What happened
On December 28, 2011, at 15:15 local time, an AS350 B3 helicopter, registered F-HAUF, was performing a reconnaissance flight near the Méribel altiport. The crew, consisting of a commander and a co-pilot, was accompanied by four passengers. As the helicopter approached the airfield, the commander observed an aircraft on the downwind leg and decided to execute a "short" circuit to land ahead of that aircraft. While the co-pilot suggested performing a right-hand procedure turn, the commander took control of the aircraft, increased power, and climbed to intercept the runway.
During this maneuver, the helicopter passed directly over a Jodel D119, registered F-PJXO, which was on its final approach. The intense turbulence generated by the helicopter's main rotor caused the Jodel to roll sharply. The pilot of the Jodel was unable to recover control, leading to a collision with the snow-covered ground. The aircraft sustained heavy damage.
The investigation
Investigators examined the flight paths of all aircraft in the circuit. At the time of the incident, three aircraft were operating in the pattern. While the helicopter crew had identified the aircraft on the downwind leg, they failed to identify the Jodel D119 on final approach. Although the pilots of the fixed-wing aircraft reported their positions via radio, the helicopter crew reported hearing only the message from the aircraft on the downwind leg. The pilot of the Jodel reported seeing the helicopter appear on his left at a similar altitude and had requested that the helicopter clear the area above the platform.
Findings
- The primary cause of the accident was the decision by the helicopter commander to deviate from the published airfield circuit.
- A lack of coordination between the various pilots contributed to the close proximity of the two aircraft.
- The helicopter was operating at a high mass, and the commander's use of increased power to accelerate created significant rotor wash. This turbulence was approximately eight times greater than that produced by an aircraft of similar mass.