Reactivation of the Thrust Reverser System after Nacelle Maintenance (ICU) [CFML]

TASK 78-30-00-440-807-A
Reactivation of the Thrust Reverser System after Nacelle Maintenance (ICU)

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
A. The Isolation Control Unit (ICU) is a safety device that lets a mechanic make the thrust reverser safe for maintenance. When the ICU is in the deactivated position, the thrust reverser cannot automatically move in the stow direction or the deploy direction.
B. When the maintenance is complete, but before flight, you must do this procedure to permit automatic operation of the thrust reverser. There is a different procedure to make the thrust reverser deactivated for flight.
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	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 71-13-00-410-803-A	Closing of the Fan Cowl Doors
Deactivation-Reactivation of the Thrust Reverser

3. Job Set-up
Subtask 78-30-00-941-089-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) Make sure that the WARNING NOTICE(S) are in position to tell persons not to operate:

The ENG/MODE selector switch
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) Make sure that the WARNING NOTICE(S) is in position to tell persons not to energize FADEC 1(2).

Subtask 78-30-00-010-095-A

B. Get Access
(1) Make sure that the fan cowl doors are open (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) Make sure that the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE is in position under the left fan cowl door.

4. Procedure
Subtask 78-30-00-440-069-A

A. Activation of the Thrust Reverser after Maintenance
(1) Remove the 98N7830H001-000 T/R INHIBITION KIT from the forward hole in the ICU (2) and the inhibit lever (1).
(2) Move the inhibit lever (1) to the active position (away from the inhibit plunger (4)).
(3) Install the tethered pin (3) from the aft hole (5) of the ICU (2) of the inhibit lever (1).
(4) Check that "ICU ACTIVE" is now visible.

5. Close-up
Subtask 78-30-00-410-077-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR
(3) Remove the access platform(s).
(4) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 04:33:49 UTC