Loss of control involving Robinson R22, VH-HGI, Adelaide River Station, Northern Territory, on 19 January 2013

On 19 January 2013, a Robinson R22 Beta II helicopter departed from a station homestead, located 10 km to the east of Manton Dam, Northern Territory. On board the helicopter were a pilot and a passenger.

On return to the homestead and on approach to land, the pilot reported that he had difficulty maintaining control of the helicopter in the hover and he elected to conduct a go-around. At about 40 ft above ground level, and at an airspeed of between 25 to 30 knots, the helicopter suddenly yawed to the right and completed 3 to 4 revolutions before impacting trees. The helicopter came to rest inverted and was seriously damaged. The pilot was able to exit with minor injuries and assisted the passenger, who was seriously injured, to exit the helicopter.

Wind will cause anti torque system thrust variations to occur in helicopters. Certain relative wind directions are more likely to cause tail rotor thrust variations than others. Knowing which direction the wind is coming from is critical – especially in light wind conditions. Any manoeuvre, which requires the pilot to operate in a high-power, low-airspeed environment with a left crosswind or tailwind creates an environment where unanticipated right yaw may occur.

Aviation Short Investigation Bulletin - Issue 18