What happened
On 23 June 2002, a Slingsby Sport Vega Glider T65D, registration BGA 2758, was conducting a private cross-country flight from Wormingford Airfield. After following a planned route toward Great Ashfield and Cambridge, the pilot decided to return directly to the airfield.
As the aircraft approached the runway, the pilot attempted a practice 'competition finish' maneuver. During this attempt, the glider crossed the runway at an altitude of less than 100 feet. Due to a lack of sufficient kinetic and potential energy, the aircraft was unable to complete the turn and descended below the tree line at the eastern end of the runway. The glider struck the upper branches of the trees, causing the wings to separate from the fuselage. The fuselage became inverted and continued into a nearby crop field. The pilot sustained serious injuries during the impact.
The investigation
An investigation by the British Gliding Association (BGA), supplemented by an AAIB inquiry into the aircraft's restraint system, examined the wreckage and flight data. GPS analysis confirmed the aircraft's speed was significantly lower than recommended for such a maneuver; while a speed above 100 kt is ideal for a competition finish, the aircraft was traveling at approximately 48 kt on approach.
Investigators also focused on the pilot's safety harness. The examination revealed that the left-hand shoulder and lap straps had disconnected from the Quick Release Fastener (QRF) during the crash. Technical analysis in the USA determined that the rotary buckle was an older model with a lower rated strength and that the harness components were mismatched, featuring webbing and fittings from different manufacturers. Furthermore, the mushroom pins within the buckle were found to be improperly secured and prone to failure under load.
Findings
- The primary cause of the accident was the pilot's failure to recognize that the aircraft lacked the necessary energy to execute the practice competition finish.
- A tailwind likely provided a false sense of security regarding ground speed.
- The pilot's decision to attempt the maneuver rather than opting for a safer, standard landing contributed to the loss of altitude.
- The failure of the harness buckle likely increased the severity of the pilot's injuries.
Safety action
Following the investigation, the AAIB issued Safety Recommendation 2004-46, advising the British Gliding Association to review its maintenance guidance for seat harnesses and belts to ensure better alignment with industry practices and to provide clearer instructions regarding airworthiness inspections.