Suspended JetBlue pilot Clayton F. Osbon plans to rely on an insanity defense in his upcoming trial on charges he disrupted a flight crew in March, forcing his co-pilot to make an emergency landing in Amarillo.

In a court motion filed Wednesday, Osbon's attorneys notified federal prosecutors he will contend he was insane at the time of his midair meltdown.

A Lubbock grand jury indicted Osbon earlier this month, alleging he "moved through the aircraft and was disruptive and had to be subdued and forcibly restrained from re-entering the cockpit," the indictment said.

At the suggestion of prosecutors and Osbon's attorneys, the 12-year JetBlue captain is undergoing a mental exam at a Fort Worth facility to determine if he is competent to stand trial.

On a March 27 flight, co-pilot Jason Dowd guided Flight 191 to Rick Husband Amarillo International Airport, diverting from a scheduled trip to Las Vegas after Osbon turned incoherent, racing inside the cabin, screaming about the Sept. 11, 2001, terrorist attacks and al-Qaida and pounding on the cockpit door, according to federal court records and passengers.

None of the 141 passengers and crew members was seriously hurt.