What happened
On August 4, 2005, an Eurocopter SA 315 B (registration F-GDFX) was performing aerial work near the Pic de la Sagette in France. The mission involved a series of eight shuttle flights between Lac de Fabrèges and a transmission site to replace a technical cabinet using sling loads. The flight plan also included transporting technicians to the site.
Upon arriving at the site, the pilot identified obstacles near the originally intended landing area, which had been selected during a prior ground reconnaissance. The pilot subsequently chose an alternative, smaller landing zone characterized by grass, rocks, and stones. This area was bordered by a stone hut and an earth embankment.
During the landing approach, the pilot attempted to land facing the slope. As the aircraft touched down, the pilot experienced resistance on the left side. While attempting to correct the aircraft's position to the right, the main rotor struck the nearby earth embankment. The impact caused the nose of the helicopter to swing left and the tail rotor to strike a slope, resulting in the aircraft rotating to the right. The pilot applied forward pressure and reduced power to bring the aircraft to a halt. One passenger sustained serious injuries during the impact, and the aircraft was destroyed.
The investigation
Investigators examined the landing site, the aircraft, and the operational procedures of the air operator. The investigation focused on the selection of the landing area and the procedures used for passenger disembarkation. The inquiry also reviewed the pilot's experience on the specific aircraft type and the regulatory framework governing the company's specialized activities.
Findings
- The pilot selected an unsuitable landing surface that was too small and contained obstacles.
- There was an insufficient consideration of the specific characteristics of the Eurocopter SA 315 B, which features a larger rotor diameter and more power than the pilot's more frequently flown Hughes 300.
- The decision was made to transport passengers during a mission that was officially restricted to cargo sling operations under the company's approved manual of special activities.
- The landing procedure for passengers was high-risk, involving the passenger opening and holding the door while the aircraft was on one skid to facilitate exit.