What happened
On February 18, 2009, an EADS Eurocopter AS 3CO B3 (registration F-GMBH) was conducting a training flight at Annemasse Aerodrome. The crew, consisting of a pilot, an instructor, and an organizer acting as a translator, were completing the final flight of a three-day proficiency training session. Following a series of autorotation practices, the instructor initiated a simulation of a fuel regulator failure by switching the fuel regulator selector from the automatic to the manual position. This action triggered the red GOV warning light and an audible alarm.
After an initial landing, the instructor decided to perform a full circuit of the airfield while maintaining the simulated failure. During the climb, at an altitude of approximately 150 feet, the pilot noticed the engine RPM was slightly high and attempted to reduce power. However, the RPM subsequently dropped to a level insufficient for the flight phase. The instructor attempted to intervene by adjusting the power control knob but found it was stuck. To avoid nearby industrial buildings, the instructor initiated a left turn to perform an emergency landing within the airfield perimeter. During the approach, the pilot began a flare too low, causing the tail boom to strike the ground, followed by a hard landing. There were no injuries to the occupants, but the aircraft was heavily damaged.
The investigation
The investigation focused on the mechanical state of the power control system and the circumstances surrounding the training maneuver. Investigators examined the fuel regulator system and found no mechanical anomalies or malfunctions in the power control mechanism. The investigation also noted that the instructor and pilot did not communicate verbally during the instructor's attempt to intervene due to the language barrier between the crew members. The flight manual's procedures for fuel regulator failure training were also reviewed in the context of the flight's execution.