Pilot Debrief

PIPER PA 32R-300 near Hector, AR — 2013-10-14

Final reportCEN14LA030
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Date
2013-10-14
Location
Hector, AR, USA
Aircraft
PIPER PA 32R-300
Registration
N5605V
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Initial climb

Probable cause

An engine failure due to crankshaft fatigue cracking for reasons that could not be determined based on the available evidence.

NTSB narrative

The pilot reported that, during climbout, he noticed that the engine was vibrating. After leveling off the airplane, the vibration worsened, and the engine subsequently experienced a total loss of power. The pilot executed a forced landing onto a road, and the airplane impacted a fence post. Examination of the engine revealed that the crankshaft was fractured through the No. 8 cheek position between the Nos. 5 and 6 pistons. Fatigue cracking emanated from the connecting rod journal where the No. 5 connecting rod mates. The No. 6 piston cooling nozzle was not found in its position, and its pieces were found in the bottom of the sump; the pieces were more intact than would be expected if they had been ground between the crankshaft and connecting rod for an appreciable amount of time. Also, there was no evidence of a gouge or other mechanical damage on the No. 5 connecting rod journal. Based on this evidence, it is unlikely that the fatigue cracking was initiated by the No. 6 cooling nozzle being lodged against the crankshaft after falling out of position. About 18 months before the accident, the engine was repaired and overhauled due to a propeller strike. Further, about 4 months before the accident, maintenance personnel performed a top overhaul of the engine, and, about 1 month before the accident, maintenance personnel replaced the No. 2 cylinder. The timing of the failure suggests that an imbalance could have been introduced to the engine during one or both of the maintenance procedures, which could have resulted in the initiation of the fatigue cracking and the subsequent falling out of the No. 6 cooling nozzle; however, the exact cause of the crankshaft fatigue cracking could not be determined.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have aborted the flight after initial engine vibration.

NTSB coding

Evidence available

  • 3 docket documents
View NTSB final reportView NTSB docket

Docket documents3

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