The Right to Bear Arms: Gunship Kits for America’s C-130s

Special Operations Command’s AC-130H/U gunships can lay down withering hails of accurate fire, up to and including 105mm howitzer shells, in order to support ground troops.

The Marines also wanted heavy aircraft that could support their Leathernecks on the ground. The bad news was that the Corps could field about 45 KC-130J aerial tankers for the price of a 12-plane AC-130J squadron, and lighter options like the AC-27J “Stinger II” would probably tally similar costs once R&D dollars were factored in. Could the Marines change tack, and offer a modular weapon package that would let them arm their existing tankers as needed? Could armed KC-130Js offer limited fire support, while loitering over the battlefield and using their unique speed range to refuel helicopters and fast jets alike? The Harvest Hawk program aims to do just that. It would give the USMC a far less capable convertible gunship option for Afghanistan, at a cost that’s about 2 orders of magnitude below a dedicated gunship fleet.

Gunships R Us: Equipping The Hercs

The Marines’ program is called Harvest Hawk. The initial plan is to field 3 kits, and the eventual plan is to have 3 roll-on/ roll-off kits per squadron. That would mean about 9 kits by 2011, and 12 kits when the last KC-130T aerial refueling squadron converts to KC-130Js after 2012. All USMC KC-130Js are expected to receive the wiring needed to carry the kits, which will be improved and refined over time.

Harvest Hawk Capability I involves a roll-on/roll-off set of surveillance displays and fire control electronics. This is coupled with a modular surveillance and targeting unit that takes up the rear portion of the inboard left external fuel tank, or may simply be mounted below that tank as a surveillance turret. The sensor choice was said to involve 2 candidates. Lockheed Martin’s AN/AAQ-30 TSS, which is also used in the Marines’ AH-1Z attack helicopter and has been installed in some SOCOM AC-130s, was the front runner. L-3 Wescam’s popular MX-15 surveillance and targeting turret was the competitor, but competing against the Harvest Hawk’s integrator is not a promising position; the AAQ-30 TSS won.

Harvest Hawk Capability II involves mounting an M299 missile rack for 4 AGM-114 Hellfires and/or up to 16 DAGR laser-guided 70mm rockets to the left wing, in place of the left-hand aerial refueling pod. This leaves the left wing carrying the weapons and some fuel, while the right wing retains full aerial refueling capabilities. The laser/GPS-guided GBU-44 “Viper Strike”/SOPGM has also been moved into this category.

Early testing for Capabilities I & II has taken place, initial orders have been placed, and testing of the first equipped aircraft is underway. Deployment to Afghanistan is now expected in summer 2010.

Harvest Hawk Capability III involves a modular 30mm cannon linked to the fire control, which is expected to be rolled in and mounted in the troop door. Daniel Watters of The Gun Zone writes to say that the Marines’ choice of 30mm gun will be interesting, and explains the tradeoffs:

“While the Mk 44 Bushmaster II [30×173mm] and M230 Chain Gun [30×113mm] are both nominally 30mm, their cartridges are very different….There is a major difference in size, power, and range. The Mk 44 Bushmaster II has already been adopted by the US Navy and USMC for other applications…. The 30×173mm uses a heavier projectile with a larger explosive filling, and is fired at a higher velocity [which] should have a noticeable maximum range advantage. Perhaps it would be easier to fabricate a stable mount for the less powerful M230 than the Mk 44… M230 and its ammunition are also lighter and more compact.”

US Special Forces tried fitting 30mm cannon to their AC-130U “Spooky” gunships, but found that the gun’s accuracy level wasn’t suited to their missions. In response, they implemented a “retrograde” to their earlier 25mm and 40mm weapons. The Marines say that the 30mm cannon will suit their objectives. Time will tell, but either way, the lack of pinpoint-accurate, extreme-volume gunfire will be one of the principal differences between SOCOM’s AC-130s and kit gunships like the KC-130Js or MC-130Ws.

Capability III has yet to even select a gun at this point, much less test and integrate one. According to US Navy NAVAIR: “capability III [will begin] when funding becomes available.”

Capability IV involves adding additional precision-guided weapons to the Harvest Hawk. Efforts are already underway to incorporate and test Northrop Grumman’s GBU-44 Viper Strike laser/GPS-guided weapons, which are also under consideration by SOCOM for its AC-130s. Those have been moved to Capability II deployment. Raytheon’s small “Griffin” missiles, which can replace Hellfires on a 3 for 1 basis, are also part of ongoing Capability IV efforts.

Specifics regarding additional weapon fit-outs are thin at the moment, but other options could conceivably include 81mm or larger mortars with General Dynamics’ RCFC GPS guidance kits; and potentially even small precision-guided bombs. Among other potential modifications, later Harvest Hawk phases will reportedly add stations for Hellfire laser-guided missiles on both wings, mounted on the outside of the plane’s outboard aerial refueling pods. There has even been talk of adding tube-launched precision-guided weapons that could be slid out the rear ramp, or even gravity-dropped through panels in the floor.

US Navy NAVAIR PMA-207 is also working with US Special Operations Command (SOCOM) to share information on Harvest Hawk, which could become an option for all of SOCOM’s ordered MC-130Js.

A similar effort is emerging from an AFSOCOM investigation into converting its MC-130W Combat Spear aircraft along Harvest Hawk lines. The MC-130Ws are newly-converted C-130H aircraft, with 12 slated for delivery as combat replacements from 2006-2011. Their roles include infiltration/ exfiltration of special operations teams, aerial refueling including combat search-and-rescue support, and psychological operations. “Project Dragon Spear” aircraft will be armed via roll-on, roll-off kits featuring added sensors, communications systems, Hellfire/DAGR missiles, and the Adaptive Carriage Environment (ACE). Armament will reportedly include a Mk.44 30mm gun, wing-mounted laser-guided Hellfire/DAGR missiles, and a 10-tube “Gunslinger” system that can launch small precision-guided weapons like the GBU-44 Viper Strike.

To learn more about the history of this program, click here.