The US Air Force's plans to operate the A-10 attack aircraft beyond 2022 have run into some turbulence. According to a report by Defense News, a third of the currently operating A-10 fleet will have to be retired soon because the Air Force has not included orders for enough replacement wings in the service's budget request. The aircraft are rapidly approaching the end of service life for their current wings.

The Air Force's Air Combat Command chief, General Mike Holmes, told Defense News that new wings have been ordered for 173 of the 283 A-10s currently in service. That amounts to six squadrons' worth of aircraft (out of the current nine squadrons). The remaining aircraft could be retired over the next five years as they hit flight-hour limits on their current wing sets.

Some aircraft could see extended lives; "We have some flexibility in the depot, we have some old wings that can be repaired or rejuvenated to go on," Holmes told Defense News. "We can work through that, so there’s some flex in there."

The Air Force moved to retain the A-10 because of delays in the deployment of the F-35A, the Air Force's version of the F-35 "Lightning II" Joint Strike Fighter. The A-10 has played a critical role in close air support (CAS) for forces combating the Islamic State in Syria and Iraq; the F-35A is supposed to take over the A-10's CAS role as it is deployed. But the F-35 is not expected to enter "full-rate" production until 2019, and there are still modifications required to the existing fleet of F-35As before they can fully take on the CAS role and other combat missions.

In addition, the Air Force last year reduced its planned purchase of F-35s for 2017. The slow-down in procurement has resulted in a slowing of pilot and crew training for the F-35 as well. In May, the Air Force and Lockheed Martin announced that the Air Force would not fly the F-35 at the Paris Air Show—Lockheed's own pilots will perform a demonstration instead.

"Due to the Air Force's limited number of aircraft, pilots, and maintenance professionals, we have decided not to develop an F-35 demonstration profile for airshows this year," an Air Force spokesperson wrote in an official statement. "While we look forward to demonstrating the unparalleled maneuverability of the F-35 to the world, we remain singularly focused on bringing the full combat capability of the F-35 to our nation."