The U.S. Air Force has revived an original mission for the A-10 ground attack aircraft; destroying small boats. Experiments have been conducted recently and, while no details were made public, the tests were considered successful. There were basically two tests. One had had experienced civilian boat operators in typical (for Iranians and others) small boats with a dummy heavy machine-gun mounted on it, sent out to use typical Iranian swarming tactics while A-10s (and some other aircraft) make simulated attacks. These attacks were electronically recorded for later analysis. The other tests had the A-10s firing training (non-explosive) ammo at remotely controlled boats. All this data can be used to prepare a training scenario for flight simulators and that scenario can also be used to develop new tactics and possible modifications to the A-10s autocannon.
The A-10 is a 23 ton, twin engine, single seat aircraft whose primary weapon is a multi-barrel GAU-8 30mm cannon originally designed to fire armored piercing shells at Russian tanks. These days the 1,174 30mm rounds are mostly high explosive. The A-10 can carry up to 1,350 rounds. The 30mm cannon fires 363 gram (12.7 ounce) rounds at the rate of about 65 a second. The cannon usually fires in one or two second bursts. Most A-10 pilots have at least some (and many a lot) of combat experience with the A-10 and have learned how to get the most out of the GAU-8 by using short, but accurate, bursts. Experienced pilots can get as many as 30 brief but accurate bursts. The GAU-8 originally had variable rate-of-fire that could be set as low as 35 rounds per second allowing up to 40 very short bursts. A few of these 30mm rounds hitting a small boat will put it out of action.
The Iranians were first seen conducting large-scale small boat swarm attacks in 2006. These training exercises tried several different swarming tactics. Many seemed to involve one or more separate squadrons each consisting of about a hundred small boats approaching U.S. warships. The boats involved were 6- 21 meters (20-70 feet) long moving at speeds of 70-90 kilometers an hour. Some 10-20 percent of the Iranian boats would be equipped with anti-ship missiles like the six meter long, 680 kg (1,500 pound) Chinese C-802. Some smaller boats have been seen equipped with anti-tank missiles. The idea is that some of these boats would make it to the American ships, 50-100 kilometers away, and inflict some damage. China was thought to be planning on the same tactics, but has apparently abandoned it as impractical for combat. Iran, however, now has several thousand of these small boats and continues to buy more. Ever since 2006 the U.S. navy has been practicing defending itself against such swarms. Combat simulations indicate the swarms would lose, but you never know. The Iranian preference for "swarm tactics" has a lot to do with their inability to build or buy anything much better. Moreover, all those small boats keep thousands of Islamic conservative militiamen occupied and that makes for great propaganda videos. The Iranians have since bought faster small boats and equipped their swarms with better missiles. Some of the boats are apparently equipped with explosives and operated by zealots willing to be a suicide boat bomber. So the swarms are still a threat.
In response the U.S. Navy added more autocannon (similar to the GAU-8 but usually 20mm or 25mm) to ships and adapted existing ones (like the 20mm Phalanx anti-missile system) to handle small boats. More 12.7mm heavy machine-guns were added as well. Having A-10s on call, which is quite common in the Persian Gulf, gives the navy another weapon available to deal with any large scale use of swarming tactics in an effort to, for example, close the Hormuz Strait by sinking some large tankers at key points or simply to make a point..
In addition to the GAU-8 the A-10 can carry seven tons of bombs and missiles. These days the A-10 goes out with smart bombs (GPS and laser guided) and Maverick missiles. It can also carry a targeting pod, enabling the pilot to use high magnification day/night cameras to scour the area for enemy activity. Cruising speed is 560 kilometers an hour and the A-10 can slow down to about 230 kilometers an hour. In Afghanistan two drop tanks are usually carried, to give the aircraft more fuel and maximum time over the battlefield. The A-10 entered service in 1978 and 716 were built between 1972 and 1984. The A-10 didn’t see combat until the 1991 Gulf War and has been worked hard ever since. When first designed the A-10 was expected to be available for attacking coastal shipping but rarely got a chance to do so. The latest such opportunity was in 2011 off Libya and that was successful.
The increased popularity of the A-10 with the air force leadership did not become official until late 2016 when Air Force finally admitted that the A-10 was actually worth keeping and since then a lot of uses that have been kept quiet are now not only out in the open but getting more financial support. Chief among these is CSAR (Combat Search and Rescue). To that end the air force has, so far, equipped 19 A-10Cs with the LARS V-12 emergency radio signal locator. All American warplanes are equipped with an emergency radio that pilots carry and when they eject and are on the ground this handheld radio broadcasts a special signal. Rescue aircraft (usually air force CSAR helicopters) have LARS and the latest (V-12) version quickly tells the LARS user what direction the signal is coming from and how far away it is. Even before the 2016 decision to stop trying to retire A-10s there were plans to equip a lot (perhaps all) A-10s with LARS.
The air force leadership, during the decades they were very anti-A-10, did not like to discuss the usefulness of A-10s in CSAR (or any other) missions. Yet this was a very popular use of the A-10 because when a pilot had to eject and was on the ground, they quickly learned that if you had the enemy nearby looking for you what you wanted to see first was not a rescue helicopter, but an A-10. The GAU-8 would make sure the rescue chopper and the downed pilots were not hurt. The A-10s regularly came in low and slow seeking out enemy troops and was, unlike most aircraft, designed and armored to deal with a lot of enemy fire.