U.S. SOCOM (Special Operations Command) is going to check out a new U.S. Marine Corps "instant gunship" system, which enables weapons and sensors to be quickly rolled into a C-130 transport and hooked up. This takes a few hours, and turns the C-130 into a gunship (similar in capabilities to the AC-130 gunships used by SOCOM). The marine system is called Harvest Hawk, and the marines take their KC-130J tankers and transform them into gunship with the addition of the portable weapons and sensors. Like the marines, SOCOM wants more gunships, and likes the idea of being able to get them as needed, without buying specially modified C-130s (AC-130s).
The U.S. Marine Corps has long noted the success of the U.S. Air Force AC-130 aircraft that SOCOM uses. But they couldn't afford them, as an AC-130 costs more than three times as much an a marine KC-130J aerial refueling aircraft. But the marines developed a solution. This is something the marines often do.
The KC-130J is the latest, and largest, USMC version of the C-130 transport used for aerial refueling. But the KC-130J can also carry cargo, and weapons (bombs and missiles) hung from the wings. Thus the Harvest Hawk version of the KC-130J adds a targeting pod, with the data going to a special cargo container containing control equipment (computers, commo and displays) enabling operators use of the day/night sensors of the targeting pod, to fire Hellfire missiles hung from the wings. A 30mm Bushmaster cannon is fired out the door, so that there would be gunfire support as well.
The Mk44 30mm Bushmaster cannon weighs 344 pounds and fires at 200 or 400 rounds per minute (up to 7 per second). The cannon has 160 rounds available, before needing a reload. That means the gunner has 25-50 seconds worth of ammo, depending on rate of fire used. Each 30mm round weighs about 25 ounces (depending on type.) Explosive anti-personnel rounds are fired when used in gunships. The fire control system and night vision sensors, enable the 30mm gunners to accurately hit targets with high explosive shells.
SOCOM experimented with putting Bushmaster 30mm cannon on their AC-130s, replacing the existing 25mm and 40mm weapons. But SOCOM was not satisfied with the lower accuracy of the Bushmaster. The marines believe the Bushmaster is accurate enough. The marines are now using Harvest Hawk in Afghanistan, and SOCOM is watching how this works out. The marines may turn out to have more effective ways of using the 30mm gun in the C-130, giving SOCOM a reason to reconsider that weapon for their use.
Existing AC-130 gunships are armed with a 105mm howitzer, a 25mm and 40mm automatic cannon. But the two smaller caliber guns are being phased out of military service. The air force is considering equipping its gunships with smart bombs and missiles.
The next version of Harvest Hawk will add a pod (hanging from the wing) containing four 107 pound Hellfire missiles, or 16 25 pound DAGR missiles. Like the Hellfire, DAGR is a laser guided missiles. DAGR is smaller than Hellfire (which is 178mm in diameter, compared to 70mm for DAGR).
The big thing with gunships is their sensors, not their weapons. Operating at night, the gunships can see what is going on below, in great detail. Using onboard weapons, gunships can immediately engage targets. But with the appearance of smart bombs (GPS and laser guided), aerial weapons are more available to hit any target that is found. So Harvest Hawk would be able to hit targets that were "time sensitive" (had to be hit before they got away), but could also call on smart bombs or laser guided missiles for targets that weren't going anywhere right away.
Ultimately, the air force and SOCOM see the potential for the Harvest Hawk approach replacing custom built AC-130 gunships. There would still be a need for specially trained gunship crews. But they, and the several cargo containers of Harvest Hawk gear, could be held ready to go wherever they are most needed.