Retraction of the Ram Air Turbine (RAT) on the Ground

TASK 29-22-00-869-006-A
Retraction of the Ram Air Turbine (RAT) on the Ground

WARNING: PUT THE SAFETY DEVICES AND THE WARNING NOTICES IN POSITION BEFORE YOU START A TASK ON OR NEAR:

THE FLIGHT CONTROLS
THE FLIGHT CONTROL SURFACES
THE LANDING GEAR AND THE RELATED DOORS
COMPONENTS THAT MOVE.

MOVEMENT OF COMPONENTS CAN KILL OR CAUSE INJURY TO PERSONS AND/OR CAN CAUSE DAMAGE TO THE EQUIPMENT.

WARNING: MAKE SURE THAT THE TRAVEL RANGES OF THE FLIGHT CONTROLS SURFACES ARE CLEAR. MOVEMENT OF FLIGHT CONTROLS CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.

WARNING: MAKE SURE THAT THE GROUND SAFETY-LOCKS ARE IN POSITION ON THE LANDING GEAR. THIS WILL PREVENT UNWANTED MOVEMENT OF THE LANDING GEAR, AND THUS POSSIBLE INJURY TO PERSONS AND DAMAGE TO THE AIRCRAFT AND/OR EQUIPMENT.

WARNING: BE CAREFUL WHEN YOU DO WORK IN THE AREA ADJACENT TO THE EXTENDED RAT. IF THE BLUE HYDRAULIC SYSTEM IS PRESSURIZED, THE RAT BLADES CAN TURN. THIS CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.

CAUTION: BE CAREFUL WHEN YOU TOUCH OR MOVE THE RAM AIR TURBINE (RAT). THE RAT BLADES ARE MADE OF COMPOSITE MATERIAL AND CAN EASILY BECOME DAMAGED.

FIN: 2GE

1. Reason for the Job
To retract the RAT after a maintenance or test procedure or RAT deployment during flight.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	COVER - PROTECTION
98D29207550001	1	PROTECTION EQUIPMENT - RAT
98D29208246001	1	DEVICE-SAFETY,RAT
98D29208581000	1	PROTECTION EQUIPMENT - RAT

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
195BB, 197EB

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 29-10-00-863-003-A	Pressurize the Blue Hydraulic System with a Hydraulic Ground Power-Cart
TASK 29-10-00-863-003-A-01	Pressurize the Blue Hydraulic System with the Blue Electric Pump
TASK 29-10-00-864-003-A	Depressurize the Blue Hydraulic System
TASK 29-22-00-210-001-A	Visual Inspection of the RAT Blades (Aluminum Blades)
TASK 29-22-00-220-002-A	Detailed Inspection of Rat Carbon Blades for Evidence of Plating Cracks
TASK 29-22-00-820-005-A	Adjustment of the RAT Interlock Proximity Switch
TASK 29-22-00-860-007-A	Installation of the Safety Device of the Ram Air Turbine
TASK 29-22-00-860-008-A	Removal of the Safety Device of the Ram Air Turbine
TASK 29-22-53-000-010-A	Removal of the RAT Actuator
TASK 29-22-53-400-010-A	Installation of the RAT Actuator
RAT Control

3. Job Set-up
Subtask 29-22-00-860-100-A

A. Aircraft Maintenance Configuration
(1) Make sure that the warning notices are in position.
(2) Make sure that the safety barriers are in position.
(3) Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002).

(4) Pressurize the Blue hydraulic system
(Ref. AMM TASK 29-10-00-863-003).

Subtask 29-22-00-865-103-A

B. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	HYD/RAT/CTL	2801GE	D14
** ON A/C NOT FOR ALL
49VU	HYD/RAT/CTL	2801GE	B13

Subtask 29-22-00-010-077-A

C. Open the access doors 197EB and 195BB.

4. Procedure
Subtask 29-22-00-860-101-C

A. Retraction of the RAT on the Ground

RAT Control

WARNING: MAKE SURE THAT THE RAT TRAVEL RANGE IS CLEAR BEFORE YOU EXTEND/RETRACT THE RAT.

(1) Remove the 98D29208581000 PROTECTION EQUIPMENT - RAT or the 98D29207550001 PROTECTION EQUIPMENT - RAT from the RAT.
(2) If the RAT deployed during flight it is necessary to do a visual inspection of the RAT blades for damage (Ref. AMM TASK 29-22-00-210-001) or (Ref. AMM TASK 29-22-00-220-002).
(3) Do an operational test of the RAT Retraction Abort:

ACTION	RESULT
1. On the RAT ground control-panel 3GE: Set the switch LAMP TEST to the test position and hold it there.	On the RAT ground control panel 3GE: The interlock warning lamp comes on. The actuator pressure lamp comes on. The RAT stowed lamp comes on.
Release the switch LAMP TEST.	All lamps go off on the panel 3GE.
2. Set the 28VDC switch to the ON position.
3. Manually set the blades of the RAT out of line with the leg assembly.
4. Pressurize the Blue Hydraulic System (Ref. AMM TASK 29-10-00-863-003).
5. On the RAT ground control-panel 3GE: Set the stow switch to the STOW position and hold it there.	On the RAT ground control-panel 3GE: The red actuator pressure light comes on. The RAT starts to retract but stops when it has travelled 8.5 deg. The interlock warning lamp comes on in amber. The red actuator pressure light goes off. NOTE: If there is a fault, the RAT may not stop when it has travelled 8.5 deg. If this happens, you must release the STOW switch before the RAT comes into contact with the aircraft. The RAT will then stop and go back to its fully extended position. If the RAT does not stop, retract it with the blades in line with the leg assembly. Do the adjustment of the interlock proximity switch (Ref. AMM TASK 29-22-00-820-005). If the fault continues, replace the RAT at the next opportunity.
6. On the RAT ground control-panel 3GE: Release the stow switch.	On the RAT ground control-panel 3GE: The stow switch moves to the center position.
Set the stow switch to the RESET position.	The interlock warning lamp goes off.
Release the stow switch.	The stow switch moves to the center position.

(4) Make sure that a second person is on the ground near the RAT to monitor its retraction.
(5) Open the door of the RAT ground control-panel 3GE.
(6) Remove the COVER - PROTECTION from the turbine blades.
(7) Turn the turbine blades with your hands until the arrows on the turbine hub and the gearbox align.
(8) On the RAT ground control-panel 3GE, set the switch 28V DC to the ON position.
(9) Retract the RAT

CAUTION: MAKE SURE THAT THE RAT IS RETRACTED COMPLETELY BEFORE YOU RELEASE THE "RAT STOW" SWITCH . IF THE RETRACTION SEQUENCE STOPS JUST BEFORE THE RAT ENTERS THE BAY IN THE FAIRTING THIS WILL CAUSE DAMAGE TO THE RAT ACTUATOR.

(a) Move the STOW/RESET switch to the STOW position and hold it there until:

The RAT STOWED indicator light comes on
The ACTUATOR PRESSURE light comes on.

(b) Make sure that the RAT retracts fully.

NOTE: The ACTUATOR PRESSURE light is on from the time the STOW/RESET switch is moved until it is released.

The ACTUATOR PRESSURE light goes off.

(d) If the retraction sequence stops immediately before the RAT starts to go into the retraction bay, do a check of the STOWED indicator light:
1 If the STOWED indicator light is off, repeat the stow sequence.
2 If the STOWED indicator light is on, replace the RAT actuator (Ref. AMM TASK 29-22-53-000-010) and (Ref. AMM TASK 29-22-53-400-010).
(e) Set the switch 28V DC to the OFF position:

The RAT STOWED light goes off.

(10) If the aircraft stays on the ground for maintenance, install the 98D29208246000 SAFETY DEVICE-RAT or the 98D29208246001 DEVICE-SAFETY,RAT (Ref. AMM TASK 29-22-00-860-007).

5. Close-up
Subtask 29-22-00-860-102-A

A. Put the aircraft back to the serviceable condition.
(1) Depressurize the Blue hydraulic system
(Ref. AMM TASK 29-10-00-864-003).
(2) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).
(3) Remove the 98D29208246000 SAFETY DEVICE-RAT or the 98D29208246001 DEVICE-SAFETY,RAT (Ref. AMM TASK 29-22-00-860-008) .

Subtask 29-22-00-410-073-A

B. Close Access
(1) Close the door of the RAT ground control panel 3GE.
(2) Close the access doors 197EB and 195BB.
(3) Remove the WARNING NOTICE(S).
(4) Remove the safety barriers.

[Rev.10 from 2021] 2026.04.01 00:25:51 UTC