A Navy plane was being towed out of a hangar last week when its tail clipped the top of the structure, leading to what could amount to millions of dollars in repairs.

An E-6B Mercury, a nuclear command-and-control aircraft, was being moved at Tinker Air Force Base, Oklahoma, on Thursday as part of its daily operations when the vertical stabilizer at the rear of the aircraft struck the hangar, said Lt. Travis Callaghan, a spokesman for Naval Air Forces. The incident has been labeled a Class-A mishap by the Naval Safety Center, meaning the damages to the aircraft likely total at least $2 million.

One person was aboard the Mercury at the time of the mishap, Callaghan said. It's standard to have a "brake rider" on board any time an aircraft is towed out of a hangar, he added.

The incident remains under investigation. Once that process is complete, Callaghan said a determination will be made "as to what repairs are required and a way ahead for the aircraft."

Photos of the damaged aircraft posted on social media the day of the mishap appear to show the vertical stabilizer broken away from the rest of the plane after it struck the top of the hangar.

The Navy's E-6B Mercury is based on a Boeing 707 commercial plane. The aircraft is part of the Navy's "Take Charge and Move Out" community. Its mission, Callaghan said, is to enable the president and defense secretary to directly communicate with U.S. submarines, bombers and missile silos during a nuclear war.

This marked the Navy's fifth Class-A aviation mishap five months into fiscal 2019, according to Naval Safety Center data.

-- Gina Harkins can be reached at gina.harkins@military.com. Follow her on Twitter @ginaaharkins.