What happened
On December 4, 2002, a Hughes 269 C helicopter, registration F-GOPH, was conducting a training flight at the Colmar Houssen aerodrome. The flight crew, consisting of an instructor and a student, departed from runway 01 to perform aerodrome circuits.
Following standard procedure, the instructor announced the aircraft's position on the downwind and final legs of the circuit. However, shortly after the final approach announcement, the helicopter struck the grass landing area. The impact caused the aircraft to overturn and ignited a fire, which was subsequently suppressed by emergency services.
The investigation
Investigators examined the wreckage of the F-G0PH and found the airframe heavily damaged by both the impact and the subsequent fire. While several components, including the tail boom, control linkages, and the rotor mast, exhibited breaks, all such failures were determined to be static ruptures resulting directly from the ground impact.
Technical analysis of the engine and transmission showed that the drive shaft showed signs of torsion, indicating the engine was delivering power at the time of the accident. The fuel was found to be free of any contaminants. Furthermore, spectral analysis of radio communications confirmed that the engine was running during the transmission of the pilots' last messages.
Witness accounts provided conflicting perspectives on the final moments. One witness observed the aircraft performing maneuvers with steep attitudes, while another reported seeing the helicopter execute a right-hand turn at an altitude of approximately 30 meters before falling rapidly. One observer noted the impression that the blades had stopped spinning, though another witness observed the blades continuing to rotate until impact.
Findings
- The technical examination of the Hughes 269 C revealed no mechanical malfunctions prior to the impact.
- Autopsies of the two occupants showed no evidence of incapacitation.
- It could not be determined if the crew was performing an autorotation exercise, as the instructor did not typically announce such maneuvers to the tower.
- The investigation could not establish a specific cause for the loss of control due to a lack of available data and the absence of flight recorders on the aircraft.