Removal of the Pylon Fire-Detector Harness

TASK 26-12-63-000-802-A
Removal of the Pylon Fire-Detector Harness

WARNING: MAKE SURE THAT THE ENGINE SHUTDOWN OCCURRED NOT LESS THAN FIVE MINUTES BEFORE YOU DO THIS PROCEDURE. IF YOU DO NOT OBEY THIS INSTRUCTION, INJURY CAN OCCUR.

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: YOU MUST NOT TOUCH HOT PARTS WITHOUT APPLICABLE GLOVES. HOT PARTS CAN CAUSE AN INJURY.

ZONE: 415
ZONE: 425
ZONE: 473
ZONE: 483
FIN: 31WD1
FIN: 31WD2
FIN: 32WD1
FIN: 32WD2
FIN: 41WD1
FIN: 41WD2
FIN: 42WD1
FIN: 42WD2

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 2M (6 FT) - ADJUSTABLE
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)
FOR [31WD1] (HARNESS-FIRE DET, ENG 1 PYLON LOOP A STUD A)
FOR [31WD2] (HARNESS-FIRE DET, ENG 2 PYLON LOOP A STUD A)
No specific	1	WRENCH - STANDARD
FOR [32WD1] (HARNESS-FIRE DET, ENG 1 PYLON LOOP A STUD C)
FOR [32WD2] (HARNESS-FIRE DET, ENG 2 PYLON LOOP A STUD C)
No specific	1	WRENCH - STANDARD
FOR [41WD1] (HARNESS-FIRE DET, ENG 1 PYLON LOOP B STUD A)
FOR [41WD2] (HARNESS-FIRE DET, ENG 2 PYLON LOOP B STUD A)
No specific	1	WRENCH - STANDARD
FOR [42WD1] (HARNESS-FIRE DET, ENG 1 PYLON LOOP B STUD C)
FOR [42WD2] (HARNESS-FIRE DET, ENG 2 PYLON LOOP B STUD C)
No specific	1	WRENCH - STANDARD

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
415	LOWER PYLON
425	LOWER PYLON
473	LOWER FAIRING
483	LOWER FAIRING
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
415AL, 415AR, 437AL, 438AR, 451AL, 452AR
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
425AL, 425AR, 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 54-51-21-000-804-A	Removal of the Pylon Lateral Access-Doors
TASK 71-13-00-010-803-A	Opening of the Fan Cowl Doors
TASK 78-30-00-040-807-A	Deactivation of the Thrust Reverser System for Nacelle Maintenance (ICU)
TASK 78-36-00-010-806-A	Opening of the Thrust Reverser Cowl Doors

3. Job Set-up
Subtask 26-12-63-861-052-A

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

Subtask 26-12-63-941-051-A

B. Safety Precautions
(1) Make sure that the engine 1(2) shutdown occurred not less than five minutes before you do this procedure.
(2) 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.
(3) 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 26-12-63-865-053-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 26-12-63-010-054-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 26-12-63-040-052-A

E. 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 nacelle maintenance (Ref. AMM TASK 78-30-00-040-807).

Subtask 26-12-63-010-055-A

F. Get Access
(1) Open the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-010-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR
(2) Put an ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position.
(3) Remove the access doors (Ref. AMM TASK 54-51-21-000-804)
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
415AL 415AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
425AL 425AR

4. Procedure
Subtask 26-12-63-020-051-B

A. Removal of the Pylon Fire-Detector Harness

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) Remove the nut (4) from the responder unit (1).
(2) Disconnect the sensing element (5) from the responder unit (1).
(3) Remove the nut (2) from the responder unit (1).
(4) Disconnect the sensing element (3) from the responder unit (1).
(5) Turn the two related quarter-turn fasteners (6) by one quarter of a turn and open the two clamps (8).
(6) Disengage the sensing elements (3) and (5) from the two clamps (8).
(7) Turn the two related quarter-turn fasteners (7) by one quarter of a turn and open the two clamps (9).
(8) Disengage the sensing elements (3) and (5) from the two clamps (9).
(9) FOR [31WD1] (HARNESS-FIRE DET, ENG 1 PYLON LOOP A STUD A), [31WD2] (HARNESS-FIRE DET, ENG 2 PYLON LOOP A STUD A)
(a) Remove the bolt (19) from the clamp (18).
(b) Remove the clamp (18) and disengage the cable (10) from the plate (17).
(c) Remove and discard the lacing tapes from the protective sleeve (12).
(d) Remove the protective sleeve (12) from the cable (10).
(e) Remove the nut (25), the washer (24) and the bolt (23).
(f) Disconnect the cable (10) from the sensing element (5).
(g) Remove the bolts (15) and the washers (16) from the pylon interface (14).
(h) Remove the plate (13).
(i) Carefully remove the two sensing elements (3) and (5) from the pylon.
(j) Disengage the sensing element (5) from the plate (13):

WARNING: USE PROTECTIVE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.

1 Cut and remove the lockwire between the two nuts (26) of the sensing elements (3) and (5).
2 Remove the nut (26) of the sensing element (5):
a Use a second WRENCH - STANDARD to hold the sensing element (5) when you remove the nut (26).
(k) Disengage the sensing element (5) from the plate (13) and remove the sensing element (5).
(10) FOR [32WD1] (HARNESS-FIRE DET, ENG 1 PYLON LOOP A STUD C), [32WD2] (HARNESS-FIRE DET, ENG 2 PYLON LOOP A STUD C)
(a) Remove the bolt (19) from the clamp (18).
(b) Remove the clamp (18) and disengage the cable (10) from the plate (17).
(c) Remove and discard the lacing tapes from the protective sleeve (12).
(d) Remove the protective sleeve (12) from the cable (10).
(e) Remove the nut (22), the washer (21) and the bolt (20).
(f) Disconnect the cable (10) from the sensing element (3).
(g) Remove the bolts (15) and the washers (16) from the pylon interface (14).
(h) Remove the plate (13).
(i) Carefully remove the two sensing elements (3) and (5) from the pylon.
(j) Disengage the sensing element (3) from the plate (13):

1 Cut and remove the lockwire between the two nuts (26) of the sensing elements (3) and (5).
2 Remove the nut (26) of the sensing element (3):
a Use a second WRENCH - STANDARD to hold the sensing element (3) when you remove the nut (26).
(k) Disengage the sensing element (3) from the plate (13) and remove the sensing element (3).
(11) FOR [41WD1] (HARNESS-FIRE DET, ENG 1 PYLON LOOP B STUD A), [41WD2] (HARNESS-FIRE DET, ENG 2 PYLON LOOP B STUD A)
(a) Remove the bolt (19) from the clamp (18).
(b) Remove the clamp (18) and disengage the cable (11) from the plate (17).
(c) Remove and discard the lacing tapes from the protective sleeve (12).
(d) Remove the protective sleeve (12) from the cable (10).
(e) Remove the nut (25), the washer (24) and the bolt (23).
(f) Disconnect the cable (11) from the sensing element (5).
(g) Remove the bolts (15) and the washers (16) from the pylon interface (14).
(h) Remove the plate (13).
(i) Carefully remove the sensing elements (3) and (5) from the pylon.
(j) Disengage the sensing element (5) from the plate (13):

1 Cut and remove the lockwire between the two nuts (26) of the sensing elements (3) and (5).
2 Remove the nut (26) of the sensing element (5):
a Use a second WRENCH - STANDARD to hold the sensing element (5) when you remove the nut (26).
(k) Disengage the sensing element (5) from the plate (13) and remove the sensing element (5).
(12) FOR [42WD1] (HARNESS-FIRE DET, ENG 1 PYLON LOOP B STUD C), [42WD2] (HARNESS-FIRE DET, ENG 2 PYLON LOOP B STUD C)
(a) Remove the bolt (19) from the clamp (18).
(b) Remove the clamp (18) and disengage the cable (11) from the plate (17).
(c) Remove and discard the lacing tapes from the protective sleeve (12).
(d) Remove the protective sleeve (12) from the cable (10).
(e) Remove the nut (22), the washer (21) and the bolt (20).
(f) Disconnect the cable (11) from the sensing element (3).
(g) Remove the bolts (15) and the washers (16) from the pylon interface (14).
(h) Remove the plate (13).
(i) Carefully remove the sensing elements (3) and (5) from the pylon.
(j) Disengage the sensing element (3) from the plate (13):

[Rev.10 from 2021] 2026.03.31 23:43:33 UTC