Pilot Debrief

DEHAVILLAND DHC-3 near Bettles, AK — 2021-08-21

Final reportANC21LA094
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Date
2021-08-21
Location
Bettles, AK, USA
Aircraft
DEHAVILLAND DHC-3
Registration
N560TR
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Approach

Probable cause

The seizure of the engine during flight for undetermined reasons, which led to a total loss of engine power.

NTSB narrative

The pilot reported that, while on the base leg approach, he heard a “loud bang,” and the engine lost total power. The pilot determined that the airplane would not be able to reach its intended destination, so he turned the airplane into the wind and made a forced landing on tundra-covered terrain, which resulted in substantial damage to the fuselage. The airplane’s maintenance records were unremarkable. Postaccident examination of the engine revealed that it had seized and sheared the propeller spline into two pieces. The accessory wall could not be removed because of the extensive internal damage to the engine. As a result, the investigation was unable to determine the reason that the engine seized during the flight.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have conducted a go-around instead of continuing the approach.

NTSB coding

Evidence available

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

Docket documents3

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