Helicopter Collision with Power Lines in the French Pyrenees (F-GPHE)

Incident Overview and Context On August 31, 2012, at 11:05 local time, a Eurocopter AS 350 B3 helicopter, registered F-GPHE, collided with power lines near the Migouélou power station in Arrens-Marsous, France, at an altitude of 1,610 meters. The aircraft was operated by a Société de travail aérien. The pilot and mechanic were injured, and the helicopter was destroyed. ## Operational Background The flight was intended to transport two painters from a helipad in the valley to a steep slope near a power line pylon that required repainting. A second flight was planned to deliver equipment to the same location using a sling load. Prior to the accident flight, the pilot had already completed several rotations from the departure helipad for another client. ## Sequence of Events During the initial approach, the pilot landed the helicopter at the pre-surveyed location (A) beneath the power lines, with the nose facing the mountain. The wind was calm. The mechanic assessed that the slope was too steep for the painters to disembark safely and informed the pilot. The pilot then moved the helicopter a few meters to the right to a new location (B). After the painters disembarked, the pilot attempted to depart by reversing without gaining altitude and turning back toward the helipad. The main rotor blades struck the power lines, causing the pilot to lose control. The helicopter crashed into the slope. ## Contributing Factors The power lines were higher on the left side than on the right. One of the painters reported seeing the helicopter turn to the right during departure. The site survey had been conducted the previous Friday by the pilot, accompanied by two painting company supervisors, but the mechanic did not participate in that survey. The pilot had estimated that the line height was sufficient for a 5-meter sling load operation. ## Personnel and Company Practices The pilot had been employed by the company since 2008, based in Préchac, and had approximately 4,000 total flight hours, including about 2,500 on type and 200 in the three months prior to the accident. The mechanic had been with the company for many years and had been assigned to the base since 1987. The company's Manual of Particular Activities (MAP) contained information on human factors but did not specify practices for conducting surveys in mountainous environments with obstacles. Following the accident, the company developed internal procedures to prevent similar incidents, covering surveys, crew composition, approach and departure trajectories near obstacles, and contingency planning during landings.