Removal of the Fan Fire Detectors from the Rail Assembly

TASK 26-12-15-000-026-A
Removal of the Fan Fire Detectors from the Rail Assembly

CAUTION: USE CARE WHEN YOU REMOVE THE FIRE DETECTOR SENSORS FROM THE RAIL ASSEMBLY. THE FIRE DETECTOR SENSOR TUBE CAN CRACK AND CAUSE SERIOUS DAMAGE TO THE UNIT.

NOTE: This procedure can be done with the rail assembly installed on the engine, or with the rail assembly removed from the engine. If this procedure is done with the rail assembly removed from the engine, go to step 4.A.(1)(c).

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	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 (4000WD1,4000WD2)
Fan Fire Detectors (4000WD1,4000WD2)

3. Job Set-up
Subtask 26-12-15-861-057-A ** ON A/C NOT FOR ALL

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

Subtask 26-12-15-941-056-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) in position 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 ENG section of the 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 the FADEC 1(2).

Subtask 26-12-15-010-065-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Put an ACCESS PLATFORM 1M(3 FT) in position.
(2) 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.

Subtask 26-12-15-865-068-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 26-12-15-020-059-A ** ON A/C NOT FOR ALL

A. Removal of the Fan Fire Detector Sensors from the Rail Assembly
(1) Remove the fan fire detector sensors (45) from the rail assembly (20).
(a) Disconnect the electrical connectors 4000WD1A and 4000WD2A from the fire detectors (45).
(b) Put the COVER - PROTECTION on the electrical connectors 4000WD1A and 4000WD2A and the fire detectors (45).
(c) Remove the bolts (50) and clamp covers (55) that attach the fire detectors (45) to the rail assembly (20).
(d) Remove the fire detector sensor tubes (45) from the inserts (60).
(e) Remove the nuts (70), ferrules (75) and ferrules (80) that attach the sensors (45) to the rail (20).
(f) Remove the nuts (5), bolts (15) and clamps (40) that attach the fire detector sensors (45) to the brackets on the accessory gearbox.
(g) Remove the fire detector sensors.

CAUTION: DO NOT DISASSEMBLE THE FIRE DETECTOR SENSORS. THE DETECTOR SENSOR IS A HERMETICALLY SEALED UNIT AND IS NOT REPAIRABLE. IF YOU TRY TO DISASSEMBLE THE DETECTOR SENSORS, YOU WILL CAUSE SERIOUS DAMAGE TO THE UNIT.

1 Remove the fire detector sensors (45) from the rail assembly (20).

[Rev.10 from 2021] 2026.03.31 23:42:38 UTC