Pilot Debrief

CESSNA 207A near Bethel, AK — 2021-11-21

Final reportANC22LA007
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Date
2021-11-21
Location
Bethel, AK, USA
Airport
BET
Aircraft
CESSNA 207A
Registration
N9794M
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Initial climb

Probable cause

The improper installation of an avionics wire harness over a fuel line, which resulted in chafing of the wire harness, arcing, and a subsequent fire.

NTSB narrative

The pilot was conducting a scheduled air taxi flight with five passengers onboard. Shortly after departure, the pilot began to smell an electrical burn odor, and he elected to return to the airport. About 1 minute later, the electrical burn smell intensified, which was followed by visible smoke in the cockpit, and the pilot declared an emergency to the tower. After landing and all the passengers had safely departed the airplane, heavy smoke filled the cockpit and passenger compartment, and the pilot saw a candle-like flame just behind the pilot and co-pilot seats, just beneath the floorboards of the airplane. Moments later, the airplane was engulfed in flames. Postaccident examination of the airframe revealed the origin of the fire to be centered behind the pilot’s row of seats, where a wire harness was found improperly installed on top of the aft fuel line from the left tank. Examination of the wire harness found a range of thermal and electrical damage consistent with chafing from the fuel line. It is likely that the installation of the wire harness permitted contact with the fuel line, which resulted in chafing, arcing, and the subsequent fire.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot could have returned to inspect ELT issue before departure.

NTSB coding

Evidence available

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

Docket documents7

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