Removal of the Exhaust Gas Temperature (EGT) Thermocouple [IAE]

TASK 77-21-15-000-010-A
Removal of the Exhaust Gas Temperature (EGT) Thermocouple

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.

FIN: 4012KS1 ** ON A/C NOT FOR ALL
FIN: 4012KS2 ** ON A/C NOT FOR ALL
FIN: 4012KS3 ** ON A/C NOT FOR ALL
FIN: 4012KS4 ** ON A/C NOT FOR ALL

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

REFERENCE	QTY	DESIGNATION
No specific	AR	ACCESS PLATFORM 1M(3 FT)
No specific	AR	CAP - BLANKING
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 78-30-00-040-012-A	Deactivation of the Thrust Reverser Hydraulic Control Unit (HCU) for Ground Maintenance
TASK 78-32-00-010-010-A	Opening of the Thrust Reverser Halves
Exhaust Gas Temperature Thermocouple

3. Job Set-up
Subtask 77-21-15-941-050-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 77-21-15-010-050-A ** ON A/C NOT FOR ALL

B. Open the fan cowls (Ref. AMM TASK 71-13-00-010-010):
(1) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(2) FOR [1000EM2] (ENGINE-2)
447AL 448AR.
(3) Put the ACCESS PLATFORM 1M(3 FT) in position.

Subtask 77-21-15-040-050-A ** ON A/C NOT FOR ALL

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

Subtask 77-21-15-010-052-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.

4. Procedure
Subtask 77-21-15-020-050-A ** ON A/C NOT FOR ALL

A. Remove the EGT thermocouples

Exhaust Gas Temperature Thermocouple ** ON A/C NOT FOR ALL

NOTE: The EGT thermocouples are installed through the vanes numbered 3, 6, 8 and 11, of the turbine exhaust case.

(1) Remove the harness ends from the thermocouple
(a) Release and remove the four nuts (3) and (7) and washers (10) and (11) that attach the harness (6) to the thermocouple connections (1) and (8).
(b) Remove the harness ends from the thermocouple.
(c) Install the nuts and washers on the terminals.
(2) Cut and discard the lockwire. Release and remove the two bolts (9) that attach the thermocouple (4) to the boss on the exhaust case. remove the thermocouple from the exhaust case.
(3) Do the procedure again for the other three EGT thermocouples.
(4) Install CAP - BLANKING to all openings.

[Rev.10 from 2021] 2026.04.01 03:18:10 UTC