At approximately 1740 hours on 11 May 1990 Cessna 500 Astec Eagle aircraft registered VH-ANQ crashed into the eastern slopes of Mt Emerald, Queensland.
VH-ANQ was engaged in operating a charter flight with one crew member and ten passengers. All occupants received fatal injuries as a result of the impact and the aircraft was destroyed.
History of the flight
Cessna 500 VH-ANQ was operating the Proserpine to Mareeba leg of a charter flight. The aircraft departed Proserpine at 1635 hours on 11 May 1990. It was being operated by Air North Queensland Pty Ltd, a Cairns based charter company.
The charter flight had been organised to transport members of five local government authorities from the Cairns/Atherton Tablelands area to a Local Government Association Conference at Airlie Beach, Queensland. The aircraft departed Cairns on the morning of 10 May 1990 and proceeded to Mareeba, to emplane further passengers, before continuing to the destination, Proserpine. The pilot and passengers remained at the conference facility overnight.
The pilot had submitted a flight plan, prior to departure from Cairns, for both the outbound flight to Proserpine and the return flight to Cairns. Late the following morning he submitted a further flight plan, by telephone, for the return flight to Cairns. The flight plan details, with the exception of the fuel endurance which had been increased to 177 minutes ex Proserpine, were the same as the previously submitted plan. The plan indicated that the flight would follow Instrument Flight Rules (IFR) and depart Proserpine at 1630 hours with a planned cruising altitude of Flight Level 330 (approximately 33,000 feet). The aircraft was planned to track via overhead Townsville then direct to Mareeba with a flight time interval of 68 minutes.
Departure from Proserpine was reported as 1635 hours and the aircraft was cleared to climb to Flight Level 330. The estimated arrival time at Mareeba was 1743 hours. The flight apparently continued normally and at 1726 hours the aircraft was cleared to descend to Flight Level 170 and instructed to call Cairns Approach.(Cairns Approach controls the airspace down to 6,000 feet above mean sea level above Mareeba Airport which has an elevation of 1,560 feet).
On first contact with Cairns Approach, the pilot advised that the aircraft was tracking for Mareeba via the 163 radial at 41 miles (76 kilometres) DME (Distance Measuring Equipment) from Biboohra. (There are no radio navigational aids at Mareeba, the nearest aids for tracking and instrument approach purposes are at Biboohra, about 16 kilometres north of Mareeba). The aircraft was advised to maintain Flight Level 170 but a short time later was cleared to descend to Flight Level 120. The pilot stated that he would not be dosing down the engines at Mareeba and that his estimated departure time was 1750 hours.
At 1735 hours VH-ANQ was cleared to descend to 10,000 feet and one minute later the pilot advised that the aircraft was "approaching over Mareeba and visual". Cairns Approach advised VH-ANQ that there would be a short delay at 10,000 feet and following a request from the pilot gave approval for the aircraft to circle over Mareeba.
At 1740:22 hours, one minute and 14 seconds after the last transmission from VH-ANQ, Cairns Approach instructed the aircraft to descend to 7,000 feet. This transmission, and other subsequent transmissions to the aircraft, went unanswered.
The Civil Aviation Authority commenced Search and Rescue procedures. An aircraft operating in the area reported hearing the signal from an Emergency Locator Transmitter at about 1820 hours. However, the aircraft was unable to determine the exact location of the transmitter because of the adverse weather in the area.
The wreckage of VH-ANQ was ultimately located on the eastern slopes of Mt Emerald, 15 kilometres south of Mareeba Airport, by searching helicopters at 0240 hours on 12 May 1990.
This accident was unusual in that the last report by the pilot indicated that the aircraft was at 10,000 feet and on a track that was 55 kilometres to the east of the accident site. There was no substantiated, and very little circumstantial evidence to suggest what caused the aircraft to descend 6,400 feet and to be displaced a considerable distance to the west of track. As a result the causal factors associated with this accident remain undetermined.