Visual Inspection of the Engine Fuel Tubes [CFMI]

TASK 73-11-49-210-040-A
Visual Inspection of the Engine Fuel Tubes

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	ACCESS PLATFORM 1M(3 FT)
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

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

C. Referenced Information

REFERENCE	DESIGNATION
TASK 71-13-00-010-040-A	Opening of the Fan Cowl Doors
TASK 71-13-00-410-040-A	Closing of the Fan Cowl Doors
TASK 73-11-49-000-040-A	Removal of the Fuel Tubes
TASK 73-11-49-400-040-A	Installation of the Fuel Tubes
CMM 710017	(for corrective action)
Engine Fuel Tubes

3. Job Set-up
Subtask 73-11-49-941-059-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 73-11-49-010-056-A ** ON A/C NOT FOR ALL

B. Get Access
(1) Open the fan cowl doors: (Ref. AMM TASK 71-13-00-010-040)
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(2) Put an ACCESS PLATFORM 1M(3 FT) in position.

4. Procedure
Subtask 73-11-49-210-051-A ** ON A/C NOT FOR ALL

A. Detailed Visual Inspection of the Engine Fuel Tubes

(1) Do a visual inspection of the engine fuel tubes

Engine Fuel Tubes ** ON A/C NOT FOR ALL

NOTE: Engine fuel tubes that are removed due to damage may be sent to the shop for repair, review and possible return to service CMM 710017.

INSPECT/CHECK	MAXIMUM SERVICEABLE LIMITS	REMARKS
1.Examine the engine fuel tubes, look for:
A.Wrinkles in bends	Maximum depth must be less than 5 percent of the tube diameter.	If the damage is more than the allowable limits, replace the tube (Ref. AMM TASK 73-11-49-000-040) and (Ref. AMM TASK 73-11-49-400-040).
B.Dents	Maximum depth must be less than 20 percent of the tube outside diameter. Maximum radius of the dent is not less than 2 times the wall thickness of the tube. Maximum of 4 dents for each 1 foot (305 mm) length of tube. Minimum distance of 1.0 in. (25.4 mm) between dents. No limit to dents permitted except in bends, no dents are permitted in bends.	If the dents are less than the allowable limits, repair the dents at 750 Flight Hours / 750 Flight Cycles / 4 calendar months (whichever the earliest). If the dents are more than the allowable limits, replace the tube (Ref. AMM TASK 73-11-49-000-040) and (Ref. AMM TASK 73-11-49-400-040).
C.Flat areas	Maximum length must be less than 3 times the outside diameter of the tube. Contour change must be less than 20 percent of the outside diameter of the tube.	If the flat areas are less than the allowable limits, repair the tube at 750 Flight Hours / 750 Flight Cycles / 4 calendar months (whichever the earliest). If the flat areas are more than the allowable limits, replace the tube (Ref. AMM TASK 73-11-49-000-040) and (Ref. AMM TASK 73-11-49-400-040).
D.Nicks, scratches, chafing in straight section	Maximum depth must be less than 10 percent of the wall thickness of the tube. There is no limit to the number of nicks, scratches or chafing permitted in the straight section of the tube.	If the damage is less than the allowable limits, repair the damage at 750 Flight Hours / 750 Flight Cycles / 4 calendar months (whichever the earliest). If the damage is more than the allowable limits, replace the tube (Ref. AMM TASK 73-11-49-000-040) and (Ref. AMM TASK 73-11-49-400-040).
E.Nicks, scratches, chafing in bends	Maximum depth must be less than 10 percent of the wall thickness of the tube.	If the damage is less than the allowable limits, repair the damage at 750 Flight Hours / 750 Flight Cycles / 4 calendar months (whichever the earliest). If the damage is more than the allowable limits, replace the tube (Ref. AMM TASK 73-11-49-000-040) and (Ref. AMM TASK 73-11-49-400-040).
F.Splits, cracks, kinks	Maximum length must be less than the tube outside diameter. Maximum length same as more than the tube outside diameter.	If damage is less than the tube outside diameter, do the weld repair at 750 Flight Hours / 750 Flight Cycles / 4 calendar months (whichever the earliest). If the damage is the same as or more than the tube outside diameter, replace the tube (Ref. AMM TASK 73-11-49-000-040) and (Ref. AMM TASK 73-11-49-400-040).

5. Close-up
Subtask 73-11-49-410-055-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 fan cowl doors: (Ref. AMM TASK 71-13-00-410-040)
(a) FOR [1000EM1] (ENGINE-1)
437AL 438AR
(b) FOR [1000EM2] (ENGINE-2)
447AL 448AR
(3) Remove the access platform(s).
(4) Remove the WARNING NOTICE(S).

[Rev.10 from 2021] 2026.04.01 02:55:42 UTC