What happened
On 29 May 2010, an Aveko S.R.O. VL3A1 Flamingo, registration ZU-VDW, was competing in the President's Trophy air race. While performing a descent toward Bela-Bela in the Limpopo Province, the aircraft experienced a catastrophic structural failure. Witnesses following the aircraft observed the wings separating from the fuselage in flight. The aircraft subsequently impacted the ground in a flat grassland area, resulting in the destruction of the aircraft and two fatalities.
The investigation
An investigation by the SACAA AIID examined the flight path, wreckage, and onboard GPS data. The aircraft was participating in a multi-leg race that included several checkpoints. Data retrieved from the onboard GPS logger indicated that during the final stages of the flight, the aircraft was descending at a rate of approximately 1720 feet per minute with an estimated true airspeed of 174 knots.
Investigators also reviewed the aircraft's technical limitations. A previous technical bulletin had reduced the aircraft's maximum operating speed (Vne) from 164 knots to 140 knots due to reported vibrations in the tail surfaces. Furthermore, the investigation found that the aircraft's takeoff mass of 609 kg exceeded its maximum certified takeoff weight of 560 kg. It was also noted that the occupants were not utilizing their shoulder harnesses at the time of the impact.
Findings
- The primary cause of the wing failure was wing flutter.
- The aircraft was operated outside of its design envelope, as the pilot had exceeded the Vne on multiple occasions both on the day of the accident and the previous day.
- The aircraft was significantly overweight, exceeding its maximum certified takeoff mass by 49 kg.
- The investigation identified poor airmanship as a contributing factor to the accident.