Forced/precautionary landing involving a Bell Helicopter Co 47G-3B1, VH-JWI, 7.5km NE of Woolner Station, NT on 20 February 1993

The helicopter was hovering about 30 feet over a swamp when the pilot heard a noise and the helicopter began to vibrate. The pilot flew the helicopter towards dry land but it began to rotate around the main rotor mast. A tail rotor failure procedure was carried out and the machine landed in the water. The helicopter suffered damage to the tailboom, drive shaft, uprights and cross tubes. Subsequent examination revealed that the tailrotor extension shaft drive pin had failed at the tailrotor gearbox.