March 2, 2012: The U.S. Marine Corps recently received the first of its KC-130J transports with a modified rear door (the Derringer Door) that enables Griffin missiles to be fired, and the missile launcher reloaded, without first depressurizing the aircraft and lowering the rear ramp.
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. This last item is the Harvest Hawk version of the KC-130J. This "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 missile launchers and four Hellfires hanging from the wings. The first U.S. Marine Corps "instant gunship" arrived in Afghanistan two years ago. Since then Harvest Hawk aircraft have fired hundreds of Hellfire and Griffin missiles, as well as spotting lots of enemy activity.
The one problem was the need to lower the rear door to fire Griffin missiles and reload the launchers. Since the aircraft usually operated at high altitude (6,400 meters/20,000 feet) the crew had to put on oxygen masks and it took time to depressurize the cargo bay and lower the rear ramp. The new door has ten Griffin launch tubes that can be used (for firing or reloading) while the ramp is closed.
It was only two years ago last year that the Griffin, which weighs 20.5 kg (45 pounds) and has a 5.9 kg (13 pound) warhead, entered service in Afghanistan. Griffin has a greater range (15 kilometers) than Hellfire because of pop-out wings that allow it to glide after launch. Griffin uses laser, GPS, and inertial guidance. 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 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. The marines want to track the bomb planters back to their base and then take out an entire roadside bomb operation.