What happened
On September 7, 2017, a Robinson R22 helicopter, registration F-GILS, was conducting an instructional air experience flight at the Mulhouse-Habsheim aerodrome. The flight, operated by Héli Rhin, involved an instructor and a student pilot. After taking off and moving to runway 16, the instructor began a series of maneuvers designed to familiarize the student with the aircraft's controls.
During a specific exercise where the student was tasked with maintaining a hover by controlling only the cyclic pitch stick, the aircraft suddenly shifted into a downward path to the left. Although the instructor attempted to intervene and twice commanded the student to release the controls, the aircraft could not be stabilized. The helicopter struck the ground with a nose-down attitude and rolled onto its left side, resulting in the destruction of the helicopter and causing one instructor and one student pilot to sustain injuries.
The investigation
The BEA examined the wreckage and found that the engine was in operating condition, though the flight controls had sustained multiple failures due to the impact. The investigation focused on the sequence of the maneuvers and the regulatory context of the flight. It was noted that the flight was part of a commercial "gift pack" offering an air experience, which the investigators identified as a form of instruction flight. The investigation also reviewed the training organization's manual and the instructor's experience, noting that the instructor was a qualified professional with 889 total flight hours.
Findings
The investigation established that the primary cause of the accident was that the student pilot over-operated the cyclic pitch stick during the hover exercise. This sudden movement caused the helicopter to lose stability.
Several contributing factors were identified:
- The limited duration of the flight prevented the instructor from properly assessing the student's dexterity and responsiveness.
- The student pilot experienced stress due to the sudden, unfamiliar situation, which led to a tightened grip on the controls and a failure to release them when instructed.
- The decision to perform low-altitude exercises near the ground reduced the safety margin available for the instructor to recover the aircraft.