Special Detailed Inspection of FWD Engine Mount Pylon Bolts [IAE]

TASK 71-21-12-200-802-A
Special Detailed Inspection of FWD Engine Mount Pylon Bolts

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

ZONE: 400

1. Reason for the Job
Refer to the MPD TASK: 712111-06
SPECIAL DETAILED INSPECTION (TC) OF FWD ENGINE MOUNT PYLON BOLTS.
This task gives the data for a special detailed inspection of the forward engine mount pylon bolts.

NOTE: The effectivity of this task is "ALL". To know if this task is applicable to your aircraft, refer to the MPD task applicability.

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 282 and 256 lbf.ft (38.23 and 34.71 m.daN )
No specific	Torque wrench: range to between 35.4 and 23.89 lbf.in (0.40 and 0.27 m.daN )
98D71203001001	1	CHEST-TORQUE SET NM - IAE V2500 ENGINE

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.V01-002)	cleaning fluid
(Material No.V02-147)	lockwire
(Material No.14SBA1)	Textile-Lint free Cotton -

C. Work Zones and Access Panels

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

D. Referenced Information

REFERENCE	DESIGNATION
TASK 70-23-11-911-013-A	General Torque Tightening Techniques
TASK 70-40-11-911-014-A	Locking Devices General Information
TASK 71-13-00-010-010-A	Opening of the Fan Cowls 437AL(447AL),438AR(448AR)
TASK 71-13-00-410-010-A	Closing of the Fan Cowls 437AL(447AL),438AR(448AR)
TASK 71-21-12-000-010-A	Removal of the Forward Engine Mount Bolts One at a Time
TASK 71-21-12-400-010-A	Installation of the Forward Engine Mount Bolts One at a Time
TASK 78-30-00-040-012-A	Deactivation of the Thrust Reverser Hydraulic Control Unit (HCU) for Ground Maintenance
TASK 78-30-00-440-012-A	Re-activation of the Thrust Reverser Hydraulic Control Unit (HCU) after Ground Maintenance
TASK 78-32-00-010-010-A	Opening of the Thrust Reverser Halves
TASK 78-32-00-410-010-A	Closing of the Thrust Reverser Halves
Forward Engine Mount Bolts

3. Job Set-up
Subtask 71-21-12-941-056-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 71-21-12-010-068-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.
(2) Put an ACCESS PLATFORM 2M (6 FT) in position.

Subtask 71-21-12-040-058-A ** ON A/C NOT FOR ALL

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

Subtask 71-21-12-010-069-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.

Subtask 71-21-12-110-052-A ** ON A/C NOT FOR ALL

E. Clean the Forward Engine Mount.
(1) Clean the forward engine mount with a Textile-Lint free Cotton - (Material No.14SBA1) made moist with cleaning fluid (Material No.V01-002) .

4. Procedure
Subtask 71-21-12-210-056-A ** ON A/C NOT FOR ALL

A. Do a torque check of the forward engine mount-bolts.

Forward Engine Mount Bolts ** ON A/C NOT FOR ALL

(1) Do not loosen the bolts before to do a check of the torque.
(2) Do the torque check one bolt at a time.
(3) Remove the nut (13), washer (12), retainers (9) and (11), washer (8) and bolt (7).
(4) Remove the lockwire:

WARNING: USE PROTECTIVE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.

(a) Remove the lockwire from the forward-center engine mount-bolt (1).
(5) Torque the bolts:

CAUTION: MAKE SURE THAT THE TORQUE WRENCH DOES NOT TOUCH THE FORWARD ENGINE MOUNT DURING TIGHTENING TO NOT CHANGE THE TORQUE APPLIED TO THE BOLTS.

(a) Use the special tool 98D71203001001 CHEST-TORQUE SET NM - IAE V2500 ENGINE to do the torque check of the forward engine mount-bolts (1) and (16).

NOTE: The given torque value includes the length of the torque wrench.

(b) Use the torque wrench from the 98D71203001001 CHEST-TORQUE SET NM - IAE V2500 ENGINE to torque the forward engine mount-bolt (16).
(c) Use the torque wrench and the load reducer from the 98D71203001001 CHEST-TORQUE SET NM - IAE V2500 ENGINE to torque the forward-center engine mount-bolt (1).
(d) TORQUE the forward engine mount-bolts (1) and (16) to between 282 and 256 lbf.ft (38.23 and 34.71 m.daN )

in the tightening direction (Ref. AMM TASK 70-23-11-911-013).
1 When you use the load reducer with the torque wrench, it changes the value of the torque selected. You must set the value to between 76.80 lbf.ft (10.41 m.daN) and 84.48 lbf.ft (11.45 m.daN) on the wrench to get the torque necessary for the forward-center engine mount-bolt (1).
(6) Do a check of the bolts and the nuts:

CAUTION: ALL BOLTS AND NUTS REMOVED BECAUSE OF FAILURE OF THE INSTALLATION TORQUE CHECK MUST BE DISCARDED.

(a) If the forward engine mount-bolts (1) or (16), or the nuts (3) or (14) turn, replace all the five bolts and nuts, one at a time (Ref. AMM TASK 71-21-12-000-010) and (Ref. AMM TASK 71-21-12-400-010).
(7) Install the lockwire:

(a) Safety the forward-center engine mount-bolt (1) with the lockwire (Material No.V02-147) (Ref. AMM TASK 70-40-11-911-014).
(8) Install the retainer assemblies on the forward engine mount-bolts (Ref. AMM TASK 71-21-12-400-010).
(9) TORQUE the bolts (7) to between 35.4 and 23.89 lbf.in (0.40 and 0.27 m.daN )

(Ref. AMM TASK 70-23-11-911-013).

5. Close-up
Subtask 71-21-12-410-069-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the thrust reverser halves (Ref. AMM TASK 78-32-00-410-010):
(a) FOR [1000EM1] (ENGINE-1)
451AL 452AR
(b) FOR [1000EM2] (ENGINE-2)
461AL 462AR.

Subtask 71-21-12-440-056-A ** ON A/C NOT FOR ALL

B. Activate the thrust reverser HCU (Ref. AMM TASK 78-30-00-440-012).

Subtask 71-21-12-410-070-A ** ON A/C NOT FOR ALL

C. Close Access
(1) Close the fan cowls (Ref. AMM TASK 71-13-00-410-010):
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR.
(2) Remove the access platform(s).
(3) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 02:30:22 UTC