Visual Inspection of the T25 Sensor [CFML]

TASK 73-21-20-210-802-A
Visual Inspection of the T25 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.

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

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	1	PLIERS - CONNECTOR, JAW, SOFT
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, 452AR
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR, 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 73-21-20-000-802-A	Removal of the T25 Sensor
TASK 73-21-20-400-802-A	Installation of the T25 Sensor
TASK 73-29-00-710-802-A	FADEC Test (Menu Mode)
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
Visual Inspection of the T25 Sensor

3. Job Set-up
Subtask 73-21-20-941-056-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 73-21-20-010-070-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 73-21-20-040-059-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 73-21-20-010-071-A

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

4. Procedure
Subtask 73-21-20-220-050-A

A. Visual Inspection of the T25 sensor
(1) Disconnect the HJ8A engine wiring harness (2) from the T25 sensor receptacle (3).
(a) If necessary, use the PLIERS - CONNECTOR, JAW, SOFT.
(2) Do the visual inspection of the T25 sensor (1) for the indications that follows:

Table 1: Visual Inspection of Mounting Surface (Sensor Housing)

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Excessive roughness	Serviceable if measured values are less than 0.000063 in. (0.0016 mm)	Replace the T25 sensor (Ref. AMM TASK 73-21-20-000-802) and (Ref. AMM TASK 73-21-20-400-802).

Table 2: Visual Inspection of All Surfaces (Entire Sensor)

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Cracks	No cracks allowed	Replace the T25 sensor (Ref. AMM TASK 73-21-20-000-802) and (Ref. AMM TASK 73-21-20-400-802).
Discoloration	A light discoloration from straw to dark grey is permitted	Replace the T25 sensor (Ref. AMM TASK 73-21-20-000-802) and (Ref. AMM TASK 73-21-20-400-802).

Table 3: Visual Inspection of Sensor Housing and Sensor Flange Except the Concave Radii Above and Below the Mounting Flange and Within 0.20 in. (5 mm) Below the Flange

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Nicks, dents and gouges	Serviceable if, nicks or dents or gouges are less than 0.025 in. (0.63 mm) in depth	Replace the T25 sensor (Ref. AMM TASK 73-21-20-000-802) and (Ref. AMM TASK 73-21-20-400-802).

Table 4: Visual Inspection of Sensor Housing (Thin-Walled Airfoil)

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Nicks, dents and gouges	Serviceable if, nicks or dents or gouges are less than 0.010 in. (0.25 mm) in depth	Replace the T25 sensor (Ref. AMM TASK 73-21-20-000-802) and (Ref. AMM TASK 73-21-20-400-802).

Table 5: Visual Inspection of Sensor Housing (Ice Wedge)

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Nicks, dents and gouges	Serviceable if, nicks or dents or gouges are less than 0.03 in. (0.76 mm) in depth	Replace the T25 sensor (Ref. AMM TASK 73-21-20-000-802) and (Ref. AMM TASK 73-21-20-400-802).
Abrasion and wear	Wear (erosion) up to 0.08 in. (2.03 mm) deep from the Leading Edge (LE) of the ice wedge is allowed	Replace the T25 sensor (Ref. AMM TASK 73-21-20-000-802) and (Ref. AMM TASK 73-21-20-400-802).

Table 6: Visual Inspection of Housing Cap

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Nicks, dents and gouges	Serviceable if, nicks or dents or gouges are less than 0.03 in. (0.76 mm) in depth	Replace the T25 sensor (Ref. AMM TASK 73-21-20-000-802) and (Ref. AMM TASK 73-21-20-400-802).

Table 7: Visual Inspection of Connector Adapter

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Nicks, dents and gouges	Serviceable if, nicks or dents or gouges are less than 0.025 in. (0.63 mm) in depth	Replace the T25 sensor (Ref. AMM TASK 73-21-20-000-802) and (Ref. AMM TASK 73-21-20-400-802).

Table 8: Visual Inspection of Weld Joints

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Nicks, dents and gouges	Not serviceable	Replace the T25 sensor (Ref. AMM TASK 73-21-20-000-802) and (Ref. AMM TASK 73-21-20-400-802).

Table 9: Visual Inspection of Connector Thread, Thread of the Captive Screw

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Worn/missing thread	Serviceable if less than 20 percent of the thread length	Replace the T25 sensor (Ref. AMM TASK 73-21-20-000-802) and (Ref. AMM TASK 73-21-20-400-802).

Table 10: Visual Inspection of Connector Pins

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Scratches, nicks, dents, marks or discoloration	Not serviceable	Replace the T25 sensor (Ref. AMM TASK 73-21-20-000-802) and (Ref. AMM TASK 73-21-20-400-802).
Missing pins	Not serviceable	Replace the T25 sensor (Ref. AMM TASK 73-21-20-000-802) and (Ref. AMM TASK 73-21-20-400-802).

Table 11: Visual Inspection of Sensor Housing: Airfoil Openings

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Foreign Object Damage (FOD)	Serviceable. Follow cleaning procedure to remove FOD

Table 12: Missing Captive Screw

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Missing captive screw	Not serviceable	Replace the T25 sensor (Ref. AMM TASK 73-21-20-000-802) and (Ref. AMM TASK 73-21-20-400-802).

Table 13: Visual Inspection of the Connector

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Incomplete fully coupled indicator line	The engagement line must have 100 percent coverage with no areas missing	Replace the T25 sensor (Ref. AMM TASK 73-21-20-000-802) and (Ref. AMM TASK 73-21-20-400-802).

Table 14: Visual Inspection of the Sensor Housing and Connector Adapter (Part Marking and 2D Datamatrix)

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
Scratches, nicks, dents, marks or discoloration	Part number, serial number and data matrix must be readable	Replace the T25 sensor (Ref. AMM TASK 73-21-20-000-802) and (Ref. AMM TASK 73-21-20-400-802).

5. Close-up
Subtask 73-21-20-710-054-A

A. Test
(1) Do the FADEC test (Menu Mode) (Ref. AMM TASK 73-29-00-710-802).

Subtask 73-21-20-410-062-A

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

Subtask 73-21-20-440-054-A

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

Subtask 73-21-20-410-063-A

D. 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] 2026.04.01 13:03:37 UTC