What happened
On 16 March 2004, a Robinson R22 Beta, registration G-BOEW, was performing an engine-off landing maneuver at Cranfield, Bedfordshire. The flight was a training session involving a commander and a student. The maneuver began at 1,000 feet agl, with the pilot confirming the aircraft's ability to reach the target area at 500 feet agl. During the descent, the pilot closed the throttle and instructed the student to manage foot pressure on the pedals.
As the aircraft descended to 300 feet agl, the pilot noted that the airspeed had dropped to 53 kt. In an attempt to increase the speed to 60 kt, the pilot applied forward cyclic control. When attempting the subsequent flare with aft cyclic, the expected deceleration did not occur. To mitigate the descent rate and forward speed, the pilot leveled the aircraft using forward cyclic and pulled the collective lever to its maximum position. This resulted in a hard touchdown on the front of the left skid, causing the skid to be torn off and the main rotor to sustain damage. The aircraft came to rest on its left side. The one minor injury was sustained by the crew member.
The investigation
The investigation examined the flight parameters, the aircraft's mechanical state, and the environmental conditions at the time of the accident. Investigators reviewed the pilot's actions during the autorotation and the impact of the wind conditions. At the time of the incident, Cranfield ATIS reported a surface wind of 220° at 18 kt, with gusts up to 25 kt. The investigation also looked into manufacturer safety guidance regarding training in gusty conditions.
Findings
- The aircraft's descent rate was likely impacted by wind shear during the landing maneuver.
- The pilot's attempt to recover airspeed via forward cyclic control at 300 feet agl contributed to the ineffective flare.
- The pilot's decision to level the aircraft and pull the collective fully was an effort to reduce the rate of descent and forward speed following the loss of airspeed.
- While the pilot's operating handbook lacks specific wind limits for this maneuver, manufacturer safety notice SN-9 advises against practicing hovering autorotations in gusty conditions.