Meet the Harvest Hawk: A Refueling Plane Turned Into a Marine War Machine

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October 25, 2019 Topic: Security Region: Americas Blog Brand: The Buzz Tags: MarinesU.S. MarinesMilitaryTechnologyWorldWar

Meet the Harvest Hawk: A Refueling Plane Turned Into a Marine War Machine



Key point: The Marines saw a need and so they modified a KC-130J tanker to fill that need.

Dropping bombs out of cargo planes has been a common measure of desperation for under-equipped air forces and opportunistic mercenaries throughout the history of aviation. However, in 2009 the U.S. Marine Corps found a way to make a virtue out of flexibility by developing Harvest Hawk, a kit which allowed their new KC-130J refueling tankers to double as missile-toting gunships and creepy aerial spying platforms that would put the Eye of Mordor to shame.


Heavily armed Hercules transports have existed since the feared AC-130 Specter gunship debuted during the Vietnam War, and the Air Force currently operates several different types. In 2009, the Marines joined in by developing the Hercules Airborne Weapons Kit, which can be bolted on to the service’s KC-130J refueling tankers.

While the Air Force and navy operate KC-135 and KC-10 tankers based on jetliners, the Marines instead adapted C-130 Hercules transport planes to serve as slower, more versatile platform that can refuel helicopters and Osprey tilt-rotors as well as fixed-wing jets. Even better, a KC-130 can top up two helicopters at a time via drogue-hoses which can pump 300 gallons a minute. A KC-130J can carry 60,000 pounds of fuel and cargo—or 84,000 pounds without cargo.

Six $22 million HAWK kits were assembled, and ten KC-130Js modified to accept them. The kits added an AAQ-30 Targeting Sighting System sensor pod under the KC-130J’s left wingtip fuel tank which can spot individuals up to ten miles away; an M299 quad-launcher capable of carrying four AGM-114P2 Hellfire II anti-tank missiles (or P2A anti-personnel models) under the right wing; and a box-launcher loaded with ten smaller AGM-176 Griffon GPS-guided missile on the cargo ramp. That’s right, the beast had to lower the cargo-bay door midflight to fire the Griffons.

The Hawk’s crew of seven included a pilot and co-pilot, two fire control officers operating a fire control system fixed on a cargo palette, a crewmaster and two cargomasters that double as Griffon missile operators.

Harvest Hawks provide ‘overwatch’ for friendly ground troops by spending hours slowly orbiting overhead, using their sensor balls to scan huge swathes of terrain and spy on what the locals below are up to. As Hawk crewmember Major Mark Blankenbricker told defense media, “We use our cameras to look at villages, watch pattern of life and assess what is going on in the [area of operation] at that time.” No less than seven onboard radios allow close coordination with ground forces and friendly aircraft. If the grunts on the ground run into trouble, the Hawks sling guided missiles fairly precisely on top of the hostiles.

A Harvest Hawk was deployed by Marine Air Refueling Squadron 352 to Afghanistan in October 2010, and first saw action at Sangin on November 4 while supporting 5th Regiment Marines, killing five Taliban insurgents with a Hellfire missile. The lone Hawk soon proved to be under constant demand by ground troops.

Improved with Experience

By 2012, Harvest Hawks were a reliable fixture of Marine air support over Helmand Province, Afghanistan as detailed profile by Code One Magazine in which Marine Major John Bulter of VMGR 252 shared a starting figure: “Our launch total was considerably more than Marine Harriers, Navy Hornets, and even Air Force A-10s. With only one aircraft, we shot close to half of all the kinetic weapons launched in theater in the nine months we were there.” The armed tankers averaged four flight hours a day, though could remain aloft as many as ten hours if necessary.

The aircraft’s sensors reportedly could distinguish humans from animals, and even adults from children. In one incident, a HAWK crew spotted a group of Taliban firing on U.S. troops while using children “as a buffer” and to resupply ammunition. Unwilling to launch missiles, the pilots instead buzzed low overhead while spraying out a rain of defensive flares. The insurgents and their captives dispersed.

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Over time, the Harvest Hawks were improved. The cheaper Griffon missiles were rarely used at first because depressurizing the cargo bay to fire them was such a pain—so a new ‘wine rack’ launcher was developed poking out the side of the paratrooper jump door. The new “Derringer Door” could also launch GBU-44/B Viper Strike glide bombs—designed to deliver very precise strikes with minimal collateral damage due to their 2-pound warheads and sub-one meter accuracy. You can see the newly configured Harvest Hawk fire Griffon and Maverick missiles in this video.

Additionally, new Intrepid Tiger electronic warfare pods gave Hawks the ability to jam hostile radio signals—particularly those that might trigger an IED from under the feet of troops on the ground. Marines in the field even scrounged a ground-based ROVER video receiver and installed it in the cargo bay of KC-130s, using it to collect video feed from all kinds of drones and aircraft.

In 2016, the Marines formulated a major upgrade called Harvest Hawk+, and announced plans to introduce HAWK-compatibility on the sixty-nine remaining un-upgraded KC-130Js. The new format swaps out the AAQ-30 bolted on the left wing for a higher-quality L3 Wescam MX-20 sensor turret permanently installed under the nose. Additionally, an ALQ-23 Intrepid Triger II electronic warfare pod allows selective jamming or spying on different radio frequencies, and may be eventually upgraded for area radar jamming capability. Finally, compatibility was added for the AGM-114P4 Hellfire, which has improved maneuverability for hitting moving vehicles. In June 2018, the Harvest+ successfully completed a five-week live-fire training at the Naval Weapons Station at China Lake. Compatibility with additional weapons such as Small Diameter Bombs, 70-millimter guided rockets, a more prodigious Hellfire missile rack, or a long-promised but long delayed 30-millimter side-firing cannon, could eventually follow.

An Osprey Hawk?

Intriguingly, the Marine Corps also declared in 2016 its interest in upgrading its fleet of MV-22 Osprey tilt-rotor aircraft with many of the Hawk+ systems. The very flexible, but expensive and accident-prone Osprey was criticized for its lack of effective armament when delivering troops to hot drop zones in Iraq.

The laundry list of proposed upgrades would turn the Osprey into a true multi-role platform: aerial refueling capability with other Ospreys, a self-defense jamming pod, a Forward Looking Infrared Sensor for both scanning for hostiles and assisting in landing, a laser designator for targeting precision-guided munitions, an MX-20 sensor ball under the chin, and even capability to guide Switchblade kamikaze drones that can be literally chucked by hand out the side door. Of course, whether funding will materialize for such an ambitious and expensive upgrade is to be determined.

The Harvest Hawk has worked so efficiently because it operates in “permissive” environments where adversaries lack the anti-aircraft weapons to effectively shoot back. In these situations, the speed and defense capabilities of expensive, fuel-gulping jet fighters is superfluous, and a lumbering cargo plane can virtually hover in place in relative safety while benefiting from greater endurance and payload. On the other hand, the Hawk mission may reduce KC-130 availability for the aerial refueling missions, which has already suffered due to the grounding of the majority of the Marine’s older KC-130T tankers after a deadly crash in July 2017.

The Hawk thus is an investment not in conventional warfighting capability, but in providing both ISR and close air support capabilities for counter-insurgency missions—a need which unlikely to go away soon as Washington doubles down on military commitments in the Middle East, Africa and Afghanistan.

Sébastien Roblin holds a master’s degree in conflict resolution from Georgetown University and served as a university instructor for the Peace Corps in China. He has also worked in education, editing and refugee resettlement in France and the United States. He currently writes on security and military history for War Is Boring. This first appeared in June 2018.

Image: Wikimedia.