AAIB report: Snowbird Mk IV, accident during ground run and taxi test
Snowbird Mk IV (G-MVOJ) accident during private flight at Newby, Cumbria.
Following a period of maintenance during which the aircraft fabric covering had been replaced, the pilot was carrying out a ground run and taxi test. During taxi the pilot heard a rattle and decided to try to identify its source and so taxied the aircraft at higher speed. To his surprise, the aircraft become airborne but right wing low. The aircraft hit a tree and then struck the ground, before ‘pole vaulting’ over a wall. The pilot suffered serious injuries but has since recovered.
The tendency for the aircraft to continuously roll right was probably caused by a slight change in the angle of attack of the outer section of the left wing due to a pair of flying wires being overly tight. The lift created by this condition was greater than the left roll control spoiler could counteract.