What happened
A charter flight operated by a private entity was traveling from Proserpine to Mareeba to transport representatives from five local government authorities to a conference in Airlie Beach. The flight, involving a Cessna 500 registered as VH-ANQ, was conducted under Instrument Flight Rules with an initial planned cruising altitude of FL330. The flight path was intended to pass over Townsville before proceeding directly to Mareeba.
During the flight, the aircraft received several descent clearances. At 17:26, the pilot was cleared to descend to FL170 and instructed to contact Cairns Approach. Upon establishing contact, the pilot reported tracking toward Mareeba via the 163 radial from Biboohra. Following further instructions, the aircraft was cleared to descend to FL120, and later to 10,000 feet. At 17:36, the pilot reported that the aircraft was approaching Mareeba and was operating under visual conditions. After a request from the pilot, air traffic control permitted the aircraft to circle over the destination.
The accident occurred after 17:40, when the aircraft failed to respond to instructions from Cairns Approach to descend to 7,000 feet. Search efforts conducted by helicopters identified the wreckage of VH-ANQ on the eastern slopes of Mt Emerald, located approximately 15 kilometres south of Mareeba Airport, in the early hours of 12 May 1990.
Findings
The aircraft initially struck the mountainside with its left wingtip while flying on a magnetic track of approximately 340 degrees. At the moment of impact, the aircraft was in a wings-level attitude with a descent angle of eight degrees. Following the initial impact, the plane struck the ground just beneath a ridge apex, resulting in the wreckage spreading in a fan shape along a track of 350 degrees magnetic.