section 15 thrust reverser

© International Aero Engines Inc 2000

NacelleNacelle

Thrust Reverser Unit (T.R.U.)Purpose:

Provide decceleration forces to slow the aircraft

during landing or abandoned take-off. It is incorporated in the ‘C’ ducts and forms an

integral part of the fan stream exhaust duct. Comprises of a fixed inner and moveable outer

(translating) assembly.


NacelleNacelle

Thrust Reverser Unit (T.R.U.) (Continued).Controls: Selection of reverse thrust, and control of engine

power is achieved by the ‘gated’ thrust lever. All signals to and from the T.R.U. are through the

Engine Interface Unit (E.I.U.)


NacelleNacelle

Thrust Reverser Unit (T.R.U.) (Continued).Features: Electrical control. Hydraulic actuation system. Positional information feedback. Actuator lock position sensors and feedback. Automatic restow system. Manual ‘deployment’ - ‘stow’ for maintenance. Manual lock-out - to allow aircraft to be

despatched with inoperative thrust reverser.


Cascade

Stowed - Forward ThrustStowed - Forward Thrust

Deployed - Reverse ThrustDeployed - Reverse Thrust



NacelleNacelleThrust Reverser

Controls and Indication: Selection and control of engine power in

reverse thrust, is by the normal thrust lever. When latch levers on the thrust lever are

lifted, the thrust lever is permitted to move rearwards approximately 12 degrees.



Controls and Indication (Continued): Thrust reverser begins to deploy. Engine power commanded to ‘idle’. When reverser has deployed to approximately

78% the EEC commands the engine to accelerate to the thrust levers selected power level.

Thrust reverser continues to deploy to fully deployed position


NacelleNacelleThrust Reverser No indication

- Reverser is fully stowed and locks are fully engaged.

Amber ‘REV’‘REV’

- Both locks are disengaged and the reverser is between fully stowed and fully deployed.

Green ‘REV’‘REV’

- Fully deployed.


0.9EPR

1.2 1.4 1.6

0.9

1.2

1.4

1.6

THRUST REVERSER

LATCHING LEVERS

THRUST CONTROL LEVERS

UPPER ECAM DISPLAY


REV REV

1.2 1.41.6

1.21.4

1.6

EPR

THRUST REVERSER

LATCHING LEVERS


UPPER ECAM DISPLAY


1.2 1.41.6

1.21.4

1.6

EPRREV REV

THRUST REVERSER

LATCHING LEVERS


UPPER ECAM DISPLAY



Hydraulic Actuation System

Purpose:

To provide the force required to move the translating cowl during thrust reverser operations.




Features: 2 linear hydraulic actuators

(Each translating cowl). One of the actuators is a non-locking type,

that incorporates a Linear Variable Differential Transducer (LVDT) to provide -

Positional feedback signals to the EEC.


NacelleNacelle

Thrust ReverserHydraulic Actuation System

Features: (Continued). One locking actuator includes a mechanism to hold

the reverser in the stowed position. The actuator includes a sensor which signals lock

position to the EEC. A Hydraulic Control Unit which incorporates an

isolation valve and a directional control valve (DCV) and a pressure switch.




Features: (Continued). Flexible hose assemblies link the upper two

actuators and incorporate the hydraulic feed connectors.

Rigid hydraulic tubes which link the upper and lower actuators.

Synchronisation system uses a flexible drive cable running inside the deploy supply tube.




Features: (Continued).

Manual drive system, (which uses the synchronising cables), to stow/deploy the translating cowl for maintenance operations


Supply

Filter

Hydraulic IsolationValve (HIV)

Return

Direction ControlValve (DCV)

Deactivating Lever

Solenoids

Pressure Switch

Normal Flight

Deploy supply

Stow supply


Supply

Filter

Hydraulic Isolation Valve (HIV)

Return

Directional Control Valve (DCV)

Deactivating Lever

Solenoids

Pressure Switch

Normal Flight

Deploy supply

Stow supply


Supply

Filter


Return


Deactivating Lever

Solenoids

Pressure Switch

Deploy

Stow supply

Deploy supply


Supply

Filter


Return


Deactivating Lever

Solenoids

Pressure Switch

Stow selection

Stow supply

Deploy supply



Hydraulic Control Unit (HCU)

Description: Self contained LRU providing safe control of the

thrust reverser actuators in response to signals from either channel of the EEC.

Comprises : An Isolation Valve, which can be mechanically

latched in the closed position during maintenance.



(HCU) - Description (Continued): A Direction Control Valve to port hydraulic

pressure to the actuators in response to stow or deploy commands.

A Pressure Switch to detect system pressurisation downstream of the Isolation Valve.



(HCU) - Description (Continued): 2 Dual-Coil Solenoid Valves to control the

operation of the Isolation and Direction Control Valves by electrical signals from either channel of the EEC.

A filter with a ‘clogging’ indicator. A ‘Bleed’ valve.



Hydraulic Control Unit (HCU)

Location: Bolted to the bottom of the engine pylon in

the Fan Case area. Access is gained by opening the left Fan

Cowl door.


Thrust Reverser Hydraulic Control Unit (HCU) location.



Manual Deploy/Stow: The reverser may be deployed or stowed

manually for maintenance - trouble shooting operations.

In order to carry out this operation ‘SAFELY’ the procedure contained in the maintenance manual MUST be followed.


Supply

Filter


Return


Deactivating Lever

Solenoids

Pressure Switch

Thrust Reverse ‘Deactivated’

Quick release pin fitted



Manual Deploy: During manual deploy operations it is

necessary to draw hydraulic fluid from the aircraft system.

This is accomplished by moving the non return valve by-pass lever, located in the hydraulic return line, to the by-pass position.


Oil return from HCU

Thrust Reverse Manual Deploy - Non Return Valve (Normal)

Location


Oil return to HCU

Thrust Reverse Manual Deploy - Non Return Valve (By-pass)

Oil return from Hydraulic Reservoir

Location



Manual Deploy: On completion of the manual deploy

operation the by-pass valve must be returned te ‘normal’ position and the access panel replaced.

A ‘baulking’ feature prevents panel replacement with the by-pass lever in the by-pass position.


Oil return to HCU

Thrust Reverse Manual Deploy - Non Return Valve (By-pass)

Oil return from Hydraulic Reservoir

Location


Oil return from HCU

Thrust Reverse Manual Deploy - Non Return Valve (Normal)

Location


Tinelock ‘Engaged’


Tinelock ‘Dis-engaged’


Ready for manual deployment


Note!


Actuator Body

Flexible Drive Shaft

Deploy Tube

Stow Tube

Wormwheel

Blanking PlugPiston

Spring

Ball Bearing

Spring

Housing Assembly

Input Shaft

Needle Bearing

Universal Joint Assembly

Guides

Pin

Body

Nut



De-activation: An inoperative thrust reverser may be

locked in the forward thrust position for flight.

2 Lock pins are used, one each for both translating cowls.



De-activation: The pins are stowed on each of their

respective cowls, and when stowed correctly they are ‘flush’ with the outer fairing skin of the Translating Cowl.

When inserted into the ‘lock’ position the pins protrude approximately 0.8 inch/2 cm.


Pin Stowage

Thrust Reverser Lockout pin stowage


Cascades

Translating Cowl Inner Sleeve ‘Stowed’ condition

Lockout Pin


CascadesLockout Pin ‘Fitted’

Translating Cowl Inner Sleeve ‘Stowed’ condition



Locking Actuator ‘Stow Mode’

Tinelock

Unlock Sleeve

Piston



Lock Sleeve

Tinelock

Piston Assembly

Lock sleeve holding Tinelock compressed, thereby preventing Piston Assembly from moving from ‘Stowed’ Position.



Lock Sleeve

Piston Assembly

Tinelock

Hydraulic pressure pushes the lock sleeve holding tinelocks to the rear.



Lock Sleeve

Piston Assembly

Tinelock

Tinelocks disengage from holding piston.



Lock Sleeve

Piston Assembly

Tinelock

Piston assembly moves under hydraulic pressure to the deployed position



Lock Sleeve

Piston Assembly

Tinelock

Actuator stowed, tinelocks engage piston and lock sleeve holds it in the locked condition (mechanically)



Deployed

Stowed

section 15 thrust reverser

Education

thrust levers

thrust reverser operations

inoperative thrust reverser

selection of reverse

gated thrust lever

normal thrust lever

indication reverser

control of engine power