After a yearlong investigation, investigators say they are unable to pinpoint exactly what caused the crash that killed golf champion Payne Stewart and five others last year.
In a final report released today, the National Transportation Safety Board said the probable cause of the crash was the loss of consciousness of two pilots caused by a loss in cabin pressure and a failure to get emergency oxygen. However, NTSB officials were unable to determine what caused the cabin pressure to drop. The investigation, the NTSB Chairman Jim Hall noted, was hampered the extensive damage to the plane and the fact that it was not equipped with a flight data recorder.
“The airplane was not equipped with a flight data recorder, an invaluable tool in most major investigations, and it had only a 30-minute cockpit voice recorder,” Hall said.
Hall noted that Payne’s Learjet 35 hit the ground at near supersonic speed and at an extremely steep angle, leaving nearly none of the plane’s components intact. The board also could not determine whether an emergency oxygen bottle had been as fully charged as it should have been or whether the pilots had lost their capability to perform before or after donning oxygen masks.
Lawsuits and Recommendations
Stewart’s plane crashed on Oct. 25, 1999, near Aberdeen, S.D. It began veering off course shortly after takeoff from Orlando, Fla., en route to Dallas. Air traffic control lost radio contact with pilots 25 minutes after takeoff, when the plane was climbing through 37,000 feet and located northwest of Gainesville, Fla. The business jet continued to head northwest for more than four hours until apparently running out of fuel.
Investigators told the NTSB the Air Force and the Air National Guard tried to intercept the jet during its fatal flight. Military pilots said the windshield of the jet appeared to be frosted or covered with condensation and that they could not see inside the crew’s cabin. They did not notice any other structural damage or abnormality to the plane.
Business associates Ivan Ardan, Bruce Borland and Robert Fraley and pilots Michael Kling and Stephanie Bellegarrigue were killed with Stewart in the accident. Stewart’s family and the families of his business associates have filed suit against SunJet Aviation Inc. and JetShares One Inc., the plane’s operator and owner, respectively. The FBI is pursuing its own investigation of SunJet and has seized company records to determine if it may have broken federal rules on maintenance and record-keeping.
In the wake of the Stewart crash, the NTSB sent 11 safety recommendations to the Federal Aviation Administration. Among other things, it urged the FAA to revise existing guidance about high-altitude operations to reflect the time of “useful consciousness and rate of performance degradation” after decompression.
In addition, the board recommended, operators of all pressurized cabin aircraft should brief pilots on the importance of a thorough preflight review of the oxygen system, including checks on supply pressure, regulator operation, oxygen flow, mask fit and communications using mask microphones. The Associated Press and Reuters contributed to this report.