What happened
On 9 August 1998, a Druine D.31 Turbulent, registration G-BIVZ, was participating in a private aerial display at Swanton Morley Airfield in Norfolk. The flight was part of a formation display involving several aircraft, including a Stampe. Following a successful initial performance earlier in the day, the team commenced a second routine involving formation take-offs and various manoeuvres, including passing under bunting suspended between poles.
During the execution of the 'Prince of Wales' break, the aircraft was observed passing the bunting at an altitude of approximately 20 feet. After passing the poles, the aircraft dipped its right wing and entered a complex sequence of manoeuvres, initially turning left before reversing into a steep, climbing right-hand turn. As the aircraft reached the top of this 'wing-over' manoeuvre, its forward momentum decreased significantly. The nose dropped through the horizon, and the right wing tucked under, leading to a near-vertical descent. Witnesses noted the aircraft appeared to stall before impacting the ground in a nose-down attitude. The impact resulted in one fatality.
The investigation
Investigators examined the wreckage and the engine to determine if mechanical failure played a role. The engine, an Ardem 4CO2 Mk 4, was found to have been rotating at the time of impact and providing power, although its general condition was noted as poor. While some witnesses reported seeing white smoke, this was identified as a common occurrence for this engine type during abrupt manoeuvres due to oil entering the breather system.
No mechanical faults or control failures were discovered in the aircraft's systems. The investigation also ruled out any collision with objects prior to the ground impact. A post-mortem examination of the pilot revealed no medical conditions that could have contributed to the accident. Additionally, a white object seen in the air near the aircraft was determined to be a discarded polystyrene carton, likely lifted by the wind, rather than debris from the aircraft.
Findings
- The aircraft was airworthy and the engine was capable of delivering power until the moment of impact.
- The pilot was performing a high-energy manoeuvre, specifically a reversed turn and wing-over.
- The pilot likely failed to manage the aircraft's energy effectively, potentially due to a focus on maintaining correct formation positioning during the fly-past.
- The specific manoeuvre performed likely required more power than the aircraft could provide without a significant loss of airspeed, leading to the stall.