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 anti-ground oriented weapons that are integrated with sophisticated sensors, navigation, and fire-control systems. Unlike other military fixed-wing aircraft, the AC-130 relies on visual targeting. Because its large profile and low operating altitudes (around 7,000 ft) make it an easy target, it usually flies close air support missions at night. The airframe is manufactured by Lockheed Martin, while Boeing is responsible for the conversion into a gunship and for aircraft support.[3] Developed during the Vietnam War as 'Project Gunship II', the AC-130 replaced the Douglas AC-47 Spooky, or 'Gunship I'. The sole operator is the United States Air Force, which uses the AC-130U Spooky and AC-130W Stinger II[4] variants for close air support, air interdiction, and force protection, with the AC-130J Ghostrider in development. 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-130Us are based at Hurlburt Field, Florida, while AC-130Ws are based at Cannon AFB, New Mexico; gunships can be deployed worldwide.[5] The squadrons are part of the Air Force Special Operations Command (AFSOC), a component of the United States Special Operations Command (SOCOM).[6] The AC-130 has a non-pressurised 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, therefore being able to fire at it for far longer than in a conventional strafing attack. The AC-130H Spectre was armed with two 20 mm M61 Vulcan cannons, one Bofors 40 mm autocannon, and one 105 mm M102 cannon; after 1994, the 20 mm cannons were removed for most missions. The upgraded AC-130U Spooky has a single 25 mm GAU-12 Equalizer in place of the Spectre's twin 20 mm cannons, an improved fire control system, and increased ammunition capacity. New AC-130Js based on the MC-130J Combat Shadow II special operations tanker were planned as of 2012. The AC-130W is armed with one 30 mm Bushmaster cannon, AGM-176 Griffin missiles, and GBU-39 Small Diameter Bombs.

Origins
During the Vietnam War, the C-130 Hercules was selected to replace the Douglas AC-47 Spooky gunship (Project Gunship I) in order 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.[8][9] AC-130H Spectre near Hurlburt Field, Florida in 1988 In 1967, JC-130A USAF 54-1626 was selected for conversion into the prototype AC-130A gunship (Project Gunship II). 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 (FLIR) in the forward part of the left wheel well, and Gatling guns fixed facing down and aft along the left side. The analog fire control computer prototype was handcrafted by RAF 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.[8] The AC-130 was later supplemented by the AC-119 Shadow (Project Gunship III), which later proved to be underpowered. Seven more warplanes were converted to the "Plain Jane" configuration like the AC-130 prototype in 1968,[10] and one aircraft received the "Surprise Package" equipment in 1969.[11] Surprise Package included the latest 20 mm rotary cannons and 40 mm Bofors cannon but no 7.62 mm close support armament. Surprise Package served as a test bed for the avionic systems and armament for the AC-130E.

In 1970, ten more AC-130As were acquired under the "Pave Pronto" project.[12] In the summer of 1971, Surprise Package equipped AC-130s were converted to the Pave Pronto configuration and assumed their new nickname 'Thor'. Conversion of C-130Es into AC-130Es for the "PAVE Spectre" project followed.[13][14]

Regardless of their project names the aircraft were more commonly referred to by the squadron's call sign 'Spectre'.

Recent and planned upgrades
AC-130U armed with two 30 mm Bushmasters, 2007

In 2007, Air Force Special Operations Command (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.[15] 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 re-installed the original 40 mm and 25 mm cannons and returned the planes to combat duty.[16] 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". There were also schedule considerations that drove the decision, he said.[17] There were also plans to possibly replace the 105 mm cannon with a breech-loading 120 mm M120 mortar, and to give the AC-130 a standoff capability using either the AGM-114 Hellfire missile, the Advanced Precision Kill Weapon System (based on the Hydra 70 rocket), or the Viper Strike glide bomb.[18] 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[19] to give them a gunship-like attack capability, such-equipped MC-130Ws are known as Dragon Spears. Air Force Special Operations Command is arming these aircraft to relieve the high operational demands on AC-130 gunships until new AC-130Js enter service.[20] The MC-130W Dragon Spear was renamed the AC-130W Stinger II in 2011.[21]

The Air Force launched an initiative in 2011 to acquire 16 new gunships based on new-built MC-130J Combat Shadow II special operations tankers outfitted with a "precision strike package" to give them an attack capability, requesting $1.6 billion from Fiscal Year 2011 through 2015. This would 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.[22] The decision to retain the C-130 came after funding for 16 C-27Js was removed from the fiscal 2010 budget.[23] The AC-130J will follow the path of the Dragon Spear program,[24] along similar lines to the USMC Harvest HAWK program.[citation needed] On 9 January 2013, the Air Force began converting the first MC-130J Combat Shadow II into an AC-130J Ghostrider[25] and delivered it to AFSOC on 29 July 2015.[26] The first AC-130J is to enter service in 2017.[27] 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 is interested in adding a directed energy weapon to the AC-130J by 2020,[28] similar to the previous Advanced Tactical Laser program. It is to produce a beam of up to 120 kW, or potentially even 180-200 kW, weigh about 5,000 lb (2,300 kg), defensively destroy anti-aircraft missiles, and offensively engage communications towers, boats, cars, and aircraft.[29][30][31] However, laser armament may only be installed on a few aircraft rather than the entire AC-130J fleet;[32] the laser would need to replace one of the plane's guns.[33] Other potential additions include an active denial system to perform airborne crowd control, and small unmanned aerial vehicles from the common launch tubes to provide remote video feed and coordinates to weapons operators through cloud cover.[34] Called the Tactical Off-board Sensor, the expendable drones would fly along a preprogrammed orbit, with a crewman only watching the feed and directing its camera. They can be used to verify targets the aircraft can't see itself because of bad weather or standing off from air defenses, and avoid collateral damage from human misidentification.[31][32] The Air Force is also interested in acquiring a glide bomb that can be launched from the common launch tubes capable of hitting ground vehicles traveling as fast as 120 km/h (70 mph) while above 10,000 ft (3,000 m); it could be ready for combat deployment by mid-2017.[35]

Future
By 2018, AC-130 gunships will have been providing close air support for special operators for 50 years. Although the aircraft have been kept relevant through constant upgrades to their weaponry, sensor packages, and countermeasures, they are not expected to be survivable in future non-permissive environments due to their high signatures and low airspeeds. Military analysts, such as the Center for Strategic and Budgetary Assessments, have suggested that AFSOC invest in more advanced technologies to fill the role to operate in future contested combat zones, including a mix of low-cost disposable unmanned and stealthy strike aircraft.[36]

Design
Underside of an AC-130U Spooky

Overview
The AC-130 is a heavily armed long-endurance aircraft carrying an array of anti-ground oriented weapons that are integrated with sophisticated sensors, navigation, and fire-control systems. It is capable of delivering precision firepower or area-saturation fire over a target area over a long period of time, at night or in adverse weather. The sensor suite consists of a television sensor, infrared sensor, and radar. These sensors allow the gunship to visually or electronically identify friendly ground forces and targets in most weather conditions.

The AC-130U is equipped with the AN/APQ-180, a synthetic aperture radar for long-range target detection and identification. The gunship's navigational devices include inertial navigation systems and a Global Positioning System. The AC-130U employs technologies developed in the 1990s which allow it to attack two targets simultaneously. It has twice the munitions capacity of the AC-130H.[3] Although the AC-130U conducts some operations in daylight, most of its combat missions are conducted at night.[37] The AC-130H's unit cost is US$132.4 million, and the AC-130U's cost is US$190 million (fiscal 2001 dollars).[6]

Upgrades
AC-130U sensor suite

During the Vietnam era, the various AC-130 versions following the Pave Pronto modifications were equipped with a magnetic anomaly detector (MAD) system called the Black Crow (AN/ASD-5), a highly sensitive passive device with a phased-array antenna located in the left-front nose radome that could pick up localized deviations in Earth's magnetic field that is normally used to detect submerged submarines. The Black Crow system was slaved into the targeting computers of the AC-130A/E/H, enabling the detection of the unshielded ignition coils of North Vietnamese trucks hidden under dense jungle foliage, typical along the Ho Chi Minh trail. It could also detect hand-held transmitter signals of air controllers on the ground to identify and locate targets. The PGM-38/U enhanced 25 mm high explosive incendiary (HEI) round was created to expand the AC-130U gunships' mission in standoff range and survivability for its 25 mm GAU-12/U gun system. This round is a combination of the existing PGU-25 HEI and a M758 fuze designated as FMU-151/B to meet the MIL-STD-1316. The FMU-151 has an improved arming delay with multi-sensitive range.[38]

Vietnam War
An AC-130 in Southern Laos circa 1970

The AC-130 gunship first arrived in South Vietnam on 21 September 1967 under the Gunship II program and began combat operations over Laos and South Vietnam that year. In June 1968, AC-130s were deployed to Tan Son Nhut AB near Saigon for support against the Tet Offensive. By 30 October 1968, enough AC-130 Gunship IIs arrived to form a squadron, the 16th Special Operations Squadron (SOS) of the 8th Tactical Fighter Wing (TFW), at Ubon Royal Thai Air Force Base, Thailand. It was at this time that the C-130A gunship was designated the AC-130A.

On 18 August 1968, an AC-130 gunship flying an armed reconnaissance mission in Vietnam's III Corps was diverted to support the Katum Special Forces Camp. The ground commander quickly assessed the accurate fire and capabilities of this weapon system and called for fire on his own perimeter when the Viet Cong attempted to bridge the wire on the west side of his position.

By December 1968, most AC-130s flew under F-4 Phantom II escort (to protect the gunship against heavy and concentrated AAA fire) from the 497th Tactical Fighter Squadron, normally three Phantoms per Gunship. On 24 May 1969, the first Spectre gunship was lost to enemy fire.[39]

In late 1969, under code name "Surprise Package", 56-0490 arrived with solid-state laser-illuminated low-light-level-TV with a companion YAG laser designator, an improved forward looking infrared (FLIR) sensor, video recording for TV and FLIR, an inertial navigation system, and a prototype digital fire control computer. The remaining AC-130s were refitted with upgraded similar equipment in the summer of 1970, and then redeployed to Ubon RTAFB. On 25 October 1971, the first "Cadillac" gunship, the AC-130E arrived in Vietnam. On 17 February 1972, the first 105 mm cannon arrived for service with Spectre and was installed on Gunship 570. It was used from mid-February until the aircraft received battle damage to its right flap. The cannon was switched to Gunship 571 and was used until 30 March when the aircraft was shot down. On 28 January 1973, the Vietnam peace accord went into effect, marking the end of Spectre operations in Vietnam. Spectre was still needed and active in the region, supporting operations in Laos and Cambodia. On 22 February 1973, American offensive operations in Laos ended and the gunships became totally committed to operations in the Cambodian conflict.

On 12 April 1975, the Khmer Rouge were threatening the capital of Phnom Penh and AC-130s were called on to help in Operation Eagle Pull, the final evacuation of American and allied officials from Phnom Penh before it fell to the communists. The AC-130 was also over Saigon on 30 April 1975 to protect the final evacuation in Operation Frequent Wind. Spectres were also called in when the SS Mayaguez was seized, on the open sea, by Khmer Rouge soldiers and sailors on 15 May 1975.

Six AC-130s and 52 air crew members were lost during the war.[39] AC-130s destroyed more than 10,000 trucks and participated in many crucial close air support missions in Vietnam.

Cold War and later action
AC-130A performs a left-hand pylon turn

With the conclusion of hostilities in Southeast Asia in the mid-1970s, the AC-130H became the sole gunship in the regular Air Force, home based at Hurlburt Field, Florida, while the AC-130A fleet was transferred to the Air Force Reserve's 919th Tactical Airlift Group (919 TAG) at Eglin AFB Auxiliary Field #3/Duke Field, Florida. With the transition to the AC-130A, the 919 TAG was then redesignated as the 919th Special Operations Group (919 SOG).

In the late 1970s, when the AC-130H fleet was first being modified for in-flight refueling capability, a demonstration mission was planned and flown from Hurlburt Field, Florida, non-stop, to conduct a 2-hour live-fire mission over Empire Firing Range in the Republic of Panama, then return home. This 13-hour mission with two in-flight refuelings from KC-135 tankers proved the validity of flying long-range missions outside the contiguous United States to attack targets then return to home base without intermediate stops.

AC-130s from both the 4th and 16th Special Operations Squadrons have been deployed in nearly every conflict the United States has been involved in, officially and unofficially, since the end of the Vietnam War.

In July 1979, AC-130H crews deployed to Howard Air Force Base, Panama, as a precaution against possible hostile actions against American personnel during the Nicaraguan Revolution. New time aloft and non-stop distance records were subsequently set by a 16th SOS 2-ship AC-130H formation flight that departed Hurlburt Field on 13 November 1979 and landed on 15 November at Andersen Air Force Base, Guam, a distance of 7,200 nautical miles (13,300 km) and 29 hours 43 minutes non-stop, refueling four times in-flight.[46][47] Refueling support for the Guam deployment was provided by KC-135 crews from the 305th Air Refueling Wing from Grissom AFB, Indiana.

In November 1979, four AC-130H gunships flew nonstop from Hurlburt Field to Anderson AFB, Guam, because of the hostage situation at the Embassy in Iran. At Guam, AC-130H crews developed communications-out/lights-out refueling procedures for later employment by trial-and-error. This deployment with the 1 SOW/CC as Task Force commander was directed from the office of the CJCS for fear that Iranian militants could begin executing American Embassy personnel who had been taken hostage on 4 November. One early option considered AC-130H retaliatory punitive strikes deep within Iran. Later gunship flights exceeded the 1979 Hurlburt-to-Guam flight. Upon return in March 1980, the four planes soon found themselves in Egypt to support the ill-fated hostage rescue attempt.

Smoke visible from Gatling gun during twilight operations in 1988

During Operation Urgent Fury in Grenada in 1983, AC-130s suppressed enemy air defense systems and attacked ground forces enabling the assault of the Point Salines Airfield via airdrop and air-land of friendly forces. The AC-130 aircrew earned the Lieutenant General William H. Tunner Award for the mission.

The AC-130Hs of the 16th Special Operations Squadron unit maintained an ongoing rotation to Howard AB, Panama, monitoring activities in El Salvador and other Central American points of interest, with rules of engagement eventually permitting attacks on FMLN targets. This commitment of Maintainers and crews started in 1983 and lasted until 1990.[48] The AC-130 is considered to have hastened the end of the Salvadoran Civil War in the 1980s. Crews flew undercover missions from Honduras and attacked guerrilla camps and concentrations.[citation needed]

AC-130s also had a primary role during the United States invasion of Panama (named Operation Just Cause) in 1989, when they destroyed Panama Defense Force headquarters and numerous command-and-control facilities, and provided close air support for US ground troops. Aircrews earned the Mackay Trophy for the most meritorious flight of the year, and the Tunner Award.

Gulf War and the 1990s
During the Gulf War of 1990–91 (Operations Desert Shield and Desert Storm), Regular Air Force and Air Force Reserve AC-130s provided close air support and force protection (air base defense) for ground forces, and battlefield interdiction. The primary interdiction targets were early warning/ground control intercept (EW/GCI) sites along the southern border of Iraq. At its standard altitude of 12,000 feet, the aircraft had a proven ability to engage moving ground targets.[49] The first gunship to enter the Battle of Khafji helped stop a southbound Iraqi armored column on 29 January 1991. One day later, three more gunships provided further aid to Marines participating in the operation. The gunships attacked Iraqi positions and columns moving south to reinforce their positions north of the city.

Despite the threat of surface-to-air missiles (SAMs) and increasing visibility during the early morning hours of 31 January 1991, one AC-130H, AF Serial No. 69-6567, call-sign Spirit 03, opted to stay to continue to protect the Marines. A lone Iraqi with a Strela-2 MANPADS shot Spirit 03 down, and all 14 crew members died.[50]

The military has used AC-130 gunships during the humanitarian operations in Somalia (Operation Restore Hope and Operation United Shield) in 1992–93, Operation Uphold Democracy in Haiti in 1994. AC-130s took part in Operation Assured Response in Liberia in 1996 and in Operation Silver Wake in 1997, the evacuation of American non-combatants from Albania.

AC-130s took part in the NATO missions in Bosnia and Herzegovina and Kosovo during the 1990s.

The AC-130U gunship set a new record for the longest sustained flight by any C-130 on 22 and 23 October 1997, when two AC-130U gunships flew 36 hours nonstop from Hurlburt Field, Florida to Taegu Air Base (Daegu), South Korea, being refueled seven times in the air by KC-135 tankers. The two gunships took on 410,000 lb (186,000 kg) of fuel. Gunships also were part of the buildup of U.S. forces in 1998 to compel Iraq to allow UNSCOM weapons inspections.

War on Terror
An AC-130U releasing flares

The U.S. has used gunships with deployments to the War in Afghanistan (Operation Enduring Freedom - Afghanistan) (2001–2014), and Iraq War (Operation Iraqi Freedom) (2003–11).

AC-130 strikes were directed by special forces on known Taliban locations during the early days of the war in Afghanistan. U.S. Special Operations Forces are using the AC-130 to support its operations. The day after arriving in Afghanistan, the AC-130s attacked Taliban and Al-Qaeda forces near the city of Konduz and were directly responsible for the city's surrender the next day. On 26 November 2001, Spectres were called in to put down a rebellion at the prison fort of Qala-i-Janghi. The 16 SOS flew missions over Mazar-i-Sharif, Kunduz, Kandahar, Shkin, Asadabad, Bagram, Baghran, Tora Bora, and virtually every other part of Afghanistan. The Spectre participated in countless operations within Afghanistan, performing on-call close air support and armed reconnaissance. In March 2002, three AC-130 Spectres provided 39 crucial combat missions in support of Operation Anaconda in Afghanistan. During the intense fighting, the planes expended more than 1,300 40 mm and 1,200 105 mm rounds.

Close air support was the main mission of the AC-130 in Iraq. Night after night, at least one AC-130 was in the air to fulfill one or more air support requests (ASRs). A typical mission had the AC–130 supporting a single brigade’s ASRs followed by aerial refueling and another 2 hours with another brigade or SOF team. The use of AC-130s in places like Fallujah, urban settings where insurgents were among crowded populations of non-combatants, was criticized by human rights groups. AC-130s were also used for intelligence gathering with their sophisticated long-range video, infrared and radar sensors.

In 2007, US Special Operations forces also used the AC-130 in attacks on suspected Al-Qaeda militants in Somalia.[51][52]

There were eight AC-130H and seventeen AC-130U aircraft in active-duty service as of July 2010.[6]

In March 2011, the U.S. Air Force deployed two AC-130U gunships to take part in Operation Odyssey Dawn, the U.S. military intervention in Libya,[53] which eventually came under NATO as Operation Unified Protector.[54] By September 2013, 14 MC-130W Dragon Spear aircraft have been converted to AC-130W Stinger II gunships. The Stinger gunships have been deployed to Afghanistan to replace the aging AC-130H aircraft and provide an example for the new AC-130J Ghostrider. Modifications began with crews cutting holes in the plane to make room for weapons, and adding kits and bomb bases for laser-guided munitions. Crews added a 105 mm cannon, 20-inch infrared and electro-optical sensors, and the ability to carry 250-pound bombs on the wings.[55]

On 3 October 2015, five attacks on a Doctors Without Borders hospital in Kunduz, Afghanistan were reportedly carried out by one or more AC-130s, causing the deaths of hospital workers and patients.[56]

On 15 November 2015, two days after the attacks in Paris by ISIL, AC-130s and A-10 Thunderbolt II attack aircraft destroyed a convoy of over 100 ISIL-operated oil tanker trucks in Syria. The attacks were part of an intensification of the U.S.-led Military intervention against ISIL called Operation Tidal Wave II (named after the original Operation Tidal Wave during World War II, a failed attempt to raid German oil fields that resulted in heavy aircraft and aircrew loss) in an attempt to cut off oil smuggling as a source of funding for the group.[57]

The U.S. has continued to use the aircraft in the War in Afghanistan (2015-present).

☀Role Fixed-wing Ground-attack and close air support gunship Manufacturer Lockheed and Boeing First flight AC-130A: 1966 Introduction AC-130A: 1968 AC-130H: 1969[1]

Retired AC-130A: 1995 AC-130H: 2015[1]

Status In service Primary user United States Air Force Number built 47 (in all variants) Unit cost

AC-130H: US$132.4 million AC-130U: US$190 million (2002)

Developed from Lockheed C-130 Hercules