WHEN pilot Des Porter, 68, took off from Monto airstrip just after 11am on Monday in his 1934 de Havilland DH84 Dragon biplane with a full complement of passengers, he had the odds stacked up against him.
He was flying into heavy weather on a route over rugged country without any navigation and flying aids and with the least effective emergency locator beacon recommended by the Australian Maritime Safety Authority.
By 1.30pm when he activated his personal locator beacon which lacked the accuracy of the more sophisticated GPS model, he was in deep trouble no longer able to navigate by the terrain below him.
As cloud closed in robbing him of spatial awareness, he would have struggled to keep the plane level.
Somehow the aircraft, which had his wife Kath, 61, Des D'evlin, 75 and his wife Janice, 61, John Dawson, 75, and his wife Carol, 63, on board, was still flying when scratchy radio contact was made at 2.30pm by Rick Harvey a crewman on the AGL Action Rescue Helicopter based at Maroochydore.
The helicopter had been dispatched by AMSA to try to locate the plane and guide it to ground.
With weather continuing to close in, contact was lost.
Soon afterwards the beacon's signal cut out and the plane, either out of fuel or because Mr Porter had become disorientated without visual reference points, smashed into a ridge 14km north-west of the Borumba Dam wall.
The personal locator beacon on board the doomed plane is a type more usually used by bushwalkers and four-wheel drivers but is authorised by the Civil Aviation Authority.