Lockheed AC-130
The Lockheed AC-130 gunship is a heavily armed, long-endurance, ground-attack variant of the C-130 Hercules transport, fixed-wing aircraft. It carries a wide array of ground-attack weapons that are integrated with sensors, navigation, and fire-control systems. Unlike other modern military fixed-wing aircraft, the AC-130 relies on visual targeting. Since its large profile and low operating altitudes around 7,000 feet make it an easy target, its close air support missions are usually flown at night.
The airframe is manufactured by Lockheed Martin, while Boeing is responsible for the conversion into a gunship and for aircraft support. Its sole operator has been the United States Air Force, which currently uses the AC-130J Ghostrider. Developed during the Vietnam War as "Project Gunship II", the AC-130 replaced the Douglas AC-47 Spooky, or "Gunship I". Since then, it has seen combat in Grenada, Panama, the Persian Gulf, Somalia, Bosnia, Kosovo, Afghanistan, Iraq, and Libya. Close air support roles include supporting ground troops, escorting convoys, and urban operations. Air-interdiction missions are conducted against planned targets and targets of opportunity. Force-protection missions include defending air bases and other facilities. AC-130Js are based at Hurlburt Field, Florida and Cannon AFB, New Mexico; gunships can be deployed worldwide. The squadrons are part of the Air Force Special Operations Command, a component of the United States Special Operations Command.
The AC-130 has an unpressurized cabin, with the weaponry mounted to fire from the port side of the fuselage. During an attack, the gunship performs a pylon turn, flying in a large circle around the target, so is able to fire at it for far longer than in a conventional strafing attack. The AC-130H Spectre was armed with two M61 Vulcan cannons, one L/60 Bofors 40 mm cannon, and an M137 cannon and M37 recoil mechanism from the M102 howitzer. After 1994, the cannons were removed. The upgraded AC-130U Spooky has a GAU-12 Equalizer cannon in place of the Spectre's two cannons, an improved fire-control system, and increased ammunition capacity. The new AC-130J was based on the MC-130J Commando II special-operations tanker. The AC-130W Stinger II is a modified C-130H with upgrades including a precision strike package.
Development
Origins
During the Vietnam War, the C-130 Hercules was selected to replace the Douglas AC-47 Spooky gunship to improve mission endurance and increase capacity to carry munitions. Capable of flying faster than helicopters and at high altitudes with excellent loiter time, the use of the pylon turn allowed the AC-47 to deliver continuous, accurate fire to a single point on the ground.In 1967, JC-130A 54-1626 was selected for conversion into the prototype AC-130A gunship. The modifications were done at Wright-Patterson Air Force Base by the Aeronautical Systems Division. A direct-view night-vision telescope was installed in the forward door, an early forward-looking infrared device was placed in the forward part of the left wheel well, with miniguns and rotary cannons fixed facing down and aft along the left side. The analog fire-control computer prototype was handcrafted by Wing Commander Tom Pinkerton at the USAF Avionics Laboratory at Wright-Patterson AFB. Flight testing of the prototype was performed primarily at Eglin Air Force Base, followed by further testing and modifications. By September 1967, the aircraft was certified ready for combat testing and was flown to Nha Trang Air Base, South Vietnam, for a 90-day test program. The AC-130 was later supplemented by the AC-119 Shadow, which later proved to be underpowered.
Seven more airframes were converted to the "Plain Jane" configuration like the AC-130 prototype in 1968, and one aircraft received the "Surprise Package" refit in 1969. The Surprise Package upgrade included the latest 20 mm rotary autocannons and 40 mm Bofors cannon, but no 7.62 mm close-support armament. The Surprise Package configuration served as a test bed for the avionic systems and armament for the AC-130E. In 1970, 10 more AC-130As were acquired under the "Pave Pronto" project. In the summer of 1971, Surprise Package AC-130s were converted to the Pave Pronto configuration and assumed the new nickname of "Thor". Conversion of C-130Es into AC-130Es for the "PAVE Spectre" project followed. Regardless of their project names, the aircraft were more commonly referred to by the squadron's call sign, Spectre.
Recent and planned upgrades
In 2007, AFSOC initiated a program to upgrade the armament of AC-130s. The test program planned for the 25 mm GAU-12/U and 40 mm Bofors cannon on the AC-130U gunships to be replaced with two 30 mm Mk 44 Bushmaster II cannons. In 2007, the Air Force modified four AC-130U gunships as test platforms for the Bushmasters. These were referred to as AC-130U Plus 4 or AC-130U+4. AFSOC, however, canceled its plans to install the new cannons on its fleet of AC-130Us. It has since removed the guns and reinstalled the original 40 mm and 25 mm cannons and returned the planes to combat duty. Brigadier General Bradley A. Heithold, AFSOC's director of plans, programs, requirements, and assessments, said on 11 August 2008 that the effort was canceled because of problems with the Bushmaster's accuracy in tests "at the altitude we were employing it". Also, schedule considerations drove the decision, he said.Plans were made for the possible replacement of the 105 mm M102 howitzer with a breech-loading variant of the 120 mm M120 mortar. The 120mm breech-loading mortar concept offers more flexibility with the use of munitions that are currently available with greater lethality, precision strike capabilities, reduction in collateral damage, and decreased casualties in danger close scenarios. Also, using the newer AGM-114 Hellfire missiles, the Advanced Precision Kill Weapon System, or the Viper Strike glide bombs can dramatically increase the standoff capability of the AC-130.
The conceptual breechloading variant of the 120 mm M120 mortar has several key advantages over the conventional M102 105 mm howitzer. 100 rounds of ammunition weighs for the M102 105 mm howitzer compared to for the M120 120 mm mortar. The recoil load is with the 105 mm howitzer compared to with the M120 120 mm mortar. The gun recoiling weight for the M102 105 mm howitzer is compared to for the M120 120 mm mortar. The muzzle pressure for the M102 105 mm howitzer is compared to for the M120 120 mm mortar.
In 2010, the Air Force awarded L-3 Communications a $61 million contract to add precision strike packages to eight MC-130W Combat Spear special-mission aircraft to give them a gunship-like attack capability; such-equipped MC-130Ws are known as Dragon Spears. AFSOC is arming these aircraft to relieve the high operational demands on AC-130 gunships until new AC-130Js enter service. The MC-130W Dragon Spear was renamed AC-130W Stinger II in 2011. The precision strike packages consist of a 30 mm gun and several precision guided munitions. Rails are mounted on the outboard pylon of the wing for four Hellfire missiles, SDBs, or SDB IIs under each. Ten common launch tubes are mounted on the rear ramp to fire Griffin A missiles; additional missiles are stored in the aircraft that can be reloaded in flight. CLTs are able to fire other small munitions able to fit inside the -diameter, -long tubes.
The AC-130J Ghostrider came from a 2011 initiative that sought to acquire 16 new gunships based on newly built MC-130J Commando II special-operations tankers outfitted with a "precision strike package" to give them an attack capability, requesting $1.6 billion from fiscal years 2011 through 2015. This was to increase the size of the gunship fleet to 33 aircraft, a net increase of eight after the planned retirement of eight aging AC-130Hs. The first aircraft would be bought in fiscal 2012, followed by two in fiscal 2013, five in fiscal 2014, and the final eight in fiscal 2015. The decision to retain the C-130 came after funding for 16 C-27Js was removed from the fiscal 2010 budget.
The AC-130J was to follow the path of the Dragon Spear program. On 9 January 2013, the Air Force began converting the first MC-130J into an AC-130J. The first AC-130J was delivered to AFSOC on 29 July 2015. The first AC-130J gunships achieved initial operational capability on 30 September 2017. The AC-130J has two planned increments: the Block 10 configuration includes an internal 30 mm gun, small diameter bombs, and laser-guided missiles launched from the rear cargo door; and Block 20 configuration adds a 105 mm cannon, large aircraft infrared countermeasures, wing-mounted Hellfire missiles, and radio-frequency countermeasures.
The Air Force decided to add a 105 mm cannon to the AC-130J in addition to the 30 mm cannon and smart bombs, the shells being more accurate and cheaper than dropping SDBs. AFSOC also pursued a directed-energy weapon on board the AC-130J by 2022, similar to the previous Advanced Tactical Laser program. It was to produce a beam of up to 120 kW, or potentially even 180–200 kW, weigh about, defensively destroy antiaircraft missiles, and offensively engage communications towers, boats, cars, and aircraft. A laser armament would have only been installed on a few aircraft rather than the entire AC-130J fleet; the laser would be mounted on the side in place of the 30 mm cannon. AFSOC eventually ruled out the idea in 2024 after the project was delayed by years, determining that placing a laser out the side of the airframe would yield so much air turbulence that it would disrupt the beam. In addition to this, while the laser weapon on the Lockheed AC-130 turned out to be a failure, Lockheed has been examining concepts for the integration of the laser module system onto the F-35 Joint Strike Fighter, he said. Other potential additions include an active denial system to perform airborne crowd control, and small unmanned aerial vehicles from the CLTs to provide remote video feed and coordinates to weapons operators through cloud cover. Called the Tactical Off-board Sensor, the drones would be expendable and fly along a programmed orbit to verify targets the aircraft cannot see itself because of bad weather or standing off from air defenses. AFSOC was to initially use the Raytheon Coyote small UAV for the TOBS mission, as it is an off-the-shelf design with a one-hour endurance, but planned to fulfill the role with a new drone capable of a four-hour endurance by 2019.
The Air Force was also interested in acquiring a glide bomb that can be launched from the CLTs, capable of hitting ground vehicles traveling as fast as 120 km/h while above. In June 2016, Dynetics was awarded a contract by SOCOM to integrate its tactical munition onto the AC-130. Designated the GBU-69/B Small Glide Munition, the weapon weighs and is armed with a blast-fragmentation warhead that can detonate by direct impact or at a selected height; despite being smaller, being unpowered allows for its warhead to be heavier than those on the Hellfire and Griffin A missiles, and, respectively. Guidance is provided by a GPS receiver with anti-spoofing software and four distributed-aperture semiactive laser seeker apertures adapted from the WGU-59/B APKWS for terminal guidance. Approval for fielding occurred in early 2017. Dynetics was awarded a contract to deliver an initial batch of 70 SGMs in June 2017, with plans to buy up to 1,000. The SGM can travel.