But the plane is designed to keep flying even if parts of the wing or one of its engines has been blown to shreds. And the cockpit is surrounded by a bullet-resistant titanium tub. The aircraft has been routinely upgraded over the years.

"The idea is the pilot in the cockpit faces the same threats as the guy in the foxhole," said Pierre Sprey, an aeronautical engineer who helped design the F-16 and A-10. "They're in the same fight, and direct contact with one another the whole way through."

That could be seen in July when two A-10s flying out of Afghanistan's Bagram air base protected 60 soldiers who were ambushed after their lead vehicle turned over during a patrol in Afghanistan. As the soldiers lay pinned behind their vehicles, taking fire, the A-10s rained down bullets and bombs until the combatants gave up.

Army Chief of Staff Gen. Raymond Odierno told the Senate Armed Services Committee this month that the "A-10 is the best close-air support platform we have today."

As good as it is in close-air support, the military classifies it as a single-role aircraft. That's the problem. The Air Force has said it wants to rid itself of one-mission planes in favor of a fleet of multi-role aircraft. These jack-of-all-trades aircraft can blast apart enemies on the ground and in the sky.

The A-10 can't dogfight. It's not stealthy. It's not supersonic.

"The Air Force never wanted the A-10, and they've been trying to get rid of it for years," said John Pike, director of GlobalSecurity.org, a website for military policy research. "They are manly men and they want jets that shoot down other jets — even though the last time they had an ace was Vietnam."

While the Air Force wants to get rid of the A-10, the Army and Marines love the aircraft, said Stan Piet, a historian at the Maryland Aviation Museum in Middle River. He said the A-10 excels in "massive land battle situations," where it can take significant damage as it rains damage on the enemy.

"It's not particularly fast, but it's designed to loiter for long periods of time," he said.

Piet said the Air Force is faced with the "tough question" of whether to keep paying to maintain and upgrade the older airplanes or whether to transition to new designs of planes, which also involve significant cost.

The A-10 replacement is the upcoming F-35 fighter jet. Known as the Joint Strike Fighter, the nearly $400 billion program for more than 2,400 jets is centered around a plan to develop a fighter plane that can be used by the Air Force, Navy and Marine Corps.

The idea is that it can take off and land on runways and aircraft carriers, as well as hover like a helicopter. No single fighter aircraft has had all those capabilities. And it is expensive. The F-35's cost per flying hour, at $35,200, is twice as much as the A-10's, according to the Government Accountability Office.

Though few believe the F-35 will ultimately be able to provide close-air support as well as the A-10, it certainly meets the Air Force's definition of "multi-role."

Therein lies the dilemma, said Todd Harrison, a defense analyst for the Center for Strategic and Budgetary Assessments in Washington, D.C. If budgets are going to be cut severely, where are the cuts going to come from: expensive new weapons that can carry out more missions, or aging, less-complex weapons?

The F-35 provides 127,000 direct and indirect jobs in 47 states and Puerto Rico. Someone is sure to be upset if there's a proposal to buy fewer of the planes, Harrison said.

"Everyone knows there needs to be cuts, but few people in Congress are brave enough to actually make them," he said. "Bottom line is there are going to be a lot of angry people in Congress — no matter what."

Baltimore Sun reporter Colin Campbell contributed to this article.