DOC AIRBUS | AMM A320FCOMMON MODES - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
1. General
The AP/FD modes common to the longitudinal and lateral axes are:
However, it is possible to leave TO and GA modes one axis after the other.
The selection of the LAND or GA mode authorizes the engagement of both APs.
The engagement of the lateral and the longitudinal cruise modes is impossible as long as the AP or the FD is engaged in LAND TRACK or GO AROUND mode below 100 ft RA.
** ON A/C NOT FOR ALL The AP/FD modes common to the longitudinal and lateral axes are:
- TAKEOFF (TO)
- ILS approach (LAND) or FMS approach (AREA.NAV)
- GO AROUND (GA).
However, it is possible to leave TO and GA modes one axis after the other.
The selection of the LAND or GA mode authorizes the engagement of both APs.
The engagement of the lateral and the longitudinal cruise modes is impossible as long as the AP or the FD is engaged in LAND TRACK or GO AROUND mode below 100 ft RA.
2. System Description
A. TAKEOFF Mode (TO)
(1) Principle
This mode provides lateral guidance function, at takeoff, on the runway centerline by means of the LOC beam and by following an optimum longitudinal flight path after rotation.
This mode is available:
Engagement of the mode is shown by the green SRS and RWY indications in the FMA columns corresponding to the longitudinal and lateral modes.
This mode provides lateral guidance function, at takeoff, on the runway centerline by means of the LOC beam and by following an optimum longitudinal flight path after rotation.
This mode is available:
- for the FD during takeoff run and in flight
- for the AP 5 seconds after lift-off.
Engagement of the mode is shown by the green SRS and RWY indications in the FMA columns corresponding to the longitudinal and lateral modes.
(2) Pitch Axis
(a) Operational use
The pitch guidance law enables holding of V2 + 10 kts in dual-engine configuration.
Prior to mode engagement, the pilot must select speed V2 on the TAKEOFF page of the MCDU.
With V2 selected, the managed speed control is activated and the TO longitudinal mode (PITCH TAKEOFF) can be engaged. Without V2 selection on the MCDU, the mode is not engaged on this axis.
Engagement of the PITCH TO mode results in managed thrust control (A/THR (aotothrust)). The A/THR is not active as long as the throttle control levers are positioned beyond the CLB gate.
The pitch guidance law enables holding of V2 + 10 kts in dual-engine configuration.
Takeoff with NAV ArmedPrior to mode engagement, the pilot must select speed V2 on the TAKEOFF page of the MCDU.
With V2 selected, the managed speed control is activated and the TO longitudinal mode (PITCH TAKEOFF) can be engaged. Without V2 selection on the MCDU, the mode is not engaged on this axis.
Engagement of the PITCH TO mode results in managed thrust control (A/THR (aotothrust)). The A/THR is not active as long as the throttle control levers are positioned beyond the CLB gate.
(b) Engage logic
The engagement conditions of the PITCH TAKEOFF mode are shown in figure.
The engagement condition on the position of the throttle control levers takes into account the following facts:
The engagement conditions of the PITCH TAKEOFF mode are shown in figure.
The engagement condition on the position of the throttle control levers takes into account the following facts:
- if a FLEX limit has been selected, the mode is engaged as soon as the MCT/FLX TO gate is reached
- if no FLEX limit has been selected, the mode is engaged as soon as at least one throttle control lever is positioned beyond the MCT/FLX TO gate.
(c) Guidance law
The SRS guidance law called when the PITCH TO mode is engaged, is shown in figure.
This law enables to hold V2 + 10 kts in dual-engine configuration (V2 is memorized in the guidance part at engagement of the PITCH TO mode).
In single-engine operation, the law enables to hold:
The SRS guidance law called when the PITCH TO mode is engaged, is shown in figure.
This law enables to hold V2 + 10 kts in dual-engine configuration (V2 is memorized in the guidance part at engagement of the PITCH TO mode).
In single-engine operation, the law enables to hold:
- the aircraft speed if it is greater than V2 when the engine failure occurs.
- V2 if aircraft speed is lower than V2 when the engine failure occurs.
- an attitude protection to reduce the A/C nose-up attitude during this phase
- a vertical speed protection to ensure a minimum climbing rate
- an attitude pre-command to initialize the aircraft rotation when the mode is engaged (this pre-command is active in PITCH GA mode only which calls the same control law, Ref. Para.3.C.).
(3) Lateral Axis
(a) Operational use
The guidance law on the lateral axis provides guidance of the aircraft on the runway centerline by means of the LOC beam. The pilot makes this possible by selecting the ILS frequency associated with the takeoff runway.
This selection can be made :
If the ILS is not available or if the ILS frequency is not selected, the TO mode is not engaged on this axis.
The guidance law on the lateral axis provides guidance of the aircraft on the runway centerline by means of the LOC beam. The pilot makes this possible by selecting the ILS frequency associated with the takeoff runway.
This selection can be made :
- implicitly by selecting the takeoff runway or departure procedure on the MCDU
- expressly, by selecting the frequency on the RMP or the MCDU.
If the ILS is not available or if the ILS frequency is not selected, the TO mode is not engaged on this axis.
(b) Engage logic
This logic takes into account certain protections:
This logic takes into account certain protections:
- possible modification of the takeoff runway ILS (through the RMP) when an implicit selection has been made through a takeoff procedure
- engagement of the mode when not yet aligned
- takeoff on a parallel runway.
- RUNWAY LOC to 30 ft.; the FD law provides guidance of the aircraft on the runway centerline
- RUNWAY TRACK from 30 ft. when the NAV mode is not armed (Ref. Para. 2.A.(3)(d)). The guidance law provides hold of the aircraft track memorized at engagement of the sub-mode.
- by engaging another lateral mode
- when the LOC signal is lost before 30 ft.
- if a difference between COM and MON channels greater than 12 deg. is detected on yaw FD bars.
(c) Guidance law
The RUNWAY guidance law called when the RUNWAY LOC sub-mode is engaged is shown in figure.
The TRACK guidance law called when the RUNWAY TRACK sub-mode is engaged is described in 22-12-00.
The RUNWAY guidance law called when the RUNWAY LOC sub-mode is engaged is shown in figure.
The TRACK guidance law called when the RUNWAY TRACK sub-mode is engaged is described in 22-12-00.
(d) Heading/track preset at takeoff
During takeoff, when the aircraft is on the ground or at an altitude less than 30 ft., the pilot can select a heading/track preset value in the HDG/TRK display on the FCU (by action on the heading/track selector knob) provided that one of the following modes is engaged : LOC CPT, LOC TRACK, LAND TRACK, FINAL DES, GO AROUND.
The NAV mode is disarmed when the preset is activated and the FCU HDG TRK window is synchronized with the aircraft heading or track. As a result, the RUNWAY mode remains engaged at 30 ft. in the RUNWAY TRACK sub-mode.
The heading preset value is cancelled by:
During takeoff, when the aircraft is on the ground or at an altitude less than 30 ft., the pilot can select a heading/track preset value in the HDG/TRK display on the FCU (by action on the heading/track selector knob) provided that one of the following modes is engaged : LOC CPT, LOC TRACK, LAND TRACK, FINAL DES, GO AROUND.
The NAV mode is disarmed when the preset is activated and the FCU HDG TRK window is synchronized with the aircraft heading or track. As a result, the RUNWAY mode remains engaged at 30 ft. in the RUNWAY TRACK sub-mode.
The heading preset value is cancelled by:
- acceptance of the preset value when the HDG or TRACK mode is engaged (pull action on the heading/track selector knob)
- engagement of the NAV mode (direct TO)
- push action on the heading/track selector knob
- AP/FD disengagement.
B. APPROACH Mode
The automatic flight control system installed enables two types of approach to be considered :
The selection of an ILS frequency on the RMP forces the selection of the ILS approach whatever the selection made on the MCDU.
The APPROACH mode (ILS or FMS) is engaged when you push the APPR pushbutton switch on the FCU.
The automatic flight control system installed enables two types of approach to be considered :
- ILS approach (LAND mode) : guidance is performed on the ILS beam (LOC and GLIDE)
- FMS approach : guidance is performed from a theoretical path computed by the FMS.
The selection of an ILS frequency on the RMP forces the selection of the ILS approach whatever the selection made on the MCDU.
The APPROACH mode (ILS or FMS) is engaged when you push the APPR pushbutton switch on the FCU.
(1) ILS Approach
(a) Characteristics
This mode provides the capture and track of the ILS beam (LOC and GLIDE) and ensures the following functions : alignment, flare and roll out.
This mode is available for the AP and FD. It enables landings to be performed in Cat. III operation. Therefore, the selection of the LAND mode authorizes the engagement of a second AP.
This mode provides the capture and track of the ILS beam (LOC and GLIDE) and ensures the following functions : alignment, flare and roll out.
This mode is available for the AP and FD. It enables landings to be performed in Cat. III operation. Therefore, the selection of the LAND mode authorizes the engagement of a second AP.
(b) Operational use
The ILS approach can be selected:
The arming of this mode enables the LOC and GLIDE modes to be armed on the lateral and longitudinal axes. The support modes, active on these axes, remain engaged until the LOC and GLIDE beams are captured.
Switching to the G/S CPT and LOC CPT modes occurs when the capture conditions are met.
When the aircraft is stabilized on the LOC and GLIDE beams:
The ILS approach can be selected:
- implicitly, through the flight plan definition. In this case, the frequency of the ILS/MMR receivers is adjusted automatically on the value read in FM memory.
- expressly, by selecting a frequency and a runway heading by means of the MCDU or the RMP.
The arming of this mode enables the LOC and GLIDE modes to be armed on the lateral and longitudinal axes. The support modes, active on these axes, remain engaged until the LOC and GLIDE beams are captured.
Switching to the G/S CPT and LOC CPT modes occurs when the capture conditions are met.
When the aircraft is stabilized on the LOC and GLIDE beams:
- the LOC TRACK and GLIDE TRACK modes are activated
- the AP/FD guides the aircraft along the ILS beam to 30 ft.
At this altitude, the LAND mode provides the alignment on the runway centerline on the yaw axis and flare on the pitch axis. When the A/THR is engaged, the thrust reduction (RETARD) is activated.
The ROLL OUT sub-mode is engaged at touchdown and provides guidance on the runway centerline.
As the LAND mode is latched below 400 ft. (switching to LAND TRACK), it can be de-activated only by engaging the GO AROUND mode. Actions on the FCU are no longer taken into account.
NOTE: The GLIDE mode can only be captured after LOC mode capture. However the GLIDE capture can be independent from the LOC capture (option activated by pin programming).
(c) Engage logic
1 LAND mode arming
The arming of the LAND mode enables arming of the LOC and GLIDE modes.
The arming of the LAND mode enables arming of the LOC and GLIDE modes.
2 LAND mode disarming
The LAND mode is disarmed in the following conditions:
The LAND mode is disarmed in the following conditions:
a Arming phase (LOC and GLIDE modes armed)
The LAND mode is disarmed by:
The LAND mode is disarmed by:
- action on the APPR pushbutton switch
- arming another mode : NAV (push action on the heading/track selector knob) or LOC (action on the LOC pushbutton switch) on the lateral axis
- engagement of the GO AROUND mode.
b Active phase (LOC and GLIDE modes active)
The LAND mode is disarmed by:
The LAND mode is disarmed by:
- action on the APPR pushbutton switch which engages the V/S mode if the GLIDE mode was active, and the HDG/TRACK mode if the LOC mode was active.
- action on the LOC pushbutton switch which engages the V/S-FPA mode if the GLIDE mode was active or causes loss of GLIDE mode arming if this mode was armed.
- pull action on the V/S-FPA selector knob when the GLIDE mode is active. Engagement of the V/S or FPA mode engages the HDG/TRACK mode on the lateral mode on the lateral axis.
- pull action on the heading/track selector knob which engages the HDG/TRACK mode. Engagement of this mode engages the V/S-FPA mode if the GLIDE mode was active.
- engagement of the GO AROUND, EXP, OPEN and NAV modes.
NOTE: The disengagement of the LAND mode below 400 ft. will be possible by action on the APPR pushbutton switch provided the aircraft has been on the ground for 10 s and the AP is disengaged.
3 GLIDE and LOC capture
Switching to G/S CPT and LOC CPT modes occurs when the capture conditions are met and provided the LOC and GLIDE modes have been armed. Switching to G/S TRACK and LOC TRACK modes occurs when associated conditions are met. All the switching conditions are given in figure.
The term delta psi is the deviation between the aircraft track (IR) and the runway heading (ILS).
Switching to G/S CPT and LOC CPT modes occurs when the capture conditions are met and provided the LOC and GLIDE modes have been armed. Switching to G/S TRACK and LOC TRACK modes occurs when associated conditions are met. All the switching conditions are given in figure.
The term delta psi is the deviation between the aircraft track (IR) and the runway heading (ILS).
4 LAND TRACK capture
The mode engage logic is shown in figure.
The LAND TRACK mode includes two sub-modes:
The mode engage logic is shown in figure.
The LAND TRACK mode includes two sub-modes:
- ALIGN which engages at 50 ft. provided the FACs are armed (below 100 ft. loss of the FACs does not cause AP/FD disengagement or loss of LAND TRACK mode).
- ROLL OUT which is activated (only below 50 ft.) using:
. wheelspeed data if the BSCU is healthy
. landing-gear shock-absorber compressed data if the BSCU has failed.
5 Flare phase
The flare phase is initiated when the flare condition is activated.
The flare phase is initiated when the flare condition is activated.
(d) Display
The selection of the LAND mode is indicated by:
CAT 1
CAT 2
CAT 3 SINGLE
CAT 3 DUAL
The selection of the LAND mode is indicated by:
- illumination of the APPR pushbutton switch on the FCU
- illumination of various indications on the flight mode annunciator (FMA) section of the PFD.
- during the arming phase:
. cyan G/S indication in the lower part of the section corresponding to the longitudinal modes
. cyan LOC indication in the lower part of the section corresponding to the lateral modes.
In addition, the active support mode indication remains visible (in green) until the LOC or GLIDE capture is effective. - during the capture phase, the indications are changed into:
green LOC* indication : the lateral support mode is disengaged and the corresponding mode indication is cancelled.
Green G/S* indication : the longitudinal support mode is disengaged and the corresponding mode indication is cancelled.
The LOC* indication can be displayed at the same time as the cyan G/S indication (G/S mode armed) but the G/S capture phase can start only after the LOC capture phase except when the GLIDE BEFORE LOC pin program is activated. - during the track phase and above 400 ft. the indications are replaced by:
LOC (green)
G/S (green) - during the track phase and below 400 ft. the green LOC and G/S indications are replaced by the green LAND indication across the line dividing the two sections corresponding to the longitudinal and lateral mode annunciations.
- in flare phase, the green LAND indication is replaced by the green FLARE indication.
- in ground roll out phase, the FLARE indication is replaced by the green ROLL OUT indication.
CAT 1
CAT 2
CAT 3 SINGLE
CAT 3 DUAL
(e) Command generation
1 Lateral axis
The following figure gives the computation principle in the various phases associated with LOC axis capture and track, alignment and roll out. These computations are characterized by:
The following figure gives the computation principle in the various phases associated with LOC axis capture and track, alignment and roll out. These computations are characterized by:
- filtering of the metric deviation from the ILS receiver and the estimated lateral speed. This enables to obtain a guidance signal which partly cancels the LOC noises and the data derivatives coming from the IRS.
- utilization for computation of the distance to the runway threshold, of estimated distance to LOC transmitter delivered by the FM part.
a LOC capture phase
The computation principle of the guidance law is given in figure.
The computation principle of the guidance law is given in figure.
b LOC track phase
The computation principle of the law in the LOC TRACK phase is given in figure.
The computation principle of the law in the LOC TRACK phase is given in figure.
c Align phase
The computation principle of the guidance law is given in figure.
The deviation between the aircraft heading and the runway heading (d PSI) is used to place the aircraft parallel to the runway centerline before touchdown. This law is also characterized by the acquisition of an estimated skidding term.
The computation principle of the guidance law is given in figure.
The deviation between the aircraft heading and the runway heading (d PSI) is used to place the aircraft parallel to the runway centerline before touchdown. This law is also characterized by the acquisition of an estimated skidding term.
d Roll out phase
The computation principle of the guidance law is given in figure.
The computation principle of the guidance law is given in figure.
2 Longitudinal axis
a GLIDE capture and track phase
The principle of the guidance law is given in figure.
The principle of the guidance law is given in figure.
(f) Speed control in LAND mode
During automatic landing, speed hold is ensured by the autothrust (A/THR) system.
At landing, speed control can be:
In the case of approaches with head wind, and in order to take precautions against wind shear, a term is added to the VAPP ; this term allows the aircraft to have a ground speed during approach at least equal to the speed it will have at the runway threshold. This term, which takes into account the difference between the wind speed provided by the control tower displayed on the MCDU and the actual wind speed, will be added in automatic speed control as soon as the approach phase of the FM part is active. In these conditions, the speed bug is magenta and is controlled by this reference on the PFD speed scale.
During automatic landing, speed hold is ensured by the autothrust (A/THR) system.
At landing, speed control can be:
- manual : reference speed = speed selected on the FCU
- automatic : reference speed = speed delivered by the FM part.
In the case of approaches with head wind, and in order to take precautions against wind shear, a term is added to the VAPP ; this term allows the aircraft to have a ground speed during approach at least equal to the speed it will have at the runway threshold. This term, which takes into account the difference between the wind speed provided by the control tower displayed on the MCDU and the actual wind speed, will be added in automatic speed control as soon as the approach phase of the FM part is active. In these conditions, the speed bug is magenta and is controlled by this reference on the PFD speed scale.
(g) Landing capabilities
Each FMGC computes its own automatic landing category according to the availability of the various sensors and functions.
LAND 2 category:
The LAND 3 FAIL OPERATIONAL capability is obtained when the two FMGCs have the LAND 3 FAIL OPERATIONAL category.
In this configuration, the objective is to continue automatic landing in spite of the simple failures which might affect the various systems used during this phase.
Each FMGC computes its own automatic landing category according to the availability of the various sensors and functions.
LAND 2 category:
- at least 1 AP engaged with the LAND mode armed or LAND TRACK mode active
- at least 1 FWC valid
- 2 PFDs valid
- 2 ILS/MMR receivers valid.
- LAND 2 conditions
- At least one A/THR function engaged
- 2 radio-altimeters valid.
- 2 APs engaged with the LAND mode armed or the LAND TRACK mode active
- at least one A/THR function engaged
- 2 FWCs valid
- FMGCs must be supplied by two separate electrical power supply systems
- 2 PFDs valid
- 2 ELACs valid
- 2 ILS/MMR receivers valid
- 2 radio-altimeters valid
- 3 IRS valid
- 3 ADCs valid
- BSCU valid
- 2 FACs valid
- No IRS or ADC failures detected by FAC 1 or 2
- 2 yaw dampers engaged
- 2 rudder trims engaged.
- when the AP and FD are disengaged for one FMGC, the landing capability corresponds to the category of the only FMGC likely to provide automatic landing.
- when the AP or FD is engaged for the two FMGCs, the landing capability corresponds to the lowest category coming from the 2 FMGCs.
The LAND 3 FAIL OPERATIONAL capability is obtained when the two FMGCs have the LAND 3 FAIL OPERATIONAL category.
In this configuration, the objective is to continue automatic landing in spite of the simple failures which might affect the various systems used during this phase.
NOTE: Below 100 ft. (radio altimeter), LAND 3 FAIL PASSIVE and LAND 3 FAIL OPERATIONAL categories are memorized until the LAND TRACK mode is disengaged or the 2 APs are disengaged.
A failure occuring below 100 ft. will thus not cause any capability downgrading.
The CAT1, CAT2, CAT3 SINGLE and CAT3 DUAL messages are displayed on the FMA according to the landing capabilities sent by the FMGCs. A failure occuring below 100 ft. will thus not cause any capability downgrading.
| ------------------------------------------------------------------- |
| ! CAPABILITY ! FMA ! |
| ------------------------------------------------------------------- |
| ! LAND 3 FAIL OPERATIONAL (FO) ! CAT 3 DUAL ! |
| !------------------------------------!----------------------------! |
| ! LAND 3 FAIL PASSIVE (FP) ! CAT 3 SINGLE ! |
| !------------------------------------!----------------------------! |
| ! LAND 2 ! CAT 2 ! |
| !------------------------------------!----------------------------! |
| ! LAND ARM or LAND TRACK ! CAT 1 ! |
| ------------------------------------------------------------------- |
(h) Controls and warnings associated with automatic landing
1 ILS TUNE INHIBIT
When the LAND mode is armed with radio height below 700 feet or LAND TRACK mode or RUNWAY mode, the FMGC sends an ILS TUNE INHIBIT signal which allows the value and validity of the selected frequency to be frozen in the ILS/MMR receivers and the runway heading to be memorized in the FMGC.
When the LAND mode is armed with radio height below 700 feet or LAND TRACK mode or RUNWAY mode, the FMGC sends an ILS TUNE INHIBIT signal which allows the value and validity of the selected frequency to be frozen in the ILS/MMR receivers and the runway heading to be memorized in the FMGC.
2 Removal of FD bars
- the pitch FD bar is removed when the ROLL OUT mode is active and no longitudinal mode is active.
- the roll FD bar is removed when the ROLL OUT mode is active and no lateral mode is active.
- the yaw FD bar is removed as long as the ROLL OUT or ALIGN mode is not active.
3 Availability of landing categories
Whatever the flight phase, each FMGC computes the following three items of information according to the validity of sensors and the AP availability:
Whatever the flight phase, each FMGC computes the following three items of information according to the validity of sensors and the AP availability:
- LAND 2 INOP
- LAND 3 FAIL PASSIVE INOP
- LAND 3 FAIL OPERATIONAL INOP.
4 Warnings
a Excessive deviations
This warning is activated if the position of the aircraft with respect to the ILS beam exceeds:
This warning is activated if the position of the aircraft with respect to the ILS beam exceeds:
- 75 microamperes for the GLIDE axis (above 100 ft. RA)
- 20 microamperes for the LOC axis (above 15 ft. RA).
b AUTOLAND warning
This warning covers several warnings:
This warning covers several warnings:
- excessive deviations
- loss of both APs.
c Capability downgrading
A triple click aural warning is generated in the event of landing capability downgrading.
A triple click aural warning is generated in the event of landing capability downgrading.
d FD bar flashing
The FMGC computes a command to make the longitudinal FD bar flash in the following conditions:
The FMGC computes a command to make the longitudinal FD bar flash in the following conditions:
- with the G/S CPT, G/S TRACK, LAND TRACK and above 100 ft. RA when the ground transmission of the GLIDE is interrupted.
- with the LOC CPT, LOC TRACK, LAND TRACK and above 15 ft. RA when the ground transmission of the LOC is interrupted.
(2) FMS Approach (AREA NAV or R.NAV)
(a) Characteristics
This mode provides lateral and longitudinal guidance of the aircraft along a theoretical profile defined by the flight plan (Ref. AMM D/O 22-70-00-00).
Guidance is ensured down to the MDA (Minimum Descent Altitude), altitude at which the pilot regains control of the aircraft. This mode is available on the AP and FD.
This mode provides lateral and longitudinal guidance of the aircraft along a theoretical profile defined by the flight plan (Ref. AMM D/O 22-70-00-00).
Guidance is ensured down to the MDA (Minimum Descent Altitude), altitude at which the pilot regains control of the aircraft. This mode is available on the AP and FD.
(b) Operational use
The AREA NAV approach is selected through the flight plan. In these conditions, the FINAL DES and NAV modes can be armed on the lateral and longitudinal axes by action on the APPR pushbutton switch on the FCU. If the NAV mode was already active, the mode will remain engaged.
The AREA NAV approach is selected through the flight plan. In these conditions, the FINAL DES and NAV modes can be armed on the lateral and longitudinal axes by action on the APPR pushbutton switch on the FCU. If the NAV mode was already active, the mode will remain engaged.
(c) Engage logic
1 Arming of FINAL DES and NAV modes
The arming logic of the FINAL DES mode is shown in figure.
The arming logic of the NAV mode is described in 22-12-00.
The arming logic of the FINAL DES mode is shown in figure.
The arming logic of the NAV mode is described in 22-12-00.
2 Disarming of NAV and FINAL DES modes
This is commanded by:
This is commanded by:
- action on the APPR pushbutton switch
- action on the LOC pushbutton switch with the ILS signal available (the LOC mode is armed)
- engagement of the GO AROUND mode.
3 De-activation of active NAV and/or FINAL DES modes
The de-activation is commanded by:
The de-activation is commanded by:
- action on the APPR pushbutton switch which engages the V/S-FPA mode if the FINAL DES mode is active and the HDG/TRACK mode if the NAV mode is active.
- push action on the LOC pushbutton switch if the ILS is available which arms the LOC mode and activates the HDG/TRACK mode if the NAV mode is active and the V/S-FPA mode if the FINAL DES mode is active.
- with the FINAL DES mode active as a result of V/S-FPA, OP CLB, OP DES or EXP mode engagement, engagement of this mode engages the HDG/TRACK mode on the lateral axis if the NAV mode is active.
- with the NAV mode active as a result of HDG/TRACK mode engagement, engagement of this mode engages the V/S-FPA mode if the FINAL DES mode is active.
- engagement of the GO AROUND mode.
(d) Displays
Selection of the AREA NAV approach is indicated by:
Selection of the AREA NAV approach is indicated by:
- illumination of the APPR pushbutton switch on the FCU
- display of various indications on the FMA section of the PFD, as follows:
. in the arming phase:
cyan FINAL indication in the lower part of the PFD section corresponding to the longitudinal modes,
cyan APP NAV indication in the lower part of the PFD section corresponding to the lateral modes.
. in the active phase:
green FINAL indication on the 1st line of the section corresponding to the longitudinal modes,
green APP NAV indication on the 1st line of the section corresponding to the lateral modes.
C. GO AROUND Mode
(1) Principle
On the lateral axis, this mode enables to hold the path followed by the aircraft when the mode was engaged.
On the longitudinal axis, it ensures managed speed control. The speed reference of the guidance law is the aircraft speed when the mode was engaged (the lower limit of this speed is the approach speed).
This mode is available on the AP and the FD. It is engaged when the pilot selects the maximum thrust by positioning the throttle control levers in the TO/GA gate.
Engagement is indicated by the green SRS and GA TRK indications displayed in the FMA sections corresponding to the longitudinal and lateral modes.
On the lateral axis, this mode enables to hold the path followed by the aircraft when the mode was engaged.
On the longitudinal axis, it ensures managed speed control. The speed reference of the guidance law is the aircraft speed when the mode was engaged (the lower limit of this speed is the approach speed).
This mode is available on the AP and the FD. It is engaged when the pilot selects the maximum thrust by positioning the throttle control levers in the TO/GA gate.
Engagement is indicated by the green SRS and GA TRK indications displayed in the FMA sections corresponding to the longitudinal and lateral modes.
(2) Engage Logic
Engagement of the GO AROUND mode results in:
The ROLL GO AROUND mode can only be disengaged by engaging another lateral mode.
When in PITCH GO AROUND mode, engagement of a cruise mode is possible only above 100 ft RA.
In dual-AP configuration, disengagement of the GO AROUND mode on one axis causes disconnection of the AP2.
Engagement of the GO AROUND mode results in:
- engagement of the PITCH GO AROUND mode on the pitch axis
- engagement of the ROLL GO AROUND mode on the roll axis.
The ROLL GO AROUND mode can only be disengaged by engaging another lateral mode.
When in PITCH GO AROUND mode, engagement of a cruise mode is possible only above 100 ft RA.
In dual-AP configuration, disengagement of the GO AROUND mode on one axis causes disconnection of the AP2.
(3) Command Generation
(a) Pitch axis
Engagement of the PITCH GO AROUND mode calls the SRS guidance law described in Para. 2.A.(2)(c). The speed reference is the aircraft speed memorized when the GA mode was engaged. However this reference speed cannot be lower than the approach speed memorized at 700 ft. during approach.
Engagement of the PITCH GO AROUND mode calls the SRS guidance law described in Para. 2.A.(2)(c). The speed reference is the aircraft speed memorized when the GA mode was engaged. However this reference speed cannot be lower than the approach speed memorized at 700 ft. during approach.
(b) Roll axis
Engagement of the ROLL GO AROUND mode calls the TRACK guidance law (Ref. Para. 2.A.(3)(c)).
The path reference of the guidance law is the path followed by the aircraft when the ROLL GO AROUND mode is engaged.
Engagement of the ROLL GO AROUND mode calls the TRACK guidance law (Ref. Para. 2.A.(3)(c)).
The path reference of the guidance law is the path followed by the aircraft when the ROLL GO AROUND mode is engaged.
(4) Heading/Track Preset
The heading/track preset function is available in LOC CPT, LOC TRACK, LAND TRACK and ROLL GO AROUND modes if the pilot selects a heading/track value on the FCU.
In ROLL GO AROUND mode, the NAV mode can be armed only by push action on the heading/track selector knob on the FCU. The preset function can be cancelled as described in Para. 2.A.(3)(d).
The heading/track preset function is available in LOC CPT, LOC TRACK, LAND TRACK and ROLL GO AROUND modes if the pilot selects a heading/track value on the FCU.
In ROLL GO AROUND mode, the NAV mode can be armed only by push action on the heading/track selector knob on the FCU. The preset function can be cancelled as described in Para. 2.A.(3)(d).
D. Display of Common Modes
(1) Flight Mode Annunciator (FMA)
(a) General rules
The common modes are always displayed in plain language. The first line indicates the active mode in green.
The second line indicates the armed mode in cyan.
In automatic landing configuration, when LAND TRACK is engaged, the message is displayed in the section common to the lateral and longitudinal modes.
The common modes are always displayed in plain language. The first line indicates the active mode in green.
The second line indicates the armed mode in cyan.
In automatic landing configuration, when LAND TRACK is engaged, the message is displayed in the section common to the lateral and longitudinal modes.
(b) List of messages
- Lateral mode section:
1st line : RWY, LOC*, LOC, APP NAV, GA TRK, RWY TRK
2nd line : LOC, APP NAV, NAV - Longitudinal mode section:
1st line : SRS, G/S*, G/S, FINAL
2nd line : G/S, FINAL - Common section:
LAND, FLARE, ROLL OUT - Landing category section:
CAT1, CAT2, CAT3, CAT3 SINGLE DUAL
(2) Automatic - Control Indicator Lights on FCU
(a) Lateral control
The associated indicator light comes on in the following cases:
The associated indicator light comes on in the following cases:
- lateral guidance is managed, i.e. the following modes are active:
RUNWAY
LOC CPT
LOC TRACK
LAND TRACK
NAV
GO AROUND. - managed lateral guidance is armed, i.e. the following modes are armed:
LOC
NAV.
(b) Longitudinal control
The associated indicator light comes on in the following cases:
The associated indicator light comes on in the following cases:
- longitudinal guidance is managed, i.e. the following modes are active:
TAKEOFF
G/S CPT
G/S TRACK
LAND TRACK
FINAL DESCENT
GO AROUND. - managed longitudinal guidance is armed, i.e. the following modes are armed:
GLIDE
FINAL DESCENT.