Pilot Debrief

Thompson Angel Hawk II near Homer, LA — 2017-06-09

Final reportCEN17LA228
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Date
2017-06-09
Location
Homer, LA, USA
Airport
5F4
Aircraft
Thompson Angel Hawk II
Registration
N335JT
Category
Airplane
Highest injury
Serious
Fatalities
0
Phase of flight
Initial climb

Probable cause

A total loss of engine power due to the engine’s unresolved high operating temperatures, which resulted in failure of the distributor rotor and drive shaft, and the pilot’s failure to maintain airspeed during the subsequent forced landing, which resulted in an aerodynamic stall and loss of control.

NTSB narrative

The private pilot reported that, during the accident flight, he planned to take off and circle the experimental, amateur-built airplane above the runway to check engine operation. Just after takeoff, the engine began sputtering. He made a left 180° turn to return to the runway and during the turn, the engine experienced a total loss of power. He stated that the airplane stalled when he was in the turn and he did not have enough time to recover before impacting the ground. The airplane had accumulated about 47 hours of run time and was in the initial flight test stage when the accident occurred. The pilot reported that he had been having trouble with increased cylinder head temperatures on the converted automotive engine. The engine had experienced a total loss of power during a previous flight, but the pilot was able to land the airplane without incident. Following that event, he replaced some ignition system components and adjusted the valves. He was then able to start the engine and reported that it "ran fine" during subsequent test runs. Postaccident examination of the airplane revealed that the fuel mixture was not adjustable in the cockpit. Examination of the engine revealed that there was melted plastic material inside the distributor rotor and the distributor drive shaft. The condition of the spark plugs was consistent with an overly lean fuel mixture and/or high temperature operation. It is likely that the melted distributor rotor was the result of the engine's high operating temperatures; the degradation of the distributor and its drive shaft would have resulted in a shift in ignition timing and a subsequent loss of engine power.

Analysis

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

NTSB coding

Evidence available

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

Docket documents4

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