Aircraft and Pilot Information
The aircraft involved was a Socata TB10 Tobago, registration G-CFME, serial number 1795, manufactured in 1996. It was powered by one Lycoming O-360-A1AD piston engine. The pilot, aged 66, held a Private Pilot's Licence and had 332 hours total flying experience, including 34 hours on type. His flying in the last 90 days was 9.5 hours, and in the last 28 days, 3 hours.
Flight Background
The accident occurred during a private flight from a private farm airstrip near Taunton, Somerset, to the aircraft's home base at Henlow Airfield near Luton. The pilot had flown to the farm on 27 September 2013 and planned to return on Sunday, but postponed to Monday, 30 September. On 27 September, during the outbound flight, the pilot returned unexpectedly to Henlow after his GPS tablet computers malfunctioned. He was advised to check GPS operation and carry a conventional chart before re-departing. The pilot carried an aviation chart but it contained only an indistinct route line.
The Accident Flight
On the morning of 30 September, the pilot telephoned an instructor at 0723 hrs to inquire about weather at Henlow. The instructor read a weather report for Luton Airport. The pilot appeared content and did not ask for further details. At about 1000 hrs, the farm owner's wife drove the pilot to the aircraft. She noted grey conditions and asked about suitability; the pilot said his route would be clear up to 6,000 ft. The aircraft took off at 1023 hrs, orbited the airfield, and headed east. Shortly after takeoff, the pilot attempted twice to contact Bristol ATC but no further transmissions were received.
Radar and GPS data showed the aircraft proceeded toward Henlow with significant deviations. It crossed the Somerset Levels and approached the Mendip Hills, where weather deteriorated with low cloud, reduced visibility, and rain. Witnesses near Stratton-on-the-Fosse reported low cloud and fog, and heard the aircraft circling or manoeuvring. Two witnesses closest to the accident site heard the aircraft pass over multiple times, getting lower. They thought it might climb, but engine noise reduced and then increased suddenly before impact.
Witnesses on the roof of Downside Abbey (a tower 166 ft agl) saw the aircraft appear very low, wings-level, headed directly toward the Abbey. It executed an avoiding manoeuvre with nose-up pitch and right roll, accompanied by full-power engine sound. The aircraft passed about 30 m from the tower. No one saw it after the manoeuvre; many heard an impact shortly afterward. The aircraft crashed in a partially wooded area within the Abbey grounds. The first 999 call was at 1052 hrs. Ambulance arrived at 1109 hrs; the pilot had suffered fatal injuries. The accident site elevation was 630 ft amsl.
Engineering Examination
Examination indicated the aircraft impacted a lightly wooded area, striking a large tree bough and ground. Wing structure was severely broken. Debris was scattered over a limited distance. The overall evidence indicated a very steep descent angle at impact. The aircraft was structurally complete. The propeller separated due to torsional failure of the forward crankshaft, consistent with engine delivering power at impact. No pre-impact internal engine failure was found. The flying control system showed no pre-impact failure. The flap actuator confirmed flaps were fully retracted at impact.