Pilot Debrief

Just HIGHLANDER near Oshkosh, WI — 2024-07-20

Final reportCEN24LA282
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Date
2024-07-20
Location
Oshkosh, WI, USA
Airport
OSH
Aircraft
Just HIGHLANDER
Registration
N707KM
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Approach

Probable cause

The reported uncommanded retraction of the flaps while on short final for unknown reasons, which resulted in a hard landing.

NTSB narrative

The pilot reported that when the airplane was on short final to land on a grass airstrip, close to the ground, the wing flaps retracted from 40° to 0° uncommanded, and the airplane started to sink. The pilot added engine power to arrest the descent; however, the airplane landed hard. The pilot taxied the airplane without further incident. A postlanding examination of the airframe revealed substantial damage to the fuselage on the right side. After the accident, the flaps were manipulated in and out of the fully extended flap position using the flap actuator handle. The flap controls were continuous and extended and retracted as designed. The flap actuator handle always remained secure in the detent. Investigators were unable to duplicate the uncommanded retraction of the flaps from 40° to 0°. There were no mechanical anomalies with the airplane or related systems that would have precluded normal operations.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot could have aborted the landing when flaps retracted uncommanded.

NTSB coding

Evidence available

  • Video
  • 5 docket documents
View NTSB final reportView NTSB docket

Docket documents5

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