What happened
On 25 September 1998, a YAK-52, registration G-BWSW, was involved in a ground accident at Dunkeswell Aerodrome in Devon. The aircraft, which was being operated for private purposes, was being used by a pilot undergoing conversion training on the type.
During the engine start sequence, the aircraft unexpectedly moved forward and toward the left at a high rate of speed. The pilot was unable to arrest the movement before the aircraft struck a wire fence and entered a wooded area located at the edge of the airfield. The incident resulted in substantial damage to the propeller, wings, and fuselage of the aircraft. There were no injuries to the pilot.
The investigation
Investigators reviewed the aircraft accident report form submitted by the pilot. The investigation established that the pilot had completed six hours of training on the YAK-52 prior to the event. The aircraft was powered by a single Vedeneyev M-14P piston engine. The movement occurred immediately upon the engine being started, with the initial intention being to taxi the aircraft across the airfield.