Accident Overview
On July 20, 2024, at approximately 1721 central daylight time, a Just Highlander airplane, registration N707KM, sustained substantial damage during a landing accident near Oshkosh, Wisconsin. The flight was conducted as a personal flight under Title 14 Code of Federal Regulations Part 91. The pilot and the sole passenger were not injured.
Pilot Report
According to the pilot, she was turning from base leg to final approach to land on a grass runway. While on short final and close to the ground, the wing flaps retracted uncommanded from 40° to 0°. The airplane began to sink, and the pilot added engine power in an attempt to arrest the descent. Despite the power addition, the airplane landed hard. After landing, the pilot taxied the airplane without further incident.
Damage and Postaccident Examination
A postlanding examination of the airframe revealed substantial damage to the fuselage on the right side. Following the accident, the flap system was tested by manipulating the flap actuator handle to extend and retract the flaps. The flap controls operated continuously and as designed, extending and retracting fully. The flap actuator handle remained secure in the detent throughout the test. Investigators were unable to replicate the reported uncommanded retraction from 40° to 0°.
Flight Control Continuity
Continuity of flight controls was confirmed from the two flight control sticks in the cockpit to the aileron and elevator control surfaces. Continuity was also confirmed from the rudder pedals aft to the rudder control surface.
Video Evidence
The passenger provided a video of the landing, which was forwarded to the NTSB Vehicle Recorders Division for analysis. The video, lasting 1 minute and 29 seconds, depicted a landing consistent with the pilot's description. However, the video did not capture any aspect of the flap extension or retraction.