Lockheed AC-130

The AC-130 gunship is a heavily-armed ground attack airplane. The basic airframe is manufactured by Lockheed, and Boeing is responsible for the conversion into a gunship and for aircraft support. It is a variant of the C-130 Hercules transport plane. The AC-130 Gunship II superseded the AC-47 Gunship I in Vietnam.

The gunship's sole user is the United States Air Force, which uses AC-130H Spectre and AC-130U Spooky variants. The AC-130 is powered by four turboprops and has an armament ranging from 20 mm Gatling guns to 105 mm howitzers. It has a standard crew of twelve to thirteen Airmen, including five officers (two pilots, a navigator, an electronic warfare officer and a fire control officer) and enlisted personnel (flight engineer, electronics operators and aerial gunners).

The US Air Force uses the AC-130 gunships for close air support, air interdiction, and force protection. Close air support roles include supporting ground troops, escorting convoys, and flying urban operations. Air interdiction missions are conducted against planned targets and targets of opportunity. Force protection missions include defending air bases and other military facilities. The gunship squadrons are part of the Air Force Special Operations Command.

Development

The C-130 Hercules was selected to replace the AC-47 Gunship I (known as Spooky or Puff the Magic Dragon) during the Vietnam War, due to its ability to carry more and heavier weapons, and better endurance.

In 1967, JC-130A USAF 54-1626 was selected for conversion into the prototype AC-130A gunship. The modifications were done that year 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 mounted 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. Then 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. Following these successes, a few more AC-130As were constructed using similar equipment and manufactured versions of the analog computer. The original 54-1626 Gunship is displayed at the USAF Museum.

The AC-130 was supplemented by the AC-119 Shadow Gunship III during this time, which would prove underpowered with warload. In 1970, an additional dozen AC-130As were acquired under the "Pave Pronto" project. Regardless of their project names, the aircraft were more commonly referred to by the Squadron's call sign of Spectre.

Design

These heavily-armed aircraft incorporate side-firing weapons integrated with sophisticated sensors, navigation and fire control systems to provide precision firepower or area-saturation fire with its varied armament. The AC-130 can spend long periods flying over their target area at night and 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 the inertial navigation systems and Global Positioning System. The AC-130U employs technologies developed in the 1990s and can attack two targets simultaneously. It also has twice the munitions capacity of the AC-130H.

During the Vietnam era the AC-130 was sometimes equipped with a Magnetic Anomaly Detector (MAD), a highly sensitive passive device which picks up localized deviations in earth's magnetic field and is normally used to detect submerged submarines. The MAD array of the C-130 could detect the ignition coils of enemy trucks hidden under dense foliage, alerting the crew to their presence.

Operational history

File:AC-130 firing night.gif

Weapons fire during a night mission.

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. 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) were activated on the above date at Ubon AB, Thailand.

One of the first seven AC-130A aircraft deployed was 53-3129, named First Lady by November 1970. This aircraft had the distinction of also being the first production C-130 built. On 25 March, 1971, it took an anti-aircraft artillery hit in the nose over the Ho Chi Mihn Trail, in Laos, when a 37 mm shell destroyed everything below the crew deck. In 1975, after the conclusion of US involvement in the hostilities in Indochina, it was transferred to the Air Force Reserve, where it served with the 711th Special Operations Squadron of the 19th Special Operations Wing. In 1980 the aircraft was upgraded from the original three-bladed propellers to the quieter four-bladed propellers and was eventually retired in late 1995. The retirement also marked an end to the Air Force Reserve flying the AC-130A. The aircraft now sits on display in the final Air Force Reserve configuration with grey paint, black markings, the four-bladed Hamilton Standard props at the USAF Armament Museum at Eglin AFB, Florida USA.

By December 1968 most AC-130s were flown under F-4 escort from the 479th TFS (Tactical Fighter Squadron), normally three Phantoms per Gunship. In late 1969, under the code name of "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, inertial navigation, and a prototype digital fire control computer. Surprise Package was equipped with the latest 20 mm Gatling guns and 40 mm Bofors cannon, but no 7.62 mm close support armament. Surprise Package was refitted with upgraded similar equipment in the summer of 1970, and then redeployed to Ubon RTAFB. Surprise Package served as a test bed for the avionic systems and armament for the AC-130E. In the summer of 1971, Surprise Package was converted to the Pave Pronto configuration, and assumed its new nickname, Thor.

The first AC-130A loss of the war, 54-1629, named The Arbitrator, occurred on 24 May 1969 while on armed reconnaissance (a.k.a. "truck hunting") over Southern Laos. The aircraft, piloted by Lieutenant Colonel W. H Schwehm, was hit by 57 mm AAA while orbiting at over 6,000 feet. LTC Schwehm had ordered his crewmen to bail out as they approached the airfield, while he attempted an emergency landing at his Ubon Air Base. As the battle damaged Spectre touched down, the right undercarriage collapsed and the Gunship veered off the runway into an obstacle, catching fire. Eleven crewmen survived, but Staff Sergeants Cecil Taylor and Jack W. Troglen were killed in action.

The second AC-130A Spectre, 54-1625, named War Lord, was lost on 22 April, 1970 while truck hunting along the southern portion of the Ho Chi Minh trail, in Laos. While strafing the trucks, the AC-130 Gunship, from the 16th SOS, was hit by 37 mm AAA, catching fire. Ten crewmen were listed as KIA. Staff Sergeant E. Fields was the only survivor.

The last four Spectres lost in the Vietnam War were in 1972. On 28 March 1972, an AC-130A, 55-0044, named Prometheus, piloted by Major Irving B. Ramsower, from the 16th SOS, 8th TFW, was destroyed by a surface-to-air missile (SAM) while truck hunting over the Ho Chi Minh Trail. There were no survivors. On 30 March 1972, the first E-model was lost when AC-130E 69-6571 of the 16th SOS was truck hunting along the Ho Chi Minh Trail. Hit by 57 mm AAA, after confirming the destruction of three "killed" trucks, it crashed near An Loc. This time there were no fatalities from the crew, as they all bailed out of the aircraft safely. However, the SAR (Search And Rescue mission) that had been set in motion, turned out to be one of the largest in US history. When it was over, it had involved 7 HH-53s (known as Jolly Green Giants), 8 A-1 Skyraiders, 3 C-130s, ll sorties of ground-attack jet aircraft, 4 EB-66s (variant of B-66 Destroyer), 6 F-105 Thunderchiefs, 14 NAIL FACs, 3 RAVENs (CIA), 3 Air America Helicopters, 4 AC-130 Spectre Gunships, and an F-4 Phantom Fast FAC. The massive search and rescue operation was eclipsed a few days later by the famous Bat 21 rescue.

On 18 June 1972, a 16th SOS AC-130A, 55-0043, name unknown, was operating approximately 25 miles southwest of Hue, South Vietnam, when a SA-7 struck its number 3 engine, tore off the wing, and caused an explosion. Three crewmen bailed out, but there were no other survivors.

The last Spectre lost in the Vietnam War was during the Linebacker II campaign. While the B-52s of Linebacker II were pounding North Vietnam, the Spectres continued their war against the truck convoys along the Ho Chi Minh Trail. On 21 December 1972, AC-130A pilot Captain Harry R. Lagerwall was attacking three trucks at nearly 8,000 feet, when he was struck by 37 mm AAA. The Spectre, 56-0490, named Thor, exploded into flames and only two crewmen managed to safely bail out; the remaining 14 crewmen perished.

In Vietnam, gunships destroyed more than 10,000 trucks and participated in many crucial close air support missions. During the Invasion of Grenada (Operation Urgent Fury) in 1983, AC-130s suppressed enemy air defense systems and attacked ground forces enabling the successful assault of the Point Salines Airfield via airdrop and air land of friendly forces. The AC-130 aircrew earned the Lt. Gen. William H. Tunner Award for the mission.

105 mm gun (foreground), 40 mm Bofors gun (background)

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

During Operation Desert Storm, 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. 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 SAMs and increasing visibility during the early morning hours of 31 January 1991, one gunship opted to stay to continue to protect the Marines. A surface-to-air missile (SAM) shot down 69-6567, call sign Spirit 03. All 14 crew members perished.

The military has used gunships during Operations Restore Hope and United Shield in Somalia, in the NATO mission in Bosnia-Herzegovina, and in the 1997 evacuation of American noncombatants in Albania. On 15 March, 1994 over the Indian Ocean (off the coast of Kenya, near the town of Malindi), aircraft 69-6576 (then known as Predator but previously called both Bad Company and Widow Maker) was lost, taking the lives of eight crewmembers. Gunships also were part of the buildup of U.S. forces in 1998 to convince Iraq to comply with U.N. weapons inspections. The United States later used gunships during the 2001 invasion of Afghanistan, and the Iraq War. In 2007 US Special Operations forces used the AC-130 in attacks on suspected al-Qaeda militants in Somalia. The AC-130 has the distinction of never having a base under its protection lost to the enemy.

Current aircraft

Smoke visible from gatling gun during twilight operation.

The AC-130H is produced at a cost of US$132.4 million, and the AC-130U is produced at a cost of US$190 million (fiscal 2001 constant dollars). Currently there are eight AC-130H and thirteen AC-130U aircraft in active duty service.

Operators

United States

• United States Air Force
  • Air Force Special Operations Command

Specifications

General characteristics

• Crew: 13
  • Officers: 5 (pilot, copilot, navigator, fire control officer, electronic warfare officer)
  • Enlisted: 8 (flight engineer, TV operator, infrared detection set operator, loadmaster, four aerial gunners)

Performance

Armament

AC-130A Project Gunship II

• 4× 7.62 mm GAU-2/A miniguns
• 4× 20 mm M61 Vulcan cannon

AC-130A Surprise Package, Pave Pronto, AC-130E Pave Spectre

20 mm Vulcan cannon ammo belt

• 4× 7.62 mm GAU-2/A miniguns
• 2× 20 mm M61 Vulcan cannon
• 2× 40 mm (1.58 in) L/60 Bofors cannon

AC-130E Pave Aegis and AC-130H Pave Spectre II

• 2× 20 mm M61 Vulcan cannon
• 1× 40 mm L60 Bofors cannon
• 1× 105 mm (4.13 in) M102 howitzer

AC-130U "Spooky" Gunship

• 1× 25 mm (0.984 in) GAU-12/U Equalizer gatling gun
• 1× 40 mm L60 Bofors cannon
• 1× 105 mm M102 howitzer

or

• 2× 30 mm Bushmaster II cannon
• 1× 105 mm M102 howitzer

Upgrades

A new program has been initiated to upgrade the armament of existing AC-130s still in service. The 25 mm GAU-12/U and 40 mm Bofors are to be replaced with two Mk 44 Bushmaster II 30 mm cannons. The first aircraft is completed, with three more to join the fleet by December 2007, and fleetwide modifications complete by 2010. There are also plans to look into replacing the M102 howitzer with a breech-loading 120 mm 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.

The Air Force has decided to use the Bushmaster for two reasons. First, the 40 mm Bofors gun is becoming progressively more difficult to maintain, with spare parts becoming more difficult to locate. Second, the 25 mm cannon, while a useful weapon, lacks ammunition with an air-burst capability and suffers from too much scatter; procuring the most desirable types of ammunition for the 30 mm Bushmaster is much easier.

PGM-38/U 25mm ammunition for AC-130U

Source: Alliant Techsystems

The PGM-38/U Enhanced 25mm High Explosive Incendiary (HEI) round was created to expand the AC-130U gunships' mission in standoff range and survivablility for its GAU-12/U 25mm gun system. This round a combination of the existing PGU-25 HEI and a M758 fuse designated as FMU-151/B to meet the MIL-STD-1316. The FMU-151 has an improved arming delay with multi-sensitive range.

• Production - 15 million 25mm rounds; 6 million M758 fuzes
• Construction - thin walled steel
• Type - composite explosive incendiary charge
• Fuse armed - pre-armed 162.5ft (5 m) from muzzle, fully armed 656ft (200m) from muzzle
• Cartridge:
  • Weight - 492g
  • Center of gravity - 135mm
  • Propellant wt - 92g
• Projectile:
  • Weight - 184g
  • Fuse - 19g
  • Explosive - 330.2g
  • Center of gravity - 50.1mm
• Variants:
  • M793 25mm companion training round/target practice cartridge

Popular culture

An AC-130 was used in the 2007 movie "Transformers" in the first scene depicting the defeat of the Decepticon Scorponok. This scene featured the AC-130's 105 mm howitzer APFSDS shells and was a turning point in the movie when the humans started to successfully fight back. The aeroplane is also featured in the video game Call od Duty 4 - Modern Warfare.

References

• Hobson, Chris. Vietnam Air Losses - United States Air Force, Navy and Marine Corps Fixed-Wing Aircraft Losses in Southeast Asia, 1961-1973. Hinckley, England: Midland Publishing, 2001. ISBN 1-85780-115-6.

External links

• "Gunship History" from the Spectre Association website.
• AC-130A aircraft names, tail numbers and current locations (if applicable), also from the Spectre Association website.
• Air Force Factsheet: the AC-130H/U GUNSHIP on which this article was originally based.
• FAS.org: AC-130H Spectre/AC-130U Spooky
• Executive summary from US investigation exonerating AC-130 crews who caused civilian casualties in Afghanistan—Headquarters United States Central Command
• AC-130 on GlobalSecurity.org
• "Powerful Gunships Prowl Iraq, and Limits Show" from All Things Considered

Related content

Related development

• Lockheed C-130 Hercules

Aircraft of comparable role, configuration, and era

• AC-47 Spooky
• AC-119 Gunship
• A-10 Thunderbolt II

Related lists

• List of active military aircraft of the United States
• List of Lockheed aircraft
• List of C-130 Hercules crashes