Five squadrons of Fairchild A-10s could be eliminated under the US Air Force's new budget proposal, accounting for one-third of all planned fleet reductions during the next five years.
USAF officials emphasised the A-10's close air support mission will not be compromised by the total reduction of 102 airframes.
"As remarkable as the A-10 is, it isn't the only machine that does close air support," said Gen Norton Schwartz, USAF chief of staff.
In addition to 246 A-10s being retained, the USAF also now flies such missions using precision-guided munitions (PGMs) carried by bombers, he said. The Lockheed Martin AC-130, equipped with a 105mm cannon and PGMs, also performs the mission, he added.
The A-10 was singled out for the heaviest reductions in the budget plans because it was limited to performing fewer missions than other fighters.
"As you get to a smaller force, one of the imperatives, in our view, was to maintain versatility," Schwartz said.
The reductions also include one squadron of Lockheed F-16s and an aggressor squadron comprised of Boeing F-15s.
The changes, if approved, would reduce the size of the USAF fighter fleet to 54 squadrons. Depending on the number of aircraft in each squadron, the total number of fighters would dwindle to between about 1,080 and 1,300. That number is significantly below the USAF's plan to buy 1,763 Lockheed F-35As, which would serve as a replacement for all its A-10s, F-15s and F-16s.
Schwartz, however, said the decision on whether to reduce the F-35A buy will not be made for at least several years.
"Please recall by 2017 we will probably have delivery of around 160 or 170 F-35s," Schwartz said. "So that call [on a possible F-35A order reduction] is well into the future."