"My requirements guys are in the process of building a draft-requirements document for a follow-on (close air-support) airplane," said Lt. Gen. Mike Holmes, the deputy chief of staff for strategic plans and requirements.
Holmes, who made the comments to reporters at a breakfast hosted by the Air Force Association
on Thursday, said the Air Force would use these combat requirements to determine what type of aircraft would best meet its needs. Potential options could include building an entirely new dedicated aircraft, using existing aircraft, or extending the life of the A-10 even further.
A spokesperson for the Air Force confirmed the ongoing requirements process to CNN.
The Air Force had originally planned for its version of the F-35 Joint Strike Fighter to replace the A-10 Thunderbolt, or Warthog, as it has been nicknamed. But the F-35 project has been beset by delays and cost overruns and the demands of the counter-ISIS mission have caused the Pentagon to reconsider its plans in the 2017 budget.
Secretary of Defense Ash Carter said in February that the A-10 had "been devastating" ISIS and that the next budget would extend its operational life by deferring the plane's retirement until 2022, at which point it would be replaced by the F-35.
But Holmes' announcement shows that the Air Force is now considering alternative replacement options.
Unlike the multi-role F-35, the A-10 is the only airplane in the Air Force specifically designed for close air support, a mission that has become urgent in the fight against ISIS.
The battle tested A-10 has seen combat in Iraq, Afghanistan and most recently in Syria where it was able to target enemy forces up close without risking friendly fire casualties because the pilots are flying slow enough to visually distinguish between enemy and friendly forces.
Rep. Martha McSally, an Arizona Republican lauded the Air Force's decision to reevaluate its plans, calling it "a big victory."
McSally, a retired Air Force colonel and former A-10 pilot who flew missions in Iraq and Afghanistan, told CNN she was "glad to see the (Obama) administration recognize the flaws in seeking to eliminate the A-10 before we have a tested, proven replacement."
"As a result of our advocacy, the Air Force will begin consideration of the follow-on platform to the A-10, including upgrading our current fleet to extend its service life. This is the exact approach for which I have advocated," said McSally, a member of the Armed Services Committee.
The A-10 can carry up to 16,000 pounds of bombs and missiles and is armed with a powerful 30 mm, seven-barrel Gatling gun, which can fire depleted uranium bullets at 3,900 rounds per minute.
Holmes added that the Air Force was trying to define exactly what was needed and that affordability would be a key consideration in determining the future of the next generation of close air-support aircraft.
The previously proposed F-35 replacement is projected to cost approximately $135 million per plane, while the unit cost of an A-10 is $18.8 million, according to a U.S. Air Force fact sheet.
Retired naval aviator Cmdr. Chris Harmer told CNN in March that using an F-35 to fly close air support against insurgents would be akin to "buying a brand new Rolls Royce to take the garbage to the dump."
Harmer estimated the cost of flying a jet like the F-35 to be about $45,000 per hour of flight, while the A-10 costs about one-third as much to operate.
Holmes said that one possible replacement for the A-10 could be a type of already-existing turbo-propeller aircraft. Examples of this category of aircraft include the A-29 Super Tucano and AT-6 Wolverine. The U.S provided four A-29s to the new Afghan air force in January to help fight the Taliban.
U.S. Central Command, which oversees military operations in Iraq and Afghanistan, recently deployed a pair of Vietnam-era OV-10 Bronco turbo-propeller planes against ISIS as part of an experiment to see if these type of aircraft are more effective in conducting counterinsurgency operations than more modern jets like the F-35.
Because they consume less fuel and can cruise at slower speeds, these turbo prop planes can loiter over the battlefield for hours like drones, but unlike unmanned aircraft, the pilot has greater visibility of the battlefield and can see the location of enemy forces and attack them directly with machine guns and more bombs and missiles than a drone can carry.
Holmes cautioned that a final decision is still "a long way off" and that future budgets would determine what the future of the close air-support aircraft will look like.