On 31 July 2013, a Bell 206B helicopter, registered VH‑SMI, departed Horn Island, Queensland for an aerial filming flight about 5 NM to the north‑east, at the Tuesday Islets. The purpose of the flight was to film a 20 m vessel travelling back and forth along a channel in between the Islets.
After having completed four passes over the vessel, the pilot positioned the helicopter for the next pass. Maintaining 200 ft, the helicopter approached the vessel from behind and to the left. The vessel was travelling into wind. As the helicopter flew abeam the vessel, the pilot initiated a climb and then commenced a right turn to pass in front. At that time, the pilot was monitoring the view finder to ensure that the helicopter’s skids did not impede the film shot.
After having completed the film shot, when at about 450 ft, the helicopter entered an uncommanded yaw right by about 25-30° and started to experience a loss of tail rotor effectiveness (LTE). The helicopter rotation stopped momentarily, but shortly after, it began to yaw right again. Despite the pilot’s attempt to recover the situation, the helicopter continued to yaw right and descend. When below 100 ft, the pilot determined that he was unable to recover and he prepared for a forced landing onto the water. The emergency flotation system was activated and the helicopter landed on the water. The occupants received nil injuries.
As a result of this occurrence, the helicopter operator has advised the ATSB that all company pilots will be required to demonstrate their ability to recover from an LTE event during regular flight checks with the Chief Pilot.
Certain operations, such as low speed aerial filming/photography flights, lend themselves to being more at risk to LTE than others. If a helicopter was placed in conditions conducive to LTE, it is crucial that pilots not only recognise the onset of LTE, but respond immediately and appropriately before the situation develops.