What happened
On Saturday, October 19, 2002, a Bell 206 B helicopter, registered F-GEQE, was conducting a flight examination for a professional pilot license at Pau aerodrome. The crew consisted of a student pilot, a safety pilot, and an examiner. Following a navigation leg from Biarritz, the student pilot approached a grassy area parallel to runway 3/13 to perform autorotation exercises with reduced engine power.
During the second exercise, the student pilot executed the flare maneuver successfully. However, after an initial application of collective pitch and achieving a horizontal attitude, the aircraft experienced a sudden, sharp descent. The helicopter struck the ground with significant force. The impact caused substantial damage to the rotor blades and the tail boom, specifically severing the tail drive shaft.
The investigation
The investigation focused on the flight dynamics during the final stages of the autorotation and the crew's performance. Investigators examined the student pilot's control of the collective pitch and the safety pilot's ability to intervene. The investigation also analyzed the meteorological conditions, specifically the wind components, and their impact on the rotor's performance during the flare.
Findings
- The student pilot failed to sufficiently control the final descent rate using the collective pitch.
- The safety pilot exhibited excessive confidence and a lack of vigilance toward the student, largely because he had been the student's primary instructor and the student was performing his 64th autorotation exercise.
- Due to the proximity to the ground and the distance of his hands from the controls, the safety pilot was unable to intervene once the sudden sink began.
- A tailwind component likely induced a vortex phenomenon, which led to the degradation of main rotor lift immediately following the flare.