What happened
On April 5, 2009, at approximately 19:45, a private Robinson R22 Beta 2 helicopter, registration F-GYHC, was performing a flight from La Baule to La Roche-sur-Yon. Upon arrival at La Roche-sur-Yon aerodrome, the pilot, operating under self-information procedures after the AFIS officer had ended their shift, observed a windsock located south of the runway. Based on this visual cue, the pilot incorrectly assessed the wind as being light and originating from the south.
After completing an approach to runway 28, the pilot taxied south toward the parking area via a taxiway. While performing a translation in ground effect, the helicopter suddenly experienced a 180-degree yaw to the right, followed by an accelerating rotation. Believing the aircraft was suffering from a tail rotor failure, the pilot lowered the collective pitch in an attempt to land. During this maneuver, the tail rotor struck the grassy ground, causing the helicopter to capsize onto its right side. The aircraft sustained heavy damage.
The investigation
The investigation focused on the mechanical condition of the wreckage and the environmental factors present during the taxi. Examination of the wreckage confirmed that all structural damage was a direct consequence of the impact with the ground. Specifically, investigators determined that the tail rotor blades struck the grass, and the force of this impact caused the failure of the rear drive shaft. The investigation also reviewed the pilot's meteorological assessment and the actual wind conditions at the time of the event.
Findings
- The primary cause of the accident was the incorrect estimation of the wind direction and strength.
- The pilot's reliance on a single visual reference (the windsock) led to a misunderstanding of the wind, which was actually blowing from 020° at 10 to 15 knots.
- The tailwind component rendered the helicopter unstable during the taxi.
- Operating a helicopter in a tailwind requires heightened pilot attention, particularly during translations in ground effect, as it increases the risk of loss of directional control.