August 22, 2011:
The first U.S. Marine Corps "instant gunship" arrived in Afghanistan ten months ago. Since then it has fired 42 Hellfire and 11 Griffin missiles, as well as spotting eleven roadside bombs. As a result of this experience, the marines are again considering mounting (on the rear ramp) a 30mm GAU-23 automatic cannon in the aircraft as well. The marines also want Harvest Hawk to carry more missiles, because in one case, all the missiles were used up before the ten hour mission was up. In cases like that, the aircraft is still useful because of its sensors, which see a lot down there.
Called "Harvest Hawk," the "instant gunship" system 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 existing AC-130 gunships). The sensor package consists of day/night vidcams with magnification capability. The weapons currently consist of ten Griffin missiles and four Hellfires. These are lightweight missiles, so more can be carried.
It was only last year that the 15.6 kg (34.5 pound) Griffin missile entered service in Afghanistan, mainly aboard UAVs. The Hellfire II missile has been around a lot longer, weighs 48.2 kg (106 pounds), carries a 9 kg (20 pound) warhead and has a range of 8,000 meters. The Griffin has a 5.9 kg (13 pound) warhead which is larger, in proportion to its size, than the one carried by the larger Hellfire missile. Griffin has pop-out wings, allowing it to glide, and thus has a longer range (15 kilometers) than Hellfire. UAVs can carry more of the smaller Griffin, typically two of them in place of one Hellfire.
Harvest Hawk enables marine KC-130J tankers to be transformed into gunships with the addition of the portable weapons and sensors. The marines had long noted the success of the U.S. Air Force AC-130 gunships that SOCOM (Special Operations Command) uses. But they couldn't afford them, as an AC-130 costs more than three times as much as 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.
The original plan was to have a 30mm Bushmaster cannon as well, so that there would be gunfire support as well. But this was made optional, as the 14 missiles seemed to provide sufficient firepower. It also meant less for Harvest Hawk to carry. The 30mm Bushmaster cannon weighs 157 kg (344 pounds) and fires at 200 or 400 rounds per minute (up to 7 per second). The Bushmaster 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 714 g (25 ounces, depending on type.) Explosive anti-personnel rounds are fired when used in gunships. The fire control system, and night vision sensors, enables the 30mm gunners to accurately hit targets with high explosive shells. Existing SOCOM 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 just with smart bombs and missiles.
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. Most of what Harvest Hawk does in Afghanistan is look for roadside bombs, or the guys who plant them. These marines want to track back to their base, and then take out an entire roadside bomb operation.
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. SOCOM will be using their version of Harvest Hawk (the Precision Strike Package) in their MC-130 transports (which are already equipped for all-weather operations.) Meanwhile, SOCOM is expanding its existing AC-130 gunship fleet to 33, with the acquisition of 16 new AC-130J models.