History of the Flight
On 16 August 2005 at 1624 UTC, a Robinson R22 Beta (registration G-CCHZ) was involved in an accident at Newtownards Airfield, Northern Ireland. The single-engine helicopter, powered by a Lycoming O-360-J2A piston engine, was operated by a student pilot on a private flight. The pilot, aged 50, had accumulated 61 flying hours, all on type, with 61 hours in the last 90 days and 20 hours in the last 28 days.
The pilot had completed a navigation exercise from Newtownards to St Angelo Airfield and returned. After an uneventful landing at St Angelo, he departed and returned to Newtownards. Weather conditions were good: surface wind from 190° at 10 kt, visibility greater than 10 km, and scattered cloud at 3,000 ft. The pilot was wearing a plastic knee board on his left leg, attached with a Velcro strap, on which his map was folded.
Prior to departure from Newtownards, the pilot performed a full and free control check of all flying controls with the kneeboard in place. The controls did not contact the kneeboard or map. During his landing at St Angelo, he experienced no control restriction difficulties.
Accident Sequence
Upon returning to Newtownards, the pilot made a normal approach parallel to Runway 22 and came to a hover just beyond Runway 16 over the grass area known as 'Heli West'. He performed a spot turn to the right and commenced hover taxiing to his parking area on the west side of the airfield. With the wind from the left, he needed to move the cyclic control to the left. At some point, the control handle caught under the kneeboard and its attachment strap. The helicopter began to drift to the right, which the pilot was unable to correct due to the limited left cyclic-control travel.
In an attempt to free the control, the pilot lifted his left foot off the left tail rotor control pedal. The helicopter yawed to the right, and the rate of yaw increased rapidly. The right landing gear skid contacted the ground, and the helicopter rolled to the right. The main rotor blades struck the ground, stopping the engine. The helicopter came to rest on its right side. The pilot closed the fuel shut-off valve and isolated the electrical system. He suffered minor cuts and bruises to his right hand and exited the helicopter through the left door unassisted. The airfield Rescue and Fire Fighting Services arrived quickly.
Analysis
The pilot had ensured adequate clearance between the cyclic control and his kneeboard during the pre-flight control checks. During the landing at St Angelo, no control restriction difficulties were encountered. At Newtownards, when the helicopter was turned to the right to hover taxi and the wind was from the left, significant left cyclic was used to correct the helicopter's drift to the right. The left tail rotor pedal is moved forward to oppose the helicopter's natural right yaw due to main rotor torque. Lifting the left foot off the tail rotor control pedal allowed the natural right yawing motion to develop rapidly.
Conclusion
The accident was caused by the control restriction created by the pilot's kneeboard. By removing his left foot from the tail rotor control pedal, the pilot allowed the helicopter to yaw to the right, and during his attempt to maintain control, the helicopter struck the ground.