General Visual Inspection of the Thrust Reverser Hydraulic Tubes and Hoses [CFML]

TASK 78-31-49-210-802-A
General Visual Inspection of the Thrust Reverser Hydraulic Tubes and Hoses

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) - 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
TASK 78-30-00-040-807-A	Deactivation of the Thrust Reverser System for Nacelle Maintenance (ICU)
TASK 78-30-00-440-807-A	Reactivation of the Thrust Reverser System after Nacelle Maintenance (ICU)
TASK 78-31-49-000-814-A	Removal of the Thrust Reverser Hydraulic Tubes
TASK 78-31-49-000-815-A	Removal of the Pylon Tubes and Hoses
TASK 78-31-49-400-814-A	Installation of the Thrust Reverser Hydraulic Tubes
TASK 78-31-49-400-815-A	Installation of the Pylon Tubes and Hoses
Thrust Reverser Hydraulic Tubes and Hoses

3. Job Set-up
Subtask 78-31-49-941-135-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 a WARNING NOTICE(S) 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) Put a WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).

Subtask 78-31-49-010-240-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) - ADJUSTABLE in position.

Subtask 78-31-49-040-183-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 nacelle maintenance (Ref. AMM TASK 78-30-00-040-807).

4. Procedure
Subtask 78-31-49-210-061-A

A. Visual Inspection of the Pylon Hoses, Pylon Tubes, and Thrust Reverser Mounted Hydraulic Tubes
(1) Examine the tubes and hoses for:

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
1.Cracks	Not serviceable.
2.Dents	Dents must not be more than a depth of 10 percent of the nominal tube or hose diameter.
3.Nicks, scratches, chafing, or scores	Depth must not be more than 5 percent of the nominal wall thickness after removal of high metal by filing.	If the tube or hose is unserviceable, replace the pylon tube or pylon hose (Ref. AMM TASK 78-31-49-000-815) (Ref. AMM TASK 78-31-49-400-815) or thrust reverser mounted hydraulic tubes (Ref. AMM TASK 78-31-49-000-814) (Ref. AMM TASK 78-31-49-400-814).

5. Close-up
Subtask 78-31-49-440-120-A

A. Do the reactivation of the thrust reverser system after nacelle maintenance (Ref. AMM TASK 78-30-00-440-807).

Subtask 78-31-49-410-131-A

B. 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 03:35:29 UTC