(Continued)
Condition Maximum Serviceable Limit
Material that is gone (Fig. 610,
48-piece segment shroud only)
Permitted, if the dimension of A is less than 0.100 inch (2.54 mm), and the
dimension of B is less than 0.100 inch (2.54mm). Material can be gone from each
end of the segment, but must not go into the seal slots. Refer to the
Over-Serviceable-Limit Extensions in this section.
SUBTASK 72-00-00-296-037-G00
(11) Use the borescope to examine the rotor blades on the 1st-stage high pressure turbine (HPT)
(Figure 613).
NOTE: There are tip notches on the convex side of the four blades that are 90 degrees apart
on the first-stage rotor. The tip notches are for reference only and are not signs of
erosion.
If it is necessary, you can clean the blades with solvent, B00148 before the inspection.
(a) Examine all the areas of the rotor blades on the 1st-stage HPT for the conditions that
follow:
Condition Maximum Serviceable Limit
Codep coat that is gone Permitted with no quantity limit, if there are no holes or cracks in the affected area.
Oxidation of the parent metal (green
or black discoloration)
Permitted with no quantity limit, if there are no holes or cracks in the oxidized area.
Plugged cooling holes Permitted.
(b) Examine the leading edges of the rotor blades on the 1st-stage HPT for the conditions
that follow:
Condition Maximum Serviceable Limit
Material that is gone and tears in
area 'A'
Permitted, one blade in each set can have one sign of this damage. The damage
must have a diameter that is less than the radial space between the leading edge
holes (0.10 inch (2.54 mm)). The damage must not extend past the gill holes.
Material that is gone from area 'B' Not permitted.
Dents and cracks from hits in area 'A' Permitted, if they do not extend past the gill holes.
Axial cracks (with no sign of a hit) in
area 'A'
Permitted, if the cracks do not extend past the gill holes.
Dents and radial cracks in area 'B'
(not in the root radius)
Permitted, if the damage has a length that is less than the space between the
leading edge holes (0.10 inch (2.54 mm)).
Dents and radial cracks in area 'B'
(includes the root radius)
Permitted, if there is no torn metal.
Axial cracks in area 'B' Not Permitted.
Radial cracks (with no sign of a hit) in
area 'B'
Permitted, if the crack does not connect two or more leading edge holes.
Radial cracks (with no sign of a hit) in
area 'A'
Permitted.
(c) Examine the trailing edges of the rotor blades on the 1st-stage HPT for the conditions
that follow:
767
AIRCRAFT MAINTENANCE MANUAL
CF6-80A SERIES ENGINES
72-00-00
NoC
Page 614
D633T1B7 Aug 22/2017
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
To Next Page
Loading...
