Incident
On 10 June 2002 at 1103 UTC, a Robinson R22 Beta helicopter registered as G-BOEW was involved in an accident at Cranfield Airport, Bedfordshire, during an aerial work training flight. The helicopter sustained a severed tail boom and damage to the tail rotor drive shaft.
Aircraft and Crew
The aircraft was a Robinson R22 Beta, manufactured in 1988, powered by a single Lycoming O-320-B2C piston engine. The crew consisted of two persons: a commander (also the flying instructor) and a student. The commander held an Airline Transport Pilots Licence (Helicopters), was 65 years old, and had accumulated 11,778 total flying hours, including 543 hours on type. In the previous 90 days, he had flown 93 hours, and in the last 28 days, 24 hours.
Sequence of Events
The flying instructor was demonstrating a practice 'engine off' landing to the student. It was the seventh such landing conducted that morning. The helicopter was landing on the grass helicopter strip designated 22, heading into wind. The surface wind was reported as 230° at 24 knots. The initial ground contact was made on the port side skid on the right hand edge of the strip, which has a boundary marked with scraped earth slightly raised above the surrounding grass.
During the run-on, one main rotor blade struck the tail boom, causing both the boom and tail rotor drive shaft to break. The pilot reported that the initial skid contact with this edge destabilised the run-on, and his subsequent attempted corrections led to large control inputs at a low main rotor speed.
Post-Event Actions
The pilot noted that there were no cockpit indications of damage, but he felt a slight vibration and a change in rotor noise following the event. The accident was observed by air traffic control (ATC), who alerted the pilot and advised him to shut down.
Outcome
Neither crew member was injured. The nature of damage was limited to the tail boom and drive shaft.