What happened
On September 22, 2005, at 17:10, a Robinson R22 Beta helicopter, registered F-GIIF, was conducting a training flight near the threshold of runway 14 at Nogaro aerodrome. The flight, operated by a flying club, involved an instructor and a student pilot performing takeoff and landing exercises.
During the fourth takeoff attempt of the afternoon, the left skid of the aircraft became trapped in a clump of dry grass. This caused the helicopter to tilt more than 15 degrees to the left. The crew was unable to counteract the resulting movement, leading to a dynamic rollover that resulted in the total destruction of the aircraft.
The investigation
The investigation focused on the environmental conditions of the takeoff area and the crew's response to the sudden movement. Investigators examined the terrain, noting that the area chosen for the maneuvers was an unmaintained meadow filled with patches of dry grass. The height of the grass obscured the true nature of the ground surface, making it difficult for the pilots to identify potential hazards.
Findings
Several contributing factors were identified in the accident:
- The use of a landing surface that was unsuitable for practicing hover and takeoff maneuvers, specifically due to the presence of unmaintained, tall grass.
- A decrease in vigilance regarding the risks of dynamic rollover.
While the instructor had previously received training regarding the dangers of dynamic rollover, the speed of the phenomenon caught the crew by surprise.