The North Carolina Republican plans to take his disappointment to the Senate floor next week.
With the 440th Airlift Wing inching closer to inactivation and the unit no longer participating in airborne operations, the Air Force has failed miserably to uphold it's promise to support the nation's largest airborne community, he said.
And that failure, he said, comes at a time where airborne operations are ever more important, and Fort Bragg leaders are pushing for more training exercises.
But their requests are falling on deaf ears, Tillis said.
Fort Bragg leaders have told Tillis they need to be able to drop 10,000 paratroopers a month to meet the requirements to prepare troops for combat. They said 8,000 drops was the "bare minimum" for proficiency.
But every month this year, the Air Force has fallen short of those expectations.
Last month, only 6,100 paratroopers exited from Air Force planes, Tillis said.
That's 1,300 fewer paratroopers dropped than in February, which is when the 440th Airlift Wing ceased participating in airborne operations.
That marked the end of an era for the unit, which moved to what was then Pope Air Force Base, and later the Army's Pope Field, as part of 2005 Base Realignment and Closure.
After two years of efforts to save the unit, the loss of airborne operations was seen as one of the final nails in the coffin for the Air Force Reserve wing, which had been hampered by attrition as airmen left the unit and were not replaced.
The 440th is scheduled to be inactivated this year.
Tillis, who pledged to watch the Air Force' support of Fort Bragg closely after the 440th was no longer able to support local paratroopers, said he was "not really," surprised that Fort Bragg wasn't getting the support it needs.
What was surprising, he said, is that the Air Force failed so quickly.
He assumed Air Force leaders would jump any hurdle necessary to prove what they've said for years, that they can support Fort Bragg without a dedicated airlift wing.
"This was show time," he said. "This was their opportunity to prove that this was going to be pro forma."
Tillis plans on taking his complaints to the Senate floor next week.
In the meantime, he said he would renew efforts to convince the Air Force, or at least others in Congress, that failing Fort Bragg is failing national security.
After 15 years of fighting in Iraq and Afghanistan, Tillis said military leaders have stressed the importance of the joint forcible entry skills the 18th Airborne Corps, 82nd Airborne Division and other parts of the nation's Global Response Force possess.
The GRF trains to deploy anywhere in the world on short notice. And is the only conventional unit capable of deploying across the globe in such short order.
That mission makes Fort Bragg "unlike anything anywhere else in the world," Tillis said. The soldiers' readiness needs to be at a modern high.
"You'd think it would be everyone's top priority," Tillis said. "But I have watched budget cutters within the Air Force slowly chip away at the ability of the commanders at Fort Bragg to adequately train their paratroopers."
If anything, the last few months have proven that lacking dedicated aircraft at Fort Bragg is too much of a risk, he said.
Earlier this year, Army leaders signed off on the inactivation of the 440th Airlift Wing based on the Air Force's promised support.
Early in February, in a letter to Congress, Army and Air Force leaders agreed that support by off-post Air Force units would work. Later that month, Maj. Gen Richard Clarke, the commander of the 82nd, said he was confident that the Air Force would do the job needed.
The Air Force already supported Fort Bragg training requirements using mostly outside aircraft.
"It's very clear, the Army thought the Air Force would do it," Tillis said. "The reality is, there's no explanation for it."
"The Air Force asked us to suspend disbelief. They told me to accept that it is more cost-effective for units to fly from Little Rock or McChord Air Force Base in Washington State and support Fort Bragg than to have planes based at Fort Bragg," Tillis said. "I did my best to ensure that the Air Force understood what the Army's requirements were and I promised them that if they moved the 440th I would be monitoring their ability to meet requirements for as long as I'm in the Senate."
Tillis is one of several lawmakers who have been involved in efforts to protect the 440th.
He inherited the fight from former Sen. Kay Hagan, his predecessor in the Senate.
But now, Tillis said he isn't telling the Air Force to reverse the decision.
"I'm not here to tell them 'how,' but to remind them what the requirement is," Tillis said. "This is about meeting the requirement."
Tillis said he wasn't fighting the Air Force, but those within the branch that are failing to uphold their promise.
If the Air Force mission is endangered, Tillis said he would be first in line provide support.
But in this case, he said, it is the Air Force that is hurting the military mission.
"They are a supplier and the Army is the customer and they aren't supporting the Army's needs," Tillis said.