Collision with terrain - Cessna 310R, VH-XGX, near Bathurst Island Aerodrome, Northern Territory, on 5 February 2011

What happened

On 5 February 2011, the pilot of a Cessna Aircraft Company 310R aircraft, registered VH-XGX, was conducting a return flight to Darwin, Northern Territory, following a charter flight to Bathurst Island. The pilot departed from Bathurst Island Aerodrome at approximately 2140 Central Standard Time and the aircraft collided with terrain shortly thereafter - approximately 1 km from the upwind end of the departure runway. The pilot, the sole occupant of the aircraft, sustained fatal injuries and the aircraft was destroyed by the impact forces and a post-impact fire.

What the ATSB found

The ATSB did not identify any technical deficiencies within the aircraft that may have contributed to the impact with terrain. The location of the wreckage, together with the dark night conditions and the relatively light load of the aircraft suggested that it was likely that the pilot was influenced by the effects of somatogravic illusion following take-off. The somatogravic illusion is a powerful human physiological illusion that produces an upward-pitching sensation under conditions of acceleration accompanied by limited visual or other references.

What has been done as a result

Following the accident, the subcontracted operator (the pilot's employer) advised of increased night operational checks of new pilots and low/medium time pilots operating from Darwin. These increased checks were implemented in November 2011.

Safety message

The somatogravic illusion can affect any pilot, and the ATSB highlights the importance of pilots being aware of the conditions under which the illusion may occur and the importance of understanding the ways in which they can manage the associated hazard. This includes strict vigilance in the use of the attitude indicator (artificial horizon) as the primary source of aircraft pitch angle information, and correct instrument scanning techniques to verify the attitude and performance of the aircraft.

Websites of the ATSB, the Civil Aviation Safety Authority and the US Federal Aviation Administration provide a number of sources of information on spatial disorientation and illusions.