Helicopter Accident at Tende, France, on 25 April 2005

Accident Overview and Flight Details On 25 April 2005, a Eurocopter AS 350 B2 helicopter, registration F-GFAQ, operated by Héli Sécurité, crashed near Tende in the Alpes-Maritimes department of France. The accident occurred at 10:20 UTC, near the Lac de La Minière at an altitude of 1,560 meters. The helicopter was engaged in aerial work, specifically transporting a sling load to the Barrage des Merveilles. The pilot, a 44-year-old male with 5,500 flight hours, was the sole occupant and was killed in the accident. ## Sequence of Events and Wreckage Analysis During the return flight from the Barrage des Merveilles to the base camp, the helicopter was observed by witnesses performing at least two full rotations around its yaw axis before disappearing from view. The helicopter crashed into a wooded area on the side of a valley, striking a tree that was severed 15 meters above the ground. The final trajectory was nearly vertical. The main wreckage was concentrated at the base of the tree, with the front section destroyed by fire. The rotor blades were severely damaged, and the engine was providing power at impact. ## Contributing Factors and Safety Lessons The investigation found that the sling cable came into contact with the tail rotor, causing the tail rotor assembly and vertical fin to detach. This led to a loss of control and the helicopter entering a spin. The ground operator had not attached a counterweight to the sling, relying instead on a 4-kilogram swivel. The manufacturer's manual and the operator's procedures emphasized the importance of using a counterweight for slings of certain lengths. The accident highlighted the risks associated with sling-load operations in mountainous terrain and the critical importance of adhering to safety procedures regarding sling management.