The plane reported engine trouble just before going down, a Nigerian aviation official said.
Soon after, the plane reports it has lost a computer protection that overrides any commands from the cockpit that would threaten the flight's stability.
An Italian pilot approaching Milan's airport from Switzerland in his four-seat propeller plane reported a landing gear problem, but for some reason veered off toward downtown Milan.
The governor's son, Roger Carnahan, 44, who was flying the plane, reported experiencing trouble with the "gyro," said an official close to the investigation who asked that no name be used.
Icing, which the crew of the plane reported shortly before the crash, is one possible reason, but Steven Chealander, the safety board member assigned to the investigation and a retired airline captain, said the aircraft had a sophisticated ice protection system.
Several passengers onboard the plane reported that Mr. Mubenga repeatedly complained that he could not breathe and that he was being held down with his head between his knees by security guards.
The crew members of the Navy surveillance plane reported that they had completed their emergency procedure for destroying sensitive equipment and computer programs aboard the plane in the harrowing minutes after the crash and before they were ordered off their crippled aircraft after landing on Chinese territory.
A crew member on a nearby plane reported that the aircraft had been hit on the left rear fuselage by intense antiaircraft fire, an image that seemed hard to imagine today on the peaceful paddies, where children were laughing and playing on the narrow dirt road and watching the man from America who arrived with roughly 40 cars, vans and buses.
One Chinese plane reported spotting spotted three orange, white and red objects floating in the sea.
