U.S. Air Force fighter pilots tracking a turboprop plane steered by an unresponsive pilot Friday weren't able to get his attention or communicate with anyone on board before it crashed, U.S. officials said, meaning the incident may never be precisely explained. But they were able to get close enough to pick up some clues to what might have caused the second such incident in less than a week.
The F-15 pilots had to break off when the Socata TBM tuboprop entered restricted Cuban airspace, and because they were running out of fuel, they had to return to their Florida base before it crashed 14 miles off the coast of Jamaica. Before then, however, one of them was able to get close enough to see inside the stricken plane and reported that the Socata pilot was breathing, even though he wasn't responding to communications.
Medical and aviation experts told NBC News that indicated that either the pilot had fallen victim to a medical emergency, like a stroke or a heart attack, or that his plane suffered a loss of cabin pressure leading to deprivation of oxygen causing a euphoric state called hypoxia.
The circumstances closely resemble those surrounding the crash of a small plane whose pilot lost consciousness and breached restricted airspace over Washington, D.C., before crashing into the Atlantic Ocean last Saturday, said Glenn King, a test pilot and director of advanced pilot training for the NASTAR Center, a federally licensed flight research and training facility in Southampton, Pennsylvania.
In that incident, two F-16 fighter jets were able to escort the single-engine Cessna until it ran out of fuel, and their pilots were able to watch it plunge into ocean. The plane that crashed Friday also is believed to have neared the limit of its fuel range, having flown more than 2½ hours past its scheduled arrival in Naples, Florida, at 11:59 a.m. ET.
The fighter jets that escorted the Socata on Friday weren't able to make it that far, but their similarly skilled pilots would have followed similar procedures, King told NBC News — they would have tried to raise the pilot through radio and electronic signals, and once those failed, they would have maneuvered in front of the plane's cockpit and waggled their wings to get his attention.
And investigators will likely be seeking similar information about the crash, which is presumed to have killed the pilot, real estate developer Larry Glazer of Rochester, New York, and his wife, Jane, the only people on board, King said.
They'll be asking these questions:
- Was there an alarm, and did it sound if the plane was too high for its cabin pressure?
- When was the plane's oxygen system last checked? Such a review should be a routine part of the preflight check list, King said.
- Could Glazer have been unable, either because of a medical emergency or because of oxygen deprivation, to put on his oxygen mask? Or could he have done everything properly, but the mask still failed for some reason?
- When was the last time Glazer had hypoxia or altitude training? Susceptibility rises and symptoms change as pilots age, and if Glazer hadn't undergone updated training within at the last five or six years, "he might not have recognized what was happening," King said.
While his plane was flying at 28,000 feet, Glazer told air traffic controllers he had a problem, and he was given permission to descend to 25,000 feet. But according to audio of the air traffic control exchange obtained by LiveATC.net, he then urgently said, "We need to get lower."
If Glazer was affected by hypoxia at 25,000 feet, he would have had as little as 1½ minutes and no more than 3½ minutes of "useful consciousness" to figure out his situation and take corrective action, according to research by the Federal Aviation Administration.
For a pilot with Glazer's experience — he logged more than 5,000 hours' flight time, according to aviation records — that should have been "plenty of time" to have at least put on an oxygen mask, King said.
"It's a simple motion of grabbing the mask, which is at your hips," he said. "It takes five seconds."
But if Glazer, for whatever reason, delayed donning the mask, "now it's too late," King said. "You sit there in a stupor, and your brain doesn't have enough oxygen to even press the transmit button."
IN-DEPTH
- 'Unresponsive Aircraft': Plane Crashes After F-15 Chase Over Atlantic
- Pilot of Crashed 'Unresponsive Aircraft' Possibly Suffered Loss of Oxygen