Pilot Debrief

CESSNA 182P near Alachua, FL — 2011-03-15

Final reportERA11LA190
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Date
2011-03-15
Location
Alachua, FL, USA
Aircraft
CESSNA 182P
Registration
N430ML
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Descent

Probable cause

A loss of engine power due to the failure of the camshaft gear teeth and crankshaft gear teeth for undetermined reasons.

NTSB narrative

While the pilot was maneuvering the airplane to set up a visual approach, the engine lost partial power. The pilot attempted to restore full engine power but was unsuccessful. Subsequently, he made a forced landing in a field, and the airplane nosed over. A postaccident examination of the engine revealed that it would only partially rotate by hand with resistance. Further examination revealed that the camshaft gear was missing nine teeth and that one tooth was damaged. The crankshaft gear was missing four consecutive teeth, and one tooth was missing from another location on the gear. A metallurgical evaluation of the camshaft gear, crankshaft gear, an exhaust valve, and a lifter revealed that the components met all the material properties requirements. The fracture surfaces on the camshaft and crankshaft gears were damaged due to post-separation contact. Debris from the oil sump was identified as nitrided gear material and lifter fragments. The engine had accumulated about 12 hours of operating time since its most recent inspection, which included an oil change. At the time of the accident, the engine had accumulated a total time of 750.7 hours. According to the owner and the engine maintenance log, no propeller strikes had occurred since the engine was installed on the airframe.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have opted for an earlier forced landing before total power loss.

NTSB coding

Evidence available

  • Photos
  • 10 docket documents
View NTSB final reportView NTSB docket

Docket documents10

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CESSNA 182P near Alachua, FL — 2011-03-15 · Pilot Debrief