Removal of the Core Engine Fire Detection Elements

TASK 26-12-17-000-804-A
Removal of the Core Engine Fire Detection Elements

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.

ZONE: 450
ZONE: 460
FIN: 4001WD1
FIN: 4001WD2

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)-ADJUSTABLE
No specific	AR	CAP - PROTECTION
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
450	ENG 1 THRUST REVERSER & EXHAUST SECTION
460	ENG 2 THRUST REVERSER & EXHAUST SECTION
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 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
TASK 71-13-00-010-803-A	Opening of the Fan Cowl Doors
TASK 78-30-00-040-809-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-36-00-010-806-A	Opening of the Thrust Reverser Cowl Doors
Core Engine Fire Detection Elements

3. Job Set-up
Subtask 26-12-17-861-063-A

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

Subtask 26-12-17-941-063-A

B. 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 26-12-17-865-075-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 4020KM1 (POWER PLANTDEMOUNTABLE, ENGINE 1)
49VU	ENGINE/1/FIRE DET/LOOP A	7WD1	A06
121VU	ENGINE/ENG1/FIRE DET/LOOP B	8WD1	Q38
FOR FIN: 4020KM2 (POWER PLANTDEMOUNTABLE, ENGINE 2)
49VU	ENGINE/2/FIRE DET/LOOP B	8WD2	A07
121VU	ENGINE/ENG2/FIRE DET/LOOP A	7WD2	Q39

Subtask 26-12-17-010-086-A

D. 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

Subtask 26-12-17-040-068-A

E. Deactivation of the Thrust Reverser System for Ground 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 ground maintenance (Ref. AMM TASK 78-30-00-040-809).

Subtask 26-12-17-010-087-A

F. Open the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-010-806):
(1) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR
(2) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR
(3) Put an ACCESS PLATFORM 1M (3 FT)-ADJUSTABLE in position.

4. Procedure
Subtask 26-12-17-020-065-A

A. Removal of the Core Engine Fire Detection Elements

CAUTION: DO NOT USE ELECTRICAL OR PNEUMATIC TOOLS TO LOOSEN OR TIGHTEN THE QUARTER-TURN FASTENER ON THE FIRE DETECTOR CLAMP. ONLY USE A MANUAL SCREWDRIVER. ELECTRICAL OR PNEUMATIC TOOLS WILL CAUSE THE FASTENER TO TURN TOO MUCH AND POSSIBLY TO BREAK.

(1) Installation of protection covers

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

(a) Install COVER - PROTECTION and CAP - PROTECTION on all the open ports, open tubes, open hoses and connectors.
(2) Remove the bolt (29) that attaches the harness (1) to the bracket (28).
(3) Remove the two bolts (2) that attach the harness (1) connectors to the responder (3).
(4) Move the lower end of the harness (1) away from the responder (3).
(5) Remove the bolt (31) that attaches the harness (30) to the bracket (32).
(6) Remove the two bolts (62) that attach the harness (30) connectors to the responder (63).
(7) Move the lower end of the harness (30) away from the responder (63).
(8) Turn the bolt (25) to open the clip (26) and remove the fireloop wire (4).
(9) Turn the bolt (23) to open the clip (24) and remove the fireloop wire (4).
(10) Turn the bolt (21) to open the clip (22) and remove the fireloop wire (4).
(11) Turn the bolt (19) to open the clip (20) and remove the fireloop wire (4).
(12) Turn the bolt (17) to open the clip (18) and remove the fireloop wire (4).
(13) Turn the bolt (15) to open the clip (16) and remove the fireloop wire (4).
(14) Turn the bolt (13) to open the clip (14) and remove the fireloop wire (4).
(15) Turn the bolt (6) to open the clip (5) and remove the fireloop wire (4).
(16) Turn the bolt (11) to open the clip (12) and remove the fireloop wire (4).
(17) Turn the bolt (8) to open the clip (7) and remove the fireloop wire (4).
(18) Turn the bolt (9) to open the clip (10) and remove the fireloop wire (4).
(19) Turn the bolt (47) to open the clip (46) and remove the fireloop wire (4).
(20) Turn the bolt (49) to open the clip (48) and remove the fireloop wire (4).
(21) Turn the bolt (51) to open the clip (50) and remove the fireloop wire (4).
(22) Turn the bolt (53) to open the clip (52) and remove the fireloop wire (4).
(23) Turn the bolt (55) to open the clip (54) and remove the fireloop wire (4).
(24) Turn the bolt (56) to open the clip (57) and remove the fireloop wire (4).
(25) Turn the bolt (58) to open the clip (59) and remove the fireloop wire (4).
(26) Turn the bolt (60) to open the clip (61) and remove the fireloop wire (4).
(27) Turn the bolt (45) to open the clip (44) and remove the fireloop wire (4).
(28) Turn the bolt (43) to open the clip (42) and remove the fireloop wire (4).
(29) Turn the bolt (41) to open the clip (40) and remove the fireloop wire (4).
(30) Turn the bolt (39) to open the clip (38) and remove the fireloop wire (4).
(31) Turn the bolt (37) to open the clip (36) and remove the fireloop wire (4).
(32) Turn the bolt (35) to open the clip (34) and remove the fireloop wire (4).
(33) Remove the four bolts (33) that attach the responder (63).
(34) Remove the four bolts (27) that attach the responder (3).
(35) Carefully remove the fire detection elements from the engine.

[Rev.10 from 2021] 2026.03.31 23:43:16 UTC