What happened
On 30 April 2016, a Slingsby T6_7M MKII Firefly, registration G-BNSO, was conducting a private general handling and aerobatic flight near Whitwell-on-the-Hill, North Yorkshire. The flight, which included a loop, proceeded normally until the aircraft passed the apex of the manoeuvre. Witnesses observed the aircraft enter a spin, during which the engine sound appeared to fluctuate. The aircraft subsequently struck a ploughed field in a steep, nose-down attitude, resulting in two fatalities.
The investigation
Investigators examined the wreckage and the flight history of the occupants. The pilot and passenger were both student pilots in the RAF, having previously trained on the Grob Tutor and Tucano aircraft. While the pilot had experience in aerobatics, he had not received type-specific spin recovery training for the Slingsby T67M MKII Firefly.
Engineering analysis of the G-BNSO revealed no evidence of structural failure, engine malfunction, or fuel system issues prior to impact. The engine was found to be in good working order, and the aircraft was within its permitted weight and centre of gravity limits. The investigation also noted that neither occupant was wearing a parachute at the time of the accident.
Findings
- The aircraft entered a spin following a looping manoeuvre.
- The pilot had been trained in spin recovery for the Grob Tutor and Tucano, which requires the control stick to be centralised during recovery.
- The application of the incorrect spin recovery technique, specifically failing to move the control column progressively forward as required by the Slingsby T67M MKII Firefly flight manual, may have delayed the recovery.
- The aircraft was at an altitude of approximately 3,500 to 4,000 feet, which should have been sufficient for recovery if the correct procedures had been applied promptly.