Amateur-built SD-1A N31313 accident near Juneau, Wisconsin

Probable cause

The pilot’s difficulty controlling the airplane due to his incorrect reinstallation of the wings, which led to a bounced precautionary landing. Contributing to the accident was the failure of the pilot and the mechanic to verify the wings’ angle of incidence.

NTSB analysis

The private pilot stated that, immediately after takeoff, the left wing felt "extremely heavy" and required "an exceptional amount of right aileron" to maintain level flight. During the precautionary landing, the airplane bounced, turned left, and the left main landing gear collapsed.

The pilot had recently reinstalled the wings; however, he made no measurements during the reinstallation, and the mechanic who signed off on the condition inspection did not confirm the wings' angle of incidence. Postaccident examination of the airplane revealed that the angle of incidence was incorrect. Given this was the first flight since the reinstallation of the wings, it is likely the incorrect angle of incidence led to the pilot's difficulty controlling the airplane.

Text from the NTSB. Open the NTSB docket for CEN17LA224 for the full record.