Background
The aircraft had been recently purchased in Germany and was flown to the United Kingdom on 11 December 2009 by the pilot of the accident flight. The new owner, a private pilot, accompanied the pilot from Germany and was the passenger during the accident. After landing at Oxford on the evening of 11 December, the pilot reported a brake problem to a maintenance organisation. The aircraft was parked outside a hangar. Minor maintenance was performed on 20 December 2009, and on 9 January 2010 the aircraft was refuelled. It was not flown again until the accident flight.
Flight
On the morning of 15 January 2010, the pilot and passenger met at Oxford Airport and prepared the aircraft for flight. The plan was to conduct an air test, though the exact nature was not established. The flight was pre-notified to RAF Brize Norton as an air test with a requested level of FL190. At 1344 hrs, the aircraft taxied to Holding Point C for Runway 19. The pilot reported "READY FOR DEPARTURE" at 1400 hrs and received clearance for a right turn after takeoff with a climb initially to FL80. The pilot requested the latest weather, and the tower controller reported: "TWO THOUSAND METRES IN MIST AND CLOUD IS BROKEN AT 200 FEET."
At 1403 hrs, takeoff commenced. Shortly after liftoff, Oxford ATC suggested contacting Brize Radar on 124.275 MHz. The pilot made contact at 1404 hrs; two-way communication was established, and a Deconfliction Service was agreed. On radar, the Brize Norton controller observed the Mode C altitude increase to about 1,500 ft, then decrease to 1,300 ft and 900 ft, before the secondary return disappeared. At 1406 hrs, the Brize Norton controller asked Oxford ATC if the aircraft had landed back; Oxford advised it had not but could be heard overhead. Brize Norton reported continuing primary contact but no SSR. At 1407 hrs, Oxford made several calls to the aircraft with no reply. The Brize Norton controller also attempted to call without success. At 1410 hrs, Oxford advised Brize Norton that smoke was visible west of the airfield and alerted emergency services.
Accident
Several witnesses saw the aircraft crash into a field west of Oxford Airport. A severe fire started soon after; bystanders could not approach the aircraft. Local emergency services were notified by witnesses at 1407 hrs.
Investigation
The post-mortem examination showed that the pilot had severe coronary heart disease. There was evidence to suggest that he may have been incapacitated, or died, prior to the collision with the ground. The passenger was a qualified private pilot but was not experienced with either the aircraft or flight in IMC.