Pilot Debrief

CESSNA 152 near Princeton, MN — 2011-11-22

Final reportCEN12LA077
Sign in to save
Date
2011-11-22
Location
Princeton, MN, USA
Airport
PNM
Aircraft
CESSNA 152
Registration
N6436P
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Initial climb

Probable cause

The inadequate installation of the threaded insert in the No. 2 cylinder spark plug hole by maintenance personnel, which resulted in a loss of engine power during initial climb.

NTSB narrative

The student pilot conducted two takeoffs and landings without incident. During initial climb after the third takeoff, he heard a loud “pop,” and the airplane started to vibrate severely and lose engine power. He executed a forced landing to a nearby field. The airplane landed hard and nosed over during the landing roll. The examination of the airplane revealed that the lower spark plug from the No. 2 cylinder and its associated threaded insert were missing. The threads in the top portion of the spark plug hole were stripped, and only the bottom three threads remained. No other engine anomalies were observed. The engine maintenance logbook indicated that, 7 days prior to the accident, the Nos. 1 and 2 cylinders had new threaded inserts installed in the lower spark plug holes.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Inspect engine thoroughly before solo flight after recent maintenance.

NTSB coding

Evidence available

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

Docket documents7

Related mishaps