Amateur-built Quickie Q2 N39425 accident near Casper, Wyoming

Probable cause

A loss of directional control on landing due to the separation of the wing leveler trim knob and resulting reduced aileron control.

NTSB analysis

While en route on a cross-country flight, the pilot attempted to adjust the roll trim of the airplane and manipulated the wing leveler knob, but the knob fell off. While struggling to replace the knob and tighten the securing hardware, the airplane ended up with a left wing-down trim that he was unable to correct. While attempting to land at the destination airport, he had to input full right-stick deflection and left rudder to maintain straight flight. He made a low approach and opted to go-around. On the second landing attempt, the airplane touched down hard and bounced, then continued off the left side of the runway. The airplane incurred substantial damage to the canard during the runway excursion. The pilot reported no mechanical failures or malfunctions with the airframe or engine prior to the accident, with the exception of the improperly safetied wing leveler trim knob. Due to the significant left wing down trim, and the need to cross-control the airplane, the pilot was unable to maintain directional control with the reduced control authority available.

Text from the NTSB. Open the NTSB docket for LAX08CA119 for the full record.