What happened
On October 7, 2014, a Robinson R44 (registration HB-XYL) was conducting a flight examination for the renewal of a type rating near Les Ecasseys, Switzerland. During the flight, the examiner instructed the pilot to perform an autorotation maneuver. Because the initial landing site was deemed unsuitable, the maneuver was aborted, and the aircraft climbed to 5,000 feet AMSL to prepare for a second attempt involving a power application (go-around) following the flare.
During this second attempt, the aircraft approached the final phase of the autorotation at a speed of 50 knots, with rotor RPM within the green sector and an estimated headwind of 5 to 7 knots. The selected landing area featured a sloping terrain. To compensate for the slope, the examiner took control of the aircraft to orient it facing the incline and executed the flare before initiating the go-around. During this process, the helicopter struck the ground with significant force before lifting off again. Following a brief period of hovering, the examiner successfully landed the aircraft on a suitable nearby field.
The investigation
The investigation focused on the sequence of events during the flight examination and the specific maneuvers performed during the second autorotation attempt. Investigators examined the aircraft's flight parameters, including airspeed, rotor RPM, and wind conditions, as well as the impact of the sloping terrain on the landing execution.
Findings
- The primary cause of the impact was the hard landing occurring during the transition from the flare to the go-around maneuver.
- The landing site presented a sloping terrain, which required specific directional adjustments.
- The aircraft sustained damage to the landing gear and airframe.
- Two occupants on board remained uninjured.