Removal of the Pylon Fire-Detector Ramp-Assembly

TASK 26-12-16-000-804-A
Removal of the Pylon Fire-Detector Ramp-Assembly

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
FIN: 3WD1
FIN: 3WD2
FIN: 4WD1
FIN: 4WD2

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	CAP - BLANKING
No specific	1	CLOTH - PROTECTIVE
No specific	1	FLASHLIGHT
No specific	1	MIRROR - INSPECTION
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
415	LOWER PYLON
425	LOWER PYLON
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 71-52-43-000-803-A	Removal of the Electrical Harness from the Pylon to the Core Fire Detector Elements
TASK 71-52-43-000-804-A	Removal of the Electrical Harness from the Pylon to the Environmental Control System (ECS) Valves
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
Pylon Fire-Detector Ramp-Assembly

3. Job Set-up
Subtask 26-12-16-861-056-A

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

Subtask 26-12-16-941-054-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 26-12-16-865-064-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 26-12-16-010-070-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 26-12-16-040-059-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 26-12-16-010-071-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.

Subtask 26-12-16-020-062-A

G. Removal of the Components
(1) Disconnect the electrical connectors of the pylon:
(a) For electrical harnesses 4204KS and 4205KS (Ref. AMM TASK 71-52-43-000-803).
(b) For electrical harness 4228KS (Ref. AMM TASK 71-52-43-000-804).

4. Procedure
Subtask 26-12-16-020-063-B

A. Removal of the Pylon Fire-Detector Ramp-Assembly

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.

CAUTION: DO NOT BEND THE MANIFOLD OF THE SENSING ELEMENT. IF YOU BEND IT, YOU CAN CAUSE DAMAGE TO THE WELDING.

(1) Put a CLOTH - PROTECTIVE below the work area to help you to find the fasteners if they fall.
(2) If necessary, use a FLASHLIGHT and an MIRROR - INSPECTION.
(3) Turn the eight quarter-turn fasteners (12) by one quarter of a turn and open the eight clamps (10) and (11).
(4) Remove the four nuts (8) and (9) and disengage the four electrical connectors (6) and (7) from the two responders (5).
(5) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.
(6) Put blanking caps on the two responders (5).
(7) Carefully disengage the four electrical cables (6) and (7) from the eight clamps (10) and (11).
(8) Remove the bolts (1) and the washers (2) from the ramp assembly (4).
(9) Carefully remove the ramp assembly (4) from the right side of the pylon (3).
(10) Make sure that the work area is clean and clear of tools and other items.

[Rev.10 from 2021] 2026.03.31 23:42:53 UTC