Removal of the N1 Speed Probe [PW11]

TASK 77-11-21-000-801-A
Removal of the N1 Speed Probe

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE AFTER SHUTDOWN. THE ENGINE CAN STAY HOT FOR A LONG TIME. IF YOU DO NOT OBEY THIS INSTRUCTION, INJURY CAN OCCUR.

ZONE: 400
FIN: 4064KS ** 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	1	COVER - PROTECTION
No specific	1	PLIERS - JAWED, SOFT

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
437AL, 438AR, 452AR
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
447AL, 448AR, 462AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 71-00-00-860-832-A	Procedure to Prevent Engine Motoring and to Stop the Electrical Supply to the EEC
TASK 71-13-00-010-802-A	Opening of the Fan Cowl Doors
TASK 78-30-00-040-805-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-36-00-010-802-A	Opening of the Thrust Reverser Cowl-Doors
N1 Speed Probe

3. Job Set-up
Subtask 77-11-21-941-050-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) Do the procedure to prevent engine motoring and to stop the electrical supply to the Electronic Engine Control (EEC)
(Ref. AMM TASK 71-00-00-860-832).

Subtask 77-11-21-010-050-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
447AL 448AR

Subtask 77-11-21-040-050-A ** ON A/C NOT FOR ALL

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 78-30-00-040-805).

Subtask 77-11-21-010-051-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Open the right thrust-reverser cowl-doors (Ref. AMM TASK 78-36-00-010-802):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENG 1)
452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENG 2)
462AR

4. Procedure

CAUTION: WIPE CLEAN ALL PARTS AND TOOLS AS NECESSARY TO REMOVE UNWANTED DEBRIS AND PREVENT DAMAGE TO THE ENGINE.

Subtask 77-11-21-020-050-A ** ON A/C NOT FOR ALL

A. Removal of the N1 Speed Probe
(1) Find the N1 speed probe (1) attached to the Compressor Intermediate Case (CIC) at the 3 o'clock position. See the sheet 1 of the figure.
(2) Remove the N1 speed probe (1) as follows: See the sheet 1 of the figure.
(a) Disconnect the wiring harnesses (W03) and (W04) connectors (P48) and (P47) from the probe (1) with the PLIERS - JAWED, SOFT.
(b) Remove the two bolts (2) from the probe (1). See the sheet 2 of the figure.
(c) Remove the probe (1) from the CIC.
(d) Remove and discard the two packings (3) and (4) from the probe (1).
(3) Installation of protection covers

CAUTION: INSTALL PROTECTION COVERS ON ALL THE OPENINGS IMMEDIATELY TO PREVENT DAMAGE TO THE ENGINE.

(a) Make sure that you install COVER - PROTECTION as necessary to prevent damage to the engine.

[Rev.10 from 2021] 2026.04.01 03:18:40 UTC