The C-130s assigned to the Montana Air National Guard may not be upgraded in time to meet the 2020 deadline from the Federal Aviation Administration.

During a Senate Appropriations subcommittee on defense hearing Wednesday morning, Sen. Jon Tester asked Air Force officials about the current plans to comply with requirements from FAA by 2020 and International Civil Aviation Organization Communication, Navigation, Surveillance/Air Traffic Management mandates by 2021.

Gen. Mark Welsh, Air Force chief of staff, said they are focusing funding and modernization efforts to meet those compliance requirements by 2021 or 2022.

Tester pressed that the FAA deadline is 2020 and Welsh said "it's a physics problem," and the Air Force will likely not meet that deadline.

Welsh said it's possible the Air Force will be able to get a waiver from the FAA, otherwise the C-130s may not be able to operate in significant portions of domestic air space.

"I don't want to end up with a fleet that's sitting on the ground," Tester said.

Last year's defense budget included funding for the avionics upgrades needed to meet the FAA and international requirements.

Welsh said that Air Mobility Command, MANG's parent command, is coordinating the upgrades and that Maj. Gen. Matthew Quinn, adjutant general of the Montana National Guard, has been part of the planning discussion.

Sen. Steve Daines also asked about the C-130 modernization and whether the older models flown by MANG would eventually be replaced.

Welsh said that 73 percent of the C-130 fleet is in the National Guard and that the Air Force was working to first replace the oldest aircraft and to eventually modernize the entire fleet.

Tester also asked about the future of the 819th RED HORSE unit at Malmstrom Air Force Base.

Last year, the 819th was not identified for deactivation, though two other RED HORSE units were.

But the unit was identified to reduce to 256 positions, which is a reduction of about 155 positions.

The unit started reducing staff last fall and there have been rumors that the unit will be consolidated with a RED HORSE unit in Guam or be moved to Guam.

Secretary of the Air Force Deborah Lee James told Tester that a decision is expected within a few months.

"I anticipate that this is going to be a very, very tough one," James said.

Tester asked what impact the changes for the 819th would have on the 219th RED HORSE, the MANG component that often works with the active duty unit.

James said she would get back to Tester on that question.

"My concern is that it would eliminate their ability to do their work," Tester said of the possibility of the 819th moving to Guam.

Daines asked James why the nuclear triad remains critical to national defense.

" I think it is crucial to maintain a flexible nuclear triad," James said. "I've never been in favor of going down to one leg or two legs, I like all three."

She told the panel that the current Air Force budget request includes $5.6 billion more over the next five years than what was included in last year's budget discussions.

"This is a reflection of how important we think it is," James said.