Visual Inspection of the High Pressure Turbine (HPT) Active Clearance Control (ACC) Valve [CFML]

TASK 75-21-05-210-801-A
Visual Inspection of the High Pressure Turbine (HPT) Active Clearance Control (ACC) Valve

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE PARTS AFTER THE ENGINE SHUTDOWN. USE APPLICABLE THERMAL GLOVES. THE ENGINE PARTS CAN STAY HOT FOR ONE HOUR AFTER SHUTDOWN AND CAN BURN YOU.

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 1M(3 FT)
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL, 438AR, 451AL
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR, 461AL

C. Referenced Information

REFERENCE	DESIGNATION
TASK 71-13-00-010-803-A	Opening of the Fan Cowl Doors
TASK 71-13-00-410-803-A	Closing of the Fan Cowl Doors
TASK 73-21-60-000-813-A	Removal of the HJ8A Engine Wiring Harness
TASK 73-21-60-400-813-A	Installation of the HJ8A Engine Wiring Harness
TASK 75-21-05-000-801-A	Removal of the High Pressure Turbine (HPT) Active Clearance Control (ACC) Valve
TASK 75-21-05-400-801-A	Installation of the High Pressure Turbine (HPT) Active Clearance Control (ACC) Valve
TASK 78-30-00-040-809-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-30-00-440-809-A	Reactivation of the Thrust Reverser System after Ground Maintenance
TASK 78-36-00-010-806-A	Opening of the Thrust Reverser Cowl Doors
TASK 78-36-00-410-806-A	Closing of the Thrust Reverser Cowl Doors

3. Job Set-up
Subtask 75-21-05-941-052-A

A. Safety Precautions
(1) On the center pedestal, on ENG panel 115VU:
(a) Make sure that the ENG/MODE selector switch is in the NORM position.
(b) Make sure that the ENG/MASTER 1(2) control switch was in the OFF position not less than five minutes before you do this procedure.
(c) Put WARNING NOTICE(S) in position to tell persons not to operate:

The ENG/MODE selector switch
The ENG/MASTER 1(2) control switch.

(2) On the ENG section of maintenance panel 50VU:
(a) Make sure that the ON legend of the FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).

Subtask 75-21-05-010-054-A

B. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR
(2) Put an ACCESS PLATFORM 1M(3 FT) in position.

Subtask 75-21-05-040-052-A

C. Deactivation of the Thrust Reverser System for Maintenance

WARNING: YOU MUST DEACTIVATE THE THRUST REVERSER BEFORE YOU DO WORK ON OR AROUND IT. IF YOU DO NOT, THE THRUST REVERSER CAN OPERATE ACCIDENTALLY AND CAUSE AN INJURY AND/OR DAMAGE.

(1) Do the deactivation of the thrust reverser system for maintenance (Ref. AMM TASK 78-30-00-040-809).

Subtask 75-21-05-010-055-A

D. Get Access
(1) Open the left thrust reverser cowl-door (Ref. AMM TASK 78-36-00-010-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL

4. Procedure
Subtask 75-21-05-210-050-A

A. Visual Inspection of the High Pressure Turbine (HPT) Active Clearance Control (ACC) Valve
(1) Do the visual inspection of the HPTACC valve as follows:

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
1.Fuel leakage	a) It is permitted to have a valve that has a fuel stain, if you do not find drops of fuel. b) A fuel leak that makes drops of fuel is not permitted. c) A fuel leak from the valve housing or shaft is not permitted.	If you find damage or contamination on the fuel fittings replace the HPTACC valve (Ref. AMM TASK 75-21-05-000-801) and (Ref. AMM TASK 75-21-05-400-801). If the fuel tubes are not installed correctly or are loose, install and tighten the fuel tube B-nuts (Ref. AMM TASK 75-21-05-400-801). If the fuel leak continues, replace the HPTACC valve (Ref. AMM TASK 75-21-05-000-801) and (Ref. AMM TASK 75-21-05-400-801).
2.Cracks and dents in the HPTACC valve	Not serviceable.	Replace the HPTACC valve (Ref. AMM TASK 75-21-05-000-801) and (Ref. AMM TASK 75-21-05-400-801).
3.Air leaks	Not serviceable.	Identify the air leakage. Install and tighten the hose clamps and coupling on the HPTACC valve (Ref. AMM TASK 75-21-05-400-801).
4.Examine electrical receptacles and connectors on the HPTACC valve	a) Small damage to electrical connector is acceptable.
	b) Damage to electrical connector that prevents correct installation is not permitted.	If damage to connector prevents correct installation, replace the wiring harness (Ref. AMM TASK 73-21-60-000-813) and (Ref. AMM TASK 73-21-60-400-813).
	c) Damage to electrical receptacle that prevents correct installation of the electrical connector is not permitted.	If damage to electrical receptacle prevents correct installation, replace the HPTACC valve (Ref. AMM TASK 75-21-05-000-801) and (Ref. AMM TASK 75-21-05-400-801).
		Damage to the electrical receptacle threads may be repaired until connector can be tightened and can hold torque.
5.Examine the insulation blanket surrounding the valve	a) Some visible damage may be present on the blanket. Dents, nicks, and scratches are permitted; cracks or tears are not permitted, as the integrity of the blanket cannot be compromised.	If the blanket is damaged beyond the specified criteria, replace HPTACC valve (Ref. AMM TASK 75-21-05-000-801) and (Ref. AMM TASK 75-21-05-400-801).

5. Close-up
Subtask 75-21-05-410-052-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the left thrust reverser cowl-door (Ref. AMM TASK 78-36-00-410-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL

Subtask 75-21-05-440-051-A

B. Do the reactivation of the thrust reverser system after maintenance (Ref. AMM TASK 78-30-00-440-809).

Subtask 75-21-05-410-053-A

C. Close Access
(1) Close the fan cowls doors (Ref. AMM TASK 71-13-00-410-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR
(2) Remove the access platform(s).
(3) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 03:14:12 UTC