Pilot Debrief

THOMAS A SIMINSKI ZENITH CH 750 near Allentown, PA — 2015-08-14

Final reportERA15LA311
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Date
2015-08-14
Location
Allentown, PA, USA
Airport
XLL
Aircraft
THOMAS A SIMINSKI ZENITH CH 750
Registration
N1750Z
Category
Airplane
Highest injury
Serious
Fatalities
0
Phase of flight
Takeoff roll

Probable cause

A partial loss of engine power due to the No. 1 spark plug being liberated from the cylinder head due to the stripped threads in the cylinder head. Contributing to the accident was the pilot’s decision to attempt to return to the airport while at a low altitude.

NTSB narrative

The pilot reported that, after takeoff, the airplane's engine lost partial power about 100 ft above ground level and that he then attempted to return to the airport. The pilot further stated that "the engine would not keep me flying and the airplane just fell into the forest." During the on-scene examination, the No. 1 spark plug was found missing from the cylinder head but still attached to the ignition lead. The threads were stripped out of the cylinder head. It is likely that the No. 1 spark plug was liberated from the cylinder head due to the stripped threads, which led to the partial loss of engine power.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have aborted takeoff after engine lost partial power.

NTSB coding

Evidence available

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

Docket documents4

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