Inspection of the Pressure Oil Tubes [IAE]

TASK 79-21-49-200-010-A
Inspection of the Pressure Oil Tubes

FIN: 1000EM1 ** ON A/C NOT FOR ALL
FIN: 1000EM2 ** ON A/C NOT FOR ALL

1. Reason for the Job
This TASK supplies the data for the inspection of the pressure oil tubes.
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	AR	WARNING NOTICE(S)

B. 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

C. Referenced Information

REFERENCE	DESIGNATION
TASK 70-42-11-300-010-A	Hand Polish and Blend Procedure
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 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

3. Job Set-up
Subtask 79-21-49-941-050-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 79-21-49-010-050-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 79-21-49-040-050-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 79-21-49-010-051-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.

4. Procedure
Subtask 79-21-49-210-050-A ** ON A/C NOT FOR ALL

A. Visually examine the pressure oil tubes for dents, nicks, fretting and scoring
(1) Dents:
(a) Smooth dents of a large area relative to depth:
1 That do not decrease the diameter of the tube by more than 10 percent at one point, accept it.
2 That decrease the diameter of the tube by more than 10 percent at a point, reject it.
3 Tubes with a diameter equal or more than 0.5 in. (12.7 mm):
a when they are not less than 0.5 in. (12.7 mm) to the end fitting, accept.
b when they are less than 0.5 in. (12.7 mm) to the end fitting, reject.
4 Tubes with a diameter less than 0.5 in. (12.7 mm):
a when they are not less than the tube diameter to the end fitting, accept.
b when they are less than the tube diameter to the end fitting, reject.
(b) Smooth dents of a small area up to 0.125 in. 2(80.6 mm2):
1 With a smooth bottom and their depth is 0.015 in. (0.38 mm) or less on the external surface of a bend, accept it.
2 When their depth is more than 0.015 in. (0.38 mm) on the external surface of a bend, reject it.
3 With a smooth bottom and their depth is 0.025 in. (0.63 mm) or less on other sections of the tube, accept it.
4 When their depth is more than 0.025 in. (0.63 mm) , reject it.
5 Tubes with a diameter equal or more than 0.5 in. (12.7 mm):
a when they are not less than 0.5 in. (12.7 mm) to the end fitting, accept.
b when they are less than 0.5 in. (12.7 mm) to the end fitting, reject.
6 Tubes with a diameter less than 0.5 in. (12.7 mm):
a when they are not less than the tube diameter to the end fitting, accept.
b when they are less than the tube diameter to the end fitting, reject.
(c) Which are not smooth, reject it.
(2) Nicks:
(a) With a smooth bottom and not more than 0.004 in. (0.1 mm) in depth and all burrs have been removed (Ref. AMM TASK 70-42-11-300-010), accept it.
(b) With a bottom that is not smooth or is more than 0.004 in. (0.1 mm) in depth, reject it.
(c) On the external surface of a bend, reject it.
(3) Fretting:
(a) Up to a maximum depth of 0.004 in. (0.1 mm), accept it.
(b) More than 0.004 in. (0.1 mm) in depth, reject it.
(4) Scoring:
(a) With a maximum depth of 0.004 in. (0.1 mm) can be blended out (Ref. AMM TASK 70-42-11-300-010).
(b) More than 0.004 in. (0.1 mm) in depth, reject it.

5. Close-up
Subtask 79-21-49-410-050-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 79-21-49-440-050-A ** ON A/C NOT FOR ALL

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

Subtask 79-21-49-410-051-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 13:14:22 UTC