DOC AIRBUS | AMM A320FLIFT AUGMENTING - DESCRIPTION AND OPERATION
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** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
A. System Configuration
The aircraft has five slats on the leading edge of each wing. Together with the flaps (Ref. AMM D/O 27-50-00-00) they are used to increase lift. The slats are installed on tracks which are attached to the leading edge of each wing.
The slats are attached, at the forward end, to circular-arc tracks. The tracks operate in guide rollers. Two tracks support each of the four slats outboard of the engine pylon. Four tracks support the slat inboard of the engine pylon. Two of the tracks inboard, and each of the tracks outboard of the engine pylon, have curved rack gears fitted.
Each curved rack gear engages with a pinion. Plug-in rotary actuators move the pinions. Power to the plug-in rotary actuators comes from the transmission. An electrically controlled hydro-mechanical Power Control Unit (PCU) gives power to move the transmission.
Two Slat/Flap Control Computers (SFCC1 and SFCC2) monitor and control the slats. An Instrumentation Position Pick-Off Unit (IPPU) is installed on the Power Control Unit (PCU). It sends signals to the Electronic Instrument System (EIS), which identifies the position of the slats.
A Feedback Position Pick-Off Unit (FPPU) gives signals of the output shaft position of the PCU. Two Asymmetry Position Pick-Off Units (APPU) give signals of the slat position or speed. The SFCC1 and the SFCC2 receive and monitor the signals from the FPPU and the APPUs.
The aircraft has five slats on the leading edge of each wing. Together with the flaps (Ref. AMM D/O 27-50-00-00) they are used to increase lift. The slats are installed on tracks which are attached to the leading edge of each wing.
The slats are attached, at the forward end, to circular-arc tracks. The tracks operate in guide rollers. Two tracks support each of the four slats outboard of the engine pylon. Four tracks support the slat inboard of the engine pylon. Two of the tracks inboard, and each of the tracks outboard of the engine pylon, have curved rack gears fitted.
Each curved rack gear engages with a pinion. Plug-in rotary actuators move the pinions. Power to the plug-in rotary actuators comes from the transmission. An electrically controlled hydro-mechanical Power Control Unit (PCU) gives power to move the transmission.
Two Slat/Flap Control Computers (SFCC1 and SFCC2) monitor and control the slats. An Instrumentation Position Pick-Off Unit (IPPU) is installed on the Power Control Unit (PCU). It sends signals to the Electronic Instrument System (EIS), which identifies the position of the slats.
A Feedback Position Pick-Off Unit (FPPU) gives signals of the output shaft position of the PCU. Two Asymmetry Position Pick-Off Units (APPU) give signals of the slat position or speed. The SFCC1 and the SFCC2 receive and monitor the signals from the FPPU and the APPUs.
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Slats - Component LocationA. Electrical Control and Monitoring (Ref. 27-81-00)
The electrical control and monitoring system of the slats has:
The slat and flap control lever controls the position of the slats. The Command Sensor Unit (CSU) identifies the position of the slat and flap control lever and sends related signals to each SFCC. Each SFCC controls the valve block of a hydraulic motor, which is part of the slat PCU.
The FPPU, which is part of the slat PCU, and the two APPUs send related signals to the SFCCs. If the SFCCs find a failure in the system, the Wing Tip Brakes (WTB) stop and hold the transmission and the PCU is stopped.
The electrical control and monitoring system of the slats has:
- a slat/flap control lever
- a Command Sensor Unit (CSU)
- two Slat/Flap Control Computers (SFCC)
- two electrically controlled valve blocks which are installed on the slat Power Control Unit (PCU)
- a Feedback Position Pick-off-Unit (FPPU)
- two Asymmetry Position Pick-off-Units (APPU)
- two Wing Tip Brakes (WTB).
The slat and flap control lever controls the position of the slats. The Command Sensor Unit (CSU) identifies the position of the slat and flap control lever and sends related signals to each SFCC. Each SFCC controls the valve block of a hydraulic motor, which is part of the slat PCU.
The FPPU, which is part of the slat PCU, and the two APPUs send related signals to the SFCCs. If the SFCCs find a failure in the system, the Wing Tip Brakes (WTB) stop and hold the transmission and the PCU is stopped.
NOTE: The SFCCs have a slat alpha lock/slat baulk function which prevents the aircraft from stalling.
B. Hydraulic Actuation and Power Transmission (Ref. 27-84-00)
A hydro-mechanical PCU supplies mechanical power to the power transmission system. The PCU has two separate hydraulic motors and two Pressure-Off Brakes (POB). Each hydraulic motor has an electrically controlled valve block, which receives signals from a SFCC.
Torque shafts and gearboxes in the fuselage and the wings transmit the mechanical power from the slat PCU to the rotary actuators which move the slats. Each slat has two rotary actuators, which are installed on the tracks. Torque limiters in the transmission system and the rotary actuators prevent the mechanical overload of the structure.
A hydro-mechanical PCU supplies mechanical power to the power transmission system. The PCU has two separate hydraulic motors and two Pressure-Off Brakes (POB). Each hydraulic motor has an electrically controlled valve block, which receives signals from a SFCC.
Torque shafts and gearboxes in the fuselage and the wings transmit the mechanical power from the slat PCU to the rotary actuators which move the slats. Each slat has two rotary actuators, which are installed on the tracks. Torque limiters in the transmission system and the rotary actuators prevent the mechanical overload of the structure.
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5. Interface
Not Applicable
** ON A/C NOT FOR ALL Not Applicable
6. Component Description
Not Applicable
** ON A/C NOT FOR ALL Not Applicable
A. Extension and Retraction of the Slats
The operation of the slats is hydro-mechanical. The PCU moves the mechanical transmission system which operates the slats.
The CSU changes the mechanical signals from the slat and flap control lever into electrical signals. These are sent to the SFCC1 and the SFCC2. They compare the position signal with that from the FPPU. When there is a difference between the signals, the SFCC sends a discrete signal to its related valve block of the slat PCU.
Each valve block lets hydraulic fluid flow to and from its hydraulic motor, in relation to the signal from the SFCC. It thus controls the direction in which the hydraulic motor turns (for extension and retraction of the slats) and its speed (low or high speed).
The torque from the hydraulic motors is transmitted to the differential gearbox, which connects the two motors. The mechanical transmission system then transmits the torque to the rotary actuators which moves the slats.
The operation of the slats is hydro-mechanical. The PCU moves the mechanical transmission system which operates the slats.
The CSU changes the mechanical signals from the slat and flap control lever into electrical signals. These are sent to the SFCC1 and the SFCC2. They compare the position signal with that from the FPPU. When there is a difference between the signals, the SFCC sends a discrete signal to its related valve block of the slat PCU.
Each valve block lets hydraulic fluid flow to and from its hydraulic motor, in relation to the signal from the SFCC. It thus controls the direction in which the hydraulic motor turns (for extension and retraction of the slats) and its speed (low or high speed).
The torque from the hydraulic motors is transmitted to the differential gearbox, which connects the two motors. The mechanical transmission system then transmits the torque to the rotary actuators which moves the slats.
B. Hydraulic Actuation and Power Transmission
The two hydraulic motors in the PCU give hydraulic actuation. Each hydraulic motor gets power from a different system, green or blue.
Each hydraulic motor has its own valve block and POB. The valve blocks control the direction of rotation and the speed of the output shaft of the PCU. The POB holds the output shaft of the hydraulic motor:
It is possible to operate the slat system, at half speed, if the failure conditions listed below occur:
The two hydraulic motors in the PCU give hydraulic actuation. Each hydraulic motor gets power from a different system, green or blue.
Each hydraulic motor has its own valve block and POB. The valve blocks control the direction of rotation and the speed of the output shaft of the PCU. The POB holds the output shaft of the hydraulic motor:
- against torque from the airloads
- when there is a failure in its related hydraulic system
- to lock the transmission at the same time as the WTB.
It is possible to operate the slat system, at half speed, if the failure conditions listed below occur:
- loss of one electrical supply
- loss of one hydraulic system
- failure of one SFCC, or failure of one of two electrical components
- failure of one engine.
C. Asymmetry and Power Transmission Monitoring
The SFCC1 and the SFCC2 continuously compare position data from the APPUs and the FPPU to monitor the system. They use this data to find asymmetry, runaway and speed failure conditions.
If the slat movement is not in the specified limits then the conditions listed below occur:
The SFCC1 and the SFCC2 continuously compare position data from the APPUs and the FPPU to monitor the system. They use this data to find asymmetry, runaway and speed failure conditions.
If the slat movement is not in the specified limits then the conditions listed below occur:
- the slat PCU is switched off
- a warning is sent to the flight crew.
D. Position Indicating
The upper display unit of the ECAM system shows the position of the slats. Installed on the PCU is an IPPU which supplies flap position data. The IPPU also gives data to the flight data recorder and the Flight Warning System (FWC) (Ref. AMM D/O 27-85-00-00).
A visual check of the position of the slats can be done through the windows in the fuselage that are adjacent to the slats. The windows to be used are identified by a brown triangle on the sidewall panel above them.
The upper display unit of the ECAM system shows the position of the slats. Installed on the PCU is an IPPU which supplies flap position data. The IPPU also gives data to the flight data recorder and the Flight Warning System (FWC) (Ref. AMM D/O 27-85-00-00).
A visual check of the position of the slats can be done through the windows in the fuselage that are adjacent to the slats. The windows to be used are identified by a brown triangle on the sidewall panel above them.
8. BITE Test
The slat system has a Built-In Test Equipment (BITE). You can do tests of the system through the Multipurpose Control and Display Unit (MCDU) in the aircraft cockpit. The MCDU also indicates any failures in the system and gives trouble shooting data for the system.
The slat system has a Built-In Test Equipment (BITE). You can do tests of the system through the Multipurpose Control and Display Unit (MCDU) in the aircraft cockpit. The MCDU also indicates any failures in the system and gives trouble shooting data for the system.