Removal of the Fan Fire Detectors

TASK 26-12-15-000-042-A
Removal of the Fan Fire Detectors

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: 4000WD1 ** ON A/C NOT FOR ALL
FIN: 4000WD2 ** 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	ACCESS PLATFORM 1M(3 FT)
No specific	AR	COVER - PROTECTION
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	SCREWDRIVER - PHILLIPS HEAD
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [1000EM1] (ENGINE-1)
437AL, 438AR
FOR [1000EM2] (ENGINE-2)
447AL, 448AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
TASK 71-13-00-010-040-B	Opening of the Fan Cowl Doors
Fan Fire Detectors

3. Job Set-up
Subtask 26-12-15-861-052-A ** ON A/C NOT FOR ALL

A. Energize the ground service network (Ref. AMM TASK 24-42-00-861-001).

Subtask 26-12-15-941-050-A ** ON A/C NOT FOR ALL

B. Safety Precautions
(1) On the center pedestal, on the ENG panel 115VU:
(a) Make sure that the ENG/MODE/CRANK/NORM/IGN/START selector switch is in the NORM position.
(b) 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 26-12-15-010-050-A ** ON A/C NOT FOR ALL

C. Get access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-040):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) put the ACCESS PLATFORM 1M(3 FT) in position.

Subtask 26-12-15-865-050-A ** ON A/C NOT FOR ALL

D. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	ENGINE/2/FIRE DET/LOOP B	8WD2	A07
49VU	ENGINE/1/FIRE DET/LOOP A	7WD1	A06
121VU	ENGINE/ENG2/FIRE DET/LOOP A	7WD2	Q39
121VU	ENGINE/ENG1/FIRE DET/LOOP B	8WD1	Q38

4. Procedure
Subtask 26-12-15-020-050-A ** ON A/C NOT FOR ALL

A. Removal of the Fan Zone Fire Detector

CAUTION: REMOVE THE FIRE DETECTORS AND THE RAIL AS ONE ASSEMBLY. THE FIRE DETECTOR SENSOR ELEMENTS CAN BE DAMAGED IF NOT SUPPORTED BY THE RAIL.

(1) Turn the screw (30) on the center mount clamp (25), then move the clamps (25) out of the brackets (10) (8 locations). Use a SCREWDRIVER - PHILLIPS HEAD to turn the screw.
(2) Disconnect the electrical connector 4000WD1-A from the Loop A fire detector sensor (45).
(3) Remove the nuts (5), bolts (15), and clamps (40) from the Loop A sensor (45).
(4) Install the nuts (5), bolts (15), and clamps (40) on the engine bracket. Tighten the nut with your hand.
(5) Disconnect the electrical connector 4000WD2-A from the Loop B fire detector sensor (45).
(6) Remove the nuts (5), bolts (15), and clamps (40) from the Loop B sensor (45).
(7) Install the nuts (5), bolts (15), and clamps (40) on the engine bracket. Tighten the nut with your hand.
(8) Put COVER - PROTECTION on the sensors and the electrical connectors.
(9) Remove the rail assembly (20) with the sensors (45) attached from the engine.

[Rev.10 from 2021] 2026.03.31 23:42:36 UTC