Aircraft and Pilot Information
The accident involved a Robinson R44 Raven II, registration G-LAVH, manufactured in 2008. It was powered by a single Lycoming IO-540-AE1A5 piston engine. The pilot, aged 50, held a Private Pilot's Licence and had 100 hours total flying experience, with 16 hours on type. His recent flying included 32 hours in the last 90 days and 10 hours in the last 28 days. The flight was private, with only the pilot on board.
Accident Sequence
On 15 May 2008 at 1350 UTC, the pilot was conducting solo hovering and hover taxi exercises at a private landing site near Bury, Lancashire. Weather conditions were good, with a light wind of about 5 knots, good visibility, and broken cloud at 4,000 feet. After 10 to 15 minutes of hovering, the pilot landed to change the radio frequency. Upon lifting back into a hover, he found the cyclic control to be "very heavy." The helicopter began to oscillate left to right. From a height of 6 to 8 feet, the pilot descended, touching down on the front of the skids in a nose-down attitude. It is possible that the rotors made contact with the ground, and the resulting vibration caused the windscreen to detach. The pilot could not recall subsequent events until he found himself standing in the field watching the helicopter, which had caught fire.
Post-Accident Fire
After the accident, flames were seen emanating from the area of the main rotor mast and around the auxiliary fuel tank. The pilot escaped with minor bruising but could not remember how he exited the aircraft. Onlookers alerted the emergency services, who attended and extinguished the fire. The helicopter, apart from the tail boom and tail rotor, was destroyed by fire.
Pilot's Observations
The pilot considered three possible causes for the heavy cyclic control: a mechanical failure, inadvertent selection of the hydraulics switch (located on the cyclic) to OFF, or the cyclic friction remaining on after landing. He had received training in flying with the hydraulic boost off during his type rating test, but could not compare the control forces experienced then with those during the accident.