Background
On 4 August 2000, a Piper PA-32-300 aircraft, registration G-MCAR, was involved in an accident at RAF Henlow, Bedfordshire. The aircraft was manufactured in 1970 and powered by a single Lycoming IO-540-K1A5 piston engine. The flight was a private operation with only the pilot on board, who held a Private Pilot's Licence and had 198 total flying hours, with 4 hours on type. The pilot planned to fly from RAF Henlow to the Channel Islands and intended to refuel before final preparations.
Accident Sequence
The pilot taxied the aircraft to the refuelling area where a Cessna was already refuelling from a bowser. G-MCAR was shut down and pushed back approximately 40 feet from the area to allow the Cessna room to taxi away. After the refuelling area was clear, the pilot attempted to start the engine but was unsuccessful. He then attempted a hot start procedure, which requires the throttle to be set 1/4 inch open, the fuel pump selected ON, and the mixture control at Idle Cut Off. The engine started on the second attempt, and the aircraft immediately began moving rapidly forward. The pilot applied the toe brakes but without apparent effect. The right hand undercarriage struck a concrete bund (a low walled area designed to contain fuel spillage) surrounding the refuelling area and broke off. The aircraft came to rest with fuel leaking from a broken fuel drain. Fuel floated on water that had collected within the bund from recent rain, creating a potential fire hazard. Airfield fire services promptly covered the area with a foam blanket.
Investigation Findings
The pilot stated that he had omitted to re-apply the parking brake after pushing the aircraft back. He also recalled that the engine started abruptly and ran up to a surprisingly high power setting. Photographs taken after the event showed skid marks on the damp earth during the final 15 feet prior to impact with the bund, but no skid marks earlier. It is therefore probable that the pilot attempted the hot start with the parking brake not applied and with the throttle set to a higher power setting than intended. As the engine started, the aircraft immediately accelerated, and with subsequent sustained application of the toe brakes, this caused the aircraft to skid into the concrete bund.