TM 55-2840-241-23
CHAPTER
6
ENGINE DISASSEMBLY
6-1. Scope.
This chapter provide sequential disassembly pro-
cedures for major functional assemblies. Procedures
are provided for disassembly only to the extent neces-
sary for Aviation Unit and Aviation Intermediate
Maintenance activities to perform cleaning, inspec-
tion, repair, and/or replacement of provisioned parts in
accordance with the Maintenance Allocation Chart
and TM 55-2840-241-23P.
6-2. Compressor Case Half Removal.
One compressor case half may be removed to inspect
the rotor blades, stator vanes, plastic coating, and front
support welds. (Refer to paragraphs 7-9 thru 7-12.)
Removal of the compressor case half is required every
300 hours when operating in environments which are
conducive to corrosion and/or sand erosion. Otherwise,
the removal of the compressor case half is authorized
only as a last resort to determine the cause of low engine
performance when foreign object damage (FOD) or sand erosion
is suspected. Before removing the case half ensure that
low engine performance is not caused by a defective
compressor bleed valve or anti-icing valve, leaking
scroll-to-rear diffuser or compressor discharge
air tube seals, or a dirty compressor.
Remove only one case half at a time. DO
NOT remove both case halves at the same
time. Ensure that the removed case half is
properly reinstalled and that the bolts are
tightened to the required torque values
before any of the bolts on the other case
half are loosened. Misalignment of the
compressor could result if both case
halves were removed simultaneously.
(Refer to paragraph 8-2.)
a. Remove the compressor bleed valve. (Refer to
paragraph 5-33.)
b. Remove the anti-icing air tubes (23, 26, figure
5-13) between the anti-icing air valve and the com-
pressor front support.
c. Mark the location of nameplate (8, figure 6-1)
when the applicable compressor case half-to-front sup-
port bolts (5) are to be removed. This is to ensure that
the nameplate will be returned to the same location at
assembly.
d. Remove one compressor case half (2) by remov-
ing 16 horizontal splitline nuts (7) and bolts (1), five
case half-to-front support nuts (3) and bolts (5), and
eight case half-to-front diffuser nuts (6) and bolts (4).
Lift the case half straight out.
Change 23 6-1
