DOC AIRBUS | AMM A320FTHRUST REVERSER STRUCTURE - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
The thrust reverser assembly encloses the engine core and gives the aerodynamic flow duct for the fan airflow
The thrust reverser is used to change the direction of the fan air flow forward to get a reverse thrust.
Each half thrust reverser cowl rotates at the 12 o'clock hinges to give access to the engine core area during maintenance and servicing operations
** ON A/C NOT FOR ALL The thrust reverser assembly encloses the engine core and gives the aerodynamic flow duct for the fan airflow
The thrust reverser is used to change the direction of the fan air flow forward to get a reverse thrust.
General Exhaust SystemEach half thrust reverser cowl rotates at the 12 o'clock hinges to give access to the engine core area during maintenance and servicing operations
2. System Description
A. Description
(1) It is a conventional cascade thrust reverser type and consists of:
- Fixed structure which provides support for cascades and actuation system,
- Translating cowl with blocker doors and link arms.
(2) The two halves make the duct around the engine and are mechanically latched together at 6 o'clock.
(3) Thrust reverser modes:
- In direct mode, the translating cowl assembly is in stow position, the thrust reverser gives the aerodynamic flow path for the engine fan airflow to add the engine thrust generation.
- In reverser mode, the translating cowl assembly is in deployed position. The thrust reverser redirects the engine fan air flow in the forward direction. The blocker doors blocks the engine fan airflow and directs it through the cascades in forward direction, to generate a reverse thrust. This mode is used during the landing of the aircraft to decrease the aircraft speed and this operation is commanded from the cockpit.
(4) The thrust reverser is stowed and deployed by a hydraulic thrust reverser actuation system. In direct mode the thrust reverser is locked by mechanical means inside the actuators, named primary lock system, secured by an electrical tertiary lock system.
(5) The thrust reverser can be inhibited for flight, in this case the thrust reverser hydraulic actuation is deactivated and a mechanical inhibition pin is installed to block the translation.
(6) The technology used to manufacture the thrust reverser panels permits to reduce the engine noise.
3. Component Location
A. General Dimensions
| Parameters | Values |
|---|---|
| Length | 2600 mm (102.36 in.) |
| Height | 2500 mm (98.43 in.) |
| Width (Fwd) | 1300 mm (51.18 in.) |
| Weight | 260 kg (573.20 lb) left hand side and 250 kg (551.16 lb) right hand side |
B. Thrust Reverser (T/R) Unit
The T/R unit consists of:
The T/R unit consists of:
- Fixed structure
- Translating structure
- Thrust Reverser Actuation System (TRAS)
- Tertiary lock system
- Latches
- Hold Open Rod (HOR) and Cowl Opening System (COS).
(1) Fixed Structure:
The main functions of the fixed structure are to:
The main functions of the fixed structure are to:
- Provide the inner wall of the engine fan airflow duct
- To support load in reverse mode and direct mode
- To guide and to link the translating structure.
- Outer fixed structure assembly
- Inner Fixed Structure (IFS) assembly.
(a) Outer fixed structure assembly:
The specific functions of the outer fixed structure are to:
The specific functions of the outer fixed structure are to:
- Link the thrust reverser to the engine
- Support the actuation system
- Make sure the transcowl position (stow and deploy).
- Forward frame
- Aft frame
- Cascades
- 12 o'clock secondary track
- Slat clearance panels.
(b) IFS assembly:
The specific functions of the IFS are to:
The specific functions of the IFS are to:
- Link the thrust reverser with the pylon
- Provide the inner wall of the engine fan airflow duct
- Enclose the engine core with thermal and fire constraint
- Provide pre-cooler scoop
- Provide system to let the cowl opening for the engine core maintenance.
- Upper structure, including 12 o'clock beam with hinges
- Acoustic inner bondment panel, including pre-cooler scoop
- Lower structure, including 6 o'clock beam with latches.
(2) Translating structure:
The specific functions of the translating structure are to:
The specific functions of the translating structure are to:
- Provide the outer wall of the engine fan airflow duct
- Provide the outer surface of the thrust reverser cowl
- Support load in direct mode and reverse mode
- Give the reverse thrust by sliding in the slider of the fixed structure and by pivoting the blocker door system.
- Acoustic outer bondment panel with primary tracks
- Outer skin with secondary tracks
- Blocker doors with acoustic treatment
- Link arms
- Transcowl latches (Latch-L4.1 and Latch-L4.2)
- Pressure seals.
(3) Latches and keepers:
The functions of the latches and keepers are to close and keep the thrust reverser halves together.
The latches and keepers consist of:
On the left thrust reverser structure:
The functions of the latches and keepers are to close and keep the thrust reverser halves together.
The latches and keepers consist of:
On the left thrust reverser structure:
- One keeper-L1
- One keeper-L2
- One keeper-L3.1
- One keeper-L3.2
- One keeper-L4.1, on the transcowl
- One keeper-L4.2, on the transcowl
- One keeper-LACC.1
- One keeper-LACC.2.
- One latch-L1
- One latch-L2
- One latch-L3.1
- One latch-L3.2
- One latch-L4.1, on the transcowl
- One latch-L4.2, on the transcowl
- One latch-LACC.1
- One latch-LACC.2.
4. Operation
(1) During aircraft flight, the thrust reverser cowl is closed and the transcowl is stowed. The thrust reverser ducts the engine fan air flow to the aft of the nacelle to provide the thrust.
(2) During aircraft landing the thrust reverser transcowl is operated by the hydraulic thrust reverser actuation system, (Ref. AMM D/O 78-31-00-00). The thrust reverser reverses the engine fan air flow to the front of the nacelle to give the reverse thrust to slow the aircraft.
B. Operation of the Thrust Reverser During Maintenance
(1) To do the engine maintenance, the thrust reverser cowls have to be opened and closed with the cowl opening system (Ref. AMM D/O 78-36-00-00).
(a) To open the cowl, the mechanics have to:
- Deactivate the TRAS for maintenance.
- Open the latch access doors and then the latches located in the 6 o'clock area in the specified sequence.
- Connect the Ground Support Equipment (GSE) pump to the actuator of the COS.
- Actuate the GSE pump to open the cowl.
- Connect the HOR on the specified fitting on the engine.
- Continue to open the cowl until the HOR is locked.
- Release the pressure in the GSE pump to load the HOR.
(b) To close the cowl, the mechanics have to:
- Connect the GSE pump to the actuator of the COS.
- Actuate the GSE pump to release the load in the HOR.
- Unlock the HOR.
- Release the pressure in the GSE pump to close the thrust reverser cowls.
- Disconnect the HOR from the dedicated fitting on the engine to store it on the thrust reverser forward frame.
- Continue to release the pressure in the GSE pump until the thrust reverser cowl is closed.
- Latch the latches at the 6 o'clock area in the specified sequence and close the latch access doors.
- Activate the TRAS after maintenance.
(2) To perform the thrust reverser maintenance deploy or stow the transcowl manually. The thrust reverser is equipped with two Manual Drive Units (MDU) one on each lower actuator:
(a) To manually deploy the transcowl, the mechanics have to:
- Deactivate the TRAS for maintenance.
- Open the aft latch access door and deactivate the tertiary lock system.
- Unlock the primary lock system on each upper actuator.
- Access the MDU in 6 o'clock area on the forward frame and connect a speeder handle or an electrical device to deploy.
- Safety the transcowl with the manual locking device installed on the right lower actuator.
(b) To manually stow the transcowl, the mechanics have to:
- Disengage the manual locking device on the right lower actuator to release the transcowl,
- Access the MDU in 6 o'clock area on the forward frame and connect a speeder handle or an electrical device to stow the transcowl,
- Check that each primary lock system is locked on the upper actuator, if not use the opposite MDU to lock the second primary lock system,
- Activate the tertiary lock system and close the aft latch access door,
- Activate the TRAS after maintenance.
C. For Flight Dispatching
The T/R or the tertiary lock can be inhibited for the flight dispatching.
The T/R or the tertiary lock can be inhibited for the flight dispatching.
(1) To do the inhibition of the thrust Reverser, the mechanics have to:
- Open the left hand side fan cowl door.
- get access to the LHS front top area to deactivate the TRAS for flight and change the inhibition control unit to inhibited position.
- Get access to the 9 o'clock thrust reverser forward frame to remove the mechanical inhibition pin from its storage bracket.
- Get access to the aft lower fixed structure left hand side 6 o'clock beam, inside the secondary duct, to remove the inhibition pin access plate, to install the pin in the dedicated inhibition hole and to reinstall the inhibition pin access plate.
(2) To do the inhibition of the TLS, the mechanics have to :
- Get access to the 6 o'clock structure to open the aft latch access panel.
- Move the lever to the inhibited position of the tertiary lock system.
- Close the aft latch access panel.