Removal of the Lower Bifurcation Latches [IAE]

TASK 78-32-53-000-010-A
Removal of the Lower Bifurcation Latches

FIN: 1000EM1 ** ON A/C NOT FOR ALL
FIN: 1000EM2 ** ON A/C NOT FOR ALL

1. Reason for the Job
This task supplies the data to remove the three lower bifurcation latches and the front latch at the forward end of the C-Duct.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	WARNING NOTICE(S)
FOR [1000EM2] (ENGINE-2)
No specific	AR	ACCESS PLATFORM 2M (6 FT)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [1000EM1] (ENGINE-1)
437AL, 438AR, 451AL, 452AR
FOR [1000EM2] (ENGINE-2)
447AL, 448AR, 461AL, 462AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 71-13-00-010-010-A	Opening of the Fan Cowls 437AL(447AL),438AR(448AR)
TASK 78-30-00-040-012-A	Deactivation of the Thrust Reverser Hydraulic Control Unit (HCU) for Ground Maintenance
TASK 78-32-00-010-010-A	Opening of the Thrust Reverser Halves
Bifurcation Latch Hook
Bifurcation Latch Keeper
Front Latch Hook
Front Latch Keeper

3. Job Set-up
Subtask 78-32-53-941-050-A ** ON A/C NOT FOR ALL

A. Safety Precautions
(1) On the center pedestal, on the ENG panel 115VU:
(a) Put a WARNING NOTICE(S) 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 overhead maintenance panel 50VU:
(a) Make sure that the ON legend of the ENG/FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) to tell persons not to energize the FADEC 1(2).

Subtask 78-32-53-010-050-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Open the fan cowls (Ref. AMM TASK 71-13-00-010-010):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR.
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR. Put the ACCESS PLATFORM 2M (6 FT) in position.

Subtask 78-32-53-040-050-A ** ON A/C NOT FOR ALL

C. Deactivate the thrust reverser.

WARNING: MAKE SURE THAT THE THRUST REVERSER HYDRAULIC CONTROL UNIT (HCU) IS DEACTIVATED BEFORE YOU DO WORK ON OR AROUND THE THRUST REVERSER. IF THE HCU IS NOT DEACTIVATED, THERE IS A RISK OF UNWANTED THRUST REVERSER OPERATION WHICH CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.

(1) Deactivate the thrust reverser hydraulic control unit (HCU) (Ref. AMM TASK 78-30-00-040-012).

Subtask 78-32-53-010-051-A ** ON A/C NOT FOR ALL

D. Open the thrust reverser halves (Ref. AMM TASK 78-32-00-010-010):
(1) FOR [1000EM1] (ENGINE-1)
451AL 452AR.
(2) FOR [1000EM2] (ENGINE-2)
461AL 462AR.

4. Procedure
Subtask 78-32-53-020-050-A ** ON A/C NOT FOR ALL

A. Remove the latch hook assembly.

Bifurcation Latch Hook ** ON A/C NOT FOR ALL

(1) Remove the nut (1), the washer (2), the bolt (4) and the bushings (3) from the latch hook housing (5).
(2) Remove the latch hook assembly (6).

NOTE: This subtask is the same for each of the three bifurcation latches.

Subtask 78-32-53-020-051-A ** ON A/C NOT FOR ALL

B. Remove the latch keeper and adjustment nut.

Bifurcation Latch Keeper ** ON A/C NOT FOR ALL

(1) Use a 5/32in. hexagonal wrench and turn the latch keeper adjustment nut (16) in a clockwise direction. Turn the adjustment nut until the latch keeper (17) is free.
(2) Remove the latch keeper and the adjustment nut from the latch keeper housing (18).

NOTE: This subtask is the same for each of the three bifurcation latches.

Subtask 78-32-53-020-052-A ** ON A/C NOT FOR ALL

C. Remove the front latch hook assembly.

Front Latch Hook ** ON A/C NOT FOR ALL

(1) Remove the upper end of the spring (31) from the spring support plate (37).
(2) Remove the nut (28), the washer (29), the bolt (35) and the bushings (30) from the latch hook housing (32).
(3) Remove the front latch hook assembly (36).
(4) Remove the spring (31) from the front latch hook housing.

Subtask 78-32-53-020-053-A ** ON A/C NOT FOR ALL

D. Remove the front latch keeper assembly.

Front Latch Keeper ** ON A/C NOT FOR ALL

(1) Remove the set screw (49) from the threaded end of the front latch keeper (48).
(2) Use a 5/32 in. hexagonal wrench and turn the latch keeper adjustment nut (16) in a clockwise direction. Turn the adjustment nut until the front latch keeper (48) is free.
(3) Remove the two screws (50) that attach the adjustment nut assembly to the keeper mount pad (47).
(4) Remove the adjustment nut assembly (16).

[Rev.10 from 2021] 2026.04.01 03:29:06 UTC