Maintenance Inspections
Teledyne Continental Motors, Inc.
TM
7-46
IOF-550 Permold Series Engine Maintenance Manual
1 April 2007
7-4.
Unscheduled Maintenance
7-4.1. Propeller Strike
A propeller strike is any incident (whether or not the engine is operating) which either
requires repair to a propeller blade (other than minor dressing of the blade) or where the
propeller makes contact with any object that results in loss of engine RPM.
Propeller strikes against the ground or any object can cause engine and component
damage even though the propeller still may continue to rotate. This damage can result in
catastrophic engine failure.
In cases where a small foreign object such as a small stone, strikes the propeller during
operation, inspect and repair the propeller in accordance with the propeller
manufacturer’s instructions. Any time foreign object damage requires removal of the
propeller for repair(s) other than minor dressing of the blades, adhere to the procedure in
the “Propeller Strike Inspection” in Section 7-4.2.
WARNING
Do not attempt to dress a propeller blade without consulting
the propeller manufacturer’s instructions. Stresses imposed on
the propeller are more concentrated in areas that are nicked
and cut that then act as stress risers. Stress risers can weaken
the blade and may eventually cause the blade to fail. If a
propeller blade is lost, the resulting imbalance can cause
separation of the entire engine from the airframe causing the
center of gravity to extend beyond specified limits rendering
the aircraft uncontrollable.
7-4.2. Propeller Strike Inspection
After a propeller strike or in cases where the propeller must be removed for repair,
perform the inspection as instructed below:
Procedure
1.
Remove the propeller - repair according to propeller manufacturer’s instructions.
2.
Disassemble the engine completely. Refer to the Engine Disassembly chapter in the
Overhaul Manual (OH-24).
3.
Inspect all engine accessories in accordance with the manufacturer’s instructions.
4.
Verify, in particular, the crankshaft surfaces forward of the front main bearing journal
are free of paint, sludge, or any substance that could mask reliable magnetic particle
testing.
5.
Check the integrity of the forward crankcase bearing support and adjacent structure.
6.
Inspect the engine according to the Overhaul Inspection chapter of the Overhaul
Manual (OH-24).
7.
Regardless of condition, replace all counterweight pins, bushings, end plates, and
snap rings.