Removal of the Finger Seals [CFML]

TASK 78-12-41-000-801-A
Removal of the Finger Seals

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: 400

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	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
400	POWER PLANT, NACELLES AND PYLONS
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL, 438AR, 451AL, 452AR, 473AL, 473AR
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR, 461AL, 462AR, 483AL, 483AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 54-57-22-000-815-A	Removal of the Rear Mount Fairing (RMF) Door
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
Finger Seals

3. Job Set-up
Subtask 78-12-41-941-050-A

A. 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 78-12-41-010-050-A

B. 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
(2) Put an ACCESS PLATFORM 1M(3 FT) in position.

Subtask 78-12-41-040-050-A

C. Deactivation of the Thrust Reverser System for nacelle 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 78-12-41-010-051-A

D. 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

Subtask 78-12-41-010-065-A

E. Remove the Rear Mount Fairing (RMF) Doors (Ref. AMM TASK 54-57-22-000-815):
(1) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
473AL 473AR.
(2) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
483AL 483AR.

4. Procedure
Subtask 78-12-41-020-050-A

A. Removal of the Finger Seals
(1) Untighten the screw (5) on the right side of the finger seal set (4) to remove the finger seal (2).

NOTE: In order to disengage the set to be removed from the above nearest set, its first screw has to be untightened.

(2) Remove the three screws (1) that attach the set of finger seals (2) to the support (3).
(3) Remove the set of finger seals (2).

NOTE: Remove the sets of finger seals (2) from the left side to the right side of the thrust reverser.

NOTE: It is possible to remove only one set of finger seals (2). To do so, pull the side laying on one adjacent set and slide it from under the other adjacent set.

NOTE: This procedure is given for one set of the finger seals (2) and it is the same for the other five sets of finger seals (2).

[Rev.10 from 2021] 2026.04.01 13:13:22 UTC