Background
On 7 August 1998, maintenance work for the renewal of the Certificate of Airworthiness was completed on Cessna T337D, registration G-BEDL, at Bournemouth International Airport. Following the work, the aircraft was refuelled to full tanks and completed three air tests and several ground runs. After these tests, the auxiliary tanks were full, and the main tanks contained sufficient fuel for approximately 30 minutes of flight. No record of subsequent refuelling exists. Shortly after the tests, the aircraft was involved in a ground collision and was not available for flight until October 1998.
After repairs, the aircraft needed to be ferried to Biggin Hill for storage. Because the Certificate of Airworthiness paperwork was incomplete, the maintenance organisation issued an 'A Conditions' certificate under the Air Navigation Order, Article 8(1) Schedule 2. This certificate authorised the ferry flight but prohibited carrying passengers.
Two pilots agreed to undertake the flight. Pilot A held a current FAA Air Transport Pilot's Licence but his UK licence had lapsed; he had previous Cessna 337 experience but was not current on type. Pilot B held a current Private Pilot's Licence valid for multi-engine aircraft but had no experience on the 337. Neither pilot considered himself the commander, and both stated the other was commander. Both were unaware the aircraft was operating under 'A Conditions'. Despite the restriction, two passengers were on board.
History of the Flight
Before departure, the pilots discussed the fuel state and agreed the fuel gauges read 'FULL'. The aircraft had four fuel tanks: one main and one auxiliary in each wing. The fuel gauges showed the contents of the selected tank. The aircraft departed Bournemouth at 1113 hours with Pilot A in the left seat as handling pilot and Pilot B in the right seat. Weather was fine. The flight was uneventful until overhead Farnham, about 35 miles from Biggin Hill, when the front engine ran roughly and then stopped. Restart attempts failed. The decision was made to continue to Biggin Hill despite the nearby availability of Farnborough airfield. At this point, both fuel gauges still read full.
Approximately five minutes later, 30 minutes after departure, the rear engine failed and could not be restarted. The handling pilot lowered landing gear and flaps and positioned for a forced landing in a field adjacent to the M25 motorway. During the latter part of the approach, after the non-handling pilot transmitted a MAYDAY call, the aircraft struck a tree, causing a large section of the left wing to separate. On impact, both pilots suffered significant injuries (one major, one minor). The passengers in the rear escaped without serious injury. There was no post-impact fire, and emergency services attended promptly.
Post-Accident Investigation
Examination at the crash site by the maintenance organisation revealed no usable fuel in the main tank of the undamaged right wing, but the right auxiliary tank was full. The fuel selector valves were in the OFF position. The fuel feed line to the rear engine was dry. When the auxiliary fuel tank was selected, fuel flowed freely. Fuel was transferred to the main tank, and on selection, fuel again flowed freely. No tests could be performed on the left fuel system due to impact damage; however, the left auxiliary tank was half full despite leaking from impact. The front engine could not be checked due to damage, but the rear engine's fuel and ignition systems were found serviceable.