What happened
On 3 October 1998, a Cessna T337D, registration G-BEDL, was performing a ferry flight from Bournemouth International Airport to Biggin Hill. The flight was being conducted under 'A Conditions' following recent maintenance and repairs. During the flight, approximately 35 miles from the destination, the front engine began running roughly before failing. Despite attempts to restart the engine, the failure persisted. Shortly after, the rear engine also failed.
As the aircraft approached a field near the M25 motorway, the crew extended the landing gear and flaps to prepare for a forced landing. During the final stages of the approach, the aircraft struck a tree, which caused a large portion of the left wing to separate. The impact resulted in one major injury and one minor injury to the crew, while the two passengers sustained minor injuries.
The investigation
The investigation focused on the cause of the dual engine failure and the regulatory status of the flight. It was established that the aircraft was being operated in violation of its 'A Conditions' certificate, which prohibited the carriage of passengers. Furthermore, the two pilots were unable to identify who was acting as the commander, and neither was current or experienced on this specific type.
Regarding the mechanical failure, investigators examined the fuel systems. While the left-hand system could not be fully inspected due to impact damage, the right-hand system revealed that the fuel selector valves had been set to the OFF position. Although the auxiliary tank in the right wing was full, there was no usable fuel in the corresponding main tank. The fuel feed line to the rear engine was found to be dry.
Findings
- The primary cause of the dual engine failure was the incorrect setting of the fuel selector valves to the OFF position.
- The flight was being conducted in breach of the 'A Conditions' certificate by carrying two passengers.
- There was a lack of clarity regarding pilot roles, as neither pilot identified themselves as the commander.
- The pilots were not current on the aircraft type and were unaware of the specific flight restrictions.