Stewart's Learjet 35 According to the FAA, Stewart's 23-year-old, eight-passenger plane had logged more than 10,000 flight hours and had no history of serious mechanical problems

October 26, 1999
Web posted at: 8:16 p.m. EDT (0016 GMT)

In this story: 'Not going to be an easy investigation' Jet, in 'premium shape,' was for sale No test to prove oxygen deprivation Memorial service for Stewart RELATED STORIES, SITES

MINA, South Dakota (CNN) -- While investigators said Tuesday that it would be difficult to determine why the plane carrying golf champion Payne Stewart went out of control and crashed, questions began to surface about whether upgraded valves regulating cabin pressure were installed as required by a directive from the Federal Aviation Administration.

Sudden decompression is being investigated as a possible contributing factor in Monday's crash of Stewart's Learjet into a South Dakota pasture. Stewart and five other people died. The FAA directive, issued January 3, 1995, covered the type of Learjet involved in the crash.

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The president of the charter company that owned the doomed aircraft, James Watkins, said he was not personally aware of the FAA's directive, and it was not immediately clear if the plane had received the upgrade.

The FAA directive tells Learjet owners to replace valves "to prevent rapid decompression of the airplane due to cracking and subsequent failure of certain outflow/safety valves."

Owners had 18 months to comply with the directive. Sunjet purchased the plane after any such maintenance would have been completed in order to comply with the directive.

Nonetheless, a Sunjet spokesperson, who declined to identify himself, said, "Obviously if it was an (FAA directive), we would have had to comply with it ... Absolutely."

Investigators proceeded cautiously as they looked for clues Tuesday, seeking to explain why the private jet went out of control and flew from Florida to South Dakota before nose-diving into the ground.

"We want to make very sure that before we start touching things, that we are certain that we are not destroying some evidence that we otherwise could get," said National Transportation Safety Board Vice Chairman Bob Francis.

'Not going to be an easy investigation'

"It's certainly not going to be an easy investigation," he told reporters at a midday briefing near Mina, a small town in north-central South Dakota. Francis stood beside the cow pasture where the Learjet 35 crashed Monday after flying for nearly 1,500 miles, apparently on autopilot.

The jet hit with a force that broke it into thousands of pieces and created a crater 10 feet deep. Francis said much of the wreckage is in the crater and, because the ground is soft, recovery would be complicated.

Investigators had not yet retrieved the plane's cockpit voice recorder.

Even if found, however, the device may not hold the answers. The tape in the voice recorder recycles every half hour meaning it is unlikely to still contain information about the first half hour of the flight when the jet is believed to have had problems.

The jet did not have a flight data recorder.

In addition to the federal investigators at the crash site, another team went to Florida, where the flight originated and the Learjet was based.

"We're asking (Sunjet Aviation, the company that owns the plane) for records on service difficulty reports and other records of this aircraft," Francis told CNN.

"We're (also) looking at our own records for any incidents or accidents (involving Learjets) that we've got records of that may be relevant," he said.

Sunjet Aviation, located in Sanford, near Orlando, said it had purchased the Learjet 35 about a month ago. It was built in 1976 and had a good maintenance record, according to the Federal Aviation Administration.

The Sunjet web site had listed the airplane as being for sale. It was described as being in "premium condition inside and out."

The company described both pilots of the chartered, twin-engine plane as experienced -- Michael Kling had 4,000 hours flying time while co-pilot Stephanie Bellegarrigue had 1,700 hours.

The possibility that the plane suddenly lost cabin pressure, causing the occupants to pass out and possibly die, is just one investigators will consider, Francis told CNN.

"There are lots of places where there are openings to the outside atmosphere in an aircraft," he said, "so those are the kinds of things that we'll be looking for."

Some tissue samples from the victims' remains were removed from the scene. Brad Randall, a special state medical examiner, said they would be tested for substances such as carbon monoxide, but there is no specific test that can be done on samples that would show oxygen deprivation.

The Learjet 35 left Orlando at 9:09 a.m. Monday and, within minutes, air traffic controllers lost contact with it, leading to speculation the plane may have suddenly lost cabin pressure soon after taking off for Dallas.

Planes that fly above 12,000 feet are pressurized, because the air at altitudes above that lacks enough oxygen for comfortable breathing. If a plane loses pressure at higher altitudes, those aboard could slowly lose consciousness or, if an aircraft broke a door or window seal, perish in seconds from lack of oxygen.

Stewart's 10-year-old son collects flowers left by well-wishers at the family home in Orlando, Florida

Once reaching a cruising altitude, pilots often switch on the autopilot. If they pass out, the plane could continue on until it ran out of fuel.

Fighter jets sent after the Learjet followed it for much of its flight but were unable to help. The pilots drew close and noticed no structural damage but were unable to see into the Learjet because its windows were frosted over, indicating the temperature inside was well below freezing.

The FAA routed air traffic around the Learjet and kept planes from flying under it.

The plane, apparently on autopilot, cruised 1,500 miles straight up the nation's midsection, across half a dozen states. Authorities say the plane was "porpoising," fluctuating between 22,000 and 51,000 feet.

It presumably ran out of fuel some four hours after it took off, then crashed in the field in South Dakota.

Five people were initially reported to have been on the plane. By late Monday, a sixth person was said to have been aboard. That person was identified as Bruce Borland, a golf course designer who worked for Golden Bear International, owned by golfing legend Jack Nicklaus.

A memorial service for Stewart, who lived in Florida, was scheduled for 11 a.m. Friday at the First Baptist Church in Orlando.

With his traditional knickers and tam-o'-shanter hat, Stewart, 42, was one of the most recognizable players in golf. He had won 18 tournaments over his career, including two U.S. Open titles.

He also was part of the team that helped the United States stage a historic comeback to beat Europe for the Ryder Cup last month.

When he died, Stewart was on his way to Texas for a business meeting on a proposed golf course near Dallas and to play in this week's TourChampionship tournament in Houston.

Although the show will go on at the Champions Golf Club, the pro-am event Tuesday was canceled. But PGA chief operating officer Henry Hughes said the 72-hole tournament will resume later this week.

"Golf has lost a great champion," said Ben Crenshaw, former captain of the U.S. Ryder Cup team. "Payne Stewart had so many friends. He had a wonderful career. He was doing the things that he wanted to achieve in this game," Crenshaw said Monday night on CNN's "Larry King Live."

Another pro golfer on the program, Tom Kite, also recalled Stewart fondly. "He was always loud and boisterous and fun to be around and showed his emotions," Kite said. "He loved the interplay with the gallery and he loved the interplay with his fellow competitors."

Stewart and his wife, Tracey, had two children, Chelsea, 13, and Aaron, 10.

Correspondents Leon Harris, Charles Zewe, Susan Candiotti and The Associated Press contributed to this report.

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