What happened
On March 9, 2002, at approximately 07:15 UTC, an Eurocopter AS 300 B1 (registration F-GJCP), operated by SAF Hélicoptères, was attempting to take off from a site near Tignes Les Boisses, France. The crew, consisting of the pilot and a winch operator, had positioned the aircraft near a hangar and a technical building for an upcoming aerial work mission.
After engine start and reaching a low-altitude hover approximately two to three seconds after liftoff, the upper portion of the aircraft's tail rotor boom struck the overhang of the hangar roof. The impact caused the helicopter to enter an uncontrolled leftward yaw rotation. The pilot attempted to correct the movement using the anti-torque pedals, but the aircraft continued to spin before being forced into the ground. The collision resulted in the destruction of the helicopter and one serious injury to the winch operator. Several vehicles parked nearby were also damaged.
The investigation
Investigators examined the wreckage and the takeoff site, noting that the designated landing area was covered in approximately ten centimeters of snow and mud. The space between the hangar and the adjacent concrete plant building was narrow, measuring no more than twenty meters in width.
Physical evidence at the hangar included deformations to the zinc roofing at a height of 5.13 meters, consistent with the rotation of the tail rotor. Traces of paint from the hangar's roof overhang were found on a tail rotor blade. Technical examinations of the tail rotor control system, including the yaw servo and the hydraulic pump drive belt, revealed no mechanical failures or malfunctions prior to the accident. The observed breaks in the control components were determined to be the result of the impact forces during the crash.
Findings
- The primary cause of the accident was an attempted takeoff from an unsuitable area in immediate proximity to buildings.
- The narrow corridor between the hangar and the adjacent building provided insufficient volume for safe maneuvering.
- Aerodynamic turbulence generated by the helicopter's own rotor system, intensified by the proximity of the structures, likely caused sudden, uncontrollable movements.
- The sensation of pedal ineffectiveness reported by the pilot may have been caused by extreme turbulence or the physical obstruction of the tail boom against the hangar lintel, which temporarily limited yaw authority.
- A contributing factor was likely time pressure related to the mission requirements, which may have influenced the decision to position the aircraft in a restricted space to avoid clearing snow from the primary landing area.