Sounds like the plane might have depressurized.
There was a golf pro a few years back that met a similar fate. The jet kept going, by the time it crashed, they were basically ice cubes. Not much left. Payne Stewart,?
That was the case w/ the Payne Stewart crash if I recall correctly.
Yup. My 1st thought.
Sure does. Jets flew along side and saw no movement, then it finally ran out of gas.
Analysis of the flight path showed the plane making normal course corrections while at 36,000 feet until just before ATC was unable to contact them further.
The altitude and course remained in a straight line from then on indicating the autopilot was controlling the aircraft until it disengaged when the fuel ran out and it couldn’t maintain altitude.
At 36,000 feet a pilot has about 30 seconds to react to a depressurization emergency and put on the secondary mask. This is a frequent part of commercial airline training but may not have been well practiced by the private pilot. He also may not have done the full checklist before takeoff that makes sure the secondary system oxygen tank was full.
In any event it appears to be very similar to the Paine Stewart Lear Jet crash that was due to depressurization at altitude.
This is how PGA star Payne Stewart died; his plane took off from Florida, somehow became depressurized, the people on board passed out and perished, and the plane continued on until it ran out of fuel and crashed in South Dakota.