(a) Damage to the stage 1-14 blades that is more than the maximum serviceable limits, the
airplane is permitted to continue in use for a maximum number of cycles allowed in the
Continue-in-Operation table if:
1) The damage is within repairable limits for borescope blending of HPC stage 1-14
rotor blades (PAGEBLOCK 72-35-00/801)
2) A maximum of one engine per aircraft has damage exceeding serviceable limits.
3) A borescope inspection of downstream HPC stages has been performed and all
blade damage is within blend repairable limits.
Condition Maximum Serviceable Limit
Cracks Permitted only on the 12th - 14th stage blades. The cracks must be in a radial
direction along the tip of the blade. Refer to the Continue-In-Operation Limits.
Nicks and dents on the center panel of
the blade
This type of damage is permitted if:
- It does not go all the way across the blade.
- It is at least 0.20 inch (5.1 mm) from the edge of the blade.
- It does not make a hole in the blade.
- It is less than 0.15 inch (3.8 mm) in diameter.
Tears, nicks, cracks, missing material,
and dents on the leading
and the trailing edges
STAGE 1-9 BLADES:
All nicks and dents are permitted, if not more than 0.05 inch (1.3 mm) in depth,
and the blade is not torn or bent. Torn edges are not permitted.
STAGE 10-12 BLADES:
If the damage is less than 0.30 inch (7.6 mm) from the tip: All nicks, dents, and
missing material are permitted, if not more than 0.05 inch (1.3 mm) in depth,
and the blade is not torn, cracked or bent. Nicks, dents, and missing material
less than 0.120 inch (3.05 mm) in depth, or cracks and tears less than 0.120
inch (3.05 mm) in length are permitted if no more than six blades in each stage
are damaged.
If the damage is more than 0.30/inch (7.6 mm) from the tip: All nicks, dents, and
missing material are permitted, if not more than 0.05 inch (1.3 mm) in depth,
and the blade is not torn or bent. Torn or cracked edges are not permitted.
STAGE 13-14 BLADES: If the damage is less than 0.50 inch (12.7 mm) from
the tip: All nicks, dents, and missing material are permitted, if not more than
0.05 inch (1.3 mm) in depth, and the blade is not torn, cracked, or bent. Nicks,
dents, and missing material less than 0.120 inch (3.05 mm) in depth or cracks
and tears less than 0.120 inch (3.05 mm) in length are permitted if no more
than six blades in each stage are damaged. If the damage is more than 0.50 inc
(12.7 mm) from the tip: All nicks, dents, and missing material are permitted if
not more than 0.05 inch (1.3 mm) in depth and the blade is not torn or bent.
Torn or cracked edges are not permitted.
Tip corners that are not there
(Figure 604)
Permitted, on a maximum of six blades on each stage if the engine vibration is
in the limits and there is no downstream damage. If you find damage, do a
borescope inspection of downstream HPC blades. Inspect through borescope
ports B1-1 through B1-6, B1-9, B1-11, B1-12, and B1-13 as applicable.
Tip clang marks (Figure 602) Permitted, if the tip is not cracked.
NOTE: Damage of this type is a sign of a compressor hard stall. Refer to the
Unusual Condition Inspection in this procedure.
Tip Curl Permitted, if it does not engage with parts of the compressor stator during
operation.
767
AIRCRAFT MAINTENANCE MANUAL
CF6-80A SERIES ENGINES
72-00-00
NoC
Page 604
D633T1B7 Dec 22/2016
ECCN 9E991 BOEING PROPRIETARY - Copyright © Unpublished Work - See title page for details
EFFECTIVITY
ABX 001-007, 011, 012, 016-019, 021, 022, 025, 101,
109, 114, 115, 314-999
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