Special Detailed Inspection (TC) of Forward Engine Mount Pylon Bolts, LH/RH [CFML]

TASK 71-21-11-220-802-A
Special Detailed Inspection (TC) of Forward Engine Mount Pylon Bolts, LH/RH

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

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.

WARNING: YOU MUST NOT TOUCH HOT PARTS WITHOUT APPLICABLE GLOVES. HOT PARTS CAN CAUSE AN INJURY.

ZONE: 400

1. Reason for the Job
Refer to the MPD TASK: 712133-01
SPECIAL DETAILED INSPECTION (TC) OF FORWARD ENGINE MOUNT PYLON BOLTS, LH/RH.
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)
No specific	Torque wrench: range to between 0.47 and 0.37 m.daN (41.59 and 32.74 lbf.in )
No specific	Torque wrench: range to between 44 and 32.8 m.daN (324.48 and 241.89 lbf.ft )
98D71203014000	1	TORQUE WRENCH SET CFM

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.14SBA1)	Textile-Lint free Cotton -

C. 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
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR, 461AL, 462AR

D. 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 71-21-11-000-804-A	Removal of the Forward Engine Mount Bolts (One at a time)
TASK 71-21-11-400-804-A	Installation of the Forward Engine Mount Bolts (One at a time)
TASK 78-30-00-040-809-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-30-00-440-809-A	Reactivation of the Thrust Reverser System after Ground Maintenance
TASK 78-36-00-010-806-A	Opening of the Thrust Reverser Cowl Doors
TASK 78-36-00-410-806-A	Closing of the Thrust Reverser Cowl Doors
Special Detailed Inspection (TC) of Forward Engine Mount Pylon Bolts

3. Job Set-up
Subtask 71-21-11-941-066-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 71-21-11-010-089-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 71-21-11-040-067-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 ground maintenance (Ref. AMM TASK 78-30-00-040-809).

Subtask 71-21-11-010-090-A

D. Get Access
(1) Open the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-010-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR

4. Procedure
Subtask 71-21-11-220-050-A

A. Special Detailed Inspection (Torque Check) of the Forward Engine-Mount Bolts

NOTE: This procedure is written for only one forward mount screw. Apply this procedure to each forward mount screws.

NOTE: Do not loosen the screw before to make the torque check.

(1) Get access to the forward engine mount at 12 O'clock area (engine junction area).
(2) Clean any dirt or unwanted material from the forward engine mount with Textile-Lint free Cotton - (Material No.14SBA1) .
(3) Torque check of the forward engine mount bolt (3):
(a) Remove the locking plates system of the forward engine mounts.
1 Remove the four screws (1) that attach the four locking plates (2) to the retainer.
2 Remove the four locking plates (2).
3 Visually examine the four screws (1), the four locking plates (2) and the retainer for indication of damage.

If there are scratches, marks and/or other damage, reject the parts.

(b) Measure the torque of the forward mount bolt (3).
1 The TORQUE value of the bolt (3) must be to between 44 and 32.8 m.daN (324.48 and 241.89 lbf.ft )

.
a Use the tool 98D71203014000 TORQUE WRENCH SET CFM to torque the bolts.
2 If the bolts (3) turn or if the torque value is less than the required torque value, replace the four bolts (3), the washers and the nuts (Ref. AMM TASK 71-21-11-000-804) and (Ref. AMM TASK 71-21-11-400-804).
3 If the torque value is correct, do the following procedure:
a Install the locking plates (2) and attach them to the retainer brackets with the screws (1).
b TORQUE the screws (1) to between 0.47 and 0.37 m.daN (41.59 and 32.74 lbf.in )

5. Close-up
Subtask 71-21-11-410-082-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the thrust reverser cowl-doors (Ref. AMM TASK 78-36-00-410-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL 452AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL 462AR

Subtask 71-21-11-440-061-A

B. Do the reactivation of the thrust reverser system after ground maintenance (Ref. AMM TASK 78-30-00-440-809).

Subtask 71-21-11-410-083-A

C. Close Access
(1) 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
(2) Remove the access platform(s).
(3) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.02 06:33:25 UTC