Removal of the Thrust Reverser Blocker Doors [CFML]

TASK 78-32-42-000-804-A
Removal of the Thrust Reverser Blocker Doors

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.

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)
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL, 438AR
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR

C. Referenced Information

REFERENCE	DESIGNATION
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 78-32-15-000-801-A	Removal of the Slat Panel
TASK 78-32-43-000-806-A	Removal of the Thrust Reverser Cascades
TASK 78-32-47-000-802-A	Removal of the Link Arm Fitting Fairing
TASK 78-32-50-010-801-A	Manually Deploy the Translating Cowl
TASK 78-36-45-000-801-A	Removal of the Thrust Reverser Hinge Access Panels
Thrust Reverser Blocker Doors
Upper Thrust Reverser Blocker Door

3. Job Set-up
Subtask 78-32-42-941-065-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 78-32-42-010-082-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 2M (6 FT) in position.

Subtask 78-32-42-040-070-A

C. Deactivation of the Thrust Reverser System 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 maintenance (Ref. AMM TASK 78-30-00-040-807).

Subtask 78-32-42-010-083-A

D. Get Access
(1) Manually deploy the translating cowl (Ref. AMM TASK 78-32-50-010-801).
(2) Remove the two adjacent thrust reverser cascades to get access to the blocker door that you will remove (Ref. AMM TASK 78-32-43-000-806).
(3) If you will remove the upper blocker door, remove the panels that follow from the applicable side of the engine:

NOTE: It is only necessary to remove these panels if you will remove the upper blocker door.

(a) Remove the hinge access panel (Ref. AMM TASK 78-36-45-000-801).
(b) Remove the slat panel (Ref. AMM TASK 78-32-15-000-801).

NOTE: Refer to figure for an example of a thrust reverser with the hinge access panel, the slat clearance panel, and the four highest cascades removed. This is the configuration necessary for removal of an upper blocker door.

4. Procedure
Subtask 78-32-42-020-063-A

A. Removal of the Thrust Reverser Blocker Door
(1) Examine the two hinges where the blocker door (9) attaches to the translating cowl to identify the two types of hinges.
(a) The hinge with two washers (12) and (14) is known as the floating hinge.
(b) The hinge with five washers (19), (22) and (23) is known as the fixed hinge.
(c) Make a written report of the position of the fixed and floating hinges to use during installation.
(2) Remove the cotter pin (3), nut (4), washer (5), bolt (8), spacer (7) and washer (1) that attach the link arm (2) to the fixed structure fitting (6) (Ref. AMM TASK 78-32-47-000-802).
(3) Move the link arm.

CAUTION: MAKE SURE THAT THE FREE END OF THE LINK ARM AND THE BLOCKER DOOR DOES NOT FALL. IF IT FALLS, THIS CAN CAUSE DAMAGE TO THE BLOCKER DOOR OR ADJACENT COMPONENTS.

(a) Carefully move the link arm (2) away from the fixed structure fitting (6).

NOTE: With the link arm disconnected, the blocker door (9) and the link arm are free to move.

NOTE: You can apply protective material to the blocker door and link arm to help prevent unwanted movement and damage.

(4) To get access to the hinges, you can move the blocker door (9) and link arm (2) to a different position.

NOTE: It could be necessary for one person to hold the blocker door while a second person removes the fasteners.

(5) Remove the nut (13), washer (12), bolt (16), washer (14), spacer (15) and spacer (11) that attach the blocker door (9) to the floating hinge (10).
(6) Remove the nut (21), washers (22), washer (23), bolt (18), washer (19) and spacer (20) that attach the blocker door (9) to the fixed hinge (17).
(7) Carefully remove the blocker door (9) with the link arm (2) attached through the opening of the two removed cascades.

Subtask 78-32-42-020-066-A

B. Removal of the Thrust Reverser Blocker Door Link Arm
(1) Remove the bolt (24), washer (25), bushing (26), washer (27), nut (28) and bushing (29).
(2) Remove the link arm (2).

[Rev.10 from 2021] 2026.04.01 13:13:34 UTC