Special Detailed Inspection (Endoscope) of the Forward Engine Mount Link Lugs [IAE]

TASK 71-21-12-200-805-A
Special Detailed Inspection (Endoscope) of the Forward Engine Mount Link Lugs

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

1. Reason for the Job
Refer to the MPD TASK: 712112-02
SPECIAL DETAILED INSPECTION (ENDOSCOPE) OF FORWARD ENGINE MOUNT LINK LUGS
This TASK gives the data for a special detailed inspection (endoscope) of the forward engine mount lugs.

NOTE: These inspection criteria are only for those parts of the engine that you can see when the engine is installed on an airplane. Refer to the CMM 71-21-12 Inspection/Check for areas of the forward engine mount link lugs that you cannot see when the engine is installed.

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE
No specific	1	BORESCOPE - FLEXIBLE
No specific	1	FLASHLIGHT
No specific	1	MIRROR - INSPECTION, FLEXIBLE
No specific	AR	WARNING NOTICE(S)

B. Consumable Materials

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

C. Work Zones and Access Panels

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

D. Referenced Information

REFERENCE	DESIGNATION
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 71-21-12-000-011-A	Removal of the Forward Engine Mount
TASK 71-21-12-400-011-A	Installation of the Forward Engine Mount
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
CMM 712112
Forward Engine Mount

3. Job Set-up
Subtask 71-21-12-941-061-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 71-21-12-010-077-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 the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in to position.

Subtask 71-21-12-040-063-A ** ON A/C NOT FOR ALL

C. Deactivate the Thrust Reverser

WARNING: MAKE SURE THAT THE THRUST REVERSER HYDRAULIC CONTROL UNIT (HCU) IS DEACTIVATED BEFORE YOU DO WORK ON OR AROUND THE THRUST REVERSER. IF THE HCU IS NOT DEACTIVATED, THERE IS A RISK OF UNWANTED THRUST REVERSER OPERATION WHICH CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.

(1) Deactivate the thrust reverser Hydraulic Control Unit (HCU) (Ref. AMM TASK 78-30-00-040-012).

Subtask 71-21-12-010-078-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 71-21-12-110-053-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 71-21-12-220-050-A ** ON A/C NOT FOR ALL

A. Detailed Inspection of the Forward Engine Mount Link Lugs

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

(1) Visually examine the links for cracks and corrosion. Give special attention to the critical areas of the links (Ref. Detail C).
(2) Use a FLASHLIGHT, MIRROR - INSPECTION, FLEXIBLE and BORESCOPE - FLEXIBLE to examine areas that are hard to see.

NOTE: The full circumference of the lugs (180°) may not be visible.

(3) Discoloration caused by corrosion is acceptable if there is no pitting or reduction in cross-sectional area of the component.
(4) No cracks are allowed. If cracks are found, remove and replace the mount (Ref. AMM TASK 71-21-12-000-011) and (Ref. AMM TASK 71-21-12-400-011).

NOTE: Discard the damaged linked assembly. Do not discard the mount. Remove and send the mount to the overhaul shop for a detailed inspection (Refer to CMM 712112).

(5) Gouges, nicks, scratches, and other surface damages.
(a) Refer to CMM 712112.

5. Close-up
Subtask 71-21-12-410-079-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 71-21-12-440-061-A ** ON A/C NOT FOR ALL

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

Subtask 71-21-12-410-080-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 WARNING NOTICE(S).
(3) Remove the access platform(s).

[Rev.10 from 2021] 2026.04.01 02:30:23 UTC