An AC-130 gunship is shown in this undated photo provided by the U.S. Air Force. (AP/U.S. Air Force)
(CBS) It's a prop plane in a jet age and an ungainly one at that. But the AC-130 gunship may well be the single-most overworked piece of equipment in the American arsenal, CBS News national security correspondent David Martin reports.
When it takes on a full load of ammunition, it becomes a flying tank, and every time special operations forces conduct a mission in Iraq and Afghanistan, an AC-130 covers them from air.
"We are the No. 1 aircraft for percentage of combat time and total time over the course of the year," Lt. Col. Mark Clawson said.
The gunship Clawson flew for a training mission has been in service for 17 years, but the war is making the gunship old before its time.
"We've been flying at a rate four times what they ever anticipated. So effectively, this is a 40-year-old C-130 in the way it reacts," he said.
The back of the plane is filled with crew members, instruments, computers, guns and ammo - so full it's at maximum gross weight.
"That basically means I'm at max throttles, max gross weight and it's max wear and tear on the aircraft on a daily basis," Clawson said.
You rarely see an AC-130 gunship in action, because they operate in secret and at night. But they are seeing so much action in Iraq and Afghanistan that it is getting harder and harder to keep them flying.
"We're flying the wings off them, literally," Captain James May said.
May said cracks are already starting to show in the wings, which will have to be replaced five years ahead of schedule. And that's just the wings. For every hour of flying, it takes 14 hours of maintenance.
"These air frames are getting so old that we've got stuff breaking on them that has never broken before," May said.
But on one flight, it was the guns that broke down. First the 40-millimeter canon jams.
"This is horrible," one crewmember said.
Then, the big 105-millimeter horowitzer refused to fire on automatic. A few love taps with a wrench, but still, no go.
"They're just old and tired," another crewmember said. Another: "It's all right, old girl."
There's one way that it does work - the old fashioned way.
Even firing manually the AC-130 is a fearsome weapon.
The one gun that does work flawlessly, the 23-millimeter gatling gun, fires at the rate of 1,800 rounds per minute.
If special operations forces ever get a chance to capture or kill Osama bin Laden, an AC-130 gunship will almost certainly be part of the operation. That is, if it's still flying by then.
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