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FED 801-815[PW 4152] THRUST REVERSER SYSTEM CONTROL - DESCRIPTION AND OPERATION

1. Thrust Reverser System Controls

A. General

FED 801-802,805-806,808-815The thrust reverser is controlled by a separate lever installedon theengine throttle control lever (Ref. Fig. 001 ) . The followingparticular safety features are provided :

FED 803-804,807The thrust reverser is controlled by a separate lever installedon theengine throttle control lever (Ref. Fig. 002 ) . The followingparticular safety features are provided :

FED 801-815

- To avoid inadvertent thrust reverser deployment when inforward thrust, the mechanical design of the throttlecontrol lever prevents actuation of the thrust reverserlever to the deploy position when the throttle control leveris not in idle position.

- To facilite reverse operation, a mechanical friction point isintroduced in the reverse control lever mechanism. Thisindicates to the crew that the idle threshold is reached.This threshold must be overriden to increase reverse thrustby moving the thrust reverser lever.

2. Component Location(Ref. Fig. 003,004,005 )

FIN FUNCTIONAL DESIGNATION PANEL ZONE ACCESS

DOOR

ATA

REF.

S304

H9

H15

S301

DRIVE UNIT - PNEUMATIC

VALVE - PRESSURE REGULATING

AND SHUT OFF

VALVE SELECTOR, SOLENOID OPERATED

ACTUATOR - MASTER AND SLAVE

STOW/DEPLOY RVDT SWITCHES (RH)

435

445

436

446

435

445

453

463

453

435AL

445AL

436AR

446AR

435AL

445AL

451AL

461AL

451AL

(Ref.78-31-01 )

(Ref.78-31-05 )

(Ref.78-31-10 )

A310-300 AMM - THRUST REVERSER SYSTEMCONTROL - DESCRIPTION AND OPERATIONRevision 18.1

P.Blk EFFECTIVITY: FED 801-815 78-31-00-00Printed - Date: 12/06/12 Time:Copyright © 12 FedEx Express Corporation, Memphis TN, 38194, All rights reserved.

of 57DEC 01/2005


DOOR

ATA

REF.

S307

STOW/DEPLOY RVDT SWITCHES (LH)

CRANK ARM - FEEDBACK

PNEUMATIC VALVE - GROUND

OPERATING AIR TRANSFER

DUCTS - SUPPLY, PDU

GEARBOX - SPLITTER

PNEUMATIC HOSE - THRUST

REVERSER

FLEXIBLE SHAFT ASSEMBLIES

THRUST REVERSER

SENSOR TUBES - THRUST REVERSER

463

454

464

453

463

436

446

435

445

435

445

435

445

453

463

435

445

453

463

461AL

452AR

462AR

451AL

461AL

436AR

446AR

435AL

445AL

435AL

445AL

435AL

445AL

451AL

461AL

435AL

445AL

451AL

461AL

(Ref.78-31-15 )

(Ref.78-31-40 )

(Ref.78-31-40 )

(Ref. AMM78-31-21)

(Ref.78-31-33 )

(Ref.78-31-34 )

(Ref.78-31-35 )

(Ref. AMM78-31-57)

(Ref.78-31-12 )

(Ref.78-31-36 )

FED 801-815POST SB 78-2019 for A/C 801-815

- To avoid inadvertent thrustreverser deployment when inforward thrust,

- the mechanical design of thethrottle control lever preventsactuation of

- the thrust reverser lever to thedeploy position when the throttle



of 57DEC 01/2005


DOOR

ATA

REF.

- control lever is not in idleposition.

- To facilite reverse operation, amechanical friction point isintroduced

- in the reverse control levermechanism. This indicates to thecrew that

- the idle threshold is reached.This threshold must be overridento increase

- reverse thrust by moving thethrust reverser lever.

2. Component Location(Ref. Fig. 003,004,006 )


DOOR

ATA

REF.

S304

H9

H15

S301

S307

DRIVE UNIT - PNEUMATIC

VALVE - PRESSURE REGULATING

AND SHUT OFF

VALVE SELECTOR, SOLENOID OPERATED

ACTUATOR - MASTER AND SLAVE

STOW/DEPLOY RVDT SWITCHES (RH)

STOW/DEPLOY RVDT SWITCHES (LH)

CRANK ARM - FEEDBACK

PNEUMATIC VALVE - GROUND

OPERATING AIR TRANSFER

DUCTS - SUPPLY, PDU

435

445

436

446

435

445

453

463

453

463

454

464

453

463

436

446

435

445

435AL

445AL

436AR

446AR

435AL

445AL

451AL

461AL

451AL

461AL

452AR

462AR

451AL

461AL

436AR

446AR

435AL

445AL

(Ref. 78-31-01 )

(Ref. 78-31-05 )

(Ref. 78-31-10 )

(Ref. 78-31-15 )

(Ref. 78-31-40 )

(Ref. 78-31-40 )

(Ref. AMM 78-31-21)

(Ref. 78-31-33 )

(Ref. 78-31-34 )



of 57DEC 01/2005


DOOR

ATA

REF.

H16

H17

GEARBOX - SPLITTER

PNEUMATIC HOSE - THRUST

REVERSER

FLEXIBLE SHAFT ASSEMBLIES

THRUST REVERSER

SENSOR TUBES - THRUST REVERSER

LOCK - SYNCHRONOUS SHAFT (RH)

LOCK - SYNCHRONOUS SHAFT (LH)

435

445

435

445

453

463

435

445

453

463

453

463

435AL

445AL

435AL

445AL

451AL

461AL

435AL

445AL

451AL

461AL

451AL

461AL

(Ref. 78-31-35 )

(Ref. AMM 78-31-57)

(Ref. 78-31-12 )

(Ref. 78-31-36 )

FED 801-815

3. Thrust Reverser Actuation System Operation

A. General(Ref. Fig. 007,009,011 )(Ref. Fig. 012,013 )These figures show the detailed scheme of the pneumaticactuation. The system is electrically controlled as describedin paragraph E.

B. Operation(Ref. Fig. 007 )

- To deploy

- To deploy the system, the throttle control lever is moved toidle and reverser control lever is rotated up. An electricaldeploy command is then applied to the latching deploysolenoid valve simultaneously with an electrical signal tothe arming solenoid valve which supplies air to the controlswitcher, shifting it to the open position.

- Inlet air flows through the manual deactivation valve, theopen control switcher, and the reference regulator of thelock actuator of RH master actuator. The safety relief valveprovides downstream component protection in the event of afailure of the reference regulator. If the ballscrew ispositioned within 1/8'' of the fully stowed position, thelock cam permits the lock actuator to stroke. This ports airto the lock actuator of LH master actuator which executes asimilar sequence, supplying air to the arming port of the



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pressure regulator and shutoff valve. The orifice checkvalve opens and air flows into the opening chamber of thevalve actuator. As the butterfly opens, the sensing portdirects regulated pressure to the feedback chamber of thevalve actuator.

- The resulting equilibrium regulates the supply air pressureto the pneumatic drive unit.

- Regulated air flows through the latching deploy solenoidvalve and shifts the electrical selector valve to the deployposition. This ports air to the deploy port of the pneumaticdrive unit and shifts the directional valve actuator to thedeploy mode. This strokes the feedback cam to the right ofboth the stow and deploy dump valves. With both dump valvesseated, the brake dump valve seats and regulated air flowsinto the brake actuator and the brake releases. Thedirectional valve, which had been rotated to the wide-opendeploy position by the directional valve actuator, directsair to the air motor to accelerate it in the deploydirection of rotation.

- The system of flexshafts, gearboxes, and ballscrewstranslates the thrust reverser sleeve toward the deployposition. The feedback screw in the pneumatic drive unitrotates in relation to the air motor and translates thefeedback nut until it contacts the feedback mechanism andstrokes it to the null position. This progressively closesthe directional valve, which causes the air motor todecelerate, and also strokes the feedback cam into contactwith the deploy dump valve poppet which is stroked and ventsthe brake dump valve, which opens and rapidly vents thebrake actuator. This applies the brake, which completesdeceleration of the system to an accurate stop in the deployposition. The feedback modules, located on the masteractuators, provide electrical position inputs to theairframe which indicate that both sleeves of the reverserare deployed and ready for application of reverse power. Thefeedback module also includes a deploy limit switch toprovide flight compartment indication that the reverser isin the deploy position.

- To stow (Ref. Fig. 009 )

- To stow the system, the reverser control lever is rotateddown into the forward thrust position. An electrical stowcommand is then applied to the latching deploy solenoidvalve which directs regulated air to shift the electricalselector valve to the stow position. Regulated air isdirected to the stow port of the pneumatic drive unit andshifts the directional valve actuator to the stow mode. Thisstrokes the feedback cam to the left of the stow and deploy



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dump valves and allows them to seat. The brake dump valveseats and air pressurizes the brake actuator which strokesto release the brake.

- The directional valve, which had been rotated to the wide-open stow position by the directional valve actuator, admitsair to the air motor to accelerate it in the stow directionof rotation to translate the system toward stow. When thefeedback nut contacts the feedback mechanism, it strokes ittoward the null position, which progressively closes thedirectional valve. The air motor decelerates and slows thesystem until stow contact is made.

- Electrical power is removed from the arming solenoid valve,which closes and vents the control switcher. RH, and thenthe LH, lock actuator return to the at-rest position,venting the arming port of the pressure regulator andshutoff valve. The orifice check valve seats, providing aslow closure of the valve and a resultant slow decay of theregulated pressure. A slot included in the contour of thedirectional valve causes the air motor to develop a residualstall torque in the stow direction when the directionalvalve is in the stow null position.

- This allows the pneumatic drive unit to apply a residualstowing torque to the flexshafts to assure stow stopcontact. As the inlet pressure slowly decays, the brake dumpvalve rapidly vents the brake actuator, which applies thebrake before the motor inlet pressure is removed, lockingthis residual torque into the flexshafts.

- The feedback module stow switches provide cockpit indicationthat the reverser is fully stowed and remove the electricalpower from the arming solenoid. The feedback module alsoprovides a dual proportional electrical feedback signal tothe electronic engine controller from an integral RVDT unit.Additional features of the actuation system include thefollowing.

- Electrical switches indicate unlock of the lock actuators inthe master actuators, and also brake release in thepneumatic drive unit. The stow dump valve is positioned sothat it is not contacted during a normal stow cycle with thepneumatic drive unit rigged into the system. However, it isprovided for use during bench calibration of the pneumaticdrive when an accurate stop is required in the stow positionto provide a repeatable basis for the rev count.

- The manual deactivation valve serves to de-activate thesystem by both manually closing the butterfly in thepressure regulator and shutoff valve and removing the sourceof control air upstream of the control switcher.



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3.FED 801-815POST SB 78-2019 for A/C 801-815

Thrust Reverser Actuation System Operation

A. General(Ref. Fig. 008,010,011 )(Ref. Fig. 012,013 )These figures show the detailed scheme of the pneumaticactuation. The system is electrically controlled as describedin paragraph E.

B. Operation(Ref. Fig. 001,008 )

- To deploy

- To deploy the system, the throttle control lever is moved toidle and reverser control lever is rotated up. An electricaldeploy command is then applied to the latching deploysolenoid valve simultaneously with an electrical signal torelay 46KM (47KM), which supplies both synchronous shaftlock solenoids and relay 48KM (49KM) coil. After 250 ms,relay 48KM (49KM) closes and an electrical signal is sent tothe arming solenoid valve which supplies air to the controlswitcher, shifting it to the open position.

- Inlet air flows through the manual deactivation valve, theopen control switcher, and the reference regulator of thelock actuator of RH master actuator. The safety relief valveprovides downstream component protection in the event of afailure of the reference regulator. If the ballscrew ispositioned within 1/8'' of the fully stowed position, thelock cam permits the lock actuator to stroke. This ports airto the lock actuator of LH master actuator which executes asimilar sequence, supplying air to the arming port of thepressure regulator and shutoff valve. The orifice checkvalve opens and air flows into the opening chamber of thevalve actuator. As the butterfly opens, the sensing portdirects regulated pressure to the feedback chamber of thevalve actuator.

- The resulting equilibrium regulates the supply air pressureto the pneumatic drive unit.

- Regulated air flows through the latching deploy solenoidvalve and shifts the electrical selector valve to the deployposition. This ports air to the deploy port of the pneumaticdrive unit and shifts the directional valve actuator to thedeploy mode. This strokes the feedback cam to the right ofboth the stow and deploy dump valves. With both dump valvesseated, the brake dump valve seats and regulated air flows



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into the brake actuator and the brake releases. Thedirectional valve, which had been rotated to the wide-opendeploy position by the directional valve actuator, directsair to the air motor to accelerate it in the deploydirection of rotation.

- The system of flexshafts released by the synchronous shaftlocks, gearboxes, and ballscrews translates the thrustreverser sleeve toward the deploy position. The feedbackscrew in the pneumatic drive unit rotates in relation to theair motor and translates the feedback nut until it contactsthe feedback mechanism and strokes it to the null position.

- This progressively closes the directional valve, which causesthe air motor to decelerate, and also strokes the feedbackcam into contact with the deploy dump valve poppet which isstroked and vents the brake dump valve, which opens andrapidly vents the brake actuator.

- This applies the brake, which completes deceleration of thesystem to an accurate stop in the deploy position. Thefeedback modules, located on the master actuators, provideelectrical position inputs to the airframe which indicatethat both sleeves of the reverser are deployed and ready forapplication of reverse power. The feedback module alsoincludes a deploy limit switch to provide flight compartmentindication that the reverser is in the deploy position.

- To stow (Ref. Fig. 010 )

- To stow the system, the reverser control lever is rotateddown into the forward thrust position. An electrical stowcommand is then applied to the latching deploy solenoidvalve which directs regulated air to shift the electricalselector valve to the stow position. Regulated air isdirected to the stow port of the pneumatic drive unit andshifts the directional valve actuator to the stow mode. Thisstrokes the feedback cam to the left of the stow and deploydump valves and allows them to seat. The brake dump valveseats and air pressurizes the brake actuator which strokesto release the brake.

- The directional valve, which had been rotated to the wide-open stow position by the directional valve actuator, admitsair to the air motor to accelerate it in the stow directionof rotation to translate the system toward stow. When thefeedback nut contacts the feedback mechanism, it strokes ittoward the null position, which progressively closes thedirectional valve. The air motor decelerates and slows thesystem until stow contact is made.

- Electrical power is removed from the arming solenoid valve,which closes and vents the control switcher. RH, and then



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the LH, lock actuator return to the at-rest position,venting the arming port of the pressure regulator andshutoff valve. The orifice check valve seats, providing aslow closure of the valve and a resultant slow decay of theregulated pressure. A slot included in the contour of thedirectional valve causes the air motor to develop a residualstall torque in the stow direction when the directionalvalve is in the stow null position.

- This allows the pneumatic drive unit to apply a residualstowing torque to the flexshafts to assure stow stopcontact. As the inlet pressure slowly decays, the brake dumpvalve rapidly vents the brake actuator, which applies thebrake before the motor inlet pressure is removed, lockingthis residual torque into the flexshafts.

- The feedback module stow switches provide cockpit indicationthat the reverser is fully stowed and remove the electricalpower from the arming solenoid. The feedback module alsoprovides a dual proportional electrical feedback signal tothe electronic engine controller from an integral RVDT unit.Ten seconds after a stow command, the synchronous shaft locksolenoids are de-energized (opening of relay 46KM (47KM)),the armature is released and the pins re-engage, whichprevents triangular rotor plate from rotating. Additionalfeatures of the actuation system include the following.

- Electrical switches indicate unlock of the lock actuators inthe master actuators, and also brake release in thepneumatic drive unit. The stow dump valve is positioned sothat it is not contacted during a normal stow cycle with thepneumatic drive unit rigged into the system. However, it isprovided for use during bench calibration of the pneumaticdrive when an accurate stop is required in the stow positionto provide a repeatable basis for the rev count.

- The manual deactivation valve serves to de-activate thesystem by both manually closing the butterfly in thepressure regulator and shutoff valve and removing the sourceof control air upstream of the control switcher.

FED 801-815

C. Safety FeaturesIf for any reason a thrust reverser sleeve leaves the stowedposition in flight, the sleeve stow switch will close. In thiscondition, the arming solenoid and stow solenoid will beenergized resulting in automatic actuation to the stowedposition.In flight malfunction of the thrust reverser system will onlyoccur due to equipment failure or to reception of an improperdeploy command signal in conjunction with an arming signal.



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Equipment FailureIn the event of an air motor, splitter gearbox, masteractuator, or flexshaft failure, the secondary locking featurebuilt into the master actuators is designed to limit reversersleeve driftback and preclude subsequent reverser deployment.Should the master actuator ballscrew move 1/8-inch out of thelocking cam within the master actuator, the secondary lockingmechanism automatically begins latching to prevent release ofthe secondary lock. Latching is complete at 1/2-inch of sleevedriftback travel at which time further system movement isprevented.Although the aircraft reverser control system is designed toprevent receipt of an inadvertent in flight deploy command, acombination of multiple failures could result in reversersystem deployment. An inadvertent reverser deployment inflightwill be apparent by observation of appropriate reverser unlocklight, and subsequent reverser deployment signals. In addition,the power for the affected engine would be returned to idle.Reverser in flight stow procedures under these circumstancesare similar to those for landing stow operation of thereverser.

D. Thrust Reverser System Electrical Supply

FED 801-815POST SB 78-2019 for A/C 801-815

C. Safety FeaturesIf for any reason a thrust reverser sleeve leaves the stowedposition in flight, the sleeve stow switch will close. In thiscondition, both synchronous shaft locks keep thrust reverser instow position. In addition the arming solenoid and stowsolenoid will be energized resulting in automatic actuation tothe stowed position.In flight malfunction of the thrust reverser system will onlyoccur due to equipment failure or to reception of an improperdeploy signal supplying synchronous shaft locks and selectorvalve deploy solenoid and removing power supply from selectorvalve stow solenoid in conjunction with an arming signal.Equipment FailureIn the event of an air motor, splitter gearbox, masteractuator, or main flexshaft failure, the transcowl driftback isprecluded by engagement (inside synchronous shaft lock) oftriangular rotor plate with either of the two pins. Thisprevents master actuator input shaft and ball screw fromrotating and sleeve from deploying.

NOTE : Each synchronous shaft lock is capable on its own ofretaining both sleeves in the fully stowed positionagainst deployment loads.



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In case of synchronous shaft lock failure, to lock thesecondary locking feature built into the master actuators isdesigned to limit reverser sleeve driftback and precludesubsequent reverser deployment.Should the master actuator ballscrew move 1/8-inch out of thelocking cam within the master actuator, the secondary lockingmechanism automatically begins latching to prevent release ofthe secondary lock. Latching is complete at 1/2-inch of sleevedriftback travel at which time further system movement isprevented.Although the aircraft reverser control system is designed toprevent receipt of an inadvertent in flight deploy command, acombination of multiple failures could result in reversersystem deployment. An inadvertent reverser deployment inflightwill be apparent by observation of appropriate reverser unlocklight, and subsequent reverser deployment signals. In addition,the power for the affected engine would be returned to idle.Reverser in flight stow procedures under these circumstancesare similar to those for landing stow operation of thereverser.

D. Thrust Reverser System Electrical Supply

FED 801-815The reverser system supply within the general electrical systemsupply isdetailed in (Ref. Fig. 016 ) .

FED 801-815POST SB 78-2019 for A/C 801-815

The reverser system supply within the general electrical systemsupply isdetailed in (Ref. Fig. 017 ) .

FED 801-815The location of the relevant circuit breakers on the circuitbreaker panelis shown in (Ref. Fig. 014 ) .

FED 801-815POST SB 78-2019 for A/C 801-815

The location of the relevant circuit breakers on the circuitbreaker panelis shown in (Ref. Fig. 015 ) .

FED 801-815

E. Electrical Control (described for engine 2)(Ref. Fig. 018,021 )



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(1) DeploymentA command to deploy the thrust reverser closes the switch(14KM) which allows energization of the arming solenoidprovided the main gear squat switch (16GB) is pressed(ground condition).At the same time a second switch (8KM) is activated bythe same command to energize the deploy solenoid. This ispossible only with the other main gear squat switch(13GB) closed.When the sleeves are out of the stowed position, stowswitches close and REV UNLK amber warning comes on.The deploy switches remain in the stowed position whilethe reverser is deploying. When the reverser is nearlyfully deployed, the deploy switches are tripped, the REVUNLK amber warning light goes off and REV green lightcomes on.

(2) StowageWhen the commanded switches (14KM and 8KM) are in thestow position after a stow order and when switch (16KM)is closed, the arming solenoid and the stow solenoid areenergized.The thrust reverser is actuated to the stowed position,with REV UNLK illuminated. When the sleeves reach thestowed position, sleeve stow switches open, this de-energizes the arming solenoid allowing the brake andlocks of the actuation system to become operative.If for any reason a thrust reverser sleeve leaves thestowed position in flight, the stow switch (S301 for RHsleeve or S307 for LH sleeve) closes. In this condition,the arming solenoid will be energized together with thestow solenoid by the corresponding relay and switch. Thethrust reverser will be actuated to the stowed position.

(3) LockingTwo separate locking provisions are provided within thethrust reverser system. The primary means of holding thesystem stowed is provided by a brake in the pneumaticdrive unit. Normally, it is spring-loaded in the brakeapplied position, preventing air motor rotation andresulting reverser translation. The brake is also appliedto secure the system once the fully deployed position isreached. To release the brake, pressurization of therelease chamber is required.A system secondary locking feature is incorporated intoeach reverser master actuator. The master actuator locksfunction only in the reverser stowed position, guardingagainst reverser sleeve driftback in the event of an air



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motor, splitter gearbox, master actuator or flexshaftfailure.During normal thrust reverse operation, the locks arereleased by pressurizing the lock actuator chambers.The thrust reverser master actuators contain crankingprovisions to allow manual translation of the reversersleeves. In order to accomplish this, the pneumatic driveunit primary brake and both of the master actuatorsecondary system locks must be manually released and heldto allow sleeve movement.

FED 801-804,806-811POST SB 78-2019 for A/C 801-804,806-811


(1) DeploymentA command to deploy (reverse throttle lever in the RevIdle position) the thrust reverser closes the switch(14KM) which after 250 ms (time necessary for time delayrelay 48KM (49KM) to close), allows energization of thearming solenoid provided the main gear squat switch(16GB) is pressed (ground condition).At the same time a second switch (8KM) is activated bythe same reverse throttle command to energize the deploysolenoid and to supply the synchronous shaft locksolenoids to unlock the locks. This is possible only withthe other main gear squat switches (13GB) and (19GB)closed.When the sleeves are out of the stowed position, stowswitches close and REV UNLK amber warning comes on.The deploy switches remain in the stowed position whilethe reverser is deploying. When the reverser is nearlyfully deployed, the deploy switches are tripped, the REVUNLK amber warning light goes off and REV green lightcomes on.As protection against a maintenance fault (rod/armincorrect installation) the throttle control lever of theother engine has to be in a position below 22 degrees tocut off power supply to selector valve stow solenoid.

(2) StowageWhen the commanded switches (14KM and 8KM) are in thestow position after a stow order and when switch (16KM)is closed, the arming solenoid and the stow solenoid areenergized.The thrust reverser is actuated to the stowed position,with REV UNLK illuminated. When the sleeves reach thestowed position, sleeve stow switches open ; this de-



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energizes the arming solenoid allowing the brake andlocks of the actuation system to become operative. Tenseconds after the stow command, the synchronous shaftlocks lock again.If for any reason a thrust reverser sleeve leaves thestowed position in flight, the stow switch (S301 for RHsleeve or S307 for LH sleeve) closes. In this condition,the arming solenoid will be energized together with thestow solenoid by the corresponding relay and switch. Thethrust reverser will be actuated to the stowed position.

(3) LockingThree separate locking provisions are provided within thethrust reverser system. The primary means of holding thesystem stowed is provided by a brake in the pneumaticdrive unit. Normally, it is spring-loaded in the brakeapplied position, preventing air motor rotation andresulting reverser translation. The brake is also appliedto secure the system once the fully deployed position isreached. To release the brake, pressurization of therelease chamber is required.A system secondary locking feature is incorporated intoeach reverser master actuator. The master actuator locksfunction only in the reverser stowed position, guardingagainst reverser sleeve driftback in the event of failureof an air motor, splitter gearbox, master actuator,flexshaft or synchronous shaft lock.During normal thrust reverse operation, the locks arereleased by pressurizing the lock actuator chambers.The third locking system consists of two synchronousshaft locks (one lock per sleeve), installed between themaster actuator and lower slave actuator, and connectedto them through flexshafts.The synchronous shaft locks are permanently locked exceptduring crew-commanded thrust reverser use. Upon selectionof reverse thrust, the synchronous shaft locks areenergized by the aircraft thrust reverser control system.The synchronous shaft locks remain energized and unlockedthroughout the entire deploy cycle.The thrust reverser master actuators contain crankingprovisions to allow manual translation of the reversersleeves. In order to accomplish this, the pneumatic driveunit primary brake, both master actuator secondary systemlocks and both synchronous shaft locks must be manuallyreleased and held to allow sleeve movement.

FED 805,812-815POST SB 78-2019 for A/C 805,812-815



of 57DEC 01/2005


(1) DeploymentA command to deploy (reverse throttle lever in the RevIdle position) the thrust reverser closes the switch(14KM) which after 250 ms (time necessary for time delayrelay 48KM (49KM) to close), allows energization of thearming solenoid provided the main gear squat switch(16GB) is pressed (ground condition).At the same time a second switch (8KM) is activated bythe same reverse throttle command to energize the deploysolenoid and to supply the synchronous shaft locksolenoids to unlock the locks. This is possible only withthe other main gear squat switch (13GB) and 19GB closed.When the sleeves are out of the stowed position, stowswitches close and REV UNLK amber warning comes on.The deploy switches remain in the stowed position whilethe reverser is deploying. When the reverser is nearlyfully deployed, the deploy switches are tripped, the REVUNLK amber warning light goes off and REV green lightcomes on.As protection against a maintenance fault (rod/armincorrect installation) the throttle control lever of theother engine has to be in a position below 22 ° to cutoff power supply to selector valve stow solenoid.

(2) StowageWhen the commanded switches (14KM and 8KM) are in thestow position after a stow order and when switch (16KM)is closed, the arming solenoid and the stow solenoid areenergized.The thrust reverser is actuated to the stowed position,with REV UNLK illuminated. When the sleeves reach thestowed position, sleeve stow switches open ; this de-energizes the arming solenoid allowing the brake andlocks of the actuation system to become operative. Tenseconds after the stow command, the synchronous shaftlocks lock again.If for any reason a thrust reverser sleeve leaves thestowed position in flight, the stow switch (S301 for RHsleeve or S307 for LH sleeve) closes. If both switches(S301 and S307) close, the arming solenoid will beenergized together with the stow solenoid by thecorresponding relay and switch. The Thrust reverser willbe actuated to the stowed position.

(3) LockingThree separate locking provisions are provided within thethrust reverser system. The primary means of holding the



of 57DEC 01/2005

system stowed is provided by a brake in the pneumaticdrive unit. Normally, it is spring-loaded in the brakeapplied position, preventing air motor rotation andresulting reverser translation. The brake is also appliedto secure the system once the fully deployed position isreached. To release the brake, pressurization of therelease chamber is required.A system secondary locking feature is incorporated intoeach reverser master actuator. The master actuator locksfunction only in the reverser stowed position, guardingagainst reverser sleeve driftback in the event of failureof an air motor, splitter gearbox, master actuator,flexshaft or synchronous shaft lock.During normal thrust reverse operation, the locks arereleased by pressurizing the lock actuator chambers.The third locking system consists of two synchronousshaft locks (one lock per sleeve), installed between themaster actuator and lower slave actuator, and connectedto them through flexshafts.The synchronous shaft locks are permanently locked exceptduring crew-commanded thrust reverser use. Upon selectionof reverse thrust, the synchronous shaft locks areenergized by the aircraft thrust reverser control system.The synchronous shaft locks remain energized and unlockedthroughout the entire deploy cycle.The thrust reverser master actuators contain crankingprovisions to allow manual translation of the reversersleeves. In order to accomplish this, the pneumatic driveunit primary brake, both master actuator secondary systemlocks and both synchronous shaft locks must be manuallyreleased and held to allow sleeve movement.

FED 801-815

F. Indicating(Ref. Fig. 024,025 )Two annunciator lights located in the flight compartmentprovide indication on the thrust reverser configuration. Assoon as any of brake or secondary lock or stow switch is open,the fan reverser configuration is indicated by REV UNLK warninglight illumination. The above warning is replaced byillumination of REV indicator light showing that the thrustreverser is fully deployed as soon as deploy switch is open. Noindication is on when the translating sleeve is fully stowed.In addition, the signal sent from the FADEC to the ECAM systemprovidesindication of the sleeves position on the CRT (Ref. Fig.026 ) .

FED 801-815



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POST SB 78-2019 for A/C 801-815

F. Indicating(Ref. Fig. 024,025 )Two annunciator lights located in the flight compartmentprovide indication on the thrust reverser configuration. Assoon as any of brake or secondary lock or stow switch is open,the fan reverser configuration is indicated by REV UNLK warninglight illumination. The above warning is replaced byillumination of REV indicator light showing that the thrustreverser is fully deployed as soon as deploy switch is open. Noindication is on when the translating sleeve is fully stowed.In addition, the signal sent from the FADEC to the ECAM systemprovidesindication of the sleeves position on the CRT (Ref. Fig.026 ) . There is no indication in the flight compartmentassociated with the synchronous shaft locks.

FED 801-815

G. Throttle Control Feedback(Ref. Fig. 027,028,030 )The master actuator of each thrust reverser duct halfincorporates a feedback mechanism which provides reverserposition feedback to the FADEC.This mechanism consists of a self-contained dual rotaryvariable differential transformer (RVDT) (see detaileddescription in paragraph H. and I.), integral reduction gearingand mechanically activated electrical switches for stow anddeploy indication, which attach to the thrust reverser masteractuators (two off) at the mechanical feedback gear drive pad.Both RVDT output signals are wired to both A & B channels ofthe FADEC. In addition, the FADEC receives throttle leverresolver signals, according to throttle control lever position.As the reverser translates through deploy and stow, each masteractuator internal gearbox drives an RVDT in direct relation totranslating sleeve travel. The RVDT provides an electricalsignal feedback via an electricalharness to the FADEC (Ref. Fig. 028 ) .In reverser deploy command, (Ref. Fig. 027 ) the FADECsoftware logic maintains an approach idle fuel flow settinguntil a signal indicating 78% of full deployment is received.Maximum reversing fuel flow cannot beattained until 90% of full deployment is indicated (Ref. Fig.030 ) .In reverser stow command (Ref. Fig. 027 ) , the FADEC softwarelogic maintains idle fuel flow until an 85% stowed indicationis received. Maximum forward power cannot be attained until a90% stowed signal is received



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(Ref. Fig. 030 ) . Should an uncommanded deploy occur, theFADEC will command idle fuel flow regardless of throttle position (Ref. Fig.030 ) .

FED 801-815POST SB 78-2019 for A/C 801-815

G. Throttle Control Feedback(Ref. Fig. 027,029,030 )The master actuator of each thrust reverser duct halfincorporates a feedback mechanism which provides reverserposition feedback to the FADEC.This mechanism consists of a self-contained dual rotaryvariable differential transformer (RVDT) (see detaileddescription in paragraph H. and I.), integral reduction gearingand mechanically activated electrical switches for stow anddeploy indication, which attach to the thrust reverser masteractuators (two off) at the mechanical feedback gear drive pad.Both RVDT output signals are wired to both A & B channels ofthe FADEC. In addition, the FADEC receives throttle leverresolver signals, according to throttle control lever position.As the reverser translates through deploy and stow, each masteractuator internal gearbox drives an RVDT in direct relation totranslating sleeve travel. The RVDT provides an electricalsignal feedback via an electricalharness to the FADEC (Ref. Fig. 029 ) .In reverser deploy command, (Ref. Fig. 027 ) the FADECsoftware logic maintains an approach idle fuel flow settinguntil a signal indicating 78% of full deployment is received.Maximum reversing fuel flow cannot beattained until 90% of full deployment is indicated (Ref. Fig.030 ) .In reverser stow command (Ref. Fig. 027 ) , the FADEC softwarelogic maintains idle fuel flow until an 85% stowed indicationis received. Maximum forward power cannot be attained until a90% stowed signal is received(Ref. Fig. 030 ) . Should an uncommanded deploy occur, theFADEC will command idle fuel flow regardless of throttle position (Ref. Fig.030 ) .

FED 801-815

H. Rotary Variable Differential Transformer (RVDT)(Ref. Fig. 031,032,033 )The RVDT provides a signal to the FADEC which is proportionalto actuator percent deployed. The zero percent deployedposition is equivalent to the actuator fully stowed on itsstops. The 100 percent deployed position corresponds to 20.84



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in. (529.3 mm) of actuator stroke. The RVDT assembly alsocontains limit switches which indicate stowed and deployedposition and also control the arming solenoid of the pressureregulator and shutoff valve.One RVDT/switch assembly is mounted on each right and leftmaster actuator.The unit operates as described when mounted on the masteractuator gearbox(Ref. Fig. 033 ) . The RVDT is a dual unit to accommodatechannel A and B inputs to the FADEC. For each channel, theprimary (input) coils of the left and right units are wired inparallel and the secondary (output)coils are wired in series (Ref. Fig. 033 ) .

I. Stow and Deploy SwitchesA stow switch for each reverser half is set such that theswitch contacts close between 0.150 in. and 0.300 in. (3.81 mmand 7.62 mm) of actuator stroke as the reverser is deployed.The switch contacts open between 0.500 in. and 0.150 in. (12.70mm and 3.81 mm) from stow as the reverser is stowed.A deploy switch for each reverser half contact closes at 95percent ±2 of the deployed position as the reverser deploys.When the reverser stows, the contacts open at or before 90percent of the deployed position.

FED 801-815POST SB 78-2019 for A/C 801-815

J. Synchronous shaft Lock

(1) DescriptionThe thrust reverser synchronous shaft lock system on eachengine consists of an electric synchronous shaft lock(sync lock) on each T/R sleeve and the wiring harnesscontaining the synchronous shaft lock solenoid commandwiring.The system includes associated brackets and clips tosecure the locks and wiring harnesses to the engine and T/R. The fan cowl doors also incorporate adhesively bondedmetallic skid plates that protect the composite structurein the event that the manual unlock lever is not returnedto the locked position after maintenance.The synchronous shaft locks are installed in theactuation system of each T/R half. The synchronous shaftlocks are bracket-mounted to the T/R torque box betweenthe master actuators and the lower slave actuators.Each synchronous shaft lock interfaces with the actuationsystem through two flexshafts : one flexshaftinterconnects between the slave actuator and thesynchronous shaft lock and the second flexshaft



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interconnects between the synchronous shaft lock and themaster actuator.The wiring harness starts at connector number D4970P atthe fan area pylon interface and terminates in connectorsat each synchronous shaft lock.

(2) Operation(Ref. Fig. 034,035 )The synchronous shaft lock is a solenoid-operated unitwhich in the normal, de-energized state, prevents T/Roperation. The synchronous shaft lock incorporates aninternal rotor with a three-lobed rotor plate near oneend. In the locked state, the rotor plate is preventedfrom rotation by two lock pins that block rotation of therotor plate. The interconnecting flexshafts interfacewith the rotor such that the flexshafts are inhibitedfrom rotation if the synchronous shaft lock is locked.When energized, the solenoid pulls in the solenoidarmature which simultaneously pulls the lock pins out ofthe path of rotation of the rotor plate thereby allowingT/R operation. In the event of system failures resultingin an uncommanded deploy such that the PDU is outputtingfull stall torque, each synchronous shaft lock is capableon its own of retaining both thrust reverser sleeves inthe stowed position.

(3) Manual unlock lever(Ref. Fig. 036,037 )In order to manually deploy the T/R for maintenance work,both synchronous shaft locks must be unlocked. Eachsynchronous shaft lock has a manual unlock lever that,when rotated, mechanically moves the solenoid armature tothe unlock position, pulling the lock pins clear of therotor plate. The manual unlock lever is held in eitherthe normal or unlocked position by a ball detent at thebase of the lever. In the event that the manual unlocklever is not returned to the normal position aftermaintenance, closure of the fan cowl door will push thelever to the normal position thus assuring dispatch withthe synchronous shaft lock properly locked.



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FED 801-802,805-806,808-815

Figure 001Figure 001. Throttle Control Handle Thrust Reverser (Sheet 1)



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Figure 002Figure 002. Throttle Control Handle Thrust Reverser (Sheet 1)



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Figure 003Figure 003. Thrust Reverser System - Component Location (Sheet 1)



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Figure 007Figure 007. Thrust Reverser Actuation System - Deploy Mode (Sheet 1)



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Figure 008Figure 008. Thrust Reverser Actuation System - Deploy Mode (Sheet 1)



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Figure 009Figure 009. Thrust Reverser Actuation System - Stow Mode (Sheet 1)



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Figure 010Figure 010. Thrust Reverser Actuation System - Stow Mode (Sheet 1)



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Figure 011Figure 011. Pressure Regulating and Shut off Valve (Sheet 1)



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Figure 012Figure 012. Pneumatic Drive Unit (Sheet 1)



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Figure 013Figure 013. Selector Valve (Sheet 1)



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Figure 014Figure 014. Circuit Breakers - Location (Sheet 1)



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Figure 015Figure 015. Circuit Breakers - Location (Sheet 1)



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Figure 016Figure 016. Thrust Reverser System - Electrical Supply (Sheet 1)



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Figure 017Figure 017. Thrust Reverser System - Electrical Supply (Sheet 1)



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Figure 018Figure 018. Thrust Reverser Control and Indicating, ENG2 Aircraft on

Ground, No Electrical Power (Sheet 1)



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Figure 024Figure 024. Thrust Reverser Indicating (Sheet 1)



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Figure 025Figure 025. Deploy/Stow Cycle - Indicating (Sheet 1)



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Figure 026Figure 026. R ECAM Display unit - GND TEST (Sheet 1)



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Figure 027Figure 027. FADEC Interface with Thrust Reverser (Sheet 1)



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Figure 028Figure 028. Thrust Reverser System Block Diagram (Sheet 1)



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Figure 029Figure 029. Thrust Reverser System Block Diagram (Sheet 1)



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Figure 030Figure 030. Thrust Limiting During Reverser Transition (Sheet 1)



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Figure 031Figure 031. RVDT Location (Sheet 1)



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Figure 032Figure 032. RVDT Feedback Module - Schematic (Sheet 1)



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Figure 033Figure 033. RVDT Electrical Wiring (Sheet 1)



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Figure 034Figure 034. Synchronous Shaft Lock (Sheet 1)



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Figure 035Figure 035. Synchronous Shaft Locking Concept (Sheet 1)



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Figure 036Figure 036. Manual Unlock Lever - Normal Position (Sheet 1)



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Figure 037Figure 037. Manual Unlock Lever - Unlocked Position (Sheet 1)



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thrust reverser system control - description and operation · pdf filefed 801-815 [pw 4152]...

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