History of the Flight
The aircraft departed Popham, Hampshire at 1050 hours on 9 September 2010 for a return trip to Bembridge Airfield on the Isle of Wight. The pilot conducted a pre-flight inspection, including physically checking the fuel contents, which he recalled as just under full. The tech log showed 15 minutes of flying since refuelling to full four days prior. The outward flight of 33 minutes was uneventful. After an hour-long stop at Bembridge, the aircraft departed at 1250 hours after a transit check; the pilot did not recheck fuel quantities. For the outward flight he had selected the left tank; for the return he selected the right tank.
The accident flight routed west from Bembridge to The Needles, orbited once over Hurst Castle, then flew north. The pilot intended to turn towards Popham once clear of the Solent Control Area (CTA). He flew at 1,800 ft amsl to remain below the CTA base at 2,000 ft. About 15 minutes after departure, the pilot heard a bang followed by a spluttering noise. Engine rpm dropped to about 1,800. He selected carburettor heat to hot and changed the fuel selector to left, with no effect; rpm declined further.
At 1308 hours the pilot transmitted a PAN call to Bournemouth Approach, reporting the engine running very slowly and that he was “looking for somewhere to put down.” He selected a field he believed he could reach, choosing one 45° below the horizon to ensure it was within glide range. He flew a curving approach, but the aircraft had insufficient energy to reach the field, struck the roof of a house, and crashed into a garden, demolishing a greenhouse. The pilot does not recall making flap selections. Another aircraft reported at 1310 hours that G-ARHN was “now down.”
The passenger recalled the flight seeming normal until the pilot started moving various knobs and said the engine lost power. The passenger’s last memory was of the aircraft approaching the roof; he then lost consciousness until after the accident.
Injuries and Witnesses
The pilot received multiple serious injuries, including head injuries and fractures to the right arm. The passenger suffered serious head injuries. Several witnesses saw parts of the forced landing approach; all reported no engine noise during the accident. One witness described the aircraft passing overhead in a curving flight path. After the crash, a witness with flying experience asked the pilot to confirm fuel and electrics were off. The pilot turned off the electrical master switch (located under his seat) and believed he turned the fuel selector to off. At some stage the magnetos were switched off and keys removed, though it is unclear when.
Accident Site and Aircraft Examination
The aircraft initially struck the roof of a chalet bungalow, dislodging ridge tiles, then impacted a flat roof extension. The nose wheel punched a hole in the roof, causing debris to fall into a bedroom. The aircraft continued downwards, struck a greenhouse in the back garden 15 m from the house, and came to rest in a left wing low attitude with left main and nose landing gear collapsed. Flaps were in the fully down position; the operating lever (handbrake type) between the front seats was likely selected to that position before impact. One propeller blade bore scuff marks from glass; minimal damage suggested the propeller was stationary at impact.
Engine and Fuel System Examination
Fuel selector was found selected to right, but due to pilot injuries and medical treatment, this is not considered reliable. The aircraft had 18 US gallon (68 litre) tanks in each wing; fuel could feed from either side but not both. During recovery, 45 litres of Avgas were recovered from the left tank with no contamination. The right tank was empty, but the fuel strainer on the firewall had been broken open, allowing any fuel to drain. The fuel selector was removed and its right tank selection confirmed. No blockages or debris were found in remaining fuel system pipes. The filler caps were original; the right cap lacked vent holes, but worn seals likely provided venting, and no history of fuel feed issues indicated this was a factor.
The engine was last overhauled in April 2009. Examination focused on engine, fuel, and ignition systems. The ignition switch had no internal failure. The magneto P lead sheaths were severely frayed near the magnetos; the left P lead sheath had separated at the firewall, exposing the inner lead. The right P lead had a severe kink with insulation broken, but no visible arcing. The possibility of intermittent arcing could not be excluded but was not considered likely to have caused the failure. The throttle, mixture, and carburettor heat controls were all fully forward at impact. Distortion on the panel and pilot’s forearm injuries suggested he may have had his hand on the throttle during impact.
Weather
Bournemouth Airport reported surface wind from 270° at 6 kt, temperature 19°C, dewpoint 13°C.