Collision with terrain involving a Robinson R22 Beta, VH-JKK, Buchanan Hwy, 14 km from Stuart Hwy intersection, Northern Territory, on 11 October 1993

The pilot, accompanied by an observer, was involved in the search for a missing child. While tracking along the Buchannan Highway, about 14 km west of the Stuart Highway intersection, footprints were noticed on the road, so it was decided to land and investigate. During the later part of the approach the pilot noticed that the GPS aerial, which is normally attached to the lid of the GPS unit, had fallen down into the area adjacent to the tail rotor anti-torque control pedals.

As the pilot brought the helicopter to a hover, he was unable to move the left pedal forward to overcome the torque from the increased power. With the pedals jammed the helicopter commenced to rotate to the right. The pilot attempted to fly forward in order to gain some airspeed for a run-on landing, but the helicopter continued to rotate rapidly to the right, completing three turns before impacting the ground. A thorough inspection of the helicopter failed to reveal any pre-impact faults or malfunctions which may have restricted the operation of the flight control system.

However, three separate items were found which could have jammed the tail rotor control pedals. These were: the detached GPS aerial, three rifle cartridge shells, and a plastic water bottle. Although all indications were that a foreign object had obstructed the tail rotor anti-torque control pedals, examination of these items did not reveal any tell-tale marks that would indicate they had been trapped between the pedals and the adjacent structure.