Former Delta pilot indicted for allegedly threatening co-pilot with gun during flight

A former Delta pilot has been indicted by a federal grand jury in Utah after allegedly intimidating his co-pilot with a firearm during a commercial flight last year.

Jonathan J. Dunn was indicted earlier this month for interfering with the crew of a commercial airline flight.

In an August 2022 flight, Dunn -- who was a first officer -- allegedly interfered with the performance of a crew member by using a firearm to assault and intimidate the captain, according to the U.S. Department of Transportation's Office of Inspector General.

"After a disagreement about a potential flight diversion due to a passenger medical event, Dunn told the Captain they would be shot multiple times if the Captain diverted the flight," the department said in a statement.

Dunn was allowed to carry a firearm on the flight through the Transportation Security Administration's Federal Flight Deck Officer program.

The TSA said in a statement to ABC News Wednesday it was "aware" of last year's incident. The agency said Dunn was removed from the Federal Flight Deck Officer program -- which authorizes certain pilots to carry a TSA issued firearm onboard planes "to defend the flight deck against an act of criminal violence or air piracy."

The Federal Aviation Administration told ABC News that Dunn does not hold a current medical certificate, which is required for flying.

The medical certificate was pulled following the incident.

The pilot was working for Delta Air Lines at the time of the incident.

"Out of respect for the ongoing aviation authority investigation of this incident, Delta will refrain from commenting on this matter but will confirm that this First Officer is no longer employed at Delta," the company said in a statement.

Dunn is set to be arraigned on Nov. 16.