Cessna 150M, G-BPAX and Diamond DA 40 D Diamond Star, G-CDEK
The pilot of G-BPAX reported that when starting the engine with the throttle set near to its idle position, it increased speed rapidly to its maximum of about 2,500 rpm. The aircraft then travelled forward and the pilot was unable to stop it using the brakes or control its direction. After travelling approximately 90 ft, G-BPAX collided with G-CDEK, which was parked. The pilot of G-BPAX was uninjured and vacated the aircraft. The pilot was unsure of the reason for the accident. The braking system was subsequently confirmed by an engineer as being serviceable.