What happened
On June 12, 2011, a Bell 206 helicopter, registration F-GHST, was conducting a flight review for a type rating extension near the Thèmes ULM airfield in France. The flight, which began at Cuers airfield, included a series of flight control exercises conducted by a student pilot under the supervision of an instructor.
During the final phase of the session, the instructor instructed the student to perform an autorotation with an engine restart. The maneuver began at an altitude of 3,000 feet with an initial airspeed of 65 knots. As the aircraft approached the ground, the student pilot executed a premature flare and failed to apply sufficient collective pitch to arrest the descent. The helicopter's skids struck the ground with significant force. As the aircraft came to a halt, the main rotor blades struck the tail boom, causing heavy damage to the airframe.
The investigation
The investigation focused on the sequence of the autorotation maneuver and the crew's reaction to the student's inputs. Investigators examined the flight parameters, noting that the student had performed previous exercises with ease, which contributed to the instructor's assessment of the student's proficiency. The investigation also reviewed the instructor's experience and the meteorological conditions, which were favorable, with visibility exceeding 10 km and light winds.
Findings
- The primary cause of the accident was the instructor's overconfidence in the student pilot's abilities due to the student's successful performance in earlier maneuvers.
- The student pilot performed a premature flare and delayed the application of collective pitch.
- The instructor was caught off guard by the student's inappropriate control inputs and was unable to intervene in time to arrest the descent or level the aircraft.
- The impact of the skids on the ground caused the fuselage to pitch forward, leading to the main rotor blades striking the tail boom.