The Air Force is moving a small group of airmen off the A-10 to help get the next-generation F-35 operational. But more must be done to help the Air Force meet the August 2016 target date, Maj. Gen. Jeffrey Harrigian, the director of the Air Force's F-35 Integration Office, told reporters Thursday.

The service is moving 18 A-10s to backup status, under a compromise approved in the fiscal 2015 Defense Authorization Act. That frees up a small number of airmen to get the F-35 ready. However, the service needs at least 1,100 maintainers -- and possibly some leniency from Congress -- to reach the August 2016 milestone.

There isn't much time remaining, Harrigian said.

"We've got work to do, because it's going to depend on what Congress is saying," he said.

The Air Force is standing up the first operational base of F-35s at Hill Air Force Base, Utah, with training now beginning at Luke Air Force Base, Arizona. The service needs its maintainers ready to start training by late summer to have them ready to get the F-35 to initial operating capability by August 2016.

The 2015 law lets the Air Force move up to 36 A-10s to "backup" non-flying status. The service said earlier this year it was moving 18 to that status – nine from Davis-Monthan Air Force Base, Arizona; six from Moody Air Force Base, Georgia; and three from Nellis Air Force Base, Nevada. All of these are from active-duty squadrons, and the service could sideline the rest of the authorized 36 this year if it needs to. The service has 283 total A-10s.

Despite the maintenance manning issues, the service is still confident it will reach initial operating capability on time. Even if that deadline is met, the service needs to keep working to get airmen ready for the F-35 so it can reach full operational capability by next summer and stand up the first Air National Guard Base at Burlington International Airport, Vermont, along with the first Pacific base at Eielson Air Force Base, Alaska, and the first European base at RAF Lakenheath, England.

The service will need to evaluate how many airmen are leaving the service through accessions, along with the requirement to keep the rest of its fourth-generation fleet of A-10s, F-15s and F-16s flying while trying to stand up the F-35.

"The plan to get to IOC is solid, but as we move beyond IOC, we've got some work to do to sort out, through accessions, what's the right level we have to have in our maintenance fleet," Harrigian said.

The Air Force does not see the demand of the rest of its fighter fleet decreasing, so it needs to stay capable with those aircraft while still bringing F-35s in, he said.

This is all dependent on what Congress lets the Air Force do, with all action on the fiscal 2016 National Defense Authorization Act so far blocking the service from retiring A-10s.

The service doesn't have a Plan B yet. The Air Force, by this fall, needs to have a plan to address its need for manpower, Harrigian said.

The Air Force still hasn't received the first 12 aircraft that it plans to send to Hill to stand up the first operational squadron. The first of the group, tail number 77, is still at the Lockheed Martin plant in Fort Worth, Texas. The jet will then need to be upgraded immediately, even though it is still on the production line, he said. The jet will need some upgrades at the depot at Hill, along with other upgrades at the base to reach the planned operational level of Block 3i software. This includes the ability to carry three internal weapons, along with basic ability to do missions such as close air support, air interdiction, destruction of enemy defenses and strategic suppression of enemy air defenses.

"We'd like to think it's easy, but it's hard," Harrigian said.