Visual Inspection of the T48 Sensor [CFML]

TASK 77-21-00-210-802-A
Visual Inspection of the T48 Sensor

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 2M (6 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, 452AR
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR, 461AL, 462AR

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 77-21-10-000-802-A	Removal of the Exhaust Gas Temperature (EGT) Sensor 1
TASK 77-21-10-000-803-A	Removal of the Exhaust Gas Temperature (EGT) Sensor 2
TASK 77-21-10-000-804-A	Removal of the Exhaust Gas Temperature (EGT) Sensor 3
TASK 77-21-10-000-805-A	Removal of the Exhaust Gas Temperature (EGT) Sensor 4
TASK 77-21-10-000-806-A	Removal of the Exhaust Gas Temperature (EGT) Sensor 5
TASK 77-21-10-000-807-A	Removal of the Exhaust Gas Temperature (EGT) Sensor 6
TASK 77-21-10-000-808-A	Removal of the Exhaust Gas Temperature (EGT) Sensor 7
TASK 77-21-10-000-809-A	Removal of the Exhaust Gas Temperature (EGT) Sensor 8
TASK 77-21-10-400-802-A	Installation of the Exhaust Gas Temperature (EGT) Sensor 1
TASK 77-21-10-400-803-A	Installation of the Exhaust Gas Temperature (EGT) Sensor 2
TASK 77-21-10-400-804-A	Installation of the Exhaust Gas Temperature (EGT) Sensor 3
TASK 77-21-10-400-805-A	Installation of the Exhaust Gas Temperature (EGT) Sensor 4
TASK 77-21-10-400-806-A	Installation of the Exhaust Gas Temperature (EGT) Sensor 5
TASK 77-21-10-400-807-A	Installation of the Exhaust Gas Temperature (EGT) Sensor 6
TASK 77-21-10-400-808-A	Installation of the Exhaust Gas Temperature (EGT) Sensor 7
TASK 77-21-10-400-809-A	Installation of the Exhaust Gas Temperature (EGT) Sensor 8
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
T48 Sensor
Inspection of the T48 Sensor

3. Job Set-up
Subtask 77-21-00-941-052-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 and 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 77-21-00-010-054-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 2M (6 FT) in position.

Subtask 77-21-00-040-052-A

C. Deactivation of the Thrust Reverser 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 77-21-00-010-055-A

D. Get Access
(1) Open the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-010-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR

4. Procedure
Subtask 77-21-00-210-051-A

A. Visual Inspection of the T48 Sensor
(1) Do the visual inspection of the T48 sensor (1), (2), (3), (4), (5), (6), (7) and (8) for the indications that follow:

Table 1: Visual inspection of the Flange and housing (D&E)

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Cracks, dent, tear, corrosion and erosion/peening	Not serviceable	Replace the T48 sensor as required: Sensor 1 (Ref. AMM TASK 77-21-10-000-802) and (Ref. AMM TASK 77-21-10-400-802) Sensor 2 (Ref. AMM TASK 77-21-10-000-803) and (Ref. AMM TASK 77-21-10-400-803) Sensor 3 (Ref. AMM TASK 77-21-10-000-804) and (Ref. AMM TASK 77-21-10-400-804) Sensor 4 (Ref. AMM TASK 77-21-10-000-805) and (Ref. AMM TASK 77-21-10-400-805) Sensor 5 (Ref. AMM TASK 77-21-10-000-806) and (Ref. AMM TASK 77-21-10-400-806) Sensor 6 (Ref. AMM TASK 77-21-10-000-807) and (Ref. AMM TASK 77-21-10-400-807) Sensor 7 (Ref. AMM TASK 77-21-10-000-808) and (Ref. AMM TASK 77-21-10-400-808) Sensor 8 (Ref. AMM TASK 77-21-10-000-809) and (Ref. AMM TASK 77-21-10-400-809).
Deposit	Serviceable

Table 2: Visual inspection of the collar (F), Terminal housing (G), Lid (H), Fill plug (J)

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Cracks, dent, tear, oxidation and erosion/peening	Not serviceable	Replace the T48 sensor as required: Sensor 1 (Ref. AMM TASK 77-21-10-000-802) and (Ref. AMM TASK 77-21-10-400-802) Sensor 2 (Ref. AMM TASK 77-21-10-000-803) and (Ref. AMM TASK 77-21-10-400-803) Sensor 3 (Ref. AMM TASK 77-21-10-000-804) and (Ref. AMM TASK 77-21-10-400-804) Sensor 4 (Ref. AMM TASK 77-21-10-000-805) and (Ref. AMM TASK 77-21-10-400-805) Sensor 5 (Ref. AMM TASK 77-21-10-000-806) and (Ref. AMM TASK 77-21-10-400-806) Sensor 6 (Ref. AMM TASK 77-21-10-000-807) and (Ref. AMM TASK 77-21-10-400-807) Sensor 7 (Ref. AMM TASK 77-21-10-000-808) and (Ref. AMM TASK 77-21-10-400-808) Sensor 8 (Ref. AMM TASK 77-21-10-000-809) and (Ref. AMM TASK 77-21-10-400-809).
Deposit	Serviceable

Table 3: Visual inspection of the collar (F)

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Nick, scoring and scratch	Not serviceable	Replace the T48 sensor as required: Sensor 1 (Ref. AMM TASK 77-21-10-000-802) and (Ref. AMM TASK 77-21-10-400-802) Sensor 2 (Ref. AMM TASK 77-21-10-000-803) and (Ref. AMM TASK 77-21-10-400-803) Sensor 3 (Ref. AMM TASK 77-21-10-000-804) and (Ref. AMM TASK 77-21-10-400-804) Sensor 4 (Ref. AMM TASK 77-21-10-000-805) and (Ref. AMM TASK 77-21-10-400-805) Sensor 5 (Ref. AMM TASK 77-21-10-000-806) and (Ref. AMM TASK 77-21-10-400-806) Sensor 6 (Ref. AMM TASK 77-21-10-000-807) and (Ref. AMM TASK 77-21-10-400-807) Sensor 7 (Ref. AMM TASK 77-21-10-000-808) and (Ref. AMM TASK 77-21-10-400-808) Sensor 8 (Ref. AMM TASK 77-21-10-000-809) and (Ref. AMM TASK 77-21-10-400-809).

Table 4: Visual inspection of the collar (F) and terminal housing (G)

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Nick, scoring and scratch	Not serviceable	Replace the T48 sensor as required: Sensor 1 (Ref. AMM TASK 77-21-10-000-802) and (Ref. AMM TASK 77-21-10-400-802) Sensor 2 (Ref. AMM TASK 77-21-10-000-803) and (Ref. AMM TASK 77-21-10-400-803) Sensor 3 (Ref. AMM TASK 77-21-10-000-804) and (Ref. AMM TASK 77-21-10-400-804) Sensor 4 (Ref. AMM TASK 77-21-10-000-805) and (Ref. AMM TASK 77-21-10-400-805) Sensor 5 (Ref. AMM TASK 77-21-10-000-806) and (Ref. AMM TASK 77-21-10-400-806) Sensor 6 (Ref. AMM TASK 77-21-10-000-807) and (Ref. AMM TASK 77-21-10-400-807) Sensor 7 (Ref. AMM TASK 77-21-10-000-808) and (Ref. AMM TASK 77-21-10-400-808) Sensor 8 (Ref. AMM TASK 77-21-10-000-809) and (Ref. AMM TASK 77-21-10-400-809).

Table 5: Visual inspection of the terminal housing (G)

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Discoloration	Serviceable	Replace the T48 sensor as required: Sensor 1 (Ref. AMM TASK 77-21-10-000-802) and (Ref. AMM TASK 77-21-10-400-802) Sensor 2 (Ref. AMM TASK 77-21-10-000-803) and (Ref. AMM TASK 77-21-10-400-803) Sensor 3 (Ref. AMM TASK 77-21-10-000-804) and (Ref. AMM TASK 77-21-10-400-804) Sensor 4 (Ref. AMM TASK 77-21-10-000-805) and (Ref. AMM TASK 77-21-10-400-805) Sensor 5 (Ref. AMM TASK 77-21-10-000-806) and (Ref. AMM TASK 77-21-10-400-806) Sensor 6 (Ref. AMM TASK 77-21-10-000-807) and (Ref. AMM TASK 77-21-10-400-807) Sensor 7 (Ref. AMM TASK 77-21-10-000-808) and (Ref. AMM TASK 77-21-10-400-808) Sensor 8 (Ref. AMM TASK 77-21-10-000-809) and (Ref. AMM TASK 77-21-10-400-809).

Table 6: Visual inspection of all part of Kp and Kn assemblies (K1, K2, K3, K4, L1, L2, L3, L4)

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Cracks, dent, tear, oxidation, erosion/peening, nick, scoring/scratch and deposits	Not serviceable	Replace the T48 sensor as required: Sensor 1 (Ref. AMM TASK 77-21-10-000-802) and (Ref. AMM TASK 77-21-10-400-802) Sensor 2 (Ref. AMM TASK 77-21-10-000-803) and (Ref. AMM TASK 77-21-10-400-803) Sensor 3 (Ref. AMM TASK 77-21-10-000-804) and (Ref. AMM TASK 77-21-10-400-804) Sensor 4 (Ref. AMM TASK 77-21-10-000-805) and (Ref. AMM TASK 77-21-10-400-805) Sensor 5 (Ref. AMM TASK 77-21-10-000-806) and (Ref. AMM TASK 77-21-10-400-806) Sensor 6 (Ref. AMM TASK 77-21-10-000-807) and (Ref. AMM TASK 77-21-10-400-807) Sensor 7 (Ref. AMM TASK 77-21-10-000-808) and (Ref. AMM TASK 77-21-10-400-808) Sensor 8 (Ref. AMM TASK 77-21-10-000-809) and (Ref. AMM TASK 77-21-10-400-809).

Table 7: Visual inspection of Weld and braze joints (M1, M2, M3, M4, M5, N1, N2, N3, N4, N5, N6 N7, N8)

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Cracks, dent, tear, oxidation, erosion/peening, nick, scoring/scratch and deposits	Not serviceable	Replace the T48 sensor as required: Sensor 1 (Ref. AMM TASK 77-21-10-000-802) and (Ref. AMM TASK 77-21-10-400-802) Sensor 2 (Ref. AMM TASK 77-21-10-000-803) and (Ref. AMM TASK 77-21-10-400-803) Sensor 3 (Ref. AMM TASK 77-21-10-000-804) and (Ref. AMM TASK 77-21-10-400-804) Sensor 4 (Ref. AMM TASK 77-21-10-000-805) and (Ref. AMM TASK 77-21-10-400-805) Sensor 5 (Ref. AMM TASK 77-21-10-000-806) and (Ref. AMM TASK 77-21-10-400-806) Sensor 6 (Ref. AMM TASK 77-21-10-000-807) and (Ref. AMM TASK 77-21-10-400-807) Sensor 7 (Ref. AMM TASK 77-21-10-000-808) and (Ref. AMM TASK 77-21-10-400-808) Sensor 8 (Ref. AMM TASK 77-21-10-000-809) and (Ref. AMM TASK 77-21-10-400-809).

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Creeping	0.0393 in. (1 mm)	If within criteria, accept as is, else, replace the T48 sensor as required: Sensor 1 (Ref. AMM TASK 77-21-10-000-802) and (Ref. AMM TASK 77-21-10-400-802) Sensor 2 (Ref. AMM TASK 77-21-10-000-803) and (Ref. AMM TASK 77-21-10-400-803) Sensor 3 (Ref. AMM TASK 77-21-10-000-804) and (Ref. AMM TASK 77-21-10-400-804) Sensor 4 (Ref. AMM TASK 77-21-10-000-805) and (Ref. AMM TASK 77-21-10-400-805) Sensor 5 (Ref. AMM TASK 77-21-10-000-806) and (Ref. AMM TASK 77-21-10-400-806) Sensor 6 (Ref. AMM TASK 77-21-10-000-807) and (Ref. AMM TASK 77-21-10-400-807) Sensor 7 (Ref. AMM TASK 77-21-10-000-808) and (Ref. AMM TASK 77-21-10-400-808) Sensor 8 (Ref. AMM TASK 77-21-10-000-809) and (Ref. AMM TASK 77-21-10-400-809).

5. Close-up
Subtask 77-21-00-410-054-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-410-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR

Subtask 77-21-00-440-052-A

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

Subtask 77-21-00-410-055-A

C. Close Access
(1) Close the fan cowl 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] 2026.04.02 06:37:52 UTC