AC-130

I heard a story on NPR today about how the AC-130 gunship may represent excessive use of force in an urban environment such as Baghdad - that the power of the AC-130 is a greater danger to innocent civilians than a threat to insurgents.

And reviewing the armament of the aircraft, it's a tempting conclusion. The armament varies from subtype to subtype, but the most common modern variant the AC-130U, appears to be armed with a 25mm Gatling gun, a 40mm gun, and a 105mm howitzer (the difference between a "gun" and a "howitzer" in this context being that a howitzer has a shorter barrel and a lower muzzle velocity than a gun). TV documentaries usually talk about this with a certain amount of boyish vim, the announcers going on and on about the devastating impact of all this, a veritable testosterone-soaked buffet of gore and slaughter.

So the average citizen thinks about an airplane using a 25mm gun, a 40mm gun, and a 105mm howitzer in a city, reflects on the gore-and-devastation angle of the documentaries, and can't help but imagine that the AC-130 is a flying slaughterhouse.

And it certainly can be. Used as the limits of its firepower, the AC-130 is indeed a first-rate killing machine, but it need not always be used at the limits of its firepower. Unlike a lot of aircraft, the AC-130 has the ability to moderate its firepower by employing the smallest weapon that will achieve the tactical end. An AC-130 fire control operator could, in principle, elect to engage a target with a single 25mm cannon round, a projectile about the size of a human thumb (or at least my human thumb). Simply because it can fire thousands of rounds per minute from three different guns, one of them powerful enough to blow the average house flat, doesn't mean that it has to.

The use of aircraft in counter-insurgency operations is tricky, at best. Say you spot insurgents on a rooftop and employ aircraft to eliminate them. About the smallest guided weapon a conventional airplane can use would be a AGM-65 Maverick, which weighs about 550 pounds (some more, some less) at launch, and has a warhead of 125 to 300 pounds of high explosive, depending on the type. The next smallest but probably more common guided weapon would be a laser-designated bomb, anywhere from 500 to 2000 pounds in weight. This is a lot of bang, as they say, enough to flatten the insurgents, the house they're on, the houses around it, and earn the lasting hatred and distrust of the innocent people who survived the attack. (This problem has led the US military to consider developing a guidance package for the currently unguided 70mm Hydra rocket, which would reduce the effective bang to about ten pounds of high explosive. Another option being considered is making guided but inert bombs that have no explosive filling at all and destroy their targets simply by crashing into them - this weapon has been referred to as the "Mosque-saver" because it could conceivably pick off tanks parked next to mosques without damaging the mosques.)

The point is that using any kind of bomb or missile in an urban environment is made difficult by the fact that current bombs and missiles are way too powerful. They cause far too much collateral damage, and almost invariably end up killing large numbers of the population whose goodwill is essential in winning the counter-insurgency campaign in the first place. The same problem also affects artillery, and perhaps even more so because artillery rounds, being unguided, are less accurate than precision-guided aircraft weapons. How much more inaccurate is a matter of some contention. The case is less unambiguous for things like tank main guns and squad-level anti-tank missiles and rockets, which are more discriminating in effect because they are basically a lot less explosive than aircraft bombs. (During the Battle of Hue in Vietnam, the use of artillery and aerial bombs was prohibited because they would cause too much damage to the historic city, so the Marines relied extensively on 3.5-inch rocket launchers (Bazookas, basically), recoilless rifles, and 90mm tank guns for fire support because they simply couldn't do as much damage as the Big Stuff.)

What does this have to do with the AC-130? This. People imagine that the AC-130, with all those guns, could cover a city with cannon rounds. And it could, and it would cause horrendous casualties if it did. But it doesn't have to. The AC-130 fire control officer can scale the firepower back to the minimum required to deal with the target at hand. The AC-130, unlike an aerial bomb, has at least some hope of engaging a point target and destroying it without blowing half a dozen houses flat and filling the hospitals and morgues with innocent victims. I'm not saying that the AC-130 can always eliminate every target without killing innocent people, but I am saying that it has a much better chance of doing so than, say, an A-10 or F-15 (or a battery of 155mm howitzers).

Some of the things that make the AC-130 useful in night operations over cities include:

1. The ability to scale firepower to the target and situation.
2. The ability to see in the dark.
3. The ability to carry enough fuel and ammunition to stay overhead all night.
4. The ability to provide fire support for friendly troops even when closely engaged.
5. The ability, in principle, to engage a point target with affecting adjacent buildings.
6. The ability to help friendly troops in unexpected ways.

The last point was made to me when I read a book about US Marine operations during the two battles of Fallujah, where an AC-130 used its powerful infrared spotlight to help guide Marines through a confusing snarl of alleys and streets. The AC-130 didn't fire a shot, but it helped guide the Marines who simply had to follow the "bouncing red ball" of the infrared spotlight.

So let's imagine I'm an insurgent. I pick up my AK and a bag of magazines and slip out the back door, intent on causing mischief, and I pause when I hear the distant whine of a multi-engined turboprop airplane somewhere in the night sky. Odds are that the airplane in question is an AC-130, whose crew can see me in the dark. They can tell US forces where I am and what I'm doing, or if the situation is right, they can wax me with a handful of 25mm cannon rounds. And the plane has enough fuel and ammunition to stay up there all night (US generals sometimes call this "dominating the battlespace").

I conclude that I'm better off going back inside, putting my AK away, and delaying my insurging for a night less dominated by AC-130s.