Mystery death behind fogged windows

ORLANDO - At 40,000 feet in the cruel, thin air of the stratosphere above the United States, Payne Stewart and his crew would never have known what was killing them.

As investigators try to unravel why the champion golfer's Learjet 35 depressurised, they only know the six men would have died from hypoxia (oxygen deprivation).

How quickly they succumbed is not known, but aviation experts say that at 40,000ft the human body would be "usefully conscious" for only 15 seconds - little more than the time it took for Stewart's 5m winning putt in this year's United States Open.

If death came as the oxygen leaked away slowly, experts say they would have become euphoric and missed the automatic warning signals which should have triggered oxygen masks.

They then would have lost consciousness leaving the plane to follow an eerie, 2414km auto-piloted course across four states.

Ironically for a golfing star whose every shot was replayed and analysed, the mystery of his death remained behind the fogged-up windows of the jet, which stopped Air Force pilots from seeing inside.

After four hours the fighter crews sent to investigate could only watch helplessly as it ran out of fuel and spiralled into an empty South Dakota field.

Investigators were last night still piecing together what happened to the top-line private aircraft after its two pilots lost contact with air controllers half an hour after leaving Orlando, Florida.

Stewart, two agents, a golf course designer and the plane's two pilots took off on Monday at 9 am local time headed for Dallas. There Stewart was due to play practice rounds in advance of the Tour Championship, the PGA Tour's final tournament of the year.

The aircraft last made contact with the ground at Gainesville, Florida; after that, nothing more was heard. Aviation authorities scrambled Air Force fighters from several bases as the plane inexplicably turned northwest and "porpoised" between 20,000ft and 50,000ft.

An F-16 pilot, Captain Chris Hamilton, said the windows of the jet were fogged - a sign the cabin had become chilled with stratospheric air.

"It's a very helpless feeling to pull up alongside another aircraft and realise the people inside potentially are unconscious ... and there's nothing I can do physically from my aircraft, even though I'm 50 to 100 feet away."

A South Dakota highway patrolman saw the plane "falling like a rag, just tumbling," before it smashed to earth. Nothing was left but a small heap of smoking wreckage in a field of tall grass.

Stewart, aged 42, was one of the best loved of American players, a man known as much for his sartorial plus-fours and tam o' shanter caps as for his exemplary professional record.

After an eight-year slump following his US PGA and Open victories in 1989 and 1991, he was making a spectacular career comeback, topped by a thrilling 5m putt on the last hole to clinch this year's US championship.

He leaves his wife, Tracey Ferguson, an Australian who watched unfolding television bulletins of the tragedy from her Orlando home, daughter Chelsea, 13, and son Aaron, 10.

President Bill Clinton, an avid golf fan, said he was profoundly sorry for the loss of a golfer with a remarkable career and impact on his sport. - AGENCIES