(TNS) — Crash investigators face a difficult task dissecting what happened aboard the private jet that cruised up and down the US East Coast on Sunday with an incapacitated pilot, especially if the cause was a lack of oxygen. The Cessna 560 Citation V carrying a Hamptons real estate agent, her daughter and a nanny flew for about two hours without responding to radio calls before finally slamming into mountainous terrain in Virginia at high speed. Especially if there are no crash-proof recorders on the jet — none were required — investigators may only be able to outline the most likely scenarios without being able to pinpoint their origins, according to aviation experts and prior accidents reviewed by Bloomberg. “It’s very difficult,” said Roger Cox, a former investigator with the National Transportation Safety Board who was an airline pilot. “When you have a high-energy impact, there’s so little evidence remaining that you usually can’t find anything useful in the wreckage to help explain the accident.”
A pilot of a fighter jet that intercepted the Cessna because it traversed some of the most sensitive government sites near Washington without permission saw its pilot slumped over, according to preliminary information from the NTSB. That suggests either he suffered a medical issue or lost consciousness because there wasn’t enough oxygen in the cabin as the jet flew at 34,000 feet (10,366 meters). A health emergency seems less likely because there is no evidence the passengers tried to intervene, Cox said. But there’s no way to test bodies for a lack of oxygen, or hypoxia, after an accident. In the 1999 fatal crash that killed golfer Payne Stewart, three other passengers and two pilots, NTSB concluded their Learjet 35 lost pressure as they climbed, a similar scenario to Sunday’s crash. After taking off from Orlando on a flight to Dallas, the pilots lost consciousness and the plane flew more than 1,000 miles to Aberdeen, South Dakota, before running out of fuel.