFD) to warn the pilot that he has to set the throttle to the CLB position, which corresponds to the climb. Above TRA, assuming that SPD/THR submode is active until the acceleration altitude, predictions are computed with A/C motion equations using the engine and aerodynamic model part of the performance data base. Predicted speed remains fixed at V2+10 kts.
Assuming ACC ALT > TRA, if an altitude constraint is below these 2 values then TRA and ACC ALT are automatically reassigned to the constrained altitude.
Below Thrust Reduction Altitude (TRA), F-PLN predictions are based upon take-off allowances provided by the performance data base. Altitude/distance, EFOB and time predictions at waypoints occurring before reaching TRA are linearly interpolated between the rotation point and the TRA. Predicted speed profile is fixed at V2+10 kts.
Upon reaching the TRA, the LVR CLB message is displayed on the FMA (on the PFD) to warn the pilot that he has to set the throttle to the CLB position, which corresponds to the climb. Above TRA, assuming that SPD/THR submode is active until the acceleration altitude, predictions are computed with A/C motion equations using the engine and aerodynamic model part of the performance data base. Predicted speed remains fixed at V2+10 kts.
Assuming ACC ALT > TRA, if an altitude constraint is below these 2 values then TRA and ACC ALT are automatically reassigned to the constrained altitude.
(b) Guidance
As there is no optimization on the whole take-off phase, the active SPD/THR mode is not under FM responsibility.
As there is no optimization on the whole take-off phase, the active SPD/THR mode is not under FM responsibility.
(4) Lateral, Vertical and Speed Auto Control (normal default mode) - Climb
(a) Predictions
From the acceleration altitude, predictions assume an acceleration to the initial ECON climb speed. The assumed climb sub-mode is SPD/THR. The trajectory considered optimum of the A/C is the one created from ECON speed control on the elevator and climb thrust. Predictions are computed taking all climb altitude and speed constraints into account. Above greendot until approach, predictions assume clean configuration.
The ECON climb speed at a specific point is defined as the minimum of:
Predictions of altitudes are based on a climbing altitude profile determined from the acceleration altitude until the interception of the first CRZ FL or the theoretical descent profile. If the optimum trajectory is above an AT or BELOW constraint, an altitude hold is assumed until the constraint is passed. If this optimum trajectory is below such constraints, they are ignored.
No DES segment is authorised during climb phase.
From the acceleration altitude, predictions assume an acceleration to the initial ECON climb speed. The assumed climb sub-mode is SPD/THR. The trajectory considered optimum of the A/C is the one created from ECON speed control on the elevator and climb thrust. Predictions are computed taking all climb altitude and speed constraints into account. Above greendot until approach, predictions assume clean configuration.
The ECON climb speed at a specific point is defined as the minimum of:
- the optimum climb speed and the downpath climb speed constraints and climb speed limits,
- the maximum of (climb speed limit, greendot speed) below the climb speed limit altitude (if defined).
Predictions of altitudes are based on a climbing altitude profile determined from the acceleration altitude until the interception of the first CRZ FL or the theoretical descent profile. If the optimum trajectory is above an AT or BELOW constraint, an altitude hold is assumed until the constraint is passed. If this optimum trajectory is below such constraints, they are ignored.
No DES segment is authorised during climb phase.
(b) Guidance
If the climb mode is active, the FM LVL/CHG AUTO CONTROL SUBMODE REQUEST is set as follows:
If ALT ACQ or ALT mode is active, the speed target remains the ECON climb guidance speed target.
If the climb mode is active, the FM LVL/CHG AUTO CONTROL SUBMODE REQUEST is set as follows:
| ---------------------------------------------------- |
| ! Elevator target ! SPD Guidance Speed Auto Target ! |
| !-----------------!--------------------------------! |
| ! Thrust target ! THR Climb Thrust ! |
| ---------------------------------------------------- |
If ALT ACQ or ALT mode is active, the speed target remains the ECON climb guidance speed target.
(5) Lateral, Vertical and Speed Auto Control (normal default mode) - Cruise
(a) Predictions
At interception of the CRZ FL, predictions assume a transition to cruise phase. ALT mode is assumed in cruise. The trajectory considered optimum by the A/C is the one created from CRZ FL hold on the elevator and ECON CRZ MACH (or SPD) hold with thrust. If steps exist in the F-PLN, they are taken into account in the cruise predictions. If a UTC constrained waypoint is in the cruise segment, predictions assume a speed change from the performance speed to the normal ECON cruise speed following the constrained waypoint. If the CRZ FL is at or below the CLB SPD LIM, the speed predictions hold the constant CAS speed limit until the associated altitude is passed.
At interception of the CRZ FL, predictions assume a transition to cruise phase. ALT mode is assumed in cruise. The trajectory considered optimum by the A/C is the one created from CRZ FL hold on the elevator and ECON CRZ MACH (or SPD) hold with thrust. If steps exist in the F-PLN, they are taken into account in the cruise predictions. If a UTC constrained waypoint is in the cruise segment, predictions assume a speed change from the performance speed to the normal ECON cruise speed following the constrained waypoint. If the CRZ FL is at or below the CLB SPD LIM, the speed predictions hold the constant CAS speed limit until the associated altitude is passed.
(b) Guidance
ALT mode is the normal guidance mode. In case a step climb or a step descent is predicted, CLB or DES mode are respectively armed. When the predicted level change mode is active, the FM requests its associated submode:
The guidance speed auto target is: MAX (VMAN FE, display speed auto target).
ALT mode is the normal guidance mode. In case a step climb or a step descent is predicted, CLB or DES mode are respectively armed. When the predicted level change mode is active, the FM requests its associated submode:
| -------------------------------------------------------------- |
| ! Level ! Step-climb ! Step-descent ! |
| ! segments ! (pre-planned or not) ! (pre-planned or not) ! |
| !------------------------------------------------------------! |
| ! ALT ACQ or ! CLB Mode ! DES Mode ! |
| ! ALT Mode ! ! ! |
| ------------!--------------!----------------------!----------------------! |
| ! Elevator ! ALT CRZ FL ! SPD guidance speed ! V/S -1000 ft/min ! |
| ! target ! ! auto target ! ! |
| !-----------!--------------!----------------------!----------------------! |
| ! Thrust ! SPD guidance ! THR Max thrust ! SPD guidance speed ! |
| ! target ! speed auto ! ! auto target ! |
| ! ! target ! ! ! |
| -------------------------------------------------------------------------- |
The guidance speed auto target is: MAX (VMAN FE, display speed auto target).
(c) MCDU and/or PFD messages
The DECELERATE message is displayed on the PFD and MCDU when:
The DECELERATE message is displayed on the PFD and MCDU when:
- the A/C is in climb or cruise phase,
and - the A/C is beyond the T/D,
and - the A/C is in automatic speed management control.
(6) Lateral, Vertical and Speed Auto Control (normal default mode) - Descent
(a) Theoretical descent profile
Predictions and guidance for descent phase are based on a computed theoretical descent profile. It is defined by a series of geometric altitude and speed targets which are functions of the distance to the destination. It is computed backwards from the DECEL point up to the last cruise flight level.
The theoretical descent profile is composed of:
Predictions and guidance for descent phase are based on a computed theoretical descent profile. It is defined by a series of geometric altitude and speed targets which are functions of the distance to the destination. It is computed backwards from the DECEL point up to the last cruise flight level.
The theoretical descent profile is composed of:
- A geometric path constructed backward from the DECEL point (treated as an AT constraint) to the Geometric Path Point (GPP: last descent altitude constrained point). It is built with several straight line segments between constraining altitude constraints.
The building of the geometric path assumes that: ascending segment must never be encountered, priority is given to the highest AT or AT OR ABOVE altitude constraints, priority is given to altitude constraint if a FPA constraint applies at the same waypoint and number of vertical manoeuvres is minimized.
Knowing the geometric altitude path, the following method of integration applies in order to determine the type of the different segments (between the constraining altitudes) and to compute the deceleration parts of the theoretical descent speed profile of the geometric path.
The determination of the type of a segment (either normal, airbrake or too steep) is based on a Flight Path Angle (FPA) comparison method. Its principle is to compute, for each segment, two reference FPA: gamma LIM CLEAN (maximum authorized descent path angle with clean A/C configuration) and gamma LIM A/B (maximum authorized descent path angle with half airbrakes extended).
If the segment FPA < gamma LIM CLEAN, the segment is normal. It can be normally flown with clean A/C configuration and slope control on elevators. SPD target is controlled by A/THR.
If gamma LIM CLEAN < FPA < gamma LIM A/B, the segment is airbrake. It can be performed with half airbrakes extended and slope control on elevators. SPD target is controlled by A/THR.
If FPA > gamma LIM A/B, the segment is a too steep path. The path is constructed between the lower point and the upper point of the too steep path based on normal descent path construction rules ignoring the upper altitude constraint. The speed is the minimum of the optimum descent speed and the speed constraints applying at the waypoint. - The second part of the theoretical descent profile is a path from the GPP:
Up to the last cruise flight level as long as the A/C is not in DES flight phase,
or
For recomputation cases in DES flight phase:
* until A/C position (laterally) when A/C is not in HM,
or
* until exit fix position (laterally) when A/C is in HM.
It can also include a repressurization segment. The path is based on the theoretical speed/thrust profiles Vth/THRth as follows:
* THRth: IDLE+delta when not in a deceleration segment, IDLE when in a deceleration segment,
* Vth: descent auto speed.
A deceleration segment can be added to the idle path, at cruise altitude, to ensure a smooth transition from cruise to descent speed profile.
A repressurization segment can be added to the idle path in order to increase the descent time; the cabin pressure variation rate is then reduced for passengers comfort. The maximum descent cabin rate is defined by the pilot on the PERF CRZ page (the default value is 350 ft/mn SL). If the cabin rate defined without any repressurization segment exceeds the maximum cabin rate and the CRZ altitude at last T/D is greater or equal to FL210 a repressurization segment is added to the idle path.
A HM is not taken into account in the theoretical descent path until the A/C sequences the deceleration point or the entry fix of the HM. Once the HM is taken into account, the theoretical descent path is computed from the destination up to and including the HM exit fix; the HM itself is not included in the path.
(b) Predictions
Predictions assume the A/C will fly the theoretical profile. If the A/C is off the theoretical descent profile in altitude and/or speed, predictions suppose an immediate return to the theoretical descent profile from A/C present position to interception of the profile in altitude and speed.
From this point:
Predictions assume the A/C will fly the theoretical profile. If the A/C is off the theoretical descent profile in altitude and/or speed, predictions suppose an immediate return to the theoretical descent profile from A/C present position to interception of the profile in altitude and speed.
From this point:
- speed/alt predictions are from the theoretical descent profile,
- other predictions (Time, EFOB, wind) are given using the speed/altitude of the theoretical descent profile and the current A/C weight and time propagated downpath using A/C equation of motion and the Perf Database.
(c) Guidance
- Guidance with descent mode
If DES mode is active, the guidance submodes and their reversion logic depend on the position of the A/C versus the theoretical descent profile. - When A/C in level flight
When the A/C is in level flight (ALT submode is engaged), the FM speed target sent to the FG is Min (Optimum descent speed; Speed constraints which apply at A/C present position). A Baro setting change must not disengaged ALT mode until the constraint point is passed.
(7) Lateral, Vertical and Speed Auto Control (normal default mode) - Approach
The approach profile nominally starts at the deceleration point and ends at runway threshold point (for precision approach) or at Missed Approach Point (MAP point at which the A/C is expected to start its deceleration toward the approach speed when the approach profile is flown). As for the descent, the approach profile is a set of altitude, speed and thrust profile computed backwards from approach profile start point up to the DECEL point.
All the parameters necessary for approach profile construction come from the data base unless explicitly specified.
The approach profile start point depends on the arrival procedure:
In the approach profile construction, all the level changes are constructed at constant speed except on the final approach and constraint FPA segments.
The final approach is built with consecutive straight lines which observe altitudes and FPA constraints backwards from the start point up to the final capture altitude which is defined as follows:
When the selected approach is:
A speed of VAPP is held from the start point along the altitude profile up to 1000 ft AGL with the A/C.
Then from 1000 ft AGL up to the final capture altitude, the A/C accelerates backwards up along the altitude profile with idle thrust and configuration are changed with the previously described assumptions.
The final approach is defined (backwards) from the start point up to the final capture altitude. The speed reached at that point is called VINTERCEPT. The intermediate approach starts at the final capture altitude.
At that altitude, the A/C levels off with idle thrust and changes configuration until reaching the smallest descent ECON speed above GREEN DOT.
The approach profile nominally starts at the deceleration point and ends at runway threshold point (for precision approach) or at Missed Approach Point (MAP point at which the A/C is expected to start its deceleration toward the approach speed when the approach profile is flown). As for the descent, the approach profile is a set of altitude, speed and thrust profile computed backwards from approach profile start point up to the DECEL point.
All the parameters necessary for approach profile construction come from the data base unless explicitly specified.
The approach profile start point depends on the arrival procedure:
- If the arrival path ends at the runway: the approach profile start point corresponds to the runway threshold (threshold displacement is taken into account) at runway threshold elevation + 50 ft (case of ILS, runway only, or some GPS, VOR, IGS, LDA, LOC only, Radio NAV, SDF or NDB approaches).
- If the arrival path ends at the MAP (case of some GPS, VOR, IGS, LDA, SDF or
* the approach profile start point is the MAP at MAP coded altitude if MAP is located before the runway threshold,
* if the MAP is located beyond the runway threshold, the approach profile start point is the intersection between the altitude coded at the MAP and the straight line drawn between runway Threshold at Runway Threshold Elevation + 50 ft (threshold displacement is taken into account) and the first approach waypoint after the MAP which has an altitude constraint at or above MAP altitude, at this altitude. - If no arrival procedure exists, the approach profile starts at the destination airport location with an altitude equal to the airport Elevation + 50 ft.
In the approach profile construction, all the level changes are constructed at constant speed except on the final approach and constraint FPA segments.
The final approach is built with consecutive straight lines which observe altitudes and FPA constraints backwards from the start point up to the final capture altitude which is defined as follows:
When the selected approach is:
- a precision approach, the final capture altitude is the glide slope capture altitude.
- a non-precision approach:
* for default approaches, it defaults to 1500 ft AGL,
* otherwise, it is the final capture altitude of the selected approach stored in the NDB and determined from the glide slope intersection point.
This point is the FAF when the FAF speed constraint is lower than VAPP, else it is the glide slope intersection at 1550 ft above runway elevation.
A speed of VAPP is held from the start point along the altitude profile up to 1000 ft AGL with the A/C.
Then from 1000 ft AGL up to the final capture altitude, the A/C accelerates backwards up along the altitude profile with idle thrust and configuration are changed with the previously described assumptions.
The final approach is defined (backwards) from the start point up to the final capture altitude. The speed reached at that point is called VINTERCEPT. The intermediate approach starts at the final capture altitude.
At that altitude, the A/C levels off with idle thrust and changes configuration until reaching the smallest descent ECON speed above GREEN DOT.
(a) Predictions
Most of assumptions for predictions in descent phase are common to the approach phase predictions.
Note that when final DES mode is engaged, the path cannot be rebuilt upon pilot entry. Thus, predictions continue to reflect the old values based on the active path.
Most of assumptions for predictions in descent phase are common to the approach phase predictions.
Note that when final DES mode is engaged, the path cannot be rebuilt upon pilot entry. Thus, predictions continue to reflect the old values based on the active path.
- When the A/C is on the approach profile, predictions follow the constructed approach profile (altitude and speed) from the decel point (or A/C position) to the runway threshold.
- When the A/C is above the approach profile, a return to the altitude profile is predicted using the same SPD/THR mode assumptions as for above path descent predictions. The assumed speed target can permit a predicted deceleration (if necessary) during the attempt to intercept the altitude profile.
(b) Guidance
When in APPR flight phase, two different FM managed vertical guidance modes can be engaged:
When in APPR flight phase, two different FM managed vertical guidance modes can be engaged:
- DES mode: this mode is used until final DES mode engages under pilot request.
- Final DES mode: this mode is armed when the pilot presses the APPR push button on the FCU.
(8) Lateral, Vertical and Speed Auto Control (normal default mode) - Descent
(a) Theoretical descent profile
Predictions and guidance for descent phase are based on a computed theoretical descent profile. It is defined by a series of geometric altitude and speed targets which are functions of the distance to the destination. It is computed backwards from the DECEL point up to the last cruise flight level.
The theoretical descent profile is composed of:
Predictions and guidance for descent phase are based on a computed theoretical descent profile. It is defined by a series of geometric altitude and speed targets which are functions of the distance to the destination. It is computed backwards from the DECEL point up to the last cruise flight level.
The theoretical descent profile is composed of:
- A geometric path constructed backward from the DECEL point (treated as an AT constraint) to the Geometric Path Point (GPP: last descent altitude constrained point). It is built with several straight line segments between constraining altitude constraints.
The building of the geometric path assumes that: ascending segment must never be encountered, priority is given to the highest AT or AT OR ABOVE altitude constraints, priority is given to altitude constraint if a FPA constraint applies at the same waypoint and number of vertical manoeuvres is minimized.
Knowing the geometric altitude path, the following method of integration applies in order to determine the type of the different segments (between the constraining altitudes) and to compute the deceleration parts of the theoretical descent speed profile of the geometric path.
The determination of the type of a segment (either normal, airbrake or too steep) is based on a Flight Path Angle (FPA) comparison method. Its principle is to compute, for each segment, two reference FPA: gamma LIM CLEAN (maximum authorized descent path angle with clean A/C configuration) and gamma LIM A/B (maximum authorized descent path angle with half airbrakes extended).
If the segment FPA < gamma LIM CLEAN, the segment is normal. It can be normally flown with clean A/C configuration and slope control on elevators. SPD target is controlled by A/THR.
If gamma LIM CLEAN < FPA < gamma LIM A/B, the segment is airbrake. It can be performed with half airbrakes extended and slope control on elevators. SPD target is controlled by A/THR.
If FPA > gamma LIM A/B, the segment is a too steep path. The path is constructed between the lower point and the upper point of the too steep path based on normal descent path construction rules ignoring the upper altitude constraint. The speed is the minimum of the optimum descent speed and the speed constraints applying at the waypoint. - The second part of the theoretical descent profile is a path from the GPP:
Up to the last cruise flight level as long as the A/C is not in DES flight phase,
or
For recomputation cases in DES flight phase:
* until A/C position (laterally) when A/C is not in HM,
or
* until exit fix position (laterally) when A/C is in HM.
As an exception to the previous rule, in DES flight phase, when active segment is a geometric segment, if any of the following events occurs:
* Modification of Cost Index (even if the new entered value is the same as before)
* Entry or modification of one or both members of the DES auto MACH/SPD target on PERF DES page (including clear or entry of the same value as before)
* A DIR TO (normal, ABEAM, RADIAL IN or RADIAL OUT) any waypoint including TO waypoint (waypoint can be in the flight plan or not) is selected.
*An altitude constraint is entered or modified (including clear or entry of the same value as before) on the active segment (including the end of the active segment).
Then the GPP shall be recomputed as if A/C was currently on an idle path.
Then an idle path shall be built from the GPP up to the current A/C position.
However, if a FPA is coded on the active segment in database, this recomputation shall only be possible by selecting a DIR TO or by inserting/modifying/clearing an altitude constraint on the active segment (modifying the CI or the DES auto MACH/SPD shall not compute an idle path).
It can also include a repressurization segment. The path is based on the theoretical speed/thrust profiles Vth/THRth as follows:
* THRth: IDLE+delta when not in a deceleration segment, IDLE when in a deceleration segment,
* Vth: descent auto speed.
A deceleration segment can be added to the idle path, at cruise altitude, to ensure a smooth transition from cruise to descent speed profile.
A repressurization segment can be added to the idle path in order to increase the descent time; the cabin pressure variation rate is then reduced for passengers comfort. The maximum descent cabin rate is defined by the pilot on the PERF CRZ page (the default value is 350 ft/mn SL). If the cabin rate defined without any repressurization segment exceeds the maximum cabin rate and the CRZ altitude at last T/D is greater or equal to FL210 a repressurization segment is added to the idle path.
A HM is not taken into account in the theoretical descent path until the A/C sequences the deceleration point or the entry fix of the HM. Once the HM is taken into account, the theoretical descent path is computed from the destination up to and including the HM exit fix; the HM itself is not included in the path.
(b) Predictions
Predictions assume the A/C will fly the theoretical profile. If the A/C is off the theoretical descent profile in altitude and/or speed, predictions suppose an immediate return to the theoretical descent profile from A/C present position to interception of the profile in altitude and speed.
From this point:
Predictions assume the A/C will fly the theoretical profile. If the A/C is off the theoretical descent profile in altitude and/or speed, predictions suppose an immediate return to the theoretical descent profile from A/C present position to interception of the profile in altitude and speed.
From this point:
- speed/alt predictions are from the theoretical descent profile,
- other predictions (Time, EFOB, wind) are given using the speed/altitude of the theoretical descent profile and the current A/C weight and time propagated downpath using A/C equation of motion and the Perf Database.
(c) Guidance
- Guidance with descent mode
If DES mode is active, the guidance submodes and their reversion logic depend on the position of the A/C versus the theoretical descent profile. - When A/C in level flight
When the A/C is in level flight (ALT submode is engaged), the FM speed target sent to the FG is Min (Optimum descent speed; Speed constraints which apply at A/C present position). A Baro setting change must not disengaged ALT mode until the constraint point is passed.
(9) Lateral, Vertical and Speed Auto Control (normal default mode) - Approach
The approach profile nominally starts at the deceleration point and ends at runway threshold point (for precision approach) or at Missed Approach Point (MAP point at which the A/C is expected to start its deceleration toward the approach speed when the approach profile is flown). As for the descent, the approach profile is a set of altitude (based on the QNH reference. QFE reference is also allowed if the Full QFE/QNH capability OPC option activated) , speed and thrust profile computed backwards from approach profile start point up to the DECEL point.
All the parameters necessary for approach profile construction come from the data base unless explicitly specified.
The approach profile start point depends on the arrival procedure:
In the approach profile construction, all the level changes are constructed at constant speed except on the final approach and constraint FPA segments.
The final approach is built with consecutive straight lines which observe altitudes and FPA constraints backwards from the start point up to the final capture altitude which is defined as follows:
When the selected approach is:
A speed of VAPP is held from the start point along the altitude profile up to 1000 ft AGL with the A/C.
Then from 1000 ft AGL up to the final capture altitude, the A/C accelerates backwards up along the altitude profile with idle thrust and configuration are changed with the previously described assumptions.
The final approach is defined (backwards) from the start point up to the final capture altitude. The speed reached at that point is called VINTERCEPT. The intermediate approach starts at the final capture altitude.
At that altitude, the A/C levels off with idle thrust and changes configuration until reaching the smallest descent ECON speed above GREEN DOT.
If the No AP/FD Disconnection below MDA/MDH OPC option is activated, the above approach FM profile will generally be valid throughout the approach profile below MDA/MDH, essentially almost all the way to ground (maximum to the arrival end point), and will not be invalidated based on any aircraft altitude considerations. It will be pilot's responsibility to decide when to take control of the aircraft.
The approach profile nominally starts at the deceleration point and ends at runway threshold point (for precision approach) or at Missed Approach Point (MAP point at which the A/C is expected to start its deceleration toward the approach speed when the approach profile is flown). As for the descent, the approach profile is a set of altitude (based on the QNH reference. QFE reference is also allowed if the Full QFE/QNH capability OPC option activated) , speed and thrust profile computed backwards from approach profile start point up to the DECEL point.
All the parameters necessary for approach profile construction come from the data base unless explicitly specified.
The approach profile start point depends on the arrival procedure:
- If the arrival path ends at the runway: the approach profile start point corresponds to the runway threshold (threshold displacement is taken into account) at runway threshold elevation + 50 ft (case of ILS ,MLS, GLS, runway only, or some GPS, VOR, IGS, LDA, LOC only, LOC BB, Radio NAV, SDF or NDB approaches).
- If the arrival path ends at the MAP (case of some LOC only, LOC BB, GPS, VOR, RNAV, IGS, LDA, SDF or
* the approach profile start point is the MAP at MAP coded altitude if MAP is located before the runway threshold,
* if the MAP is located beyond the runway threshold, the approach profile start point is the intersection between the altitude coded at the MAP and the straight line drawn between runway Threshold at Runway Threshold Elevation + 50 ft (threshold displacement is taken into account) and the first approach waypoint after the MAP which has an altitude constraint at or above MAP altitude, at this altitude. - If no arrival procedure exists, the approach profile starts at the destination airport location with an altitude equal to the airport Elevation + 50 ft.
In the approach profile construction, all the level changes are constructed at constant speed except on the final approach and constraint FPA segments.
The final approach is built with consecutive straight lines which observe altitudes and FPA constraints backwards from the start point up to the final capture altitude which is defined as follows:
When the selected approach is:
- a precision approach, the final capture altitude is the glide slope capture altitude.
- a non-precision approach:
* for default approaches, it defaults to 1500 ft AGL,
* otherwise, it is the final capture altitude of the selected approach stored in the NDB and determined from the glide slope intersection point.
This point is the FAF when the FAF speed constraint is lower than VAPP, else it is the glide slope intersection at 1550 ft above runway elevation.
A speed of VAPP is held from the start point along the altitude profile up to 1000 ft AGL with the A/C.
Then from 1000 ft AGL up to the final capture altitude, the A/C accelerates backwards up along the altitude profile with idle thrust and configuration are changed with the previously described assumptions.
The final approach is defined (backwards) from the start point up to the final capture altitude. The speed reached at that point is called VINTERCEPT. The intermediate approach starts at the final capture altitude.
At that altitude, the A/C levels off with idle thrust and changes configuration until reaching the smallest descent ECON speed above GREEN DOT.
If the No AP/FD Disconnection below MDA/MDH OPC option is activated, the above approach FM profile will generally be valid throughout the approach profile below MDA/MDH, essentially almost all the way to ground (maximum to the arrival end point), and will not be invalidated based on any aircraft altitude considerations. It will be pilot's responsibility to decide when to take control of the aircraft.
- FLS and Mix LOC/VNAV functionalities:
FLS: The Final part of Non-Precision Approaches (NDB, VOR, GPS, RNAV) can be flown using an ILS look-like concept, if the FLS function is activated by OPC option.
Mix LOC/VNAV: A virtual glide can be flown for Loc only, Loc Back-Beam or ILS with a deselected Glideslope approaches if both FLS and Mix LOC/VNAV functions are activated by OPC option.
There is no interaction between the FLS / Mix LOC/VNAV vertical path and the FMS vertical path construction described here above. The FMS vertical approach path is still used for predictions whereas the FLS / Mix LOC/VNAV approach path is used for guidance purpose (similar to the use of a G/S for an ILS).
For both FLS and Mix LOC/VNAV approaches, the aircraft will be guided (by the FG) along a virtual landing beam called FLS beam which is built by FM independently from the flight plan and is composed of:
* An anchor point (defined by its lat/long and its elevation).
* A FLS beam course (not used in Mix LOC/VNAV mode).
* A FLS beam slope.
In case no FLS beam can be computed as a result of missing NDB data or the geometry of the approach, the FLS is invalidated within FMS and the NO FLS FOR THIS APPR MCDU scratchpad message is issued for crew awareness.
(a) Predictions
Most of assumptions for predictions in descent phase are common to the approach phase predictions.
Note that when final DES mode is engaged, the path cannot be rebuilt upon pilot entry. Thus, predictions continue to reflect the old values based on the active path.
Most of assumptions for predictions in descent phase are common to the approach phase predictions.
Note that when final DES mode is engaged, the path cannot be rebuilt upon pilot entry. Thus, predictions continue to reflect the old values based on the active path.
- When the A/C is on the approach profile, predictions follow the constructed approach profile (altitude and speed) from the decel point (or A/C position) to the runway threshold.
- When the A/C is above the approach profile, a return to the altitude profile is predicted using the same SPD/THR mode assumptions as for above path descent predictions. The assumed speed target can permit a predicted deceleration (if necessary) during the attempt to intercept the altitude profile.
- There is no impact of the FLS and Mix LOC/VNAV functions on the prediction computation.
(b) Guidance
When in APPR flight phase, two different FM managed vertical guidance modes can be engaged, DES and Final DES:
When in APPR flight phase, two different FM managed vertical guidance modes can be engaged, DES and Final DES:
- DES mode: this mode is used until final DES mode engages under pilot request.
Where COND is TRUE: a path is defined and DES mode becomes engaged, or, a path becomes defined and DES mode was already engaged. - Final DES mode: this mode is armed when the pilot presses the APPR push button on the FCU.
When F.DES mode is engaged, the submode is VPATH/SPD and is latched as such as long as F.DES mode remains engaged.
- When the FLS OPC option is activated, the F.DES mode is replaced by the FLS mode and guidance on the FLS beam is under FG responsibility:
FLS mode (F-G/S + F-LOC modes): This mode is armed instead of F.DES when the pilot presses the APPR push button on the FCU if the FLS OPC option is activated. When the FLS mode is engaged, the aircraft is laterally and vertically guided on the FLS beam by the FG. - When the FLS and Mix LOC/VNAV OPC options are activated and for LOC only, LOC back-beam and ILS with G/S deselected, the lateral guidance becomes based on the LOC beam and the vertical guidance based on the FLS beam (FG responsibility):
Mix LOC/VNAV (F-G/S + LOC modes): This mode is armed for LOC only, LOC back- beam or ILS with glideslope deselected when the pilot presses the APPR push button on the FCU if both FLS and Mix LOC/VNAV OPC options are activated. When the Mix LOC/VNAV mode is engaged, the aircraft is laterally guided on the LOC beam and vertically guided on the FLS beam by the FG.
When FLS or Mix LOC/VNAV function is activated, the FMS computes a specific baro-temp corrected A/C altitude based on the FCU barometric reference and the temperature at destination. This temperature correction is only required for destination temperatures below the standard temperature at destination. This prevents an important inverted correction (in the sense of lowering the aircraft real altitude).
(10) Lateral, Vertical and Speed Auto Control (normal default mode) - Go-Around
(a) Predictions
Predictions (EFOB, time, route reserve, final and extra at primary and alternate destination) are available only if the go-around phase is active. However, waypoint predictions are not provided and are dashed on the F-PLN page. Predictions are computed from A/C position to the primary destination.
Predictions (EFOB, time, route reserve, final and extra at primary and alternate destination) are available only if the go-around phase is active. However, waypoint predictions are not provided and are dashed on the F-PLN page. Predictions are computed from A/C position to the primary destination.
(b) Guidance
The FM does not control the guidance during the whole Go Around phase. The guidance speed auto target is set as follows on transition to Go Around: MAX (VMANFE; display speed auto target).
Transition to OPEN CLIMB mode at acceleration altitude during Go Around phase is ensured by the FG part.
The FM does not control the guidance during the whole Go Around phase. The guidance speed auto target is set as follows on transition to Go Around: MAX (VMANFE; display speed auto target).
Transition to OPEN CLIMB mode at acceleration altitude during Go Around phase is ensured by the FG part.
(11) Lateral Auto Control and Vertical Auto Control and Speed Manual Mode
Only differences with the lateral, vertical and speed auto control case are described.
The speed manual mode can be engaged either manually by pulling the FCU SPD knob, or automatically if the pilot has preselected a manual speed for the climb and/or cruise phase on the related MCDU Perf page. The SPD manual mode is disengaged if pilot pushes the FCU SPD knob, it cannot be disengaged automatically, if expedite mode is engaged.
Only differences with the lateral, vertical and speed auto control case are described.
The speed manual mode can be engaged either manually by pulling the FCU SPD knob, or automatically if the pilot has preselected a manual speed for the climb and/or cruise phase on the related MCDU Perf page. The SPD manual mode is disengaged if pilot pushes the FCU SPD knob, it cannot be disengaged automatically, if expedite mode is engaged.
(a) Climb
1 Predictions
If the A/C is in preflight or take off with a preselected manual climb speed or the A/C is in climb and in manual speed selection mode, F-PLN predictions will suppose that the pilot will return to the automatic speed management mode at the next climb speed limit or climb speed constraint where ECON climb speed target becomes greater than the manual selected speed.
If there are no speed limit or speed constraint points, predictions suppose that the pilot will return to automatic speed management mode at the T/C. From the deselection point, predictions assume an acceleration to the ECON climb speed.
Predictions assume a switch from CAS to the complementary MACH at the FM computed crossover altitude if this altitude is below the first CRZ FL.
If the A/C is in preflight or take off with a preselected manual climb speed or the A/C is in climb and in manual speed selection mode, F-PLN predictions will suppose that the pilot will return to the automatic speed management mode at the next climb speed limit or climb speed constraint where ECON climb speed target becomes greater than the manual selected speed.
If there are no speed limit or speed constraint points, predictions suppose that the pilot will return to automatic speed management mode at the T/C. From the deselection point, predictions assume an acceleration to the ECON climb speed.
Predictions assume a switch from CAS to the complementary MACH at the FM computed crossover altitude if this altitude is below the first CRZ FL.
2 Guidance
The guidance is identical to that specified in lateral, vertical and speed auto control chapter, except that the target speed is the manually selected speed.
The guidance is identical to that specified in lateral, vertical and speed auto control chapter, except that the target speed is the manually selected speed.
(b) Cruise
1 Predictions
If the A/C is in preflight, take-off, or climb phase with a preselected manual cruise speed or the A/C is in cruise and in manual speed selection mode, F-PLN predictions will assume the following:
If the A/C is in preflight, take-off, or climb phase with a preselected manual cruise speed or the A/C is in cruise and in manual speed selection mode, F-PLN predictions will assume the following:
- For constant altitude portion, predictions assume that the (pre)selected speed, MACH or CAS will be maintained until T/D.
- For a (pre)selected CAS, predictions assume a switch from CAS to the complementary MACH at the FM-computed CAS croos-over altitude only during a step climb. For a step descent that passes through the CAS cross-over altitude, predictions will maintain a constant CAS.
- For a (pre)selected MACH, predictions assume a switch from MACH to the complementary CAS at the FM-computed MACH cross-over altitude only during a step descent. For a step climb that passes through the MACH cross-over altitude, predictions will maintain a constant MACH.
2 Guidance
The guidance is identical to that specified in lateral, vertical and speed auto control chapter, except that the target speed is the manually selected speed and under FG responsibility.
The guidance is identical to that specified in lateral, vertical and speed auto control chapter, except that the target speed is the manually selected speed and under FG responsibility.
(c) Descent
The theoretical descent profile is always computed versus the ECON (or AUTO) descent speed profile.
The theoretical descent profile is always computed versus the ECON (or AUTO) descent speed profile.
1 Predictions
Predictions only consider manual speed selection when descent phase is active.
F-PLN predictions suppose that the pilot will return to the automatic speed management mode at start of deceleration to the next restrictive descent speed limit or descent speed constraint such that the restrictive speed (including ICAO limits) is just satisfied upon crossing the associated point.
From the deselection point, predictions assume an deceleration to the ECON descent speed. Prediction assumptions for above and below path are identical, except that manual speed is assumed until the deselection point.
Predictions only consider manual speed selection when descent phase is active.
F-PLN predictions suppose that the pilot will return to the automatic speed management mode at start of deceleration to the next restrictive descent speed limit or descent speed constraint such that the restrictive speed (including ICAO limits) is just satisfied upon crossing the associated point.
From the deselection point, predictions assume an deceleration to the ECON descent speed. Prediction assumptions for above and below path are identical, except that manual speed is assumed until the deselection point.
2 Guidance
If A/C is below profile, the same logic as in speed auto control is used but the speed controlled is FCU speed.
If A/C is on or above profile, the DES mode is VPATH/SPD except if the A/C is overspeed (in this case it is SPD/THR), else the same logic as in speed auto control is used.
If A/C is below profile, the same logic as in speed auto control is used but the speed controlled is FCU speed.
If A/C is on or above profile, the DES mode is VPATH/SPD except if the A/C is overspeed (in this case it is SPD/THR), else the same logic as in speed auto control is used.
(d) Approach
1 Predictions
Predictions assume immediate deselection of manual SPD selection mode and return to auto speed management mode if the selected speed is greater than the approach display speed auto target:
Predictions assume immediate deselection of manual SPD selection mode and return to auto speed management mode if the selected speed is greater than the approach display speed auto target:
- at the start of the approach segment, when not in the approach,
- or at the A/C position, when in the approach.
2 Guidance
The guidance is identical to that stated in descent.
The guidance is identical to that stated in descent.
(12) Lateral Auto Control and V/S (or FPA) Mode
This mode allows to climb above (resp. to descent below) the FCU altitude by selecting a V/S > 0 (resp. V/S < 0) and pulling V/S knob with the A/C already at or above (resp. at or below) the FCU altitude. V/S is a vertical manual mode: altitude constraints are ignored in guidance but FCU ALT is taken into account.
This mode allows to climb above (resp. to descent below) the FCU altitude by selecting a V/S > 0 (resp. V/S < 0) and pulling V/S knob with the A/C already at or above (resp. at or below) the FCU altitude. V/S is a vertical manual mode: altitude constraints are ignored in guidance but FCU ALT is taken into account.
(a) Climb, cruise, descent and approach
1 Predictions
Predictions on F-PLN page always suppose the immediate deselection of the mode and immediate recovery in level change auto control with speed auto control assumption if speed auto is currently engaged, or with speed manual control assumption if speed manual is currently engaged. Predictions assume a return to the current phase with current assumptions.
Predictions on F-PLN page always suppose the immediate deselection of the mode and immediate recovery in level change auto control with speed auto control assumption if speed auto is currently engaged, or with speed manual control assumption if speed manual is currently engaged. Predictions assume a return to the current phase with current assumptions.
2 Guidance
The guidance mode logic is made by FG.
The guidance mode logic is made by FG.
(13) Lateral Auto Control and Expedite Mode
Expedite mode is engaged by a pilot action (by depressing EXPED P/B on FCU) to perform a rapid (MAX CLB thrust in EXP CLB, IDLE thrust in EXP DES) climb or descent.
In Climb, cruise descent and approach: same assumptions as for V/S are made for predictions computations. FM expedite speeds are also used for PRED TO ALT computation on CLB/DES PERF pages.
Expedite mode is engaged by a pilot action (by depressing EXPED P/B on FCU) to perform a rapid (MAX CLB thrust in EXP CLB, IDLE thrust in EXP DES) climb or descent.
In Climb, cruise descent and approach: same assumptions as for V/S are made for predictions computations. FM expedite speeds are also used for PRED TO ALT computation on CLB/DES PERF pages.
(14) Lateral Auto Control and Open Profile Modes
Open profiles are vertical manual mode basically selected by pulling the altitude FCU knob. Constraints (altitude, speed) are ignored in guidance, but FCU ALT is taken into account. Predictions assume deselection of open profile and immediate return to vertical auto control.
Control law is speed on elevators/thrust (MAX CLB in climb, IDLE in des).
Open profiles are vertical manual mode basically selected by pulling the altitude FCU knob. Constraints (altitude, speed) are ignored in guidance, but FCU ALT is taken into account. Predictions assume deselection of open profile and immediate return to vertical auto control.
Control law is speed on elevators/thrust (MAX CLB in climb, IDLE in des).
- In speed auto control, target speeds are like ones defined in V/S (FPA) mode.
- In climb phase with open des, the target speed is climb econ speed.
- In cruise phase, guidance is the same as vertical auto control or speed auto control or speed manual control.
- In descent or approach phase, when in open climb, the speed target in speed auto control follows the descent econ speed profile.
(15) Lateral manual control
In LAT MAN control there is no vertical auto control but speed auto control can be provided. The logic for mode engagement is made in FG in accordance with FCU selections.
Predictions assume an immediate return to the lateral F-PLN including a return to lateral F-PLN with 45 deg. intercept turn and a recovery to vertical auto control.
The guidance speed target is MAX (VMANFE; above display speed target or VAPP in approach phase).
In LAT MAN control there is no vertical auto control but speed auto control can be provided. The logic for mode engagement is made in FG in accordance with FCU selections.
Predictions assume an immediate return to the lateral F-PLN including a return to lateral F-PLN with 45 deg. intercept turn and a recovery to vertical auto control.
The guidance speed target is MAX (VMANFE; above display speed target or VAPP in approach phase).
(16) Lateral Auto Control and V/S (or FPA) Mode
This mode allows to climb above (resp. to descent below) the FCU altitude by selecting a V/S > 0 (resp. V/S < 0) and pulling V/S knob with the A/C already at or above (resp. at or below) the FCU altitude. V/S is a vertical manual mode: altitude constraints are ignored in guidance but FCU ALT is taken into account.
This mode allows to climb above (resp. to descent below) the FCU altitude by selecting a V/S > 0 (resp. V/S < 0) and pulling V/S knob with the A/C already at or above (resp. at or below) the FCU altitude. V/S is a vertical manual mode: altitude constraints are ignored in guidance but FCU ALT is taken into account.
(a) Climb, cruise, descent and approach
1 Predictions
Predictions on F-PLN page always suppose the immediate deselection of the mode and immediate recovery in level change auto control with speed auto control assumption if speed auto is currently engaged, or with speed manual control assumption if speed manual is currently engaged. Predictions assume a return to the current phase with current assumptions.
Predictions on F-PLN page always suppose the immediate deselection of the mode and immediate recovery in level change auto control with speed auto control assumption if speed auto is currently engaged, or with speed manual control assumption if speed manual is currently engaged. Predictions assume a return to the current phase with current assumptions.
2 Guidance
The guidance mode logic is made by FG.
The guidance mode logic is made by FG.
(17) Lateral Auto Control and Expedite Mode
Expedite mode is engaged by a pilot action (by depressing EXPED P/B on FCU) to perform a rapid (MAX CLB thrust in EXP CLB, IDLE thrust in EXP DES) climb or descent.
In Climb, cruise descent and approach: same assumptions as for V/S are made for predictions computations. FM expedite speeds are also used for PRED TO ALT computation on DES PERF pages.
Expedite mode is engaged by a pilot action (by depressing EXPED P/B on FCU) to perform a rapid (MAX CLB thrust in EXP CLB, IDLE thrust in EXP DES) climb or descent.
In Climb, cruise descent and approach: same assumptions as for V/S are made for predictions computations. FM expedite speeds are also used for PRED TO ALT computation on DES PERF pages.
(18) Lateral Auto Control and Open Profile Modes
Open profiles are vertical manual mode basically selected by pulling the altitude FCU knob. Constraints (altitude, speed) are ignored in guidance, but FCU ALT is taken into account. Predictions assume deselection of open profile and immediate return to vertical auto control.
Control law is speed on elevators/thrust (MAX CLB in climb, IDLE in des).
Open profiles are vertical manual mode basically selected by pulling the altitude FCU knob. Constraints (altitude, speed) are ignored in guidance, but FCU ALT is taken into account. Predictions assume deselection of open profile and immediate return to vertical auto control.
Control law is speed on elevators/thrust (MAX CLB in climb, IDLE in des).
- In speed auto control, target speeds are like ones defined in V/S (FPA) mode.
- In climb phase with open des, the target speed is climb econ speed.
- In cruise phase, guidance is the same as vertical auto control or speed auto control or speed manual control.
- In descent or approach phase, when in open climb, the speed target in speed auto control follows the descent econ speed profile.
(19) Lateral manual control
In LAT MAN control there is no vertical auto control but speed auto control can be provided. The logic for mode engagement is made in FG in accordance with FCU selections.
Predictions assume an immediate return to the lateral F-PLN including a return to lateral F-PLN with 45 deg. intercept turn and a recovery to vertical auto control.
The guidance speed target is MAX (VMANFE; above display speed target or VAPP in approach phase).
In LAT MAN control there is no vertical auto control but speed auto control can be provided. The logic for mode engagement is made in FG in accordance with FCU selections.
Predictions assume an immediate return to the lateral F-PLN including a return to lateral F-PLN with 45 deg. intercept turn and a recovery to vertical auto control.
The guidance speed target is MAX (VMANFE; above display speed target or VAPP in approach phase).
V. PRINTER Functions
The Printer function allows various FMS reports to be printed, either automatically or on manual action. Several types of reports can be printed:
This function is completely independent of the Aircraft Communication Addressing and Reporting System (ACARS) function and is available (as an option) even if ACARS function is not enabled. Additionally, several features of the PRINT function are optionally programmable either through the AMI file or through manual selection on the MCDU.
This function is completely independent of the Aircraft Operational Control (AOC) function and is available (as an option) even if AOC function is not enabled. Additionally, several features of the PRINT function are optionally programmable either through the AMI file or through manual selection on the MCDU.
The Printer function allows various FMS reports to be printed, either automatically or on manual action. Several types of reports can be printed:
- flight plan initialization data,
- take-off data,
- wind data,
- flight report data.
This function is completely independent of the Aircraft Communication Addressing and Reporting System (ACARS) function and is available (as an option) even if ACARS function is not enabled. Additionally, several features of the PRINT function are optionally programmable either through the AMI file or through manual selection on the MCDU.
This function is completely independent of the Aircraft Operational Control (AOC) function and is available (as an option) even if AOC function is not enabled. Additionally, several features of the PRINT function are optionally programmable either through the AMI file or through manual selection on the MCDU.
(1) MCDU Mechanization: PRINT FUNCTION page
The PRINT function is selected either through the DATA INDEX A page or the ACARS FUNCTION page.
The PRINT FUNCTION page displays the selection state of the automatic printing function for the ACARS and flight report functions. This state is dependent on the selected options in the AOC policy file of the AMI and can be modified by the pilot. The PRINT FUNCTION page also allows the manual printing of the flight reports and of the current FM flight plan initialization data, take-off data and wind data.
The PRINT function is selected either through the DATA INDEX A page or the ACARS FUNCTION page.
The PRINT FUNCTION page displays the selection state of the automatic printing function for the ACARS and flight report functions. This state is dependent on the selected options in the AOC policy file of the AMI and can be modified by the pilot. The PRINT FUNCTION page also allows the manual printing of the flight reports and of the current FM flight plan initialization data, take-off data and wind data.
(2) MCDU Mechanization: PRINT FUNCTION page
The PRINT function is selected either through the DATA INDEX A page or the AOC FUNCTION page.
The PRINT FUNCTION pages display the PRINT functions enabled and disabled for the FMS AOC PRINT configuration and allow selection of whether or not an automatic report of an AOC uplink message is printed upon reception, allow selection of whether or not an automatic flight report is printed upon triggering the report and allow manual printing of F-PLN initialization, take-off data, wind data and flight reports.
The PRINT function is selected either through the DATA INDEX A page or the AOC FUNCTION page.
The PRINT FUNCTION pages display the PRINT functions enabled and disabled for the FMS AOC PRINT configuration and allow selection of whether or not an automatic report of an AOC uplink message is printed upon reception, allow selection of whether or not an automatic flight report is printed upon triggering the report and allow manual printing of F-PLN initialization, take-off data, wind data and flight reports.
(3) Report printing
(a) Flight plan initialization report
A flight plan initialization report is printed automatically upon reception of a flight plan initialization or a performance initialization uplink message if the AOC flight plan initialization function is enabled, the auto-print of AOC uplinks and auto-print of flight plan uplink features are enabled within the AMI file, and the auto-print option has not been manually disabled via the PRINT FUNCTION page.
Active flight plan reports, consisting of active flight plan and performance data, are printed upon manual selection from the PRINT FUNCTION page and contains data associated to the different waypoints of the active flight plan or to data related to the active flight plan.
A flight plan initialization report is printed automatically upon reception of a flight plan initialization or a performance initialization uplink message if the AOC flight plan initialization function is enabled, the auto-print of AOC uplinks and auto-print of flight plan uplink features are enabled within the AMI file, and the auto-print option has not been manually disabled via the PRINT FUNCTION page.
Active flight plan reports, consisting of active flight plan and performance data, are printed upon manual selection from the PRINT FUNCTION page and contains data associated to the different waypoints of the active flight plan or to data related to the active flight plan.
(b) Take-off data
A take-off data initialization report is printed automatically upon reception of a take off data initialization uplink message if the AOC take-off data initialization function is enabled and the auto-print of AOC uplinks and auto-print of take-off data uplink features are enabled within the AMI file and the auto-print option has not been manually disabled via the PRINT FUNCTION page.
The active take-off data can also be printed upon selection of the manual prompt on the PRINT FUNCTION page.
A take-off data initialization report is printed automatically upon reception of a take off data initialization uplink message if the AOC take-off data initialization function is enabled and the auto-print of AOC uplinks and auto-print of take-off data uplink features are enabled within the AMI file and the auto-print option has not been manually disabled via the PRINT FUNCTION page.
The active take-off data can also be printed upon selection of the manual prompt on the PRINT FUNCTION page.
(c) Wind data
A wind data initialization report is printed automatically upon reception of a wind data initialization uplink message if the AOC wind data function is enabled and the auto-print of AOC uplinks and auto-print of wind uplink features are enabled within the AMI file and the auto-print option has not been manually disabled via the PRINT FUNCTION page. The active wind data can also be printed upon selection of the manual print prompt on the PRINT FUNCTION page.
A wind data initialization report is printed automatically upon reception of a wind data initialization uplink message if the AOC wind data function is enabled and the auto-print of AOC uplinks and auto-print of wind uplink features are enabled within the AMI file and the auto-print option has not been manually disabled via the PRINT FUNCTION page. The active wind data can also be printed upon selection of the manual print prompt on the PRINT FUNCTION page.
(d) Flight summary print reports
The flight report for active FM flight plan can be either a pre-flight, in-flight or post-flight report, depending on current active FM flight phase. All these reports are exclusive of one another.The flight report for secondary flight plan, whatever the flight phase, can be either created as a pre-flight or in-flight report depending on current secondary state. This state is defined by the way the secondary flight plan is created and format of the print is in accordance.
In the PREFLIGHT phase, the pre-flight report gives:
After transition to TAKE-OFF and prior to DONE, the in-flight report is available and gives:
In the DONE phase, the post-flight report gives a complete overview of the flight:
Active flight report can be printed either manually or automatically. Secondary flight report can only be printed manually. A flight report is manually printed by pressing the PRINT prompt, followed by a selection star, of the flight report line on the PRINT FUNCTION page and/or on the SEC INDEX page. The pre-flight, in-flight and post-flight reports for active flight plan are printed automatically if the auto-print of flight reports option has been enabled within the AMI file and the auto-print trigger for the respective report has not been manually disabled. The triggering events for automatic printing are:
The flight report for active FM flight plan can be either a pre-flight, in-flight or post-flight report, depending on current active FM flight phase. All these reports are exclusive of one another.The flight report for secondary flight plan, whatever the flight phase, can be either created as a pre-flight or in-flight report depending on current secondary state. This state is defined by the way the secondary flight plan is created and format of the print is in accordance.
In the PREFLIGHT phase, the pre-flight report gives:
- the A/C and engine types on which the F-PLN optimizations and predictions are based,
- Navigation database identifier and Navigation database cycle,
- flight plan data that the crew has inserted during the initialization process as well as miscellaneous data needed for performance calculations,
- predicted data along the flight plan,
- the results of the fuel planning computation,
- each loadable element identifier.
After transition to TAKE-OFF and prior to DONE, the in-flight report is available and gives:
- the same general data as the pre-flight report,
- flight plan data consisting of a mixture of history values for sequenced waypoints and of predicted values for the remaining part of the F-PLN.
In the DONE phase, the post-flight report gives a complete overview of the flight:
- the same general data as the Inflight report,
- flight plan data consisting of history data relative to the flight plan,
- a fuel and time summary,
- IRS data.
Active flight report can be printed either manually or automatically. Secondary flight report can only be printed manually. A flight report is manually printed by pressing the PRINT prompt, followed by a selection star, of the flight report line on the PRINT FUNCTION page and/or on the SEC INDEX page. The pre-flight, in-flight and post-flight reports for active flight plan are printed automatically if the auto-print of flight reports option has been enabled within the AMI file and the auto-print trigger for the respective report has not been manually disabled. The triggering events for automatic printing are:
- Engine Start for the pre-flight report,
- Transition to take-off for the in-flight report,
- Engine Shut Down for the post-flight report.
W. Aircraft Communication Addressing and Reporting System (ACARS) Functions
Through the ACARS, the FM section is able to send information or requests to the ground and in turn receive information or requests from the ground, for information.
The ACARS functions are divided into different categories:
The ACARS function is available only if both of AOC option is activated and AMI datalink inhibit is set to NO. If either discrete is disabled, then the ACARS functions are inhibited, dedicated ACARS prompts are not displayed and ACARS specific pages cannot be reached.
Morever, when at least AOC option or mini ACARS option is activated, the transmission of broadcast data to ATSU is activated.
The different ACARS functions are:
Through the ACARS, the FM section is able to send information or requests to the ground and in turn receive information or requests from the ground, for information.
The ACARS functions are divided into different categories:
- uplink messages: reception of data allowing flight plan, take-off and wind data initializations, or requests for downlink reports sent by the ground station ,
- downlink messages: sending of flight reports or requests to the ground station for data initialization.
The ACARS function is available only if both of AOC option is activated and AMI datalink inhibit is set to NO. If either discrete is disabled, then the ACARS functions are inhibited, dedicated ACARS prompts are not displayed and ACARS specific pages cannot be reached.
Morever, when at least AOC option or mini ACARS option is activated, the transmission of broadcast data to ATSU is activated.
The different ACARS functions are:
X. AOC function
AOC functions can be installed with various options that can be enabled or disabled via the AOC policy values of the AMI.
Through AOC functions, the FMS is able to send information or requests to the ground and to receive, from the ground, information or requests for information in turn. The AOC functions are divided into different categories:
The different AOC functions are:
All the uplink data messages may be automatically printed based on the customer programming of the AMI file.
AOC functions can be installed with various options that can be enabled or disabled via the AOC policy values of the AMI.
Through AOC functions, the FMS is able to send information or requests to the ground and to receive, from the ground, information or requests for information in turn. The AOC functions are divided into different categories:
- uplink messages: reception of data or requests sent by the ground station,
- downlink messages: sending of reports or requests to the ground station.
The different AOC functions are:
- F-PLN initialization data:
An uplink message answering a manual request, or automatically sent by the ground. The crew can send a request for flight plan data to the ground indicating the flight number and/or the company route. In response to this request, or automatically, the ground sends a flight plan and associated performance data to the A/C. - TAKE-OFF data:
An uplink message answering a manual request, or automatically sent by the ground. The crew can send a request for take-off data to the ground relative to up to 2 runways indicating the take-off conditions on these runways (configuration, wind, contamination). In response to this request, or automatically, the ground sends the take-off speeds associated with up to 4 runways and the take-off conditions which have been taken into account to elaborate these take-off speeds. - WIND data:
An uplink message answering a manual request, or automatically sent by the ground. The crew can send a request for wind data to the ground. In response to this request, or automatically, the ground sends climb, cruise, descent and alternate wind data to the A/C. - FLIGHT reports:
An automatic or manual downlink message. A position or a progress report gives information on the A/C's actual position or progress and can be sent manually or automatically upon ground request or preselected trigger conditions. A flight plan or performance data report gives active route information and can be sent manually or automatically upon ground request. - Broadcast data:
A set of data permanently transmitted by the FMS to the ACARS MU/ATSU giving information on A/C actual attitude and situation relative to the flight plan.
All the uplink data messages may be automatically printed based on the customer programming of the AMI file.
Y. ACARS/AOC Functions - Flight Plan Initialization
The flight plan initialization function allows the request and reception of lateral and vertical flight plan data as well as related performance data from a ground based station. The crew can manually send a request for flight plan initialization data to a ground station indicating a company route or a flight number. In response to this request, the ground station can send a flight plan and associated performance data to the A/C. Additionally, the ground station can send a flight plan and performance data automatically to the A/C without a previous solicitation. Flight plan initialization uplinks are most commonly performed when A/C is on the ground.
When the uplinked flight plan message is received, the AOC XXX F-PLN UPLINK scratchpad message is displayed.
If a valid uplinked performance data message is associated to the uplinked flight plan message, the INIT DATA UPLINK scratchpad message is displayed. If the uplinked performance data message is not valid, the INVALID INIT UPLINK scratchpad message is displayed.
For a manually initiated flight plan initialization request, designated messages are downlinked to the ground station requesting flight plan information and performance data. In response, the ground station uplinks the appropriate flight plan information and performance data messages to the A/C. Upon reception and validation of the uplinked messages, the flight plan information and performance data are extracted from the messages and used by the FMS.
When flight plan initialization data is uplinked, it is inserted, either automatically or after manual approval, into either the active or secondary flight plan routes. It is not possible to directly preview the data prior to insertion.
The uplinked flight plan initialization information can concern either the active or the secondary flight plan. Additionally, alternate flight plan data can be received in association with active or secondary flight plan data.
Active, active alternate, secondary and secondary alternate flight plan data can be described as a company route, a random flight plan or a combination of the two.
(A random flight plan is an ATC-language described flight plan).
Active INIT A page allows a request to be sent to the ground for flight plan data and performance data if no active flight plan exists (without any waypoint other than a PPOS or T-P) and prior to first engine start. Secondary INIT A page allows a request to be sent to the ground for flight plan data and performance data during any phase. AOC FUNCTION page allows a request to be sent to the ground for flight plan data and performance data during any phase. A flight plan initialization request is not allowed if an uplink message is pending. Only one request can be initiated at a time. During the time from the transmission of the request until a response is received, the button pushes and modifications of any F-PLN element (INIT, F-PLN, LAT REV, VERT REV PERF pages) or weight data are allowed. If it is empty, the flight plan information uplink message is immediately processed and inserted into either the active (before engine starts) or secondary flight plan route.
Uplinked active flight plan is re-directed to secondary flight plan:
Before engine start when flight plan exists in active and secondary, a flight plan initialization uplink message is automatically inserted on SEC INIT A page and SEC INDEX page, overwriting existing data.
The flight plan initialization function allows the request and reception of lateral and vertical flight plan data as well as related performance data from a ground based station. The crew can manually send a request for flight plan initialization data to a ground station indicating a company route or a flight number. In response to this request, the ground station can send a flight plan and associated performance data to the A/C. Additionally, the ground station can send a flight plan and performance data automatically to the A/C without a previous solicitation. Flight plan initialization uplinks are most commonly performed when A/C is on the ground.
When the uplinked flight plan message is received, the AOC XXX F-PLN UPLINK scratchpad message is displayed.
If a valid uplinked performance data message is associated to the uplinked flight plan message, the INIT DATA UPLINK scratchpad message is displayed. If the uplinked performance data message is not valid, the INVALID INIT UPLINK scratchpad message is displayed.
For a manually initiated flight plan initialization request, designated messages are downlinked to the ground station requesting flight plan information and performance data. In response, the ground station uplinks the appropriate flight plan information and performance data messages to the A/C. Upon reception and validation of the uplinked messages, the flight plan information and performance data are extracted from the messages and used by the FMS.
When flight plan initialization data is uplinked, it is inserted, either automatically or after manual approval, into either the active or secondary flight plan routes. It is not possible to directly preview the data prior to insertion.
The uplinked flight plan initialization information can concern either the active or the secondary flight plan. Additionally, alternate flight plan data can be received in association with active or secondary flight plan data.
Active, active alternate, secondary and secondary alternate flight plan data can be described as a company route, a random flight plan or a combination of the two.
(A random flight plan is an ATC-language described flight plan).
Active INIT A page allows a request to be sent to the ground for flight plan data and performance data if no active flight plan exists (without any waypoint other than a PPOS or T-P) and prior to first engine start. Secondary INIT A page allows a request to be sent to the ground for flight plan data and performance data during any phase. AOC FUNCTION page allows a request to be sent to the ground for flight plan data and performance data during any phase. A flight plan initialization request is not allowed if an uplink message is pending. Only one request can be initiated at a time. During the time from the transmission of the request until a response is received, the button pushes and modifications of any F-PLN element (INIT, F-PLN, LAT REV, VERT REV PERF pages) or weight data are allowed. If it is empty, the flight plan information uplink message is immediately processed and inserted into either the active (before engine starts) or secondary flight plan route.
Uplinked active flight plan is re-directed to secondary flight plan:
- before engine start, if active flight plan is not empty,
- after engines start in any phase.
Before engine start when flight plan exists in active and secondary, a flight plan initialization uplink message is automatically inserted on SEC INIT A page and SEC INDEX page, overwriting existing data.
Z. ACARS/AOC Functions - Take-off Data
The take-off data function allows the request of load information data for up to 2 runways and the reception of load information data generated by the airline ground based station for up to 4 runways.
The crew can manually send a request for take-off data to a ground station indicating the departure airport and runway idents, take-off center of gravity, gross weight and environmental conditions (baro setting, runway wind and contamination and temperature). In response, the ground sends take-off velocities (V1, VR, V2) for up to 4 runways. This data can be applied to runways different from the ones for which the request was performed. Uplinked take-off data can be inserted in the system only for the runway defined in the active flight plan. Additionally, the ground can send these velocities and related data automatically without a previous solicitation. For each uplinked runway, take-off velocities are computed for max take-off, flex take-off or optionally derated take-off conditions (when the derated take-off option is selected).
This function needs the implementation of two different take-off pages:
The crew can manually send a request for take-off data to a ground station indicating the departure airport and runway idents, take-off center of gravity, gross weight and environmental conditions (baro setting, runway wind and contamination and temperature). In response, the ground sends take-off velocities (V1, VR, V2) for up to 4 runways. This data can be applied to runways different from the ones for which the request was performed. Uplinked take-off data can be inserted in the system only for the runway defined in the active flight plan and if all mandatory items were uplinked for that runway. Additionally, the ground can send these velocities and related data automatically without a previous solicitation. For each uplinked runway, take-off velocities are computed for max take-off, flex take-off or optionally derated take-off conditions (when the derated take-off option is selected).
This function needs the implementation of two different take-off pages:
On the UPLINK TO DATA REQ page, no default value is defined for the temperature and wind fields; and the pilot has the possibility to define a temperature on this page.
The take-off data function allows the request of load information data for up to 2 runways and the reception of load information data generated by the airline ground based station for up to 4 runways.
The crew can manually send a request for take-off data to a ground station indicating the departure airport and runway idents, take-off center of gravity, gross weight and environmental conditions (baro setting, runway wind and contamination and temperature). In response, the ground sends take-off velocities (V1, VR, V2) for up to 4 runways. This data can be applied to runways different from the ones for which the request was performed. Uplinked take-off data can be inserted in the system only for the runway defined in the active flight plan. Additionally, the ground can send these velocities and related data automatically without a previous solicitation. For each uplinked runway, take-off velocities are computed for max take-off, flex take-off or optionally derated take-off conditions (when the derated take-off option is selected).
This function needs the implementation of two different take-off pages:
- UPLINK TO DATA REQ page which allows the crew to send a request to the ground.
- UPLINK XXX TO DATA page which displays take-off velocities and parameters received from the ground. There are two sets of AOC TAKE-OFF pages: one for MAX take-off (XXX=MAX), and one for FLEX take-off (XXX=FLX) or for DERATED take-off (XXX=DRT) when the option is activated.
The crew can manually send a request for take-off data to a ground station indicating the departure airport and runway idents, take-off center of gravity, gross weight and environmental conditions (baro setting, runway wind and contamination and temperature). In response, the ground sends take-off velocities (V1, VR, V2) for up to 4 runways. This data can be applied to runways different from the ones for which the request was performed. Uplinked take-off data can be inserted in the system only for the runway defined in the active flight plan and if all mandatory items were uplinked for that runway. Additionally, the ground can send these velocities and related data automatically without a previous solicitation. For each uplinked runway, take-off velocities are computed for max take-off, flex take-off or optionally derated take-off conditions (when the derated take-off option is selected).
This function needs the implementation of two different take-off pages:
- UPLINK TO DATA REQ page which allows the crew to send a request to the ground.
- UPLINK XXX TO DATA page which displays take-off velocities and parameters received from the ground. There are two sets of AOC TAKE-OFF pages: one for MAX take-off (XXX=MAX), and one for FLEX take-off (XXX=FLX) or for DERATED take-off (XXX=DRT) when the option is activated.
On the UPLINK TO DATA REQ page, no default value is defined for the temperature and wind fields; and the pilot has the possibility to define a temperature on this page.
AA. ACARS/AOC Functions - Wind Data
The wind data function allows the uplink of forecasted climb, cruise, descent, and alternate atmospheric data. This message is received in response to a crew manual request or automatically without any solicitation. A manual request is initiated from the ACARS FUNCTION page or from any available WIND page.
The wind data function allows the uplink of forecasted climb, cruise, descent, and alternate atmospheric data. This message is received in response to a crew manual request or automatically without any solicitation. A manual request is initiated from the AOC FUNCTION page or from any available WIND page.
The WIND pages can be accessed on ground from the INIT A page and on ground or in flight from the DATA B or the VERT REV pages. When winds are manually requested, a downlink message is sent and is composed of one or more of the following request depending on flight phase: climb winds, cruise winds, descent winds, alternate wind. The subsequent uplink message can contain one or more of the following: climb winds, cruise winds, descent winds, alternate wind.
The uplinked winds are directly displayed on the WIND pages; one WIND page exists per flight phase (CLIMB, CRUISE, and DESCENT, with the alternate wind displayed on the DESCENT WIND page). When inserted, valid uplink wind data overwrites all the previously defined wind data for the corresponding flight phase.
Winds are sent either by altitude only or by an altitude/waypoint combination depending on the flight phase:
Uplinked cruise winds are sent with the associated waypoints and are linked to cruise flight levels (cruise and step flight levels) defined in the flight plan.
A manual wind request from a WIND page can be initiated from either the active or secondary flight plan. The subsequent uplink is then associated to the flight plan from which the request was initiated. Otherwise, when a wind uplink is received which does not correspond to a pending request, the wind uplink is associated with active flight plan, when defined.
When wind data are uplinked, whether automatically or in response to a manual request, the pilot has the opportunity to view the winds prior to insertion in the receiving flight plan. However, if the A/C is on the ground prior to engine start and data have not yet been entered or inserted on any WIND page of the receiving flight plan, then wind data are directly inserted into that flight plan without passing through a review state.
The WIND REQUEST prompt is added to the existing WIND pages. It provides a means to send to the ground a downlink request for wind data. It is displayed on each accessible WIND page, depending on the current flight phase.
Pressing the WIND REQUEST prompt from any WIND page initiates a wind request for one or more of the following sets of atmospheric data: climb, cruise, descent, and alternate. The WIND REQUEST prompt is displayed on active and secondary WIND pages. However, since only one downlink wind request can be pending at a time, selection of the prompt is invalidated on both flight plans when a request is pending from either flight plan.
The wind bearing reference in the AOC messages (uplink and downlink) is always in true reference.
The wind data function allows the uplink of forecasted climb, cruise, descent, and alternate atmospheric data. This message is received in response to a crew manual request or automatically without any solicitation. A manual request is initiated from the ACARS FUNCTION page or from any available WIND page.
The wind data function allows the uplink of forecasted climb, cruise, descent, and alternate atmospheric data. This message is received in response to a crew manual request or automatically without any solicitation. A manual request is initiated from the AOC FUNCTION page or from any available WIND page.
The WIND pages can be accessed on ground from the INIT A page and on ground or in flight from the DATA B or the VERT REV pages. When winds are manually requested, a downlink message is sent and is composed of one or more of the following request depending on flight phase: climb winds, cruise winds, descent winds, alternate wind. The subsequent uplink message can contain one or more of the following: climb winds, cruise winds, descent winds, alternate wind.
The uplinked winds are directly displayed on the WIND pages; one WIND page exists per flight phase (CLIMB, CRUISE, and DESCENT, with the alternate wind displayed on the DESCENT WIND page). When inserted, valid uplink wind data overwrites all the previously defined wind data for the corresponding flight phase.
Winds are sent either by altitude only or by an altitude/waypoint combination depending on the flight phase:
- in climb and descent, winds are sent by altitude only,
- in cruise, winds are sent with the associated F-PLN waypoints and are linked to various flight levels.
Uplinked cruise winds are sent with the associated waypoints and are linked to cruise flight levels (cruise and step flight levels) defined in the flight plan.
A manual wind request from a WIND page can be initiated from either the active or secondary flight plan. The subsequent uplink is then associated to the flight plan from which the request was initiated. Otherwise, when a wind uplink is received which does not correspond to a pending request, the wind uplink is associated with active flight plan, when defined.
When wind data are uplinked, whether automatically or in response to a manual request, the pilot has the opportunity to view the winds prior to insertion in the receiving flight plan. However, if the A/C is on the ground prior to engine start and data have not yet been entered or inserted on any WIND page of the receiving flight plan, then wind data are directly inserted into that flight plan without passing through a review state.
The WIND REQUEST prompt is added to the existing WIND pages. It provides a means to send to the ground a downlink request for wind data. It is displayed on each accessible WIND page, depending on the current flight phase.
Pressing the WIND REQUEST prompt from any WIND page initiates a wind request for one or more of the following sets of atmospheric data: climb, cruise, descent, and alternate. The WIND REQUEST prompt is displayed on active and secondary WIND pages. However, since only one downlink wind request can be pending at a time, selection of the prompt is invalidated on both flight plans when a request is pending from either flight plan.
The wind bearing reference in the AOC messages (uplink and downlink) is always in true reference.
AB. ACARS/AOC Functions - Flight Reports
The Flight reports uplink and downlink messages are processed only if AOC function is enabled.
Flight Reports provide real time information to the ground concerning the A/C current situation and position. Several types of flight reports are available and consist of:
These reports can generally be manually initiated via a MCDU prompt or sent automatically in response to a ground request or upon satisfying predetermined conditions, though not all reports have the same activation mechanism.
The Flight reports uplink and downlink messages are processed only if AOC function is enabled.
Flight Reports provide real time information to the ground concerning the A/C current situation and position. Several types of flight reports are available and consist of:
- Position report: provides current A/C position information to the ground,
- Progress report: provides data relative to the destination,
- Flight plan report: provides the active lateral flight plan route to the ground,
- Performance data report: provides the active performance data currently used by the FMS.
These reports can generally be manually initiated via a MCDU prompt or sent automatically in response to a ground request or upon satisfying predetermined conditions, though not all reports have the same activation mechanism.
(1) Position (POS) report
The POS downlink message allows the transmission of a position report to the ground. This message is sent in response to a ground request for position report or automatically upon crossing a designated position reporting fix. Position reporting fixes are designated only by the ground in a POS uplink message. The POS downlink message can also be sent manually via a prompt on the MCDU. The manual sending of a POS message can be inhibited via the AMI file relative to the active flight plan.
The manual POS downlink prompt is located on the REPORT page (SEND*). This prompt, when pressed, results in the transmission of the POS downlink message to the ground.
The POS downlink message allows the transmission of a position report to the ground. This message is sent in response to a ground request for position report or automatically upon crossing a designated position reporting fix. Position reporting fixes are designated only by the ground in a POS uplink message. The POS downlink message can also be sent manually via a prompt on the MCDU. The manual sending of a POS message can be inhibited via the AMI file relative to the active flight plan.
The manual POS downlink prompt is located on the REPORT page (SEND*). This prompt, when pressed, results in the transmission of the POS downlink message to the ground.
(2) POS report (overhead parameter)
The overhead parameter (FROM waypoint) will be furnished in the POS downlinked message.
The overhead parameter (FROM waypoint) will be furnished in the POS downlinked message.
(3) Progress (PRG) report
The PRG downlink message allows the transmission of a progress report to the ground. Generally, a progress report contains data relative to the A/C arrival time and EFOB at the destination. This message is sent in response to a ground request for progress report or automatically upon crossing a designated trigger. Specific trigger values can be customized by the airline in the AMI file. The PRG downlink message cannot be sent manually in a direct manner (via a dedicated prompt). However, the message can result from a pilot action (changing the destination). Progress reports are only sent relative to the active flight plan.
The PRG downlink message allows the transmission of a progress report to the ground. Generally, a progress report contains data relative to the A/C arrival time and EFOB at the destination. This message is sent in response to a ground request for progress report or automatically upon crossing a designated trigger. Specific trigger values can be customized by the airline in the AMI file. The PRG downlink message cannot be sent manually in a direct manner (via a dedicated prompt). However, the message can result from a pilot action (changing the destination). Progress reports are only sent relative to the active flight plan.
(4) Flight plan report
The flight plan report downlink message allows the transmission of flight plan data from the active route to the ground. This message is sent either via a manual selection of a prompt on the MCDU or automatically in response to a ground request for the flight plan report. The flight plan report uplink and downlink messages are processed only if AOC function is enabled. Additionally, manual sending of the flight plan report is allowed only if the flight plan report option is inhibited within the AMI file.
The flight plan report downlink message allows the transmission of flight plan data from the active route to the ground. This message is sent either via a manual selection of a prompt on the MCDU or automatically in response to a ground request for the flight plan report. The flight plan report uplink and downlink messages are processed only if AOC function is enabled. Additionally, manual sending of the flight plan report is allowed only if the flight plan report option is inhibited within the AMI file.
(5) Flight plan report (MCDU prompt)
A MCDU prompt located on the ACARS FUNCTION page permits the manual sending of a flight plan report to the ground. This prompt, when pressed, results in the transmission of the flight plan report downlink message to the ground.
A MCDU prompt located on the ACARS FUNCTION page permits the manual sending of a flight plan report to the ground. This prompt, when pressed, results in the transmission of the flight plan report downlink message to the ground.
(6) Flight plan report (MCDU prompt)
A MCDU prompt located on the AOC FUNCTION page permits the manual sending of a flight plan report to the ground. This prompt, when pressed, results in the transmission of the flight plan report downlink message to the ground.
A MCDU prompt located on the AOC FUNCTION page permits the manual sending of a flight plan report to the ground. This prompt, when pressed, results in the transmission of the flight plan report downlink message to the ground.
(7) Performance data report
The performance data report downlink message allows the transmission of performance data from the active route to the ground. This message is sent automatically in response to a ground request for the performance data report. The performance data report uplink and downlink messages are processed only if AOC function is enabled.
The performance data report downlink message allows the transmission of performance data from the active route to the ground. This message is sent automatically in response to a ground request for the performance data report. The performance data report uplink and downlink messages are processed only if AOC function is enabled.
AC. ACARS/AOC Functions - Broadcast Data
This is a set of data which is automatically broadcast by the FMS on the output ACARS bus to the ACARS MU/ATSU if AOC option is activated or, if mini ACARS option is activated. This set of data is not printed by any FMS function. Nevertheless, some data can be part of printed reports or uplink printouts.
This is a set of data which is automatically broadcast by the FMS on the output ACARS bus to the ACARS MU/ATSU if AOC option is activated or, if mini ACARS option is activated. This set of data is not printed by any FMS function. Nevertheless, some data can be part of printed reports or uplink printouts.
AD. ATC Function
With the ATC function, the FM can operate with the ATSU and is compatible with the FMS part of the ATC datalink applications. The ATC function operates when the two OPC FANS A and AOC options are available.
With the ATC function, the FM can operate with the ATSU and is compatible with the FMS part of the ATC datalink applications. The ATC function operates when the OPC FANS A option is available.
With the ATC function, the FM can operate with the ATSU and is compatible with the FMS part of the ATC datalink applications. The ATC function operates when the two OPC FANS A and AOC options are available.
With the ATC function, the FM can operate with the ATSU and is compatible with the FMS part of the ATC datalink applications. The ATC function operates when the OPC FANS A option is available.
(1) ATC flight plan initialization/modification
The ATC flight plan initialization/modification function allows the crew to request an ATC clearance for a new route or a modified route, and to receive from the ATC center the route that the crew is allowed to fly. This function can be invoked on the ground as well as in flight.
When the crew wants to initiate an ATC flight plan request, the requested route is first prepared in the secondary flight plan and then manually sent by the crew to the ATC center.
When the ATC flight plan is received, it is stored automatically in the secondary flight plan after the crew has reviewed it and activated the LOAD function on the DCDU.
An ATC flight plan uplink is composed of multiple elements which are processed as MCDU inputs.
Two different types of ATC flight plan messages can be received:
The ATC flight plan initialization/modification function allows the crew to request an ATC clearance for a new route or a modified route, and to receive from the ATC center the route that the crew is allowed to fly. This function can be invoked on the ground as well as in flight.
When the crew wants to initiate an ATC flight plan request, the requested route is first prepared in the secondary flight plan and then manually sent by the crew to the ATC center.
When the ATC flight plan is received, it is stored automatically in the secondary flight plan after the crew has reviewed it and activated the LOAD function on the DCDU.
An ATC flight plan uplink is composed of multiple elements which are processed as MCDU inputs.
Two different types of ATC flight plan messages can be received:
- flight plan uplink messages as follows:
. uplink message 80: cleared (route clearance),
. uplink message 83: At (position) cleared (route clearance),
. uplink message 79: cleared to (position) via (route clearance). - time constraints messages as follows:
. uplink message 51: Cross (position) at (time),
. uplink message 52: Cross (position) at or before (time),
. uplink message 53: Cross (position) at or after (time).
(2) ATC reports
An ATC report request is an ATC request to the crew to send a specific report downlink when a specific condition is met.
ATC Reports function provides help to the crew by:
An ATC report request is an ATC request to the crew to send a specific report downlink when a specific condition is met.
ATC Reports function provides help to the crew by:
- monitoring (upon ATSU request) the establishment of the condition to send the requested report,
- informing the ATSU when the condition is actually met by providing it with the requested report downlink plus various reports depending on aircraft context.
- report back on route (message 127),
- report leaving altitude (message 128),
- report level (altitude) (message 129),
- report passing (position) (message 130),
- report reaching (altitude) (message 175),
- report reaching block (altitude) to (altitude) (message 180).
- back on route (message 41),
- leaving (altitude) (message 28),
- level (altitude) (message 37),
- passing (position) (message 31),
- reaching (altitude) (message 72),
- reaching block (altitude) to (altitude) (message 76).
(3) ATC position reports
An ATC position report is sent to the ATC center upon request or at each ATC waypoint sequencing.
The automatic ATC position report function provides help to the crew by:
The list of elements composing the ATC position report is the following:
If an offset is active, the downlink message 80: Deviating (distance-offset) (direction) of route, can be sent to the ATSU with the distance and the direction of the active offset.
An ATC position report is sent to the ATC center upon request or at each ATC waypoint sequencing.
The automatic ATC position report function provides help to the crew by:
- monitoring (without any ATSU request) the sequencing of each ATC waypoint in the active flight plan,
- informing the ATSU when an ATC waypoint is actually sequenced by providing it with the ATC position report plus additional reports depending on aircraft context.
- each time an ATC waypoint is sequenced,
- upon an ATC position report request.
The list of elements composing the ATC position report is the following:
- current A/C Lat/Long,
- current A/C time reference at ATC position report computation,
- current A/C altitude (reference depending on current A/C altitude reference),
- NEXT ATC waypoint,
- estimated time of arrival at NEXT ATC waypoint,
- ENSUIG ATC waypoint,
- estimated time at destination,
- current static air temperature,
- current wind direction and speed,
- current speed or Mach depending on guidance mode,
- current ground speed,
- current vertical direction + rate,
- current track angle (true or mag depending on current North reference),
- current true heading,
- last ATC sequenced waypoint,
- time of sequence of the last ATC sequenced waypoint,
- A/C altitude at last ATC sequenced waypoint (reference depending on A/C attitude reference at this waypoint).
If an offset is active, the downlink message 80: Deviating (distance-offset) (direction) of route, can be sent to the ATSU with the distance and the direction of the active offset.
(4) ATC confirm
ATC confirm function provides (upon ATSU request) immediate real time information to the ATSU concerning the aircraft current situation and position.
Several types of confirmation are available and consist of:
The FMS response consists of:
Note that the downlink message 32: Present altitude (altitude), (in response to the upluik message 133: Confirm altitude) will be completed by downlink message 29: Climbing to (altitude), or message 30: Descending to (altitude).
ATC confirm function provides (upon ATSU request) immediate real time information to the ATSU concerning the aircraft current situation and position.
Several types of confirmation are available and consist of:
- current aircraft data,
- aircraft target parameters,
- flight planning elements,
- position report.
The FMS response consists of:
- the requested parameter(s),
- additional parameters depending on aircraft context.
- confirm position (message 132),
- confirm altitude (message 133),
- confirm speed (message 134),
- confirm assigned altitude (message 135),
- confirm assigned speed (message 136),
- confirm assigned route (message 137),
- confirm time over reported waypoint (message 138),
- confirm reported waypoint (message 139),
- confirm next waypoint (message 140),
- confirm next waypoint ETA (message 141),
- confirm ensuring waypoint (message 142),
- confirm heading (message 145),
- confirm ground track (message 146),
- report distance (to/from) (position) (message 181).
- present position (message 33),
- present altitude (message 32),
- climbing to altitude (message 29),
- descending to altitude (message 30),
- deviating (distance offset) (direction) of route (message 80),
- present speed (message 34),
- assigned altitude (message 38),
- assigned speed (message 39),
- assigned route (message 40),
- time over reported waypoint (message 46),
- reported waypoint (message 45),
- next waypoint (message 42),
- next waypoint ETA (message 43),
- ensuing waypoint (message 44),
- present heading (message 35),
- present ground track (message 36),
- at time distance to/from position (message 78).
Note that the downlink message 32: Present altitude (altitude), (in response to the upluik message 133: Confirm altitude) will be completed by downlink message 29: Climbing to (altitude), or message 30: Descending to (altitude).
(5) ATC deferred clearances:
An ATC deferred clearance is an ATC clearance that is activated when a specific condition (AT (time) PROCEED DIRECT TO (position)) is met. An ATC deferred clearance consists of two parts:
ATC deferred clearances function provides help to the crew by:
An ATC deferred clearance is an ATC clearance that is activated when a specific condition (AT (time) PROCEED DIRECT TO (position)) is met. An ATC deferred clearance consists of two parts:
- a conditional part (AT (time)),
- a clearance (PROCEED DIRECT TO (position)).
ATC deferred clearances function provides help to the crew by:
- monitoring the establishment of the conditional part of the deferred clearances,
- informing the ATSU that the condition is predicted to be met in 30 sec in most of the cases,
- informing the ATSU when the condition is actually met.
(6) ADS Applications
ADS applications are managed by the ATSU.
Therefore, ATSU is in charge of receiving ground contracts, concentrating required information and responding to the ground in the given time.
FMS broadcasts periodically all the parameters necessary to format complete ADS reports.
ATSU gathers and formats these paramaters according to norms.
ADS functions require the transmission downlink of many FMS parameters (from FMS to ATSU) and of some parameters uplink (from ATSU to FMS) necessary for FM computations.
Two different collection mechanisms are used to transmit ADS data:
ADS applications are managed by the ATSU.
Therefore, ATSU is in charge of receiving ground contracts, concentrating required information and responding to the ground in the given time.
FMS broadcasts periodically all the parameters necessary to format complete ADS reports.
ATSU gathers and formats these paramaters according to norms.
ADS functions require the transmission downlink of many FMS parameters (from FMS to ATSU) and of some parameters uplink (from ATSU to FMS) necessary for FM computations.
Two different collection mechanisms are used to transmit ADS data:
- frames for groups of data requiring consistency.
- dynamic labels for other data.
- a basic frame indicating aircraft location associated to the quality of this location,
- a predicted route frame with flight plan waypoints predicted location and time,
- an intermediate intent frame providing the next intermediate waypoints where an altitude target, track target or speed target change is predicted to occur,
- a fixed intent frame providing the predicted location of the aircraft at a given time.
- 1 second for basic frame,
- 10 seconds for predicted route, intermediate intent, fixed intent frames.
8. Bite Description
The FMS BITE function basically:
** ON A/C NOT FOR ALL The FMS BITE function basically:
- detects failures (from internal or external LRU) which affect the functioning of the FM part,
- performs internal hardware and software tests at long or short term power-up, at self test and during steady state operations,
- transmits failure reports to the FIDS for maintenance activity,
- acquires failure reports from the MCDU and transmit them to the FIDS for maintenance activity,
- performs the following enhanced functions:
* tracking of multiple faults over at least 32 flight legs,
* tracing back and data recording of the MCDU key strokes to restore scenario,
* data recording: either automatically or on pilot request,
* easy and fast data collecting and analysis: possibility to download on a floppy disk, the history data without the removal of the LRU.
9. MCDU Backup Navigation
A. General
The MCDU (MCDU1 and MCDU2) contains a Backup Navigation function that provides a simple point to point, GPIRS or GPS (if GPS fitted in Autonomous configuratgion) IRS based navigation. It is used after FM1 and FM2 loss (starting with the last known simplified active primary flight plan).
The MCDU F-PLN may contain a maximum of 150 legs with only TF, DF or IF legs. Only point to point F-PLN is available (for example radial, holding pattern, heading leg cannot be part of the MCDU F-PLN) and the downloaded leg information includes waypoint position, waypoint identifier, leg type, discontinuity, overfly and turn direction information.
The main functions are:
The MCDU (MCDU1 and MCDU2) contains a Backup Navigation function that provides a simple point to point, GPIRS or GPS (if GPS fitted in Autonomous configuratgion) IRS based navigation. It is used after FM1 and FM2 loss (starting with the last known simplified active primary flight plan).
The MCDU F-PLN may contain a maximum of 150 legs with only TF, DF or IF legs. Only point to point F-PLN is available (for example radial, holding pattern, heading leg cannot be part of the MCDU F-PLN) and the downloaded leg information includes waypoint position, waypoint identifier, leg type, discontinuity, overfly and turn direction information.
The main functions are:
- Limited lateral Flight planning (no secondary or temporary flight plan)
- Distance, TTG and Crosstrack computations
- Auto-sequencing (no guidance management)
- Transmission of the Backup Navigation F-PLN to the ND.
B. Backup Navigation selection / deselection
The Select NAV B/UP prompt on the MCDU MENU page is the only way to activate the Backup Navigation function.
Backup navigation is available on MCDU 1 and MCDU 2 if with their J1 and J2 connectors are wired. When available Backup navigation is always selectable, except in the following case: onside FM is Healtly and offside FM is failed.
If active, Backup Navigation is deactivated upon one of the following events:
Upon Backup Nav deactivation, the Backup Nav functions are disabled and the FM is given back control of the Nav Display.
The Select NAV B/UP prompt on the MCDU MENU page is the only way to activate the Backup Navigation function.
Backup navigation is available on MCDU 1 and MCDU 2 if with their J1 and J2 connectors are wired. When available Backup navigation is always selectable, except in the following case: onside FM is Healtly and offside FM is failed.
If active, Backup Navigation is deactivated upon one of the following events:
- The Deselect NAV B/UP prompt is pushed on the MCDU MENU page
- The following condition becomes true: onside FM is Healtly and offside FM is failed
- The FM subsystem is selected via its menu text prompt on the MENU page.
Upon Backup Nav deactivation, the Backup Nav functions are disabled and the FM is given back control of the Nav Display.
C. MCDU Backup Navigation Pages
Six pages are available when Backup Navigation is active.
These are as follows:
Six pages are available when Backup Navigation is active.
These are as follows:
- B/UP F-PLN
- B/UP F-PLN for Direct-To functions refered to as B/UP DIRECT-TO
- B/UP PROGRESS
- B/UP IRSn for the onside IRS (n = 1 or 2)
- B/UP IRSn for the offside IRS (n = 3)
- B/UP GPS for the GPS used by the Backup Navigation function when the GPS is fitted.
10. Equipment Characteristics and Installation
A. Overview of Dual Operation
The DUAL philosophy must be consistent with cockpit concept: two cockpit sides working independently, each one using onside inputs sensors and managing output peripheral systems. In the basic configuration, the A/C is equipped with two FMGCs and two primary MCDU. Each FMGC is able to communicate with each MCDU and vice-versa. Additionally, an intersystem bus between the FMs allow the FMs to exchange information and synchronize themselves.
With this configuration, three modes of FM operation are available:
The DUAL philosophy must be consistent with cockpit concept: two cockpit sides working independently, each one using onside inputs sensors and managing output peripheral systems. In the basic configuration, the A/C is equipped with two FMGCs and two primary MCDU. Each FMGC is able to communicate with each MCDU and vice-versa. Additionally, an intersystem bus between the FMs allow the FMs to exchange information and synchronize themselves.
With this configuration, three modes of FM operation are available:
- DUAL mode: the DUAL mode is the normal mode of operation when both FMs are healthy and operating properly. It is based on a Master/Slave concept and is totally independent of the FM Source Select switch.
- INDEPENDENT mode: this mode exists when both FMs are healthy but conditions exist to prevent communication with each other or the FMs are in disagreement on a certain set of parameters.
- SINGLE mode: this mode exists when one of the FMs has failed. This mode supersedes both the DUAL and INDEPENDENT modes.
B. Databases and Configuration Files - Load and Cross-load
This function allows to bring up to date operational software and data bases by loading or cross-loading from a specific FMS onto the opposite side all these loadable elements.
This function allows to bring up to date operational software and data bases by loading or cross-loading from a specific FMS onto the opposite side all these loadable elements.
(1) Conditions for cross-load function availability
This function allows a specified FM to load elements into the opposite side FM. The mechanization for the loadable element cross-load function is performed via the P/N STATUS pages. It allows to save time during maintenance activities (retrofit, NDB update,...) compared to use of dataloader.
Cross-load function is available if all the following conditions are met:
This function allows a specified FM to load elements into the opposite side FM. The mechanization for the loadable element cross-load function is performed via the P/N STATUS pages. It allows to save time during maintenance activities (retrofit, NDB update,...) compared to use of dataloader.
Cross-load function is available if all the following conditions are met:
- no data-load operation is in progress or armed on the FMS,
- the FMS source select switch is set to NORMAL if the aircraft is fitted with this switch,
- current flight phase is PREFLIGHT or DONE,
- aircraft is on the ground,
- P/N discrepancy exists,
- cross-load operation is available,
- all mandatory elements are completely loaded on this side,
- compatibility rules are satisfied,
- aircraft/engine configuration is compatible with the Performance Data Base.
(2) Arming and activating CROSSLOAD
The side on which a START XLOAD prompt is chosen determines the transmitting FMS (opposite FMS is the receiving FMS). Upon selection, the START XLOAD prompt is removed from the transmitting side. The START XLOAD prompt is also removed from the receiving side if previously displayed. On both sides, A/C STATUS, NEXT PAGE and PREV PAGE prompts are not displayed until the cross-load operation terminates. Any subsequent MCDU key press relative to the FMS subsystem is ignored while the two FMS establish cross-load communication and attempt to arm for cross-load.
The side on which a START XLOAD prompt is chosen determines the transmitting FMS (opposite FMS is the receiving FMS). Upon selection, the START XLOAD prompt is removed from the transmitting side. The START XLOAD prompt is also removed from the receiving side if previously displayed. On both sides, A/C STATUS, NEXT PAGE and PREV PAGE prompts are not displayed until the cross-load operation terminates. Any subsequent MCDU key press relative to the FMS subsystem is ignored while the two FMS establish cross-load communication and attempt to arm for cross-load.
(3) Transmitting the loadable elements
Selecting the CONFIRM prompt on the P/N XLOAD page causes the receiving FMS to display the P/N STATUS page of each loadable element. P/N STATUS pages are displayed in increasing order and when a crossload of one element is finished. The CROSSLOAD COMPLETE message is displayed in the scratchpad of both MCDU at the end of the full crossload.
Selecting the CONFIRM prompt on the P/N STATUS causes each FMS to display the P/N STATUS page with the XLOAD IN PROCESS message. The loadable element stored in the transmitting FMS automatically begins to overwrite the receiving FMS loadable element memory. The transfer includes pilot defined elements when the NDB is involved.
During the processing, both FMS are effectively suspended and any MCDU FM mode key selection on either side is ignored and results in the display of the NOT ALLOWED scratchpad message.
The P/N STATUS page or P/N XLOAD page with the XLOAD IN PROCESS message on the transmitting side displays the expected remaining time to complete the transfer.
Upon successful completion of any cross-load, both sides remain on the P/N STATUS or P/N XLOAD page with all the prompts displayed in accordance with their display rules. CROSSLOAD COMPLETE message is displayed in the scratchpad of both sides.
Selecting the CONFIRM prompt on the P/N XLOAD page causes the receiving FMS to display the P/N STATUS page of each loadable element. P/N STATUS pages are displayed in increasing order and when a crossload of one element is finished. The CROSSLOAD COMPLETE message is displayed in the scratchpad of both MCDU at the end of the full crossload.
Selecting the CONFIRM prompt on the P/N STATUS causes each FMS to display the P/N STATUS page with the XLOAD IN PROCESS message. The loadable element stored in the transmitting FMS automatically begins to overwrite the receiving FMS loadable element memory. The transfer includes pilot defined elements when the NDB is involved.
During the processing, both FMS are effectively suspended and any MCDU FM mode key selection on either side is ignored and results in the display of the NOT ALLOWED scratchpad message.
The P/N STATUS page or P/N XLOAD page with the XLOAD IN PROCESS message on the transmitting side displays the expected remaining time to complete the transfer.
Upon successful completion of any cross-load, both sides remain on the P/N STATUS or P/N XLOAD page with all the prompts displayed in accordance with their display rules. CROSSLOAD COMPLETE message is displayed in the scratchpad of both sides.
(4) Mandatory loadable elements
The FMS will lock on the P/N STATUS (and also A/C STATUS) pages as long as the following loadable elements have not been correctly loaded:
The FMS will lock on the P/N STATUS (and also A/C STATUS) pages as long as the following loadable elements have not been correctly loaded:
- FMS operational software,
- Performance Date Base,
- OPC file,
- Navigation Data Base,
- AMI file if one of the two AMI file is not a default one.
(5) Cross-loadable elements
The FMS allows the cross-load on the P/N STATUS page of the following loadable elements:
The FMS allows the cross-load on the P/N STATUS page of the following loadable elements:
- Performance Date Base,
- OPC file,
- Navigation Data Base,
- AMI file.
(6) Cross-loading procedure
The FMS checks the compatibility of the loadable elements before crossloading. When a compatibility problem is raised, a cross problem status is displayed with an information of what is the problem. Cross-loading process for a loadable element cannot be initiated as long as incompatibility problems are detected for this element between both sides.
No compatibility check is performed prior the loading of a loadable element except between the FG and the FM operational software.
The mechanization for the loadable element cross-load function is performed via the P/N STATUS pages.
The FMS checks the compatibility of the loadable elements before crossloading. When a compatibility problem is raised, a cross problem status is displayed with an information of what is the problem. Cross-loading process for a loadable element cannot be initiated as long as incompatibility problems are detected for this element between both sides.
No compatibility check is performed prior the loading of a loadable element except between the FG and the FM operational software.
The mechanization for the loadable element cross-load function is performed via the P/N STATUS pages.
(7) Mandatory/Optional loadable elements
The following list gives the loadable elements that are necessary for normal FM operation.
On either side, the FMS displays only the P/N STATUS pages and any MCDU mode key button push relative to the FMS is ignored as long as all the following loadable elements have not been correctly loaded:
The following loadable elements are not mandatory:
The following list gives the loadable elements that are necessary for normal FM operation.
On either side, the FMS displays only the P/N STATUS pages and any MCDU mode key button push relative to the FMS is ignored as long as all the following loadable elements have not been correctly loaded:
- FMS software: this software will be common to all Airbus aircraft family. Aircraft specificities (such as aircraft type or engine type identification) are indicated to the FMS via hardware program pins wired on the FMGC box,
- Navigation Data Base file: it contains only navigation data, formatted according to Arinc 424 specifications,
- OPC file: this database contains the software pin programs used to activate software options,
- Performance Data Base file: this database is no longer considered as part of the operational software in the objective of independent update and certification. Performance tables comply with a predefined format, compatible with the software. As long as this format is respected, a Performance Database update consists in data update only and can be compared to a Navigation Database update (currently done every month via data loading),
- Magnetic Variation Data Base file: this database contains one magnetic variation model only.
The following loadable elements are not mandatory:
- AMI file (Default loadable elements is included in the operational software): this database is a customization file. This database allows the airline to accommodate some specific FMS functions to its particular policy,
- Flight Test file (No default loadable element is included in the operational software): dedicated to development and flight tests means.
(8) Cross-loadable elements
The FMS allows the cross-load on the P/N STATUS pages to the following loadable elements:
The FMS allows the cross-load on the P/N STATUS pages to the following loadable elements:
- FMS software,
- NDB file,
- OPC file,
- AMI file,
- Perf DB file,
- Magnetic Variation DB file,
- Flight test file.
(9) Compatibility checks
(a) Power-up operations
Prior data-load operations, have assured that any loadable elements existing in the onside FMS at power-up satisfy the following compatibility conditions:
Prior data-load operations, have assured that any loadable elements existing in the onside FMS at power-up satisfy the following compatibility conditions:
- FM software is compatible with host hardware,
- OPC file is compatible with FM software,
- AMI file is compatible with FM software,
- NDB file is compatible with FM software,
- Performance Data Base file is compatible with FM software,
- Flight test file is compatible with FM software,
- Magnetic Variation DB file is compatible with FM software.
- check whether FM software is compatible with FG software,
- determine which mandatory elements have not been loaded.
- the P/N STATUS page related to the relevant loadable element is displayed on the onside MCDU,
- selection of any MCDU FM mode key on the onside MCDU is ignored and results in the display of the NOT ALLOWED scratchpad message as long as mandatory elements need to be loaded or the FM software is not compatible with the FG soft.
(b) Data-load compatibility checks
Due to the important data-loading time, compatibility checks of the loadable element are performed at the beginning of the data-load operation. This early check prevents any loss of time due to a complete data-load of any non-compatible version of loadable elements.
Due to the important data-loading time, compatibility checks of the loadable element are performed at the beginning of the data-load operation. This early check prevents any loss of time due to a complete data-load of any non-compatible version of loadable elements.
(c) Cross-load compatibility checks
At power-up, if a mismatch of loadable elements is detected between the two FMS, both sides revert to the relevant P/N STATUS page. These are mismatches when an element differs from one side to the other side or when one side is not loaded with all the elements.
Mismatch checks of the loadable elements with the elements of the opposite side are performed at the beginning of the cross-load operation. Cross-load of data files elements cannot be initiated until the FM software of the two FM matches. When a cross-load problem is raised, the XLOAD PROBLEM INFO is displayed with information about the problem.
At power-up, if a mismatch of loadable elements is detected between the two FMS, both sides revert to the relevant P/N STATUS page. These are mismatches when an element differs from one side to the other side or when one side is not loaded with all the elements.
Mismatch checks of the loadable elements with the elements of the opposite side are performed at the beginning of the cross-load operation. Cross-load of data files elements cannot be initiated until the FM software of the two FM matches. When a cross-load problem is raised, the XLOAD PROBLEM INFO is displayed with information about the problem.
(10) Loading procedure
The loading procedure is as follows:
The loading procedure is as follows:
- Open the FMGC x circuit breaker in the cockpit (x = 1 or 2 depending on the side you want to load information).
- Select the FMGC 1 or 2 to be loaded (with MDDU selector if installed or through the connection of a portable data loader (PDL) to the dedicated FMGC plug).
- Insert the first disk of the loadable element into the data loader,
- Close the FMGC x circuit breaker.
- Wait for transfer and change the disk when required by the data loader.
- When finished, the FMGC displays again the P/N STATUS of the loaded element if the loaded element is a database. The FMGC does not start again, reset it by opening and closing FMGC circuit breaker to guarantee a good safety level after loading.
- De-select the FMGC that has been loaded (MDDU selector back to neutral if installed or through the disconnection of the PDL from the dedicated FMGC plug).
(11) Loading procedure
The loading procedure is as follows:
The loading procedure is as follows:
- Open the FMGC x circuit breaker in the cockpit (x = 1 or 2 depending on the side you want to load information).
- Select the FMGC 1 or 2 to be loaded (with the Data Loading Selector (DLS)).
- Close the FMGC x circuit breaker.
- Wait for transfer and change the disk when required by the data loader.
- When finished, the FMGC displays again the P/N STATUS of the loaded element if the loaded element is a database. The FMGC does not start again, reset it by opening and closing FMGC circuit breaker to guarantee a good safety level after loading.
- De-select the FMGC that has been loaded (Data Loading Selector (DLS) back to neutral).