A sudden and violent high-altitude decompression following a blow-out could be the cause of Monday's aircraft crash in South Dakota which killed the US Open golf champion Payne Stewart and up to five companions, investigators confirmed yesterday.
A US transportation safety board team began their its at the crash site yesterday, sifting through thousands of pieces of wreckage and human bodies in the crater that was created when the Learjet nose-dived into the prairie.
The decompression possibility was "only one theory", the board's vice chairman, Mr Bob Francis, said at the site. He added that toxicology tests on the bodies and any evidence of lack of oxygen in the bloodstreams of the victims would help to evaluate the blow-out theory.
The Learjet did not carry a black box flight recorder of the type required for commercial airliners, but Mr Francis said he was hopeful of recovering the flight voice recorder which might contain clues about the aircraft's final moments.
The jet, operated by Sunjet Aviation, had been inspected twice in the three days before the crash, company officials said. The 23-year-old aircraft had logged more than 10,000 hours of flight time, but had no history of serious mechanical problems, the federal aviation authority said.
Six people are now believed to have died when the Lear 35 ran out of fuel and crashed following an eerie 1,400-mile flight at nearly 39,000 feet across the United States after taking off from Orlando, Florida, on Monday en route to Dallas.
The other victims were Stewart's agents, Mr Robert Fraley and Mr Van Ardan, as well as the pilots, Mr Michael Kling and Ms Stephanie Bellegarrigue. A golf course designer, Mr Bruce Borland, who joined the flight at the last minute, was also believed to have been on board.
The likelihood that they might have died from lack of oxygen in the freezing high altitude early on in the flight was supported by evidence from one of the pilots who shadowed the doomed jet on its last journey.
"It looked as if the front cockpit windshield was condensed or fogged over," US Air Force Capt Chris Hamilton said. "I could not see into the cockpit . . . neither could I see inside the passenger windows." Capt Hamilton flew his F-16 to within 50 feet of the unresponsive Lear, but said he could see no damage to the aircraft.
"Almost certainly something blew out," Mr John Nance, an aviation analyst, said yesterday. "It could have been a window, a door seal or a duct seal. Whatever it was, it doesn't take much to empty the cabin of a Lear."
It emerged yesterday that the golfer's Australian-born wife Tracey had followed live television reports of the aircraft as it flew out of control. "She was trying to ring him on his mobile and couldn't raise him," her brother, Mr Mike Ferguson, told Australian radio.