Teledyne TSIO-360-RB, Maintenance Manual

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5-11
5-7 UNSCHEDULED MAINTENANCE
Unscheduled maintenance events include but are not limited to:
PROPELLER STRIKES
A propeller strike is: (1) any incident, whether or not the engine is operating, that requires
repair to the propeller other than minor dressing of the blades or (2) any incident while the
engine is operating in which the propeller makes contact with any object that results in a
loss of engine RPM. Propeller strikes against the ground or any object, can cause engine
and component damage even though the propeller may continue to rotate. This damage
can result in catastrophic engine failure.
A. PROPELLER STRIKE INSPECTIONS.
Following any propeller strike a complete engine disassembly and inspection is
mandatory and must be accomplished prior to further operation. Inspect all engine
accessories in accordance with the manufacturer's instructions. In addition to the
engine component inspection requirements set forth in the appropriate overhaul
manual, pay particular attention to the following areas while performing the
specified non-destructive testing:
1. Crankshaft surfaces forward of the front main bearing journal. These surfaces
must be free of sludge, paint or any other substance that could mask reliable
magnetic particle inspection indications.
2. Forward crankcase bearing support and adjacent structure.
NOTE:. . . In addition to any part that is damaged, TCM recommends for counterweight
equipped engines, replacement of all counterweight pins, bushings, end plates and snap
rings regardless of their condition.
B. MINOR FOREIGN OBJECT DAMAGE (FOD) INSPECTION.
For instances where the propeller is damaged by a small foreign object during
operation, such as a small stone, inspection and repair must be accomplished in
accordance with the propeller manufacturer's published instructions. Any time
foreign object damage requires propeller removal for repairs other than minor
dressing of the blades, the incident is considered a propeller strike and must be
inspected as outlined in paragraph A above.
HYDRAULIC LOCK
GENERAL INFORMATION
Hydraulic lock is defined as a condition in which a volume of liquid, equal to or greater
than the clearance volume of the combustion chamber, is drawn into the cylinder during
starting. This liquid, being incompressible, restricts piston travel during the compression
stroke. Damage only occurs after the preceding cylinder or cylinders in the firing order
have fired, thereby providing the required force to drive the piston of the fluid filled cylinder
through the compression stroke.
Most hydraulic lock events in horizontally opposed aircraft engines are due to fuel
accumulation in the induction system and/or cylinder assembly. Over priming prior to or
during engine starting will allow fuel to accumulate in the induction system or cylinder
faster than the system drains can evacuate it. Other causes of hydraulic lock can be
attributed to:
1. Restricted or clogged induction system or cylinder drain(s).
2. Extended operation of the electric boost pump:
a. During failed engine start.