What happened
On 24 October 2016, a Robinson R44 II helicopter, registration ZS-HAV, was engaged in a commercial game counting operation near Louis Trichardt. The flight, operated by Messina Chopper Services (Pty) Ltd, departed from a pad in Musina with the pilot and two passengers on board. While flying over a private game farm approximately 15nm northwest of Louis Trichardt, the pilot spotted a herd of impala and initiated a right-hand turn to follow the animals.
During this maneuver, a low rotor RPM warning sounded. The pilot attempted to recover by lowering the collective, but the aircraft continued to lose altitude while at approximately 45 feet above the ground. As the helicopter neared the surface, the pilot performed a flare and pulled the collective to cushion the impact. During this sequence, the main rotor blades struck nearby trees, and the tail boom was severed from the fuselage. The aircraft subsequently impacted the ground and settled in an upright position. Following the impact, the pilot deactivated the fuel valve and the occupants disembarked the aircraft without assistance.
The investigation
The investigation into the incident examined the flight history, the pilot's credentials, and the mechanical state of the Robinson R44 II. The pilot, a 51-year-old male, held a valid commercial license and had 550.9 hours of experience on this specific type of aircraft.
Technical examination of the aircraft revealed that the airframe had accumulated 1046.4 total hours. The engine, a Textron Lycoming IO-540-AE1AS, also showed 1046.4 hours since new. Maintenance records indicated that the most recent mandatory periodic inspection had been completed on 19 August 2016, with only 41.4 hours flown since that inspection.
Findings
- The primary cause of the accident was an unsuccessful forced landing following a low rotor RPM.
- The incident occurred during a turning maneuver intended to track wildlife.
- There were no injuries to the pilot or the two passengers.
- The aircraft sustained significant damage, including impacts to the main rotor blades, tail rotor, fuselage, left windscreen, and the left-hand skid.