In the Mid-1960's, the US Air Force decided to buy the LTV A-7 for use as a close air support aircraft. The A-7 was currently being tested by the Navy and the USAF directed several changes be incorporated into the design. One major change was the upgrade of the Pratt & Whitney TF30 turbofan engine (11,350 lbs. thrust) with an Allison TF-41 (license-built Rolls Royce Spey) turbofan of 14,250 lbs. thrust. The Air Force also directed the two Mk 12 cannons of the Navy A-7A be changed to a single M61A1 20-mm cannon for the USAF A-7D. The probe and drogue in-flight refueling system was also scheduled to be upgraded to the receptacle and boom system favored by the Air Force.

The first five A-7D's built were delivered to the USAF for service testing and given the temporary designation: YA-7D. The first two aircraft delivered (67-14582 and 67-14583) retained the Navy TF30 engine for initial flight testing. Both aircraft were later retrofitted with the TF41. The first flight of the A-7D was on 6 April 1968. The first production delivery aircraft was received in December 1968 and the first delivery to the Tactical Air Command was in August 1969. All YA-7D's retained the Navy-style probe for in-flight refueling. The first YA-7D built (shown above) was transferred to the USAF Test Pilot School at Edwards AFB and remained in service until retired in August 1992.

The USAF Museum has an A-7D on display in the Modern Flight Hangar. This aircraft was flown on Nov. 18, 1972, by Major Colin A. Clarke on a nine-hour rescue support mission in Southeast Asia for which he was awarded the Air Force Cross, the Air Force's second highest award for valor in combat.

TYPE
YA-7D
A-7D

Number Built/Converted
5
454

Mission and Description (Dec 86)
The principal mission of the A-7D Aircraft is the destruction of ground targets in support of ground forces. The A-7D is a single place transonic aircraft and has an all-weather combat capability.

The A-7D has fixed wing incidence and a high-lift system composed of leading edge flaps and single slotted trailing edge flaps.

Primary flight control is provided by outer panel ailerons, spoiler deflectors on the center section, unit horizontal tail and a rudder. A dual channel, three-axis, stick-steering autopilot is provided.

The fuel system incorporates both in-flight and single-point ground refueling capabilities. A Head-Up Display (HUD) system is provided to put all steering and attack displays between the pilot's eyes and the windshield.

A Navigation/Weapon Delivery system integrates many of the aircraft's avionic subsystems to provide for navigation to the target, computed run on target, computed weapon release, and return navigation.

There are two fuselage and six wing pylon store stations.

A KB-18A strike camera system is located in the forward section of the engine compartment.

The USAF Museum has an A-7D on display in the Modern Flight Hangar. This aircraft was flown on Nov. 18, 1972, by Major Colin A. Clarke on a nine-hour rescue support mission in Southeast Asia for which he was awarded the Air Force Cross, the Air Force's second highest award for valor in combat.

TYPE
YA-7D
A-7D

Number Built/Converted
5
454

The A-7D began to arrive at Korat RTAFB, Thailand during the late summer of 1972. By the end of October, the A-7D had taken over the combat close air support (Sandy) mission from the Douglas A-1E "Skyraider". The A-7D was also used during the closing months of the war as an escort on gunship missions and as a tactical bomber during the Linebacker II campaign. The development of the Head-Up Display (HUD) allowed the pilot to view all steering and attack information on a small display mounted above the main instrument panel between the windshield and the pilot's line of sight.

The A-7D was delivered in significant numbers to the Air National Guard (ANG) -- many new from the factory. The ANG continued to improve the A-7D throughout the 1970's. One significant upgrade was the addition of the Pave Penny seeker system for detecting laser marked targets. The Pave Penny pod was mounted just below the engine air intake. The Pave Penny system was so successful it was incorporated in the A-10 design. Another improvement done by the Air National Guard was the addition of advanced maneuvering flaps to increase the agility of the aircraft at low levels, especially during attack runs.

The USAF Museum has an A-7D on display in the Modern Flight Hangar. This aircraft was flown on Nov. 18, 1972, by Major Colin A. Clarke on a nine-hour rescue support mission in Southeast Asia for which he was awarded the Air Force Cross, the Air Force's second highest award for valor in combat.

TYPE
YA-7D
A-7D

Number Built/Converted
5
454

The USAF Museum has an A-7D on display in the Modern Flight Hangar. This aircraft was flown on Nov. 18, 1972, by Major Colin A. Clarke on a nine-hour rescue support mission in Southeast Asia for which he was awarded the Air Force Cross, the Air Force's second highest award for valor in combat.

Major. Clarke took off from Korat Air Base, Thailand before dawn on November 18th to fly rescue combat air patrol in support of a rescue attempt for two crewmen of a Republic F-105G shot down on November 16th. The downed crew was located in the Thanh Hoa "Dragon's Jaw" area of North Vietnam, just north of the DMZ. The weather was bad and a heavy overcast extended down below the highest mountain peaks in rescue area.

The rescue force consisting of close air support A-7D's (Sandy), F-4's for MiG combat air patrol (MiGCAP), HC-130 mission airborne command post (King) and HH-53 rescue helicopters (Jolly) arrived in the rescue area at dawn. The weather kept the force from attempting a rescue immediately and they were forced to wait for the weather to clear. As the morning continued and the weather did not clear, the Jolly's were forced to return to their home base at Nakhom Phanom Air Base, Thailand. However, a second pair of HH-53's was called in to support the mission. Meanwhile Major Clarke continued to search for a break in the clouds to enable him to guide the rescue helicopters to the downed "Weasel" crew. The A-7D was fired upon by anti aircraft batteries in the area and still Clarke could find no way to get the rescue choppers in. The second pair of helicopters finally found a break which would allow them to get below the clouds and into the rescue area; however, these helicopters were running low on fuel and had to depart the area. Clarke was by this time low on fuel and had to temporarily depart the area to refuel his plane. It was approaching noon and Clarke had been flying for more than 6 hours.

By the time the A-7D's were refueled, another pair of Jollys were ready for a rescue attempt. Clarke led the helicopters and drew heavy anti aircraft (AAA) fire. It was time for the A-7D to go into action. Major Clarke and two other Sandy's bombed and strafed the AAA guns set up on the ridgelines of the Thanh Hoa valley. The work of the A-7's allowed the Jolly to get in and pick up the F-105G crew and departed the area. Clarke was not so lucky, his A-7D was hit by anti aircraft fire forcing him to divert to Da Nang Air Base for an emergency landing. Major Clarke successfully landed his A-7D at about 1:30 PM completing a mission of more than 9 hours. For his bravery and refusal to abort the mission because of terrible weather, Major Clarke was awarded the Air Force Cross, the second highest combat medal given by the USAF.

TYPE
YA-7D
A-7D

Number Built/Converted
5
454

The YA-7F "A-7 Plus" (originally A-7 Strikefighter) was developed in response to an Air Force request for an improved fast close air support and ground attack aircraft. Two A-7D's were sent back to the contractor for extensive modifications. The new design called for a new engine, either the Pratt & Whitney F100 or General Electric F110. Initially the F100 was installed. To accommodate the new engine, the fuselage was lengthened about 4 feet. New fuselage sections were inserted in both the forward and aft fuselage - a 30 inch section in front of the wing and 18 inch section behind the wing. The wing was strengthened and fitted was new augmented flaps, leading edge extensions and automatic maneuvering flaps. The vertical stabilizer height was increased about 10 inches.

Besides the engine and structural changes, the A-7 Plus featured an updated avionics package including a Forward Looking Infrared (FLIR) system.

The A-7 Plus project was begun in the Mid-1980's and the actual modifications started in 1987. The first flight of the YA-7D was in late November 1989. The flight test program continued through 1990 with good results, however, the Air Force decided to use F-16's for the CAS/ground attack mission and canceled the A-7 Plus program.

The USAF Museum has an A-7D on display in the Modern Flight Hangar. This aircraft was flown on Nov. 18, 1972, by Major Colin A. Clarke on a nine-hour rescue support mission in Southeast Asia for which he was awarded the Air Force Cross, the Air Force's second highest award for valor in combat.

TYPE
YA-7F

Number Built/Converted
2 (cv)

Mission and Description (Dec 86)
The A-7K is a two place turbofan, light attack airplane derived from the A-7D Corsair II series. It is an attack aircraft designed for close support and interdiction missions. Eight external store stations provide a large ordnance capacity and freedom of ordnance choice. In-flight refueling capability is provided. Features to expedite maintenance and airplane turnaround are important A-7K design characteristics.

The A-7K has fixed wing incidence and a high-lift system composed of leading edge flaps and single slotted trailing edge flaps. The A-7K low speed maneuvering performance is enhanced by the incorporation of the automatic maneuvering flap (AMF). Primary flight control is provided by outer panel ailerons, spoiler deflectors on the center section, unit horizontal tail, and a rudder, superior stability and control qualities over the entire aircraft speed envelope, including transonic, are features of the A-7K.

A dual-channel, three-axis, stick-steering autopilot is provided.

The A-7K was designed as a combat crew training aircraft to support the A-7D's in service with the Air National Guard. To accommodate the second crew position, the aircraft was lengthened by 34 inches - an 18 inch section was inserted in front of the wing and a 16 inch section inserted behind the wing. The in-flight refueling receptacle was moved from the offset left position on the A-7D to the fuselage centerline on the A-7K. The -K was capable of performing the same missions as the A-7D and retained the Pave Penny laser target seeker system. One A-7D (S/N 73-1008) was modified and tested as the YA-7K. LTV built 30 production aircraft as A-7K with 1979-1981 serial numbers.

The USAF Museum has an A-7D on display in the Modern Flight Hangar. This aircraft was flown on Nov. 18, 1972, by Major Colin A. Clarke on a nine-hour rescue support mission in Southeast Asia for which he was awarded the Air Force Cross, the Air Force's second highest award for valor in combat

TYPE
YA-7K
A-7K

Number Built/Converted
1
30

The Northrop A-9A was developed in response to a US Air Force request for a dedicated Close Air Support (CAS) / ground attack aircraft capable of operating from short unimproved runways, have a long loiter time over the battlefield area, and have a relatively high cruise speed to get from the home field to the battle field.

The Air Force issued a request for proposal (RFP) to 12 aircraft manufacturers. Six companies responded with specific designs and two companies were selected to build prototypes for a fly-off competition. Northrop was one company selected and Fairchild Republic was the other. The Northrop entry was designated A-9 while the Fairchild aircraft was designated A-10.

The A-9A was a high wing, twin engine, single place aircraft. The plane was designed for exceptional maneuverability and had large flight control surfaces. The engines were specifically designed for the project by Lycoming. Each of the YF102-LD-100 turbofans developed 7,500 lbs. of thrust at maximum power. Offensive firepower consisted of a 20mm "Vulcan" cannon and up to 16,000 lbs. of ordnance carried on 10 external wing stations. The winner of the A-X fly-off would incorporate the 30mm GAU-8 cannon into production aircraft, but the gun was under parallel development during the A-X competition and wasn't ready for flight testing during the fly-off between October and December 1972. The A-9A featured a triple redundant hydraulic system, foam filled self-sealing fuel tanks and armor plating protecting vital systems including a titanium "bathtub" surrounding the cockpit (note: an aluminum "bathtub" was fitted in the prototype).

The first flight of the A-9A was on 30 May 1972 and the fly-off competition ran between 10 October and 9 December 1972. The Air Force selected the A-10 as the winner of the A-X fly-off on 18 January 1973. The two prototype A-9A's were transferred to NASA for flight testing before being retired.

TYPE
A-9A

Number Built/Converted
2

The design of the YA-10A had several advantages over its competitor, the Northrop A-9A. The engines were mounted high on the aft fuselage making them less susceptible to foreign object damage when operating on unimproved airfields close to the battle area. The engine location also allowed the entire wing to be used for weapons. Eleven ordnance pylons were fitted to the lower surface of the wing -- 3 on each outboard wing and 5 in the center section between the main landing gear. The engines also made it possible for maintenance and rearming "quick turns" with the engines running.

The YA-10 was designed for ease of maintenance, ruggedness and survivability in combat. The aircraft included a number of off-the-shelf components including the use of the General Electric TF34 turbofan which was originally developed for the US Navy's S-3A "Viking". The YA-10 also had many interchangeable parts. The ailerons, rudders, elevators, main landing gear, and engines were all usable on either the right or left side of the aircraft. The cockpit was surrounded by a titanium "bathtub" of armor plating. The hydraulic system was triple redundant. There was also an onboard auxiliary power unit (APU) to supply compressed air for engine starting.

The fly-off with the A-9A began on October 10th, 1972 and concluded on December 9th of the same year. The competition was held at the Air Force Flight Test Center (AFFTC), Edwards AFB, CA, and was primarily intended to identify differences in aircraft performance. The two aircraft were equally accurate in weapons delivery and gun tests. The General Electric GAU-8 "Avenger" 30 mm cannon was not ready during this period, so both the YA-10A and A-9A were fitted with the 20 mm "Vulcan" cannon for testing. The YA-10A was flown a total of 138.5 hours during 87 flights while the A-9A was flown 123 times for a total of 146 hours.

Although both aircraft were judged to be acceptable Close Air Support aircraft, the YA-10 was selected based on a number of advantages. The larger wing was easier to access for weapons loading and had more overall space for large ordnance loads. The A-10 had superior ground handling, especially on unimproved fields. The YA-10 was judged closer to an acceptable production version and could be operational in a shorter time. The A-10 was a simpler aircraft and the USAF was confident it could meet the $1.4 million per aircraft production cost target.

The USAF Museum has the second YA-10A prototype (S/N 71-1370) on display in the Airpark. Although the aircraft was upgraded several times with production A-10A equipment - notably the GAU-8/A 30 mm cannon, it still retains the characteristic vertical stabilizer shape. The lower forward edge of the vertical stab was straight on the YA-10A and curved on the production aircraft. The USAF Museum also has a production A-10A on display in the Modern Flight Hangar.

TYPE
YA-10A

Number Built/Converted
2

The first six production A-10A's (S/N 73-1664 to 73-1669) were used for Development Test & Evaluation (DT&E). The DT&E program was designed to qualify the production aircraft for all aspects of its operational mission in preparation for initial deliveries to active duty Air Force units. The first DT&E aircraft (73-1664) was delivered to the Air Force Test and Evaluation Center (AFTEC) at Edwards Air Force Base, California in January 1975. The aircraft made its first flight on 15 February 1975. The Initial Operational Test & Evaluation (IOT&E) Phase II flight test program started a month later on March 19th.

During 1975 a number of DT&E programs were completed. The IOT&E Phase II program was completed on June 19th. Initial performance measurements, flying qualities and control surface flutter programs tested the basic aircraft. A number of weapons integration and operation test programs were conducted including bombing accuracy, gun firing and accuracy, munitions effectiveness against ground targets (tanks, armored personnel carriers, trucks, etc.). The "Pave Penny" laser spot seeker system was also tested during the initial phases of A-10 DT&E. The "Pave Penny" was designed to detect a laser spot "painted" on a ground target and direct a laser guided bomb to the target. In flight refueling tests were also done.

A number of ground tests were done to simulate long term effects on the aircraft. The most important of these tests was the fatigue failure. Although the test airframe developed (23 October 1975) a crack at about the 5,000 hour point (80% of expected lifetime), an airframe strengthening modification was incorporated into the test assembly and testing was successfully completed to the expected lifetime point of 6,000 hours.

The first production A-10A (S/N 75-258) made its first flight on 21 October 1975. Tactical Air Command accepted the first A-10A on 30 March 1976.

The USAF Museum has the second YA-10A prototype (S/N 71-1370) on display in the Airpark. Although the aircraft was upgraded several times with production A-10A equipment - notably the GAU-8/A 30 mm cannon, it still retains the characteristic vertical stabilizer shape. The lower forward edge of the vertical stab was straight on the YA-10A and curved on the production aircraft. The USAF Museum also has a production A-10A on display in the Modern Flight Hangar.

TYPE
YA-10A
A-10A

Number Built/Converted
2
713

In the early 1960s, the Air Force investigated the conversion of the Cessna T-37 jet-powered primary trainer for counterinsurgency (COIN) missions. The project was intended to provide an inexpensive aircraft for the US export market. In 1962, two T-37B's (S/N 62-5950 and 62-5951) were modified and tested at Eglin AFB, Florida. The aircraft retained the T-37's Continental J69 engines, but since gross weight increased to accommodate the ordnance and attack avionics, the aircraft was underpowered and performed poorly.

In 1963, the Air Force updated the requirement and reissued a contract for two improved aircraft and assigned them the YAT-37D designation. In order to meet contract delivery dates, Cessna used the two original YAT-37 prototypes for the update program. Several major changes were incorporated into the design including new engines. The J69 jet engines were replaced by General Electric J85 turbojets of 2,400 lbs. thrust -- more than double the thrust of the J69's. The wings were strengthened for 6 ordnance (3 per wing) hard points and the wingtips were fitted with 95 gallon fuel tanks. Self-sealing fuel tanks were put in the wings and armor plating was installed to protect the pilot. The YAT-37D was upgraded with various avionics upgrades including a target acquisition system. A General Electric GAU-2/A 7.62 mm "mini-gun" with a 1,500 round capacity was mounted in the forward left nose section. A radar ranging gun site for the pilot and a gun camera complemented the GAU-2/A gatling gun. The YAT-37D's first flight was on 22 October 1963. After testing was completed, the YAT-37D's were unneeded and the first prototype was sent to the USAF Museum in December 1964.

In August 1966, the YAT-37D at the USAF Museum was recalled for additional flight testing. The war in Vietnam highlighted a need for a Close Air Support (CAS) / COunterINsurgency (COIN) to complement and possibly replace the Douglas A-1 "Skyraider". The aircraft was modified with an additional hard point on each wing and redesignated YA-37A. The test program was successful and the Air Force ordered the conversion of 39 T-37's to the YA-37A standard for immediate combat testing in Vietnam. These aircraft were designated A-37A's.

The YA-37A was permanently retired to the USAF Museum in July, 1970 and remains on display in the Vietnam Aircraft section of the Air Power Gallery.

TYPE
YA-37A
A-37A
A-37B

Number Built/Converted
2
39
577

The first production A-10A (S/N 75-258) made its first flight on 21 October 1975. Tactical Air Command accepted the first A-10A on 30 March 1976. The first production A-10's were delivered to the 333rd Tactical Fighter Training Squadron (TFTS), 364th Tactical Training Wing (TTW) at Davis-Monthan AFB, Arizona. The first operational A-10A unit was the 354th Tactical Fighter Wing (TFW) based at Myrtle Beach, South Carolina. The 354th TFW achieved initial combat readiness during the summer of 1978.

The first overseas unit to equip with the A-10A was the 81st Tactical Fighter Wing based at RAF Bentwaters and RAF Woodbridge, UK. The 81st TFW was an unusually large unit composed of 6 squadrons -- 108 total aircraft at full strength. The A-10's of the 81st TFW were in Europe primarily to support NATO operations against potential enemy armor invasions of central and Southern Europe. Many A-10's of the 81 TFW were deployed to forward operating areas (i.e. Sembach AB, Germany) throughout Europe to provide a quick reaction anti-armor weapon close to potential battle fronts.

The first use of the A-10A in combat came in January 1991 with the start of Operation Desert Storm.

The USAF Museum has the second YA-10A prototype (S/N 71-1370) on display in the Airpark. Although the aircraft was upgraded several times with production A-10A equipment - notably the GAU-8/A 30 mm cannon, it still retains the characteristic vertical stabilizer shape. The lower forward edge of the vertical stab was straight on the YA-10A and curved on the production aircraft. The USAF Museum also has a production A-10A on display in the Modern Flight Hangar.

TYPE
YA-10A
A-10A

Number Built/Converted
2
713

The first use of the A-10A in combat came in January 1991 with the start of Operation Desert Storm. The A-10A on display at the USAF Museum (S/N 78-0681) was involved in the first of two well publicized missions. Capt. Paul Johnson was the pilot for both missions.

Paul Johnson earned the Air Force Cross leading a daring mission deep into Iraq to rescue a downed Navy pilot. Born in 1958 in Gadsden, Alabama, Johnson grew up in Tennessee. In 1980, he earned a degree in Agriculture from Murray State University in Kentucky. After five years in farming including "sloppin' hogs," he joined the Air Force. He completed Officer Training School, and then went to Laughlin AFB, Texas to earn his pilot's wings. He chose an assignment to fighters and upgraded to the Fairchild Republic A-10 "Warthog" at Davis Monthan AFB, Arizona. At his first operational unit, the 353rd Tactical Fighter Squadron (TFS) at Myrtle Beach AFB, South Carolina, Johnson demonstrated exceptional ability flying the "hog."

When Iraq invaded Kuwait in 1990, the squadron deployed to King Fahd Royal Airport, Saudi Arabia, but Johnson was sent to Fighter Weapons School at Nellis AFB, Nevada. As a distinguished graduate, he rejoined the 353rd TFS "Panthers." In preparation for combat, the squadron went on alert for a mission they had long trained, combat search and rescue. Four days after the beginning of the air war over Iraq; 21 January 1991, Johnson and a fellow "Panther" pilot, Capt. Randy Goff, launched on a mission to find the crew of a downed Grumman F-14 Tomcat, Lts. Devon Jones and Larry Slade. Deeper in enemy airspace than any A-10 before, Johnson was met by unknown enemy defenses, bad weather, and confusion about the downed Navy pilot's position. The mission demanded clear thinking to orchestrate the rescue force that included helicopters, tankers, fighters, and airborne warning and control aircraft. The mission was successful and a first for the A-10. The A-10A (S/N 78-0681) flown by Capt. Johnson on this mission is on display at the USAF Museum. Capt Johnson was awarded the Air Force Cross, the Air Force's second highest award for valor.

A few days later on 6 February 1991, Johnson demonstrated his skills again when another aircraft he was flying was hit by enemy fire. Johnson; flying A-10A - S/N 78-0664, was attacking a Surface to Air Missile (SAM) site when his aircraft was hit by portable shoulder-mounted SAM. The explosion left a gaping hole in the right wing of the A-10, disabled one of the aircraft's two hydraulic systems, and crippled the right engine. He managed to fly the badly damaged "Warthog" back to Saudi airspace, where he air refueled as he recovered at King Fahd AB. Johnson feared that when the right gear was lowered, he might lose the outer wing, but fortunately he got "three in the green." Having bought the aircraft home "on a wing and a prayer," he flew a no-flap approach to a smooth landing, despite a blown tire which shredded on touchdown!

The USAF Museum also has the second YA-10A prototype (S/N 71-1370) on display in the Airpark.

TYPE
YA-10A
A-10A

Number Built/Converted
2
713

In March 1979, the first reproduction A-10A (S/N 73-1664 was returned to the Republic factory for conversion to a prototype two-place variant of the A-10. The modifications took about 3 months and when complete the aircraft was redesignated Night / Adverse Weather (N/AW) A-10. As the name suggests, the A-10 N/AW was designed to operate at night and during weather conditions unsuitable for the A-10A.

The modification work consisted of rebuilding the forward airframe to accommodate a second cockpit equipped with dual controls for the Electronic Warfare Officer (EWO). The canopy was changed from the clamshell type to a side-opening type divided between the cockpits by an "A-frame" structure. The A-10 N/AW was equipped with ACES-II type ejection seats designed to fire "thru-the-canopy." A large cockpit fairing was added to house additional avionics components. The Head-Up Display (HUD) system was upgraded. A Forward Looking InfraRed (FLIR) system was added as well as a Low Light Level Television (LLLTV). Additional components added to support the night/adverse weather mission included a laser ranging device, terrain following radar, inertial navigation system (INS), radar altimeter, and an electronic moving map display. The FLIR and laser ranger were housed in an external pod mounted on pylon 6 (the center fuselage station). The terrain following radar was also housed in an external pod, in this case hung from station 4 (center wing closest to the left main landing gear). The LLLTV replaced the Pave Penny pod. The vertical stabilizers were rebuilt with a 20" extension added to the top. The aircraft retained the GAU-8/A 30 mm gatling gun, but had a smaller ammunition drum with a capacity of 750 rounds.

Flight testing of the A-10 N/AW began on 23 October 1979 at the Air Force Flight Test Center, Edwards AFB, California. During the Air Force Preliminary Flight Evaluation (AFPE) which ended on 4 December 1979, the aircraft was flown for a total of 48.6 hours during 28 missions. About one third of the missions were conducted at night. Although the A-10 N/AW test program was successful, the program was canceled because of advancements in night attack equipment (i.e. LANTIRN).

Besides the A-10 N/AW the USAF investigated the conversion of a limited number of A-10A's into two-place trainer aircraft. These trainers were to be designated A-10B, but the program was canceled before any aircraft were modified.

The USAF Museum has two A-10's on display: the second YA-10A prototype (S/N 71-1370) in the Airpark and A-10A (S/N 78-0681) on display in the Modern Flight Hangar.

TYPE
YA-10A
A-10A
A-10A
N/AW A-10
YA-10B

Number Built/Converted
2
6
707
1 (cv)
-

On 23 August 1966, the USAF directed the establishment of a program to evaluate the A-37 in a combat environment. The project was named "Combat Dragon" and was designed to test the effectiveness of the A-37 in Close Air Support, Counterinsurgency and escort missions in Vietnam. Besides testing the aircraft operationally, the project was also used to evaluate the maintenance, supply and manpower requirements. The Tactical Fighter Weapons Center directed the program and established a 350-man squadron with 25 A-37A's at England AFB, Louisiana in early 1967. The unit was designated as the 604th Air Commando Squadron (ACS). Initial instructor pilot training began on 29 March 1967, initial operations and combat orientation started on May 1st. Phase I of "Combat Dragon" was done between 19 June and 16 July 1967 at England AFB. Phase I measured data collection and analysis procedures to be used during the actual combat evaluation, train the A-37A pilots, establish a bombing and gunnery baseline, and identify and fix problems with the aircraft.

The 604th ACS was moved to Bien Hoa Air Base, South Vietnam between 17 July and 14 August 1967. Phase II of "Combat Dragon" began on August 15th and ended on September 6th. This phase of the project was used to familiarize the pilots was the operational areas of Vietnam and Laos. The data collection and evaluation system was also refined using forms and methods already in use in Southeast Asia. Phase III of "Combat Dragon" began on September 7th and the first actual ground strike missions were flown. Phase III operations continued until 27 October. Phase IV of "Combat Dragon" was done between October 28th and 30th and tested accelerated (maximum sortie generation) mission scheduling. Phase V began on November 1st and tested the ability of the aircraft to operate from a forward operating location. Seven aircraft were deployed to Pleiku Air Base and flew combat mission through December 2nd. The remaining 18 aircraft remained at Bien Hoa AB and flew normal (Phase III) combat strike missions.

The 604th ACS flew about 5,000 training and combat sorties during the five phases of the "Combat Dragon" project. During Phase III each aircraft averaged between 3 and 4 missions every 2 days. During Phase IV, the maximum sortie rate reached 6.3 missions per day per aircraft. During Phase V, three new missions were flown: Forward Air Control (FAC), armed reconnaissance and night interdiction. In addition to missions with South Vietnam, Phase V missions were flown in southeast Laos. in the Tigerhound areas.

The operational test phases of the "Combat Dragon" project were concluded in early December 1967 and the evaluation team returned to the United States to finish data analysis and make recommendations. During combat operations, "Combat Dragon" A-37A's flew 4,463 sorties and dropped over 19,000 pieces of ordnance during the 107 day evaluation period. The team found the maintenance requirements of the A-37A to be lower than expected. The size of the squadron was acceptable for Phase III sortie rates, but would have to be increased for higher rates (i.e. there weren't enough pilots, crew chiefs and maintenance personnel to support high sortie generation rates). The A-37A was dependable and easy to maintain so logistics and supply issues were not a major concern. The A-37A was judged to be an effective ground attack aircraft in the South Vietnam and Tigerhound areas (combat radius to 240 nm max.). The A-37A was also an adequate Close Air Support aircraft; however, the low wing and limited right aft quadrant visibility when an observer wasn't flying (normally only a pilot flew) in the cockpit's right seat. One major problem identified involved the lack of fuel quantity gauges for the wingtip tanks and external drop tanks carried. For long duration missions, the pilot ran a significant risk of running out of fuel. Overall, the A-37A was judged an effective weapons system and full scale production of the A-37B proceeded based in part on the recommendations of the "Combat Dragon" team.

The YA-37A was permanent retired to the USAF Museum in July, 1970 and remains on display in the Vietnam Aircraft section of the Air Power Gallery.

TYPE
YA-37A
A-37A
A-37B

Number Built/Converted
2
39
577

The A-37B was an improved version of the A-37A. One improvement was the installation of fully rated J85 jet engines capable of producing 2,850 lbs. of thrust at maximum power. The J85 engines fitted to the -A model "Dragonfly" were derated to 2,400 lbs. thrust maximum. Another major difference was the inclusion of an in flight refueling (IFR) system with the refueling probe fitted to the nose of the aircraft. The A-37B used the probe and drogue method of IFR rather than the boom and receptacle method normally used on USAF fixed wing aircraft. The increased thrust of the engines gave the aircraft a maximum gross takeoff weight of 14,000 lbs. The use of the IFR system allowed the aircraft to fly with a maximum gross weight of 15,000 lbs. -- the aircraft would takeoff with a heavy load of ordnance and limited fuel, conduct an IFR, then proceed on its mission. Other changes included improvements in the gun system: a selectable firing rate of 3,000 or 6,000 rounds per minute, an upgraded optical gun site, a nose mounted gun camera, and a strike camera mounted in the lower center fuselage. The control system also had some improvements: redundant control cables to the rudder and elevators and aileron boost tabs.

Cessna built a total of 577 A-37B's. The aircraft was used for a relatively short period by the USAF; however, many aircraft had long service lives flying for the Air Force Reserves and Air National Guard. The United States also supplied many aircraft to foreign countries including South Vietnam during the late 1960's and early 1970's. The 4532nd Combat Crew Training Squadron at England Air Force Base in Louisiana initially trained over 100 South Vietnamese Air Force pilots. Each VNAF student received 112 hours of ground instruction and 85 hours of flight training. After training was completed, the VNAF pilots returned to Vietnam to fly A-37's supplied under the US Military Assistance Program (MAP). South Vietnam had 10 squadrons of A-37's at peak strength during the early 1970's.

The YA-37A was permanent retired to the USAF Museum in July, 1970 and remains on display in the Vietnam Aircraft section of the Air Power Gallery.

TYPE
YA-37A
A-37A
A-37B

Number Built/Converted
2
39
577

In the early 1960s, Air Force Systems Command began experimenting with side-firing weapons systems for possible use in Vietnam in point defense and night Close Air Support (CAS) roles. In late 1964, the first gunship conversion of a World War II Douglas C-47D was done. The gunship version of the C-47D was initially designated FC-47D (Fighter-Cargo), but was changed to AC (Attack Cargo) primarily because of complaints by traditional fighter pilots. The aircraft had several nicknames: "Spooky", Puff the Magic Dragon", and "Puff".

The AC-47D(S/N 43-48579) was equipped with three SUU-11A 7.62 mm "miniguns" with a 6,000 round per minute rate of fire. The miniguns were mounted in the aft left fuselage, one gun was installed in the aft passenger door area. The other two guns were mounted just forward of the passenger door with the gun barrels pointed out window ports. The AC-47D carried about 16,500 rounds of ammunition on a typical mission.

For night missions, the aircraft carried approximately 48 MK-24 flares. Each flare would last up to three minutes (Mod 3 version) and produced a light of 2 million candlepower. The delivery system was extremely simple, the loadmaster armed and dropped the flare out the cargo door when the pilot signaled by flashing a cargo compartment light.

AC-47 Operations Bulletin #56 - 13 Feb 67 (PACAF)
As employed in Southeast Asia, the flight crew consisted of seven USAF personnel, as well as a Vietnamese observer assigned to aid in the "delta" missions. The aircraft commander (pilot) fired the gun while the copilot performs the normal piloting duties and coordinated the activities of the crew. In the target area the navigator and Vietnamese Air Force observer (8th crewman if assigned) collaborate to accurately pinpoint objectives and coordinate with the ground forces. Two gunners accomplish the preflight, gun loading and in-flight troubleshooting of the SUU-11 guns. The loadmaster arms and manually drops the flares from the rear entrance door upon a light signal from the aircraft commander. A flight mechanic rounds out the crew and is responsible for aircraft systems operation.

The basic missions on which the AC-47 was employed were:
1. Defense of ground positions (friendly forts and outposts).
2. Escort and patrol.
3. Pre-planned strikes against suitable targets.
4. Forward air controlling for fighter strikes.

Initial attack procedures began with the aircraft in straight and level flight, and the target just outside and forward of the left prop dome. Usual altitude is between 2500-3000 feet above ground level (AGL); however, this could be adjusted to allow for such variables as weather, ground fire and target identification difficulties. As the target passed under the engine cowling, the aircraft was rolled into a level 30° bank turn. When the (gun site) pipper came on target, firing was commenced in bursts of 3-7 seconds, as required. When the pipper moved off the target to the rear, the firing was ceased and a slight turn was made away from the target for repositioning and subsequent firing passes. If the pipper moved off the target to the front, the degree of bank was increased to realign on target. Airspeed during the maneuver was normally 120 knots indicated air speed (KIAS). Each minigun fired at a rate of 6000 rounds per minute. This provided a coverage over an elliptical area approximately 52 yards in diameter, placing a projectile within every 2.4 yards during a 3 second burst.

The guns were configured for a 12° declination to allow shallower bank angles and more precise aircraft control.

The USAF Museum does not have an AC-47D on display, but does have a C-47D in the Modern Flight Hangar.

TYPE
AC-47D

Number Built/Converted
53

The combat use of the C-47 in Vietnam began in February 1962 when the aircraft was used to drop flares to illuminate outposts and small villages under night attack by Viet Cong (VC) forces. These C-47 flareships were based at Bien Hoa Air Base and were part of the Operation Farmgate (initially Jungle Jim) program to train VNAF forces in counterinsurgency operations.

When Operation Farmgate ended on 28 July 1963, the C-47 flareships were transferred to the 1st Air Commando Squadron (ACS) at Bien Hoa AB. The first test use of the AC-47 gunship (initially FC-47) in combat occurred on 15 December 1964 with testing continued into early 1965. One early and significant success happened on the night of 23-24 December 1964. The AC-47 defended a small outpost at Tranh Yend just 37 minutes after the request was issued. The "Spooky" fired 4,500 rounds of ammunition and broke the Viet Cong attack, forcing a retreat. The AC-47 was then called to defend another outpost (Trung Hung) about 20 miles away. The aircraft again broke the VC attack forcing a retreat.

The AC-47D combat test program was very successful and the Air Force created the 4th Air Commando Squadron in August 1965 as the first operational unit equipped with the "Spooky" gunship. Although the 4th ACS was based at Tan Son Nhut AB, it operated several forward operating locations throughout South Vietnam (Bien Hoa, Pleiku, Na Trang, Da Nang & Can Tho). In November 1965, the 4th ACS was assigned 16 operational aircraft with 4 more assigned as "advanced attrition" aircraft. Because of a shortage of SUU-11A gun pods, the AC-47D's were fitted with only two miniguns rather than three. A few aircraft were temporarily fitted with 8 or 10 .30-cal. M2 machine guns, but all were later refitted with miniguns. By early 1966, production of the minigun increased so each of the 16 AC-47D's was equipped with all three guns.

With the success of the AC-47 gunship, two more squadrons were created: the 3rd and 5th ACS, all under the 14th Air Commando Wing (ACW). In August 1968, the unit designations were changed from Air Commando to Special Operations.

The US Air Force converted 53 C-47's for use as gunships during the Vietnam War. Although the AC-47 was an effective attack system, it was also vulnerable to enemy fire. Fifteen aircraft were lost between December 17th, 1965 when the first AC-47 was lost due to ground fire and 5 September 1969 when an VNAF AC-47D crashed due to pilot error. In 1969, the USAF turned over its AC-47D's to the VNAF under the "Vietnamization" program.

The lessons learned with the AC-47D Gunship I program were used to design an improved version in the Gunship II program using the Lockheed C-130 as the base platform. Later, the Gunship III program converted Fairchild C-119's into side-firing gunships.

The USAF Museum does not have an AC-47D on display, but does have a C-47D in the Modern Flight Hangar.

TYPE
AC-47D

Number Built/Converted
53

Although the AC-47D (Gunship I) was successfully used as a gunship, the Air Force needed a larger aircraft capable of carrying a greater weapons load. Two cargo aircraft were evaluated under programs Gunship II and Gunship III. The Lockheed C-130A was evaluated in the Gunship II program and the Fairchild C-119 was tested in the Gunship III program. Because of the urgent need for gunships in Vietnam, the USAF decided to create two models of the AC-119. The first, designated AC-119G, involved a relatively easy and quick conversion from a C-119G cargo/transport aircraft. Twenty six aircraft were modified between May and October 1968. Four SUU-11 7.62 mm "miniguns" were installed in the aft left side of the cargo compartment. A maximum of 50,000 rounds of 7.62 mm ammunition could be carried for day missions and 35,000 rounds for night missions. Like the AC-47D, the pilot fired the guns and the left side window of the cockpit had a gunsight mounted. A LAU-74/A flare launcher was installed and the aircraft carried between 24 and 60 flares for night missions.

The first AC-119G Shadow operational sortie was flown on 5 January 1969 and from that time until 8 March 1969, the aircraft was in a combat evaluation phase. During this evaluation, primary emphasis was given to close air support for troops in contact, but the aircraft also flew armed reconnaissance and interdiction, as well as forward air controller missions. By 7 February 1969, the full complement of AC-119G aircraft had arrived in the Republic of Vietnam (RVN) and were initially located at Tan Son Nhut, Phan Rang, and Nha Tang Air Bases. The aircraft were assigned to the 17th Special Operations Squadron (SOS) of the 14th Special Operations Wing (SOW) and under the operational control of Headquarters 7th Air Force. The aircraft performed all of its missions in a satisfactory manner. The Shadow gunship operated in much the same manner as the AC-47, although the AC-119G Night Observation Device (NOD) and illuminator gave the aircraft an increased capability over the Spooky gunship.

TYPE
AC-119G

Number Built/Converted
26

The AC-119K "Stinger" was an improved version of the AC-119G "Shadow" and was the built as the second phase of the Gunship III program. The AC-119K had several major improvements incorporated into the design. Armament included the four 7.62 miniguns of the "Shadow" but added two 20 mm cannons. Two pods housed General Electric J85 jet engines with 2850 lbs. thrust each. The J85s allowed the aircraft to takeoff at a much larger gross weight of 80,400 lbs. -- more than 15,000 lbs. higher than the AC-119G. The "Stinger" also had a significantly upgraded avionics capability. A forward looking, terrain avoidance radar and a Forward Looking Infrared Radar (FLIR) system were installed. The Night Observation Device, automatic flare launcher and 1.5 million candlepower illuminator of the AC-119G were retained. A beacon tracking radar system was initially installed but removed in December 1970.

The first of 26 AC-119K gunship arrived in Vietnam at the end of 1969. By February 1970, 18 gunships were available for combat. The "Stingers" formed the 18th Special Operations Squadron of the 14th Special Operations Group and were initially home based at Phan Rang Air Base with two detachments operated at Da Nang AB and Phu Cat AB. Because of the AC-119s' advanced sensors and increased armament, the aircraft's mission was more oriented toward armed reconnaissance and "truck killing" than the AC-119G.

By April 1971, the aircraft were distributed at Da Nang AB and Nakhon Phanom (NKP) AB, Thailand. The flight at DA Nang was primarily concerned with armed reconnaissance in the Steel Tiger region of Laos with a secondary mission of providing close air support for troops in contact in the northern region of South Vietnam. The flight at NKP was primarily oriented toward close air support for troops in contact in the Barrel Roll region of Laos with a secondary mission of armed reconnaissance in the "Plain of Jars" (central Laos).

The AC-119K was extremely effective as a truck killer, but had to be careful to avoid areas of heavy antiaircraft artillery (AAA) concentrations. The AC-119K's relatively slow speed and predictable attack pattern made it vulnerable to AAA. In areas where there was no enemy AAA, the "Stinger" used 5,500 feet above ground level (AGL) as a working altitude and in areas with AAA present, 7,000 AGL was used (truck killer missions). Normal working altitude for close air support (CAS) of troops in contact (with the enemy) was 3,500 AGL. This enabled the AC-119K to shoot accurately with both the 20 mm cannon and 7.62 miniguns and be relatively safe from small arms fire.

TYPE
AC-119K

Number Built/Converted
26

With the success of the AC-47D "Spooky" gunships in Vietnam, the US Air Force created two modification programs for improved and larger gunships. The Fairchild AC-119G and -K's were developed under the Gunship III program and the Lockheed AC-130A was developed under the Gunship II program.

Compared to the AC-47D, the AC-130A "Spectre" gunship was equipped with more and bigger guns -- four MXU-470 7.62 mm miniguns and four M61A1 20 mm cannons. Gunship II was also equipped with a more sophisticated avionics suite including the Night Observation Device, Forward Looking InfraRed (FLIR), side looking radar, beacon tracking radar and a fire control computer system. The AC-130A was also equipped with an 20 kilowatt (1.5 million candlepower) illuminator and a flare launcher.

On February 26, 1967, the first aircraft (JC-130A S/N 54-1626) was selected for conversion into the prototype AC-130 gunship. The modifications were done in April and May, 1967 at Wright-Patterson AFB by the Aeronautical Systems Division. Flight testing of the prototype was done primarily at Eglin AFB, Florida and began on June 6th, 1967. Testing and additional modifications were done throughout the summer of 1967. By early September, the aircraft was certified ready for combat testing. The prototype was flown to Nha Trang Air Base, South Vietnam arriving on 21 September 1967 for a 90-day test program.

TYPE
AC-130A

Number Built/Converted
1

Project PAVE SPECTRE was the USAF program to acquire and modify C-130E's to gunship configuration. The initial plan called for converting eight aircraft, two prototypes (69-6567 & 69-6568) and six operational planes (69-6569 to 69-6574) for delivery not later than 1 January 1972 since the gunships were needed for Commando Hunt VII - interdiction of enemy trucks and sampans moving through the panhandle of Laos (Steel Tiger area). Six additional aircraft were reserved for PAVE SPECTRE conversion; however, only three were modified (69-6575 to 69-6577).

The AC-130E was an improved version of the AC-130A "PAVE PRONTO" aircraft. The C-130E was equipped with more powerful versions of the Allison T56 turboprop engines. The aircraft also had a maximum gross takeoff weight more than 30,000 lbs. more than the AC-130A. Consequently, the AC-130E had more armor plating and could carry additional ammunition and equipment.

The AC-130E had an improved digital fire control system (FCS) based on the LTV A-7 "Corsair II" system. In using an existing FCS, the program managers expected to take advantage of the training, maintenance, supply and logistics already in place to minimize the chances of a deployment delay for the operational aircraft. The FCS also featured a head up display (HUD) gunsight for the pilot and a moving map display for the navigator. The AC-130E retained the low light level television (LLLTV), forward looking infrared (FLIR), Black Crow ignition sensor, moving target indicator (MTI) and beacon tracking system successfully used on the PAVE PRONTO AC-130A.

TYPE
AC-130A
AC-130A
AC-130A
AC-130A
AC-130E

Number Built/Converted
1 (cv)
7 (cv)
1 (cv)
10 (cv)
11 (cv)

During the early 1970's, the 10 operational AC-130Es were upgraded with additional and improved systems and redesignated AC-130H. Many of the new systems were designed to provide better protection in high threat operating environments. The Electronic Countermeasure (ECM) system was improved to include two AN/ALQ-87 ECM pods mounted on pylons added between the engines on both wings. The AC-130H also had improved an threat detection and warning system installed. More traditional countermeasures could be fitted on the outboard wing pylons. Flare dispensers were used to counter heat seeking missiles and chaff dispensers countered radar guided missiles.

The 16th Special Operations Squadron (SOS) was the only combat unit flying the AC-130H and it remained at Ubon Royal Thai Air Force Base (RTAFB) until July 1974 when the unit moved to Korat RTAFB. In December 1975, the 16th SOS moved once more to Hurlburt Field, Florida. The 16th SOS, now part of the 16th Special Operations Wing, is currently active at Hurlburt Field.

The AC-130H fleet has undergone several modification programs to continually improved its capabilities. One major improvement was the addition of an in flight refueling (IFR) system to give the aircraft virtually unlimited range. An extensive upgrade program was completed in the early 1990s -- major updates were done to the fire control system, forward looking infrared (FLIR), and weapons subsystems (head up display, gun mounts, targeting, etc.). Global Positioning System (GPS) equipment was added and another ECM equipment upgrade program was completed.

The AC-130H has participated in many notable combat operations since the end of the Vietnam War including the attempted rescue of the crew of the USS Mayaguez in 1975, the Grenada operation in October 1983, Operation Just Cause in Panama (1989-1990), Operation Desert Storm in Iraq (1991), Operation Restore Hope in Somalia (1993-1994), and Operation Deliberate Force in Bosnia (1995).

On 31 January 1991, the first AC-130H was lost in combat supporting coalition forces engaged in ground combat during the battle of Khafji in Operation Desert Storm. A second aircraft supporting operations in Somalia was lost on 15 March 1994 when the 105 mm cannon exploded while the aircraft was airborne. The eight remaining AC-130H "Spectre" gunships are still flying with the 16th SOS.

TYPE
AC-130A
AC-130A
AC-130A
AC-130A
AC-130E
AC-130H

Number Built/Converted
1 (cv)
7 (cv)
1 (cv)
10 (cv)
11 (cv)
10 (cv)

The PAVE AEGIS development program was started in early 1971 and was designed to test the feasibility of adding a large caliber weapon to the AC-130 gunship. A variety of weapons between 75 mm and 105 mm were considered with the 105 mm M-102 Howitzer finally selected.

The prototype AC-130A S/N 54-1626 (currently on display at the USAF Museum) was selected for proof of concept testing. The aircraft was modified for the cannon during the summer of 1971 and initial firing tests were done from 11-17 September. On a typical sortie, the cannon was fired from 8,000 feet above ground level using a standard left banking attack pattern at a speed between 150-160 knots. Testing was successfully completed and the Aeronautical Systems Division proposed the modification of the AC-130E. The operational units in Southeast Asia initially opposed the program since the PAVE SPECTRE AC-130Es were badly needed for the Commando Hunt VII campaign - an air interdiction campaign to impede the overland flow of supplies from North Vietnam, Laos and Cambodia during the "dry" season from October through April . However, an agreement was reached in early November to convert the sixth AC-130E (S/N 69-6572) to the PAVE AEGIS configuration for operational combat testing.

The prototype PAVE AEGIS AC-130E was scheduled for completion of its PAVE SPECTRE modifications by the end of December 1971. In January 1972, it was flown to Eglin AFB, Florida for modifications to add the M-102 cannon. To install the 105 mm weapon, the aft 40 mm cannon and beacon tracking radar were removed to make room for the new weapon, two 105 mm ammunition racks were installed (72 and 24 round capacity). The gun had a three-foot blast deflector added to the cannon muzzle to protect the left wing from blast damage when the gun was fired. The 105 mm cannon had a travel range between 0° and 20° azimuth (aft) and between 0° and -40° elevation. The cannon had a safety cage installed to protect the gunners from the 4 foot recoil when the gun was fired. Each 105mm shell weighed 42 pounds and was 31 inches long. The total modification program added about 5,000 lbs. to the aircraft gross weight. The engineers and maintenance personnel determined the 105 mm cannon modification could be completed at Ubon Royal Thai Air Force Base (RTAFB), home the 16th Special Operation Squadron (SOS), in about 12 to 15 hours.

The PAVE AEGIS AC-130E flew two combat training missions from Ubon RTAFB on 22 and 23 February 1972. The missions allowed the crews to become familiar with the new weapon system and solve any operational problems encountered. The first actual combat mission was flown on February 24th. The AC-130E flew a Commando Hunt VII armed reconnaissance mission, spotted 12 trucks, destroyed 3 and damaged 4 more with the 105 mm cannon. The 40 mm cannon damaged or destroyed the other 5 trucks. On March 15th, the PAVE AEGIS aircraft was hit and damaged by a 57 mm antiaircraft (AAA) round. Maintenance personnel at Ubon RTAFB removed the 105 mm cannon from the damaged aircraft and reinstalled on another AC-130E (S/N 69-6571).

The initial combat test period ended on 30 March with a total of 32 combat sorties flown. Of the 239 trucks sighted, 229 were attacked and 218 were damaged or destroyed. The 105 mm cannon was credited with 76% of the damaged or destroyed trucks. On March 30th, the PAVE AEGIS AC-130E was shot down after being hit be 57 mm AAA fire. Another AC-130 gunship provided Close Air Support (CAS) for the Combat Search and Rescue (CSAR) effort to rescue the crew. The Forward Looking Infrared (FLIR) system was used to "see" the crew members and direct them to protective cover. The entire crew was rescued on 31 March.

The 7th Air Force had approved the installation of a 105 mm cannon on a second AC-130E before the loss of the first PAVE AEGIS AC-130E. Consequently, the 16th SOS maintenance personnel completed the conversion on AC-130E S/N 69-6570 to keep the PAVE AEGIS strength at one aircraft. The second aircraft conversion was delayed until May 1st, 1972 waiting for the replacement (third) 105 mm conversion kit to arrive at Ubon RTAFB.

Because of its awesome destructive power, the PAVE AEGIS AC-130E quickly earned several unofficial nicknames including "Big Gun" and "Big Bertha."

TYPE
AC-130A
AC-130A
AC-130A
AC-130A
AC-130E

Number Built/Converted
1 (cv)
7 (cv)
1 (cv)
10 (cv)
11 (cv)

The AC-130U is the latest in a long line of side firing gunships which began in the early 1960's with the AC-47D "Spooky." The AC-130U is named for the AC-47D and has the "Spooky" nickname rather than the "Spectre" nickname used by all other AC-130 gunships.

"The AC-130U Gunship program consists of 13 new C-130H airframes that Rockwell International Corporation modified for improved armament, avionics, battle management, sensors and countermeasures. The modifications allow the aircraft to perform the full range of special operations and conventional gunships missions. The AC-130U Gunship is capable of operating at low levels at night and in adverse weather, providing precision fire support and loitering for long periods over targets. (Fielding of the AC-130U Gunship - AFAA)

The prototype AC-130U (S/N 87-128) made its first flight on 20 December 1990 on a short flight from the Lockheed Palmdale facility to Edwards Air Force Base (AFB), California. The initial flight test period lasted from 20 December 1990 through 21 December 1991. 48 test flights were flown for a total of 165 hours. Thirteen aircraft were built and all are currently assigned to the 4th Special Operations Squadron "Ghostriders", 16th Special Operations Wing, Hurlburt Field, Florida.

The AC-130U incorporated a variety of upgraded systems. The weapons array consists of a 105 mm cannon, a 40 mm cannon and a 25 mm gatling gun. The aircraft has a dual inertial navigation system (INS). The fire control system (FCS) is integrated with the global positioning system (GPS) for increased targeting accuracy under all conditions. Targeting equipment installed in the gunship includes an All Light Level Television (ALLTV) system with a laser illuminator, laser target designator, laser range finder, infrared detection set, and night vision goggles for the pilots. The AC-130U has in flight refueling capability and a full range of electronic warfare countermeasures.

TYPE
AC-130A
AC-130A
AC-130A
AC-130A
AC-130E
AC-130H
AC-130U

Number Built/Converted
1 (cv)
7 (cv)
1 (cv)
10 (cv)
11 (cv)
10 (cv)
13

In May 1971, the Aeronautical Systems Division (ASD) at Wright-Patterson AFB, Ohio began work on a project to evaluate the potential use of armed light utility short takeoff and landing (STOL) aircraft in Southeast Asia. The program, named Credible Chase, was designed to add mobility and firepower to the South Vietnamese Air Forces (RVNAF) in a relatively short time. Two commercial aircraft were selected for testing: the Fairchild Porter and the Helio Stallion. Initial performance testing was conducted with leased aircraft at Eglin AFB, Florida and was successful enough to warrant a combat evaluation. The Porter, designated AU-23A, was fitted with a side-firing 20 mm XM-197 gatling cannon, four wing pylons and a center fuselage station for external ordnance. The 20 mm cannon was essentially a three barrel version of the M61 "Vulcan" 6-barrel 20 mm cannon. The aircraft could carry a variety of ordnance including forward firing gun pods, 500 and 250 lb. bombs, napalm units, cluster bomb units, flares, rockets, smoke grenades and propaganda leaflet dispensers.

The combat evaluation, PAVE COIN, was done in June and July 1971. The AU-23A was tested for eight possible missions: armed escort of helicopters, close air support, hamlet defense, STOL airlift and resupply, armed reconnaissance, border surveillance, forward air control, and counter infiltration. USAF crews flew 73 missions (94 sorties) and RVNAF crews flew 68 missions (85 sorties). Several types of weapons were test dropped/fired including 2.75" rockets (explosive and smoke), cluster bomb units (CBU-14), MK 6 Mod 3 flares, and MK 81, 82 and 106 practice bombs. More than 8,000 rounds of 20 mm ammunition was fired also - both high explosive incendiary (HEI) and target practice tracer (TPT) types. Several problems were discovered during the PAVE COIN program, the most serious was the extreme vulnerability of the aircraft to all but the lightest antiaircraft fire (below 12.7 mm). Despite the problems, the USAF continued with the development program and ordered 15 AU-23A's for further testing.

The 4400th Special Operations Squadron (Provisional) was created to complete the operational test and evaluation (OT&E) of the Credible Chase aircraft. The first AU-23A (72-1306) was delivered to the 4400th SOS on 2 January 1972 followed by two more aircraft (72-1304 & 72-1305) at the end of the month. Testing continued until 4 February when the three aircraft were grounded because of cracks in the rudder assemblies. The first three aircraft were returned to Fairchild for repair and delivery of new aircraft resumed in late April 1972. On 10 May 1972, an AU-23A (S/N 72-1309) crashed after an in-flight engine failure. The pilot was unhurt, but all AU-23A's were grounded until 22 May during the accident investigation. The last AU-23A was delivered on June 7th and testing was completed on June 28th.

The 4400th recommended the aircraft not be used in combat without a major upgrade program. Specific problems identified included a slow combat speed (135 knots), a low working altitude, no capability for "zoom" escapes after delivering ordnance, and a complete lack of armor protection for the crew and vital aircraft systems. On June 30th 1972, the 4400th SOS ferried the AU-23A's to Davis-Monthan AFB, Arizona for storage.

The AU-23A's were eventually supplied to Thailand under the Military Assistance Program (MAP) for use in border surveillance and counterinfiltaration roles.

TYPE
AU-23A

Number Built/Converted
15

Description T.O. 1U-24A-1
The AU-24A, manufactured by Helio Aircraft Company, a division of General Aircraft Corporation, is a high performance, lightweight single engine turbo prop, high wing monoplane. The wing is a full cantilever and all metal construction. The fuselage is semi-monocoque construction with the landing gear set well forward to permit excessive braking. The empennage is of all metal construction with ribs and spars. The AU-24A is designed for Short Take Off and Landing (STOL) performance and equipped with long span single slotted flaps which span from the root section to the aileron, and aerodynamically automatic full span leading edge slats. Roll control is maintained during slow flight operations by short span fabric covered ailerons, mechanically interconnected to leading edge integrated interceptors. Pitch control is maintained by a stabilator (slab tail). Pitch trim is provided by both manually operated and electrically operated controls. Aileron trim is electrically operated and rudder trim is mechanically operated. The AU-24A is equipped with air-to-ground armament delivery capabilities. Four wing pylons and a fuselage centerline bomb rack allow for rocket, bombs, target marker flares, and parachute flare delivery. The aft weapons compartment mounts an XM-197 20 mm automatic gun system. Pilot control for arming and delivery of weapons is provided by the armament control panel located in the forward cabin above the instrument panel.

The AU-24A was the second aircraft evaluated for potential use in Southeast Asia as an armed light utility short take off and landing gunship. The program, designated Credible Chase, began in May 1971 and was designed to add firepower and mobility to the South Vietnamese Air Force (RVNAF) in a relatively short time. The combat evaluation, Project PAVE COIN, of the Fairchild AU-23A and Helio AU-24A was done in June and July of 1971. The AU-24A, like the AU-23A, was found to be unsuitable for combat operations. Major problems identified included a low attack speed of about 135 knots, a low operating altitude below 5000 feet, so "zoom" escape capability after an attack run, and an extreme vulnerability to antiaircraft fire. Further testing was recommended after the aircraft were updated to combat standards.

In January 1972, the second test phase for the AU-24A began at Eglin AFB, Florida. The initial aircraft used (S/N 72-1319) was leased from Helio and retained its civilian configuration but it allowed basic flight testing to begin. The combat evaluation of the Credible Chase program was canceled in February 1972, but the initial (stateside) evaluation was kept on the program schedule. The first combat equipped AU-24A was delivered on March 4th, 1972 and operational test and evaluation (OT&E) began on 17 March, but was delayed after a review of contractor quality control began on April 3rd. On April 10th, the review imposed a number of flight restrictions on the AU-24A limiting maximum airspeed, dive and bank angles, and all instrument, weather and night test flights. The OT&E of the AU-24A was officially started over on April 22nd and by May 3rd, the aircraft was again in trouble. This time the problem was a dynamic instability during flight. The problems were resolved by May 12th and the test program continued until completion on May 22nd. Starting on June 28th, the AU-24A's were flown to Davis-Monthan AFB, Arizona for storage. The Credible Chase program was canceled and no AU-24A was delivered to the South Vietnamese Air Force.

Fourteen AU-24A's were supplied to Cambodia under the Foreign Military Sales (FMS) program for use in border surveillance and counter infiltration roles where the threat of encountering antiaircraft fire (other than small arms) was minimal.

TYPE
AU-24A

Number Built/Converted
15