AVON PARK From the cockpit of his A-10 Thunderbolt II fighter jet, a pilot speaks words known to warm the hearts of U.S. ground troops under fire."I’ve got 100 rounds 30 Mike Mike," says the pilot, seeking permission to let loose a short burst from the aircraft’s 30mm Gatling gun — rounds powerful enough to stop a tank.This flight is just an exercise over Central Florida scrubland for an airplane affectionately known as the Warthog. It’s something of a throwback for the Air Force with its single seat and simple mission: support troops on the ground. "The A-10 is an awesome aircraft," says Hal Sullivan, operations manager at the Avon Park Air Force Range.Sullivan should know. He sees all manner of aircraft in his current position and used to call in airstrikes flown by A-10s when he held the dangerous job known as JTAC, or Air Force joint terminal attack controller.A squadron of 10 Warthogs from the 122nd Fighter Wing of the Indiana Air National Guard is flying in and out of MacDill Air Force Base to drill at Avon Park. The exercise comes as the A-10 returns to combat in Afghanistan for the first time in four years.But the airplane’s future faces dangers beyond the battlefield. The simplicity of mission that endears it to the troops counts as a strike against the A-10 as new planes are designed to perform a number of tasks.The Air Force has tried to mothball the fleet to save money. And now age, compounded by a budget impasse in Washington, threatens to strike another blow.•••Sullivan is standing near Avon Park’s south village, a grouping of adjustable shipping containers arranged at the moment to replicate a Middle Eastern town, complete with a mosque in the center. On a blustery late January afternoon, the A-10s are taking part in Guardian Blitz. The training exercise is designed to help pilots and JTACs hone their close-air support skills and to help pilots train for additional roles — observation and search-and-rescue.The Air Force just announced that a squadron of A-10s has been sent to Afghanistan for the first time since 2014 and is attacking Taliban targets. But many of the jets, first deployed in 1977, need new wings. The work is delayed by the federal budget impasse, which comes during a tug of war between a Congress determined to keep the planes flying and Air Force cost-cutting efforts.Sullivan doesn’t like the idea of killing off the Warthogs."I can understand the political aspects," he said, "but I can tell you right now, all JTACs love the A-10 because of its past performance."Pilots of other aircraft fly a variety of missions, such as air-to-air combat and interception, as well as close-air support. These include the F-15 Eagle, F-16 Fighting Falcon, and the newer F-22 Raptor and F-35 Lightning II.Warthog jockeys spend more hours preparing to support troops under fire — at least 35 percent of their training time compared to 11 percent for some of the other planes, says Air Force spokeswoman Jennifer Spradlin.Says Sullivan, "Today’s multirole aircraft can do close air support, but not as good as the A-10 because that’s all the A-10 does."As if to punctuate his argument, a tremendous "brrrrt" sound rocks the scrubland of the range as a pilot fires a burst from his cannon."We call that an elephant fart," Sullivan says.A flock of resident sandhill cranes squawks in reaction.•••The Air Force has 281 A-10s, including those that arrived at MacDill on Jan. 19 for the two-week exercise.They were built by Fairchild-Republic Corp. to be rugged enough for close combat and powerful enough to kill Soviet tanks. Northrup-Grumman bought Fairchild-Republic and now partners with Lockheed-Martin.The A-10 is designed around a titanium "bathtub" that protects the pilot from injury. It has redundant flight control systems allowing pilots to fly a battle-damaged aircraft and comes with the deadly, seven-barreled GAU-8/A Gatling gun in its nose and the capability of carrying rockets, bombs or other instruments under its wings.Technological advances have allowed for upgrades through the years in avionics, radars and night vision capabilities.Over the years, 173 A-10s have received new wings, but 109 still need them, said Air Force spokeswoman Ann Stefanek. To pay for the work, the Air Force included $103 million in its current budget request to restart the production line and buy the first four new sets of wings. Additional money will be requested in the next budget as well, Gen. Mike Holmes, commander of Air Combat Command, said at a public event last week.But the budget impasse, blamed for one government shutdown and threatening more, means the Defense Department is operating on temporary spending plans — called continuing resolutions — that don’t allow for new expenses, Stefanek said."If the continuing resolutions continue, at some point some of the aircraft will be affected," she said. "But we don’t know where that break-even point is."The Air Force is resolved to keep A-10s in the air at least into the 2030s, Gen. Holmes told a recent Brookings Institute gathering. He wasn’t sure how many of the nine squadrons that would involve."It will depend on what we have, what we need and what’s useful on the battlefield year to year."•••Lt. Col. Josh Waggoner, one of the A-10 pilots training out of MacDill, flew the aircraft during its last mission in Afghanistan and took park in the first A-10 attacks against the so-called Islamic State."Your heart rate increases a bit," when troops are under fire, says Waggoner, 42, standing next to one of the 10 jets parked on the MacDill flightline. "But we train to the point that we can execute in any environment."At Avon Park, they are training for a variety of missions — attacking the enemy as it fires on U.S. troops, taking out tanks and Russian anti-aircraft systems.Before A-10s, Waggoner flew the multipurpose F-16s. The A-10, he said, has its advantages."The A-10 can stick around longer and get closer," he says. "You can get down and see the whites of their eyes. The F-16 needs to be higher and faster and makes a lot wider turns."When troops find out he flies the A-10, they want to thank him, he says."It may not be me or someone in my squadron, but they all have memories of what an A-10 can do and what it has done for them."Contact Howard Altman at [email protected] or (813) 225-3112. Follow @haltman.