TM 55-2835-208-23
2-5 INSPECT COMPRESSOR ROTOR (Continued)
2-5
4.
Using a machinists scale and a
small
mirror,
measure
the
depth of any eroded areas near
the
root of
the
compressor
blade
(1)
Measure
short
blades (2) as
well
as long
blades (3).
Erosion up to 0.060 inch
depth permits continued
APU operation but requires
a 10 hour APU operation
inspection cycle.
Maximum
use is 50 hours or until
the availability of a
replacement APU.
5.
Erosion at blade roots shall
not exceed 0.125 inch depth,
measured
axially
from
blade
leading edge (4).
Replace APU
assembly if
erosion
exceeds
0.125 inch.
GO TO NEXT PAGE
2-11
