2.
Dents
_
3.
Scratches
_
4.
Intermittent crazing
_
_
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72-31-01
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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
(d) Flyback Limits (50 hours maximum)
1) Composite material delamination or peeling, chipping, particles, or dents not more than that which follows: a) The depth is no more than 0.060 inch (1.524 mm). b) The damage has a diameter of no more than 1.50 inches
(38.10 mm). 2) Local cracks which are not longer than 0.500 inch (12.700 mm). 3) If the damage is in the above limits, the airplane is permitted to flyback.
4) If there are through cracks, dents, or surface peeling more than the above flyback limits, replace the inlet cone segment (AMM 72-31-01/401).
NOTE: The front segment of the inlet cone can be
____ continued in service if there are through cracks. But the front segment of the inlet cone must attach to the rear segment.
5) Any crack that ends less than 2.0 inches (50.8 mm) away from the trailing edge is permitted for the flyback limit only. a) Replace the inlet cone segment if the damage is more
than the given flyback limits above (AMM 72-31-01/401).
S 416-004-N00
(3) Install the front segment of the inlet cone (AMM 72-31-01/401).
TASK 72-31-01-206-005-N00
3. Inlet Cone External Surface Inspection.
______________________________________
A. References
(1)
AMM 72-31-01/401, Inlet Cone
B.
Access
(1)
Location Zone
412 Engine 1 - Front LPC Hub
422 Engine 2 - Front LPC Hub
432 Engine 3 - Front LPC Hub
442 Engine 4 - Front LPC Hub
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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
////////////////////////A / PW4000 SERIES /747-400 / ENGINES/MAINTENANCE MANUAL ////////////////////////
C. Procedure
S 226-006-N00
(1) Examine the inlet cone segments for chipping, cracks and
delamination:
NOTE: Chipping is an area with erosion where small particles of
____ surface material are gone. Chipping is pitting that was not caused by corrosion.
(a) Examine the external surface of the inlet cone segments for chipping, visual cracks and delamination caused by foreign object damage (FOD).
NOTE: FOD is caused by bird strike, ice that enters the inlet
____
cowl, or tools.
(b) Continue-In-Service Limits
1) The FOD visual limits of the external cone surface are given as follows: a) The damage that follows is permitted if it does not
cause crazing with the primary path to the inner surface of the cone:
1.
Small paint particles
_
2.
Dents
_
3.
Scratches
_
4.
Chipping
_
2) If there are cracks through the composite material on a surface location, you must replace the inlet cone. a) Cracks are permitted in the black protective paint but
must not progress into the composite material and must be within the limits that follow:
1.
Maximum crack length is 12.0 inches (304.8 mm) for
_ each crack.
2.
A maximum of 10 cracks are permitted for each inlet
_
cone.
3.
The cracks must be in the resin rich areas and must
_ not go into the composite material. Find the correct crack deptch by lightly sanding the surface with Emery Paper (P05-055).
4.
The cracks must not cause delamination.
_
5.
The end of the crack must be a minimum of 2.0
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