What happened
On 12 May 2001, a Rand KR-2, registration G-BWNN, was conducting a private flight near Sturgable Airfield, Lincolnshire. The flight was intended for general handling checks following recent modifications to the aircraft. After taking off from Runway 09 in warm, sunny conditions, the aircraft reached an altitude of approximately 300 feet when the engine began running very roughly.
Attempts to rectify the issue by adjusting the throttle were unsuccessful. To maintain sufficient airspeed, the pilot lowered the nose and identified a nearby grass field for an emergency landing. During the descent, the aircraft struck a large tree. The impact caused the aircraft to land heavily on all three wheels, resulting in the nose landing gear breaking off and the aircraft flipping onto its back. The engine became detached from the left wing during the impact. The pilot sustained serious injuries, including several fractured ribs, but eventually made a full recovery.
The investigation
The investigation examined the engine performance and the circumstances surrounding the loss of power. It was noted that the engine, a Revmaster converted Volkswagen piston engine, showed no obvious external signs of mechanical failure and continued to turn freely after the accident. Investigators considered the possibility of vapour-locking due to the warm weather and the delay on the ground, though no conclusive evidence was found to support this theory. The engine was later recovered for a detailed strip-down inspection to identify any internal faults.