What happened
On 9 October 2021, a RotorWay Executive 162F helicopter, registration ZU-RDX, was performing a private scenic flight from Morning Star Airfield in the Western Cape. The flight, operated by the owner, began with a routine takeoff and transition into flight under Visual Flight Rules (VFR).
While the aircraft was approximately 58 metres into its flight path, the pilot reported hearing and feeling a loud, palpable thud. This was immediately followed by a leftward yaw and a sudden change in engine power. The pilot attempted a flare to manage the descent, but the helicopter struck the soft sand on its left skid. This impact triggered a dynamic rollover, during which the main rotor blades struck the tail boom, severing it. The aircraft eventually came to rest on its right side.
The investigation
Investigators from the SACAA AIID examined the wreckage and the flight history of the aircraft and pilot. The inspection of the ZU-RDX revealed significant structural damage, including a severed tail boom and a broken drive belt. Analysis of the main rotor blades showed deformation and fractures consistent with metal-to-metal contact and mast bumping during the rollover.
Regarding the aircraft's status, investigators found that the Authority to Fly had expired nine days prior to the accident. While the aircraft was within its annual inspection interval, the investigation noted that the total takeoff weight was approximately 0.5kg above the maximum takeoff weight (MTOW) when using the occupants' provided weights. The pilot had not flown for six months prior to this occurrence.
Findings
- The primary sequence of the accident was initiated by an audible thud and subsequent loss of directional control.
- The aircraft's tail boom was severed by the main rotor blades during the dynamic rollover.
- The helicopter was operating slightly above its maximum takeoff weight.
- The pilot's previous flight had taken place six months before the accident.
- The aircraft's Authority to Fly had expired shortly before the flight.