What happened
On December 17, 2024, a Hélicoptères Guimbal Cabri G2 was conducting an introductory flight at the Donauwörth-Genderkingen landing site as part of a local radio station promotion. The flight was intended to allow a passenger, with no prior flying experience, to briefly control the aircraft under the supervision of a flight instructor. During the flight, the instructor allowed the passenger to attempt to maintain heading using the pedals while the instructor maintained primary control of the cyclic and collective.
While performing a series of left turns in a hover, the aircraft began to drift. As the instructor attempted to arrest a rightward tilt of approximately 30 degrees and transition back into a stable hover, the helicopter lost altitude. The right skid made contact with the grass adjacent to the paved runway, triggering a dynamic rollover. The aircraft came to rest on its right side with significant damage to the main rotor blades, tail boom, and tail rotor.
The investigation
The BFU examined video footage from both internal and external cameras, as well as ADS-B flight data. The investigation reviewed the aircraft's Electronic Pilot Monitor (EPM) data, which showed fluctuations in the Multiple Limits Indicator (MLI) and rotor RPM (NR) during the maneuvers. The operator suggested that potential carburetor icing might have caused a reduction in engine power during the recovery attempt. However, the manufacturer's analysis of the recordings found no evidence of carburetor icing or malfunctions in the carburetor heat system, concluding that the available power and control authority were sufficient to prevent the contact with the ground.
Findings
- The primary cause of the accident was a dynamic rollover initiated by the right skid contacting the ground during a lateral drift maneuver.
- The aircraft was operating at a takeoff mass of approximately 673 kg, which was within the allowable limits.
- There were no findings of mechanical failure or engine power deficiency related to icing.
- The crew and passenger were uninjured and able to exit the aircraft independently.