Pilot Debrief

Rans S12 near McClure, OH — 2018-12-16

Final reportCEN19LA047
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Date
2018-12-16
Location
McClure, OH, USA
Airport
PVT
Aircraft
Rans S12
Registration
N3165V
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Initial climb

Probable cause

The cold seizure of the cylinder/piston due to the pilot’s failure to adequately warm the engine before takeoff, which resulted in a loss of engine power during a departure climb.

NTSB narrative

The pilot warmed the engine to 120°F before taxiing to the runway for departure on a personal flight. While the airplane was climbing through 50 to 100 ft above ground level, the engine lost partial power. He ensured the throttle control was full forward and pumped the throttle control twice, but the engine speed continued to decrease. The pilot performed an off-airport landing on a field, during which the airplane stuck a power line pole and the right wing impacted the ground. After the accident, the pilot reported the engine had low cylinder compression and scoring on the piston and cylinder walls. There were also aluminum fragments within the cylinder. He said that the engine was overhauled about 1 year before his purchase of the airplane by the previous owner. He stated that he was "fairly certain" that the engine did not have any problems before the accident flight. He said the engine radiator was not covered for cold weather operation. He believed the piston failure was due to cold seizure. According to the Rotax 2-Stroke Maintenance Schedule, the engine had a minimum coolant temperature of 150°F. Given the available information, it is likely that the engine lost partial power due to a cold seizure of the cylinder/piston.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Performing a cylinder compression check before the flight could have identified issues.

NTSB coding

Evidence available

  • 5 docket documents
View NTSB final reportView NTSB docket

Docket documents5

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