Check the ACC Valve Position and ACC Valve Rod End Bearing for Looseness [IAE]

TASK 75-24-51-200-010-A
Check the ACC Valve Position and ACC Valve Rod End Bearing for Looseness

FIN: 1000EM1 ** ON A/C NOT FOR ALL
FIN: 1000EM2 ** ON A/C NOT FOR ALL

1. Reason for the Job
Refer to the MPD TASK: 752400-I1
CHECK THE ACC VALVE POSITION AND ACC VALVE ROD END BEARING FOR LOOSENESS
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [1000EM1] (ENGINE-1)
437AL, 438AR, 451AL, 452AR
FOR [1000EM2] (ENGINE-2)
447AL, 448AR, 461AL, 462AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 71-13-00-010-010-A	Opening of the Fan Cowls 437AL(447AL),438AR(448AR)
TASK 71-13-00-410-010-A	Closing of the Fan Cowls 437AL(447AL),438AR(448AR)
TASK 75-24-51-000-010-B	Removal of the HPT/LPT ACC Air Valve
TASK 75-24-51-400-010-B	Installation of the HPT/LPT ACC Air Valve
TASK 78-30-00-040-012-A	Deactivation of the Thrust Reverser Hydraulic Control Unit (HCU) for Ground Maintenance
TASK 78-30-00-440-012-A	Re-activation of the Thrust Reverser Hydraulic Control Unit (HCU) after Ground Maintenance
TASK 78-32-00-010-010-A	Opening of the Thrust Reverser Halves
TASK 78-32-00-410-010-A	Closing of the Thrust Reverser Halves
HPT/LPT ACC Air Valve

3. Job Set-up
Subtask 75-24-51-941-051-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) to tell persons not to start the engine.
(2) Make sure that the engine 1(2) shutdown occurred not less than 5 minutes before you do this procedure.
(3) On the overhead maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).

Subtask 75-24-51-010-055-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Open the fan cowls (Ref. AMM TASK 71-13-00-010-010):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Put the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in to position.

Subtask 75-24-51-040-050-A ** ON A/C NOT FOR ALL

C. Deactivate the thrust reverser

WARNING: MAKE SURE THAT THE THRUST REVERSER HYDRAULIC CONTROL UNIT (HCU) IS DEACTIVATED BEFORE YOU DO WORK ON OR AROUND THE THRUST REVERSER. IF THE HCU IS NOT DEACTIVATED, THERE IS A RISK OF UNWANTED THRUST REVERSER OPERATION WHICH CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.

(1) Deactivate the thrust reverser Hydraulic Control Unit (HCU) (Ref. AMM TASK 78-30-00-040-012).

Subtask 75-24-51-010-051-A ** ON A/C NOT FOR ALL

D. Open the thrust reverser halves (Ref. AMM TASK 78-32-00-010-010):
(1) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(2) FOR [1000EM2] (ENGINE-2)
461AL 462AR

Subtask 75-24-51-020-055-B ** ON A/C NOT FOR ALL

E. Disconnect the actuator rod assembly from the High Pressure Turbine/Low Pressure Turbine (HPT/LPT) ACC air valve (Ref. AMM TASK 75-24-51-000-010).

4. Procedure
Subtask 75-24-51-210-050-A ** ON A/C NOT FOR ALL

A. Inspection of the ACC Air Valve
(1) Examine the valve position of the HPT/LPT ACC air valve
(a) Extend the valve rod fully.
(b) Make sure that the HPT valve vane is in the almost fully open position.
(c) Make sure that the LPT valve vane is in the almost fully open position.
(d) Retract the valve rod fully.
(e) Make sure that the HPT valve vane is in the almost fully closed position.
(f) Make sure that the LPT valve vane is in the reverse open to 40 percent (approximately 36 degrees) position.
(g) Reject the HPT/LPT ACC air valve if the above conditions do not occur.
(2) Examine the rod end bearing of HPT/LPT ACC air valve.

HPT/LPT ACC Air Valve ** ON A/C NOT FOR ALL

(a) Worn - greater than 0.010 in. (0.254 mm) in radial play, reject it within next 10 flight cycles or 25 flight hours which comes first.

5. Close-up
Subtask 75-24-51-420-054-B ** ON A/C NOT FOR ALL

A. Connect the actuator rod assembly to the HPT/LPT ACC air valve (Ref. AMM TASK 75-24-51-400-010).

Subtask 75-24-51-410-054-A ** ON A/C NOT FOR ALL

B. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the thrust reverser halves (Ref. AMM TASK 78-32-00-410-010):
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR

Subtask 75-24-51-440-051-A ** ON A/C NOT FOR ALL

C. Activate the thrust reverser HCU (Ref. AMM TASK 78-30-00-440-012).

Subtask 75-24-51-410-051-A ** ON A/C NOT FOR ALL

D. Close Access
(1) Close the fan cowls (Ref. AMM TASK 71-13-00-410-010):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Remove the access platform(s).
(3) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 03:11:36 UTC