MAULE AEROSPACE TECHNOLOGY, INC.
MAINTENANCE MANUAL
FOR
MT-7-420
9/02
15
10
Power tur-
bine sup-
port scav-
enge oil
strut
Inspect and clean in-
ternal carbonaceous
deposits.
300 hr max.
Follow procedures in Inspec-
tion and Cleaning of Power
Turbine Support Scavenge
Oil Strut, para 3-166.
11
External
sump
Visually inspect for
internal carbonaceous
deposits.
300 hr max.
Clean or replace sump as
required.
Special Engine Inspections
Special inspections are required when the engine has been subjected to abnormal operat-
ing conditions, when engine damage is suspected, or when associated parts are removed from
the engine. The special occurrence, the component or system to be inspected, and the nature
of the inspection are given in Table III-11, Allison Operating and Maintenance Manual.
Sudden Stoppage Inspection
The following inspections must be satisfactorily completed whenever the propeller strikes a
moving or stationary object.
NOTE: Sudden stoppage is the momentary or complete interruption in the rotation of the air-
craft propeller and engine drive system when the aircraft propeller comes in contact with the
ground, water, trees, or other obstacles. The shock felt by the drive system requires that the
engine be inspected and/or overhauled by a designated overhaul facility as a result of possible
damage.
If the aircraft propeller strikes an object causing damage to the propeller which can be cor-
rected by light grinding or filing and normal blending of the blades (nicks, gouges, scratches,
etc.) in accordance with applicable propeller service instructions, complete the following in-
spection:
a.
Inspect the engine inlet for foreign objects.
b.
Inspect the compressor blades and vanes for foreign object damage.
c.
Inspect the compressor case for evidence of blade tip rub.
d.
Inspect all magnetic plugs for metal accumulation. (Refer to Magnetic Plug, Para 3-172
and Table III-14.)
e.
Rotate the propeller by hand and check for unusual noise.
f.
Motor the engine and check for unusual noise.
g.
Operate the engine for 30 minutes on the ground then check the magnetic plugs for met-
al accumulation.
