What happened
On Wednesday, May 19, at 20:05, a Hughes 269 C helicopter, registered F-GDRE, was performing aerial spraying operations over greenhouses in Saint-Hilaire-de-Riez. The pilot, an experienced professional with over 6,600 total flight hours, had been flying for two and a half hours that day.
While conducting the mission, the pilot noted a medium-voltage power line running perpendicular to the spraying path at the northern edge of the treatment area. To ensure thorough coverage, the pilot decided to fly at a speed of approximately 20 km/h underneath the power lines. During this maneuver, the pilot spotted an anemometer mounted on a pylon atop a greenhouse. In an attempt to avoid this obstacle, the pilot initiated a slight left bank. During this movement, the tail rotor struck one of the three electrical cables, causing the aircraft to roll to the right and crash into a greenhouse structure. The aircraft was caught by the greenhouse's tubular frame, preventing further impact.
The investigation
The investigation focused on the flight path and the pilot's decision-making regarding obstacle clearance. Investigators established that the vertical clearance between the power lines and the greenhouse roof was approximately 5 meters. The investigation also reviewed the pilot's experience and the meteorological conditions at the time, which were characterized by calm winds, high visibility (CAVOK), and a temperature of 26 °C.
Findings
- The primary cause of the accident was risk-taking due to overconfidence.
- The tail rotor made direct contact with a medium-voltage electrical cable during an evasive maneuver.
- The aircraft was destroyed, and damage was sustained to the greenhouse structures.