Pilot Debrief

STORCH FL-156C near Upland, CA — 2019-05-01

Final reportWPR19LA129
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Date
2019-05-01
Location
Upland, CA, USA
Airport
CCB
Aircraft
STORCH FL-156C
Registration
N156LZ
Category
Airplane
Highest injury
Serious
Fatalities
0
Phase of flight
Initial climb

Probable cause

The pilot’s improper installation of the No. 3 cylinder valve cover, which resulted in an oil leak, oil starvation, and a subsequent total loss of engine power.

NTSB narrative

Shortly after takeoff, the engine lost oil pressure and subsequently lost total power. The pilot maneuvered the airplane to return to the airport, but the airplane touched down in a field and came to rest upright. Postaccident examination of the engine revealed evidence of an oil leak. The leak likely came from the No. 3 cylinder, as the valve cover was loose, with a gap between the cylinder and the valve cover, which was likely the result of an improperly torqued allen screw. The improper torquing likely occurred during the pilot’s recent inspection of the crankcase throughbolts and re-installation of the engine’s four valve covers. Eventually, the No. 3 allen screw became loose during the engine run-up and continued to loosen during the taxi, takeoff, and climb phases of flight, which resulted in a loss of engine oil and a subsequent total loss of engine power due to oil starvation.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot should have ensured valve covers were properly torqued before flight.

NTSB coding

Evidence available

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

Docket documents5

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