Just for information, this is the 4th worst air crash in Aussie history.
Eight dead in auto pilot flight
From ROD McGUIRK, SHARON LABI, LIZ GOSCH and RAY SANTHASEELAN of AAP
A LIGHT aircraft today flew on automatic pilot for nearly 3000km across the country from Perth to north Queensland before crashing in the outback, killing all eight people on board.
Two other aircraft could not make radio contact as they shadowed the Beechcraft King Air 200 twin-engine prop plane across the Northern Territory and Queensland after it failed to land in the West Australian goldfields.
Police believe the plane depressurised, rendering the pilot and seven mine workers on board unconscious as it flew for almost four hours across three states on a relatively steady course for 2840km.
"It appears it may have depressurised," a Queensland police spokeswoman said.
The plane eventually crashed south-east of Burketown, north of Mt Isa in Queensland's northern gulf country, at 2.10am (AEDT), igniting on impact and causing a bushfire in the local area.
Fog hampered early search and rescue attempts but Queensland police spokesman Brian Swift said Burketown police had reached the crash site.
However, the man who owned the property where the plane crashed had already confirmed there were no survivors, he said.
The Australian Maritime Safety Authority, the national air search co-ordinator, was alerted to the problem shortly after the Beechcraft plane failed to land at Leonora, north of Kalgoorlie, at 7.30pm (AWST).
A Royal Flying Doctor Service aircraft and a commercial plane located the Beechcraft over the Northern Territory near Alice Springs and shadowed it across the Queensland border until it crashed.
The Australian Transport Safety Bureau's deputy director Barry Sargeant said the pilot and passengers were probably unconscious for most of the flight after the plane depressurised soon after taking off from Perth.
"It seems like that may have accounted for certainly the pilot's incapacitation and may well have accounted for why the passengers may not have been able to contact anyone," he said.
"It would appear that the pilot certainly was incapacitated for whatever reason, it is consistent with some sort of a problem with the cabin pressurisation system or oxygen system.
"It would appear as though the aeroplane was on autopilot, certainly on heading hold and it would have maintained a constant heading until the aircraft ran out of fuel, at least on one engine anyway."
Authorities said the light plane was chartered by one of Australia's largest gold producers, Sons of Gwalia, to fly seven mineworkers from Perth to Leonora but did not make its scheduled landing.
The mining company said it would bring in counsellors today to assist staff and relatives.
"We're focusing on obviously talking to everybody at site and making sure that everybody's counselled and providing support for everyone concerned," Sons of Gwalia managing director Mark Cutifani said.
"The most important thing for us at the moment is the relatives and the workmates."
He declined to give any details of the people on board.
Flight recorders were not required on the light plane so investigators would have to solve the mystery of what happened after the plane took off with other information.
The tragedy had eerie similarities to a crash in the US last October in which two-time US Open golf champion Payne Stewart and five others died when his Learjet drifted on auto-pilot for hours before running out of fuel and crashing in South Dakota.
Stewart was en route from Orlando to Texas for the PGA tour championship when his plane lost contact with air traffic controllers about 20 minutes after take off.
Also killed were Stewart's agents, Robert Fraley and Van Ardan, golf course architect Bruce Borland and two pilots, identified as Michael Kling and Stephanie Bellegarrigue.
US authorities believe the passengers and pilot in that accident had died slowly from a lack of oxygen after the plane lost cabin pressure.