Beckett and Rice developed a basic platform meeting these requirements, then attempted to build a fiberglass prototype in a garage. The effort produced enthusiastic supporters and an informal pamphlet describing the concept. W. H. Beckett, who had retired from the Marine Corps, went to work at North American Aviation to sell the aircraft.

The aircraft's design supported effective operations from forward bases. The OV-10 had a central nacelle containing a crew of two in tandem and space for cargo, and twin booms containing twin turboprop engines. The visually distinctive feature of the aircraft is the combination of the twin booms, with the horizontal stabilizer that connected them at the fin tips. The OV-10 could perform short takeoffs and landings, including on aircraft carriers and large-deck amphibious assault ships without using catapults or arresting wires. Further, the OV-10 was designed to take off and land on unimproved sites. Repairs could be made with ordinary tools. No ground equipment was required to start the engines. And, if necessary, the engines would operate on high-octane automobile fuel with only a slight loss of power.

The aircraft had responsive handling and could fly for up to 5½ hours with external fuel tanks. The cockpit had extremely good visibility for both pilot and co-pilot, provided by a wrap-around "greenhouse" that was wider than the fuselage. North American Rockwell custom ejection seats were standard, with many successful ejections during service. With the second seat removed, the OV-10 could carry 3,200 pounds (1,500 kg) of cargo, five paratroopers, or two litter patients and an attendant. Empty weight was 6,969 pounds (3,161 kg). Normal operating fueled weight with two crew was 9,908 pounds (4,494 kg). Maximum takeoff weight was 14,446 pounds (6,553 kg).

The bottom of the fuselage bore sponsons or "stub wings" that improved flight performance by decreasing aerodynamic drag underneath the fuselage. Normally, four 7.62 mm (.308 in) M60C machine guns were carried on the sponsons, accessed through large forward-opening hatches. The sponsons also had four racks to carry bombs, pods, or fuel. The wings outboard of the engines contained two additional hardpoints, one per side. Racked armament in the Vietnam War was usually seven-shot 2.75 in (70 mm) rocket pods with white phosphorus marker rounds or high-explosive rockets, or 5" (127 mm) four-shot Zuni rocket pods. Bombs, ADSIDS air-delivered/para-dropped unattended seismic sensors, Mk-6 battlefield illumination flares, and other stores were also carried.

Operational experience showed some weaknesses in the OV-10's design. It was significantly underpowered, which contributed to crashes in Vietnam in sloping terrain because the pilots could not climb fast enough. While specifications stated that the aircraft could reach 26,000 feet (7,900 m), in Vietnam the aircraft could reach only 18,000 feet (5,500 m). Also, no OV-10 pilot survived ditching the aircraft.

The OV-10 served in the U.S. Air Force, U.S. Marine Corps, and U.S. Navy, as well as in the service of a number of other countries. In U.S. military service, the Bronco was operated until the early Nineties, and obsoleted USAF OV-10s were passed on to the Bureau of Alcohol, Tobacco, and Firearms for anti-drug operations. A number of OV-10As furthermore ended up in the hands of the California Department of Forestry (CDF) and were used for spotting fires and directing fire bombers onto hot spots.

This was not the end of the OV-10 in American military service, though: In 2012, the type gained new attention because of its unique qualities. A $20 million budget was allocated to activate an experimental USAF unit of two airworthy OV-10Gs, acquired from NASA and the State Department. These machines were retrofitted with military equipment and were, starting in May 2015, deployed overseas to support Operation “Inherent Resolve”, flying more than 120 combat sorties over 82 days over Iraq and Syria. Their concrete missions remained unclear, and it is speculated they provided close air support for Special Forces missions, esp. in confined urban environments where the Broncos’ loitering time and high agility at low speed and altitude made them highly effective and less vulnerable than helicopters.

Furthermore, these Broncos reputedly performed strikes with the experimental AGR-20A “Advanced Precision Kill Weapons System (APKWS)”, a Hydra 70-millimeter rocket with a laser-seeking head as guidance - developed for precision strikes against small urban targets with little collateral damage. The experiment ended satisfactorily, but the machines were retired again, and the small unit was dissolved.

However, the machines had shown their worth in asymmetric warfare, and the U.S. Air Force decided to invest in reactivating the OV-10 on a regular basis, despite the overhead cost of operating an additional aircraft type in relatively small numbers – but development and production of a similar new type would have caused much higher costs, with an uncertain time until an operational aircraft would be ready for service. Re-activating a proven design and updating an existing airframe appeared more efficient.

The result became the MV-10H, suitably christened “Super Bronco” but also known as “Black Pony”, after the program's internal name. This aircraft was derived from the official OV-10X proposal by Boeing from 2009 for the USAF's Light Attack/Armed Reconnaissance requirement. Initially, Boeing proposed to re-start OV-10 manufacture, but this was deemed uneconomical, due to the expected small production number of new serial aircraft, so the “Black Pony” program became a modernization project. In consequence, all airframes for the "new" MV-10Hs were recovered OV-10s of various types from the "boneyard" at Davis-Monthan Air Force Base in Arizona.

While the revamped aircraft would maintain much of its 1960s-vintage rugged external design, modernizations included a completely new, armored central fuselage with a highly modified cockpit section, ejection seats and a computerized glass cockpit. The “Black Pony” OV-10 had full dual controls, so that either crewmen could steer the aircraft while the other operated sensors and/or weapons. This feature would also improve survivability in case of incapacitation of a crew member as the result from a hit.

The cockpit armor protected the crew and many vital systems from 23mm shells and shrapnel (e. g. from MANPADS). The crew still sat in tandem under a common, generously glazed canopy with flat, bulletproof panels for reduced sun reflections, with the pilot in the front seat and an observer/WSO behind. The Bronco’s original cargo capacity and the rear door were retained, even though the extra armor and defensive measures like chaff/flare dispensers as well as an additional fuel cell in the central fuselage limited the capacity. However, it was still possible to carry and deploy personnel, e. g. small special ops teams of up to four when the aircraft flew in clean configuration.

Additional updates for the MV-10H included structural reinforcements for a higher AUW and higher g load maneuvers, similar to OV-10D+ standards. The landing gear was also reinforced, and the aircraft kept its ability to operate from short, improvised airstrips. A fixed refueling probe was added to improve range and loiter time.

Intelligence sensors and smart weapon capabilities included a FLIR sensor and a laser range finder/target designator, both mounted in a small turret on the aircraft’s nose. The MV-10H was also outfitted with a data link and the ability to carry an integrated targeting pod such as the Northrop Grumman LITENING or the Lockheed Martin Sniper Advanced Targeting Pod (ATP). Also included was the Remotely Operated Video Enhanced Receiver (ROVER) to provide live sensor data and video recordings to personnel on the ground.

To improve overall performance and to better cope with the higher empty weight of the modified aircraft as well as with operations under hot-and-high conditions, the engines were beefed up. The new General Electric CT7-9D turboprop engines improved the Bronco's performance considerably: top speed increased by 100 mph (160 km/h), the climb rate was tripled (a weak point of early OV-10s despite the type’s good STOL capability) and both take-off as well as landing run were almost halved. The new engines called for longer nacelles, and their circular diameter markedly differed from the former Garrett T76-G-420/421 turboprop engines. To better exploit the additional power and reduce the aircraft’s audio signature, reversible contraprops, each with eight fiberglass blades, were fitted. These allowed a reduced number of revolutions per minute, resulting in less noise from the blades and their tips, while the engine responsiveness was greatly improved. The CT7-9Ds’ exhausts were fitted with muzzlers/air mixers to further reduce the aircraft's noise and heat signature.

Another novel and striking feature was the addition of so-called “tip sails” to the wings: each wingtip was elongated with a small, cigar-shaped fairing, each carrying three staggered, small “feather blade” winglets. Reputedly, this installation contributed ~10% to the higher climb rate and improved lift/drag ratio by ~6%, improving range and loiter time, too.

Drawing from the Iraq experience as well as from the USMC’s NOGS test program with a converted OV-10D as a night/all-weather gunship/reconnaissance platform, the MV-10H received a heavier gun armament: the original four light machine guns that were only good for strafing unarmored targets were deleted and their space in the sponsons replaced by avionics. Instead, the aircraft was outfitted with a lightweight M197 three-barrel 20mm gatling gun in a chin turret. This could be fixed in a forward position at high speed or when carrying forward-firing ordnance under the stub wings, or it could be deployed to cover a wide field of fire under the aircraft when it was flying slower, being either slaved to the FLIR or to a helmet sighting auto targeting system.

The original seven hardpoints were retained (1x ventral, 2x under each sponson, and another pair under the outer wings), but the total ordnance load was slightly increased and an additional pair of launch rails for AIM-9 Sidewinders or other light AAMs under the wing tips were added – not only as a defensive measure, but also with an anti-helicopter role in mind; four more Sidewinders could be carried on twin launchers under the outer wings against aerial targets. Other guided weapons cleared for the MV-10H were the light laser-guided AGR-20A and AGM-119 Hellfire missiles, the Advanced Precision Kill Weapon System upgrade to the light Hydra 70 rockets, the new Laser Guided Zuni Rocket which had been cleared for service in 2010, TV-/IR-/laser-guided AGM-65 Maverick AGMs and AGM-122 Sidearm anti-radar missiles, plus a wide range of gun and missile pods, iron and cluster bombs, as well as ECM and flare/chaff pods, which were not only carried defensively, but also in order to disrupt enemy ground communication.

In this configuration, a contract for the conversion of twelve mothballed American Broncos to the new MV-10H standard was signed with Boeing in 2016, and the first MV-10H was handed over to the USAF in early 2018, with further deliveries lasting into early 2020. All machines were allocated to the newly founded 919th Special Operations Support Squadron at Duke Field (Florida). This unit was part of the 919th Special Operations Wing, an Air Reserve Component (ARC) of the United States Air Force. It was assigned to the Tenth Air Force of Air Force Reserve Command and an associate unit of the 1st Special Operations Wing, Air Force Special Operations Command (AFSOC). If mobilized the wing was gained by AFSOC (Air Force Special Operations Command) to support Special Tactics, the U.S. Air Force's special operations ground force. Similar in ability and employment to Marine Special Operations Command (MARSOC), U.S. Army Special Forces and U.S. Navy SEALs, Air Force Special Tactics personnel were typically the first to enter combat and often found themselves deep behind enemy lines in demanding, austere conditions, usually with little or no support.

The Shooting Star began to enter service in late 1944 with 12 pre-production YP-80As. Four were sent to Europe for operational testing (demonstration, familiarization, and possible interception roles), two to England and two to the 1st Fighter Group at Lesina Airfield, Italy. Because of delays in delivery of production aircraft, the Shooting Star saw no actual combat during the conflict. The initial production order was for 344 P-80As after USAAF acceptance in February 1945. A total of 83 P-80s had been delivered by the end of July 1945 and 45 assigned to the 412th Fighter Group (later redesignated the 1st Fighter Group) at Muroc Army Air Field. Production continued after the war, although wartime plans for 5,000 were quickly reduced to 2,000 at a little under $100,000 each. A total of 1,714 single-seat F-80A, F-80B, F-80C, and RF-80s were manufactured by the end of production in 1950, of which 927 were F-80Cs (including 129 operational F-80As upgraded to F-80C-11-LO standards). However, the two-seat TF-80C, first flown on 22 March 1948, became the basis for the T-33 trainer, of which 6,557 were produced.

Shooting Stars first saw combat service in the Korean War, and were among the first aircraft to be involved in jet-versus-jet combat. Despite initial claims of success, the speed of the straight-wing F-80s was inferior to the 668 mph (1075 km/h) swept-wing transonic MiG-15. The MiGs incorporated German research showing that swept wings delayed the onset of compressibility problems, and enabled speeds closer to the speed of sound. F-80s were soon replaced in the air superiority role by the North American F-86 Sabre, which had been delayed to also incorporate swept wings into an improved straight-winged naval FJ-1 Fury.

This prompted Lockheed to improve the F-80 to keep the design competitive, and the result became the F-80E, which was almost a completely different aircraft, despite similar outlines. Lockheed attempted to change as little of the original airframe as possible while the F-80E incorporated two major technical innovation of its time. The most obvious change was the introduction of swept wings for higher speed. After the engineers obtained German swept-wing research data, Lockheed gave the F-80E a 25° sweep, with automatically locking leading edge slots, interconnected with the flaps for lateral stability during take-off and landing, and the wings’ profile was totally new, too. The limited sweep was a compromise, because a 35° sweep had originally been intended, but the plan to retain the F-80’s fuselage and wing attachment points would have resulted in massive center of gravity and mechanical problems. However, wind tunnel tests quickly revealed that even this compromise would not be enough to ensure stable flight esp. at low speed, and that the modified aircraft would lack directional stability. The swept-wing aircraft’s design had to be modified further.

A convenient solution came in the form of the F-80’s trainer version fuselage, the T-33, which had been lengthened by slightly more than 3 feet (1 m) for a second seat, instrumentation, and flight controls, under a longer canopy. Thanks to the extended front fuselage, the T-33’s wing attachment points could accept the new 25° wings without much further modifications, and balance was restored to acceptable limits. For the fighter aircraft, the T-33’s second seat was omitted and replaced with an additional fuel cell. The pressurized front cockpit was retained, together with the F-80’s bubble canopy and out fitted with an ejection seat.

The other innovation was the introduction of reheat for the engine. The earlier F-80 fighters were powered by centrifugal compressor turbojets, the F-80C had already incorporated water injection to boost the rather anemic powerplant during the start phase and in combat. The F-80E introduced a modified engine with a very simple afterburner chamber, designated J33-A-39. It was a further advanced variant of the J33-A-33 for the contemporary F-94 interceptor with water-alcohol injection and afterburner. For the F-80E with less gross weight, the water-alcohol injection system was omitted so save weight and simplify the system, and the afterburner was optimized for quicker response. Outwardly, the different engine required a modified, wider tail section, which also slightly extended the F-80’s tail.

The F-80E’s armament was changed, too. Experience from the Korean War had shown that the American aircrafts’ traditional 0.5” machine guns were reliable, but they lacked firepower, esp. against bigger targets like bombers, and even fighter aircraft like the MiG-15 had literally to be drenched with rounds to cause significant damage. On the other side, a few 23 mmm rounds or just a single hit with an explosive 37 mm shell from a MiG could take a bomber down. Therefore, the F-80’s six machine guns in the nose were replaced with four belt-fed 20mm M24 cannon. This was a license-built variant of the gas-operated Hispano-Suiza HS.404 with the addition of electrical cocking, allowing the gun to re-cock over a lightly struck round. It offered a rate of fire of 700-750 rounds/min and a muzzle velocity of 840 m/s (2,800 ft/s).In the F-80E each weapon was provided with 190 rounds.

Despite the swept wings Lockheed retained the wingtip tanks, similar to Lockheed’s recently developed XF-90 penetration fighter prototype. They had a different, more streamlined shape now, to reduce drag and minimize the risk of torsion problems with the outer wing sections and held 225 US gal (187 imp gal; 850 l) each. Even though the F-80E was conceived as a daytime fighter, hardpoints under the wings allowed the carriage of up to 2.000 lb of external ordnance, so that the aircraft could, like the straight-wing F-80s before, carry out attack missions. A reinforced pair of plumbed main hardpoints, just outside of the landing gear wells, allowed to carry another pair of drop tanks for extra range or single bombs of up to 1.000 lb (454 kg) caliber. A smaller, optional pair of pylons was intended to carry pods with nineteen “Mighty Mouse” 2.75 inches (70 mm) unguided folding-fin air-to-air rockets, and further hardpoints under the outer wings allowed eight 5” HVAR unguided air-to-ground rockets to be carried, too. Total external payload (including the wing tip tanks) was 4,800 lb (roughly 2,200 kg) of payload

The first XP-80E prototype flew in December 1953 – too late to take part in the Korean War, but Lockheed kept the aircraft’s development running as the benefits of swept wings were clearly visible. The USAF, however, did not show much interest in the new aircraft since the proven F-86 Sabre was readily available and focus more and more shifted to radar-equipped all-weather interceptors armed with guided missiles. However, military support programs for the newly founded NATO, esp. in Europe, stoked the demand for jet fighters, so that the F-80E was earmarked for export to friendly countries with air forces that had still to develop their capabilities after WWII. One of these was Germany; after World War II, German aviation was severely curtailed, and military aviation was completely forbidden after the Luftwaffe of the Third Reich had been disbanded by August 1946 by the Allied Control Commission. This changed in 1955 when West Germany joined NATO, as the Western Allies believed that Germany was needed to counter the increasing military threat posed by the Soviet Union and its Warsaw Pact allies. On 9 January 1956, a new German Air Force called Luftwaffe was founded as a branch of the new Bundeswehr (Federal Defence Force). The first volunteers of the Luftwaffe arrived at the Nörvenich Air Base in January 1956, and the same year, the Luftwaffe was provided with its first jet aircraft, the US-made Republic F-84 Thunderstreak from surplus stock, complemented by newly built Lockheed F-80E day fighters and T-33 trainers.

A total of 43 F-80Es were delivered to Germany in the course of 1956 and early 1957 via freight ships as disassembled kits, initially allocated to WaSLw 10 (Waffenschule der Luftwaffe = Weapon Training School of the Luftwaffe) at Nörvenich, one of three such units which focused on fighter training. The unit was quickly re-located to Northern Germany to Oldenburg, an airfield formerly under British/RAF governance, where the F-80Es were joined by Canada-built F-86 Sabre Mk. 5s. Flight operations began there in November 1957. Initially supported by flight instructors from the Royal Canadian Air Force from Zweibrücken, the WaSLw 10’s job was to train future pilots for jet aircraft on the respective operational types. F-80Es of this unit were in the following years furthermore frequently deployed to Decimomannu AB on Sardinia (Italy), as part of multi-national NATO training programs.

The F-80Es’ service at Oldenburg with WaSLw 10 did not last long, though. In 1963, basic flight and weapon system training was relocated to the USA, and the so-called Europeanization was shifted to the nearby Jever air base, i. e. the training in the more crowded European airspace and under notoriously less pleasant European weather conditions. The remaining German F-80E fleet was subsequently allocated to the Jagdgeschwader 73 “Steinhoff” at Pferdsfeld Air Base in Rhineland-Palatinate, where the machines were – like the Luftwaffe F-86s – upgraded to carry AIM-9 Sidewinder AAMs, a major improvement of their interceptor capabilities. But just one year later, on October 1, 1964, JG 73 was reorganized and renamed Fighter-Bomber Squadron 42, and the unit converted to the new Fiat G.91 attack aircraft. In parallel, the Luftwaffe settled on the F-86 (with more Sabre Mk. 6s from Canada and new F-86K all-weather interceptors from Italian license production) as standard fighter, with the plan to convert to the supersonic new Lockheed F-104 as standard NATO fighter as soon as the type would become available.

M7 Aerosystems started on a blank sheet, even though Northrop-Grumman’s A-12 influence was clearly visible, and to a certain degree the aircraft shared the basic layout with the F-117A. The A-14 was tailored from the start to the ground attack role, and therefore a subsonic design. Measures to reduce radar cross-section included airframe shaping such as alignment of edges, fixed-geometry serpentine inlets that prevented line-of-sight of the engine faces from any exterior view, use of radar-absorbent material (RAM), and attention to detail such as hinges and maintenance covers that could provide a radar return. The A-14 was furthermore designed to have decreased radio emissions, infrared signature and acoustic signature as well as reduced visibility to the naked eye.

The resulting airframe was surprisingly large for an attack aircraft – in fact, it rather reminded of a tactical bomber in the F-111/Su-24 class than an alternative to the A-10. The A-14 consisted of a rhomboid-shaped BWB (blended-wing-and-body) with extended wing tips and only a moderate (35°) wing sweep, cambered leading edges, a jagged trailing edge and a protruding cockpit section which extended forward of the main body.

The majority of the A-14’s structure and surface were made out of a carbon-graphite composite material that is stronger than steel, lighter than aluminum, and absorbs a significant amount of radar energy. The central fuselage bulge ended in a short tail stinger with a pair of swept, canted fins as a butterfly tail, which also shrouded the engine’s hot efflux. The fins could have been omitted, thanks to the aerodynamically unstable aircraft’s fly-by-wire steering system, and they effectively increased the A-14’s radar signature as well as its visual profile, but the gain in safety in case of FBW failure or physical damage was regarded as a worthwhile trade-off. Due to its distinctive shape and profile, the A-14 quickly received the unofficial nickname “Squatina”, after the angel shark family.

The spacious and armored cockpit offered room for the crew of two (pilot and WSO or observer for FAC duties), seated side-by-side under a generous glazing, with a very good field of view forward and to the sides. The fuselage structure was constructed around a powerful cannon, the five-barrel GAU-12/U 25 mm ‘Equalizer’ gun, which was, compared with the A-10’s large GAU-8/A, overall much lighter and more compact, but with only little less firepower. It fired a new NATO series of 25 mm ammunition at up to 4.200 RPM. The gun itself was located under the cockpit tub, slightly set off to port side, and the front wheel well was offset to starboard to compensate, similar in arrangement to the A-10 or Su-25. The gun’s ammunition drum and a closed feeding belt system were located behind the cockpit in the aircraft’s center of gravity. An in-flight refueling receptor (for the USAF’s boom system) was located in the aircraft’s spine behind the cockpit, normally hidden under a flush cover.

Due to the gun installation in the fuselage, however, no single large weapon bay to minimize radar cross section and drag through external ordnance was incorporated, since this feature would have increased airframe size and overall weight. Instead, the A-14 received four, fully enclosed compartments between the wide main landing gear wells and legs. The bays could hold single iron bombs of up to 2.000 lb caliber each, up to four 500 lb bombs or CBUs, single laser-guided GBU-14 glide bombs, AGM-154 JSOW or GBU-31/38 JDAM glide bombs, AGM-65 Maverick guided missiles or B61 Mod 11 tactical nuclear weapons, as well as the B61 Mod 12 standoff variant, under development at that time). Retractable launch racks for defensive AIM-9 Sidewinder air-to-air missiles were available, too, and additional external pylons could be added, e.g. for oversize ordnance like AGM-158C Long Range Anti-Ship Missile (LRASM) or AGM-158 Joint Air to Surface Standoff Missile (JASSM), or drop tanks for ferry flights. The total in- and external ordnance load was 15,000 lb (6,800 kg).

The A-14 was designed with superior maneuverability at low speeds and altitude in mind and therefore featured a large wing area, with high wing aspect ratio on the outer wing sections, and large ailerons areas. The ailerons were placed at the far ends of the wings for greater rolling moment and were split, making them decelerons, so that they could also be used as air brakes in flight and upon landing.

This wing configuration promoted short takeoffs and landings, permitting operations from primitive forward airfields near front lines. The sturdy landing gear with low-pressure tires supported these tactics, and a retractable arrester hook, hidden by a flush cover under the tail sting, made it possible to use mobile arrested-recovery systems.

The leading edge of the wing had a honeycomb structure panel construction, providing strength with minimal weight; similar panels covered the flap shrouds, elevators, rudders and sections of the fins. The skin panels were integral with the stringers and were fabricated using computer-controlled machining, reducing production time and cost, and this construction made the panels more resistant to damage. The skin was not load-bearing, so damaged skin sections could be easily replaced in the field, with makeshift materials if necessary.

Power came from a pair of F412-GE-114 non-afterburning turbofans, engines that were originally developed for the A-12, but de-navalized and lightened for the A-14. These new engines had an output of 12,000 lbf (53 kN) each and were buried in blended fairings above the wing roots, with jagged intakes and hidden ducts. Flat exhausts on the wings’ upper surface minimized both radar and IR signatures.

Thanks to the generous internal fuel capacity in the wings and the fuselage, the A-14 was able to loiter and operate under 1,000 ft (300 m) ceilings for extended periods. It typically flew at a relatively low speed of 300 knots (350 mph; 560 km/h), which made it a better platform for the ground-attack role than fast fighter-bombers, which often have difficulty targeting small, slow-moving targets or executing more than just a single attack run on a selected target.

A mock-up was presented and tested in the wind tunnel and for radar cross-section in late 2008. The A-14’s exact radar cross-section (RCS) remained classified, but in 2009 M7 Aerosystems released information indicating it had an RCS (from certain angles) of −40 dBsm, equivalent to the radar reflection of a "steel marble". With this positive outcome and the effective design, M7 Aerosystems eventually received federal funding for the production of prototypes for an official DT&E (Demonstration Testing and Evaluation) program.

Three prototypes/pre-production aircraft were built in the course of 2010 and 2011, and the first YA-14 made its maiden flight on 10 May 2011. The DT&E started immediately, and the machines (a total of three flying prototypes were completed, plus two additional airframes for static tests) were gradually outfitted with mission avionics and other equipment. This included GPS positioning, an inertial navigation system, passive sensors to detect radar usage, a small, gyroscopically stabilized turret, mounted under the nose of the aircraft, containing a FLIR boresighted with a laser spot-tracker/designator, and an experimental 3-D laser scanning LIDAR in the nose as a radiation-less alternative to a navigation and tracking radar.

Soon after the DT&E program gained momentum in 2012, the situation changed for M7 Aerosystems when the US Air Force considered the F-35B STOVL variant as its favored replacement CAS aircraft, but concluded that the aircraft could not generate a sufficient number of sorties. However, the F-35 was established as the A-14’s primary rival and remained on the USAF’s agenda. For instance, at that time the USAF proposed disbanding five A-10 squadrons in its budget request to cut its fleet of 348 A-10s by 102 to lessen cuts to multi-mission aircraft in service that could replace the specialized attack aircraft.

In August 2013, Congress and the Air Force examined various proposals for an A-10 replacement, including the A-14, F-35 and the MQ-9 Reaper unmanned aerial vehicle, and, despite the A-14’s better qualities in the ground attack role, the F-35 came out as the overall winner, since it was the USAF’s favorite. Despite its complexity, the F-35 was – intended as a multi-role tri-service aircraft and also with the perspective of bigger international sales than the more specialized A-14 – regarded as the more versatile and, in the long run, more cost-efficient procurement option. This sealed the A-14’s fate and the F-35A entered service with U.S. Air Force F-35A in August 2016 (after the F-35B was introduced to the U.S. Marine Corps in July 2015). At that time, the U.S. planned to buy 2,456 F-35s through 2044, which would represent the bulk of the crewed tactical airpower of the U.S. Air Force, Navy, and Marine Corps for several decades.

The Shooting Star began to enter service in late 1944 with 12 pre-production YP-80As. Four were sent to Europe for operational testing (demonstration, familiarization, and possible interception roles), two to England and two to the 1st Fighter Group at Lesina Airfield, Italy. Because of delays in delivery of production aircraft, the Shooting Star saw no actual combat during the conflict. The initial production order was for 344 P-80As after USAAF acceptance in February 1945. A total of 83 P-80s had been delivered by the end of July 1945 and 45 assigned to the 412th Fighter Group (later redesignated the 1st Fighter Group) at Muroc Army Air Field. Production continued after the war, although wartime plans for 5,000 were quickly reduced to 2,000 at a little under $100,000 each. A total of 1,714 single-seat F-80A, F-80B, F-80C, and RF-80s were manufactured by the end of production in 1950, of which 927 were F-80Cs (including 129 operational F-80As upgraded to F-80C-11-LO standards). However, the two-seat TF-80C, first flown on 22 March 1948, became the basis for the T-33 trainer, of which 6,557 were produced.

Shooting Stars first saw combat service in the Korean War, and were among the first aircraft to be involved in jet-versus-jet combat. Despite initial claims of success, the speed of the straight-wing F-80s was inferior to the 668 mph (1075 km/h) swept-wing transonic MiG-15. The MiGs incorporated German research showing that swept wings delayed the onset of compressibility problems, and enabled speeds closer to the speed of sound. F-80s were soon replaced in the air superiority role by the North American F-86 Sabre, which had been delayed to also incorporate swept wings into an improved straight-winged naval FJ-1 Fury.

This prompted Lockheed to improve the F-80 to keep the design competitive, and the result became the F-80E, which was almost a completely different aircraft, despite similar outlines. Lockheed attempted to change as little of the original airframe as possible while the F-80E incorporated two major technical innovation of its time. The most obvious change was the introduction of swept wings for higher speed. After the engineers obtained German swept-wing research data, Lockheed gave the F-80E a 25° sweep, with automatically locking leading edge slots, interconnected with the flaps for lateral stability during take-off and landing, and the wings’ profile was totally new, too. The limited sweep was a compromise, because a 35° sweep had originally been intended, but the plan to retain the F-80’s fuselage and wing attachment points would have resulted in massive center of gravity and mechanical problems. However, wind tunnel tests quickly revealed that even this compromise would not be enough to ensure stable flight esp. at low speed, and that the modified aircraft would lack directional stability. The swept-wing aircraft’s design had to be modified further.

A convenient solution came in the form of the F-80’s trainer version fuselage, the T-33, which had been lengthened by slightly more than 3 feet (1 m) for a second seat, instrumentation, and flight controls, under a longer canopy. Thanks to the extended front fuselage, the T-33’s wing attachment points could accept the new 25° wings without much further modifications, and balance was restored to acceptable limits. For the fighter aircraft, the T-33’s second seat was omitted and replaced with an additional fuel cell. The pressurized front cockpit was retained, together with the F-80’s bubble canopy and out fitted with an ejection seat.

The other innovation was the introduction of reheat for the engine. The earlier F-80 fighters were powered by centrifugal compressor turbojets, the F-80C had already incorporated water injection to boost the rather anemic powerplant during the start phase and in combat. The F-80E introduced a modified engine with a very simple afterburner chamber, designated J33-A-39. It was a further advanced variant of the J33-A-33 for the contemporary F-94 interceptor with water-alcohol injection and afterburner. For the F-80E with less gross weight, the water-alcohol injection system was omitted so save weight and simplify the system, and the afterburner was optimized for quicker response. Outwardly, the different engine required a modified, wider tail section, which also slightly extended the F-80’s tail.

The F-80E’s armament was changed, too. Experience from the Korean War had shown that the American aircrafts’ traditional 0.5” machine guns were reliable, but they lacked firepower, esp. against bigger targets like bombers, and even fighter aircraft like the MiG-15 had literally to be drenched with rounds to cause significant damage. On the other side, a few 23 mmm rounds or just a single hit with an explosive 37 mm shell from a MiG could take a bomber down. Therefore, the F-80’s six machine guns in the nose were replaced with four belt-fed 20mm M24 cannon. This was a license-built variant of the gas-operated Hispano-Suiza HS.404 with the addition of electrical cocking, allowing the gun to re-cock over a lightly struck round. It offered a rate of fire of 700-750 rounds/min and a muzzle velocity of 840 m/s (2,800 ft/s).In the F-80E each weapon was provided with 190 rounds.

Despite the swept wings Lockheed retained the wingtip tanks, similar to Lockheed’s recently developed XF-90 penetration fighter prototype. They had a different, more streamlined shape now, to reduce drag and minimize the risk of torsion problems with the outer wing sections and held 225 US gal (187 imp gal; 850 l) each. Even though the F-80E was conceived as a daytime fighter, hardpoints under the wings allowed the carriage of up to 2.000 lb of external ordnance, so that the aircraft could, like the straight-wing F-80s before, carry out attack missions. A reinforced pair of plumbed main hardpoints, just outside of the landing gear wells, allowed to carry another pair of drop tanks for extra range or single bombs of up to 1.000 lb (454 kg) caliber. A smaller, optional pair of pylons was intended to carry pods with nineteen “Mighty Mouse” 2.75 inches (70 mm) unguided folding-fin air-to-air rockets, and further hardpoints under the outer wings allowed eight 5” HVAR unguided air-to-ground rockets to be carried, too. Total external payload (including the wing tip tanks) was 4,800 lb (roughly 2,200 kg) of payload

The first XP-80E prototype flew in December 1953 – too late to take part in the Korean War, but Lockheed kept the aircraft’s development running as the benefits of swept wings were clearly visible. The USAF, however, did not show much interest in the new aircraft since the proven F-86 Sabre was readily available and focus more and more shifted to radar-equipped all-weather interceptors armed with guided missiles. However, military support programs for the newly founded NATO, esp. in Europe, stoked the demand for jet fighters, so that the F-80E was earmarked for export to friendly countries with air forces that had still to develop their capabilities after WWII. One of these was Germany; after World War II, German aviation was severely curtailed, and military aviation was completely forbidden after the Luftwaffe of the Third Reich had been disbanded by August 1946 by the Allied Control Commission. This changed in 1955 when West Germany joined NATO, as the Western Allies believed that Germany was needed to counter the increasing military threat posed by the Soviet Union and its Warsaw Pact allies. On 9 January 1956, a new German Air Force called Luftwaffe was founded as a branch of the new Bundeswehr (Federal Defence Force). The first volunteers of the Luftwaffe arrived at the Nörvenich Air Base in January 1956, and the same year, the Luftwaffe was provided with its first jet aircraft, the US-made Republic F-84 Thunderstreak from surplus stock, complemented by newly built Lockheed F-80E day fighters and T-33 trainers.

A total of 43 F-80Es were delivered to Germany in the course of 1956 and early 1957 via freight ships as disassembled kits, initially allocated to WaSLw 10 (Waffenschule der Luftwaffe = Weapon Training School of the Luftwaffe) at Nörvenich, one of three such units which focused on fighter training. The unit was quickly re-located to Northern Germany to Oldenburg, an airfield formerly under British/RAF governance, where the F-80Es were joined by Canada-built F-86 Sabre Mk. 5s. Flight operations began there in November 1957. Initially supported by flight instructors from the Royal Canadian Air Force from Zweibrücken, the WaSLw 10’s job was to train future pilots for jet aircraft on the respective operational types. F-80Es of this unit were in the following years furthermore frequently deployed to Decimomannu AB on Sardinia (Italy), as part of multi-national NATO training programs.

The F-80Es’ service at Oldenburg with WaSLw 10 did not last long, though. In 1963, basic flight and weapon system training was relocated to the USA, and the so-called Europeanization was shifted to the nearby Jever air base, i. e. the training in the more crowded European airspace and under notoriously less pleasant European weather conditions. The remaining German F-80E fleet was subsequently allocated to the Jagdgeschwader 73 “Steinhoff” at Pferdsfeld Air Base in Rhineland-Palatinate, where the machines were – like the Luftwaffe F-86s – upgraded to carry AIM-9 Sidewinder AAMs, a major improvement of their interceptor capabilities. But just one year later, on October 1, 1964, JG 73 was reorganized and renamed Fighter-Bomber Squadron 42, and the unit converted to the new Fiat G.91 attack aircraft. In parallel, the Luftwaffe settled on the F-86 (with more Sabre Mk. 6s from Canada and new F-86K all-weather interceptors from Italian license production) as standard fighter, with the plan to convert to the supersonic new Lockheed F-104 as standard NATO fighter as soon as the type would become available.

Beckett and Rice developed a basic platform meeting these requirements, then attempted to build a fiberglass prototype in a garage. The effort produced enthusiastic supporters and an informal pamphlet describing the concept. W. H. Beckett, who had retired from the Marine Corps, went to work at North American Aviation to sell the aircraft.

The aircraft's design supported effective operations from forward bases. The OV-10 had a central nacelle containing a crew of two in tandem and space for cargo, and twin booms containing twin turboprop engines. The visually distinctive feature of the aircraft is the combination of the twin booms, with the horizontal stabilizer that connected them at the fin tips. The OV-10 could perform short takeoffs and landings, including on aircraft carriers and large-deck amphibious assault ships without using catapults or arresting wires. Further, the OV-10 was designed to take off and land on unimproved sites. Repairs could be made with ordinary tools. No ground equipment was required to start the engines. And, if necessary, the engines would operate on high-octane automobile fuel with only a slight loss of power.

The aircraft had responsive handling and could fly for up to 5½ hours with external fuel tanks. The cockpit had extremely good visibility for both pilot and co-pilot, provided by a wrap-around "greenhouse" that was wider than the fuselage. North American Rockwell custom ejection seats were standard, with many successful ejections during service. With the second seat removed, the OV-10 could carry 3,200 pounds (1,500 kg) of cargo, five paratroopers, or two litter patients and an attendant. Empty weight was 6,969 pounds (3,161 kg). Normal operating fueled weight with two crew was 9,908 pounds (4,494 kg). Maximum takeoff weight was 14,446 pounds (6,553 kg).

The bottom of the fuselage bore sponsons or "stub wings" that improved flight performance by decreasing aerodynamic drag underneath the fuselage. Normally, four 7.62 mm (.308 in) M60C machine guns were carried on the sponsons, accessed through large forward-opening hatches. The sponsons also had four racks to carry bombs, pods, or fuel. The wings outboard of the engines contained two additional hardpoints, one per side. Racked armament in the Vietnam War was usually seven-shot 2.75 in (70 mm) rocket pods with white phosphorus marker rounds or high-explosive rockets, or 5" (127 mm) four-shot Zuni rocket pods. Bombs, ADSIDS air-delivered/para-dropped unattended seismic sensors, Mk-6 battlefield illumination flares, and other stores were also carried.

Operational experience showed some weaknesses in the OV-10's design. It was significantly underpowered, which contributed to crashes in Vietnam in sloping terrain because the pilots could not climb fast enough. While specifications stated that the aircraft could reach 26,000 feet (7,900 m), in Vietnam the aircraft could reach only 18,000 feet (5,500 m). Also, no OV-10 pilot survived ditching the aircraft.

The OV-10 served in the U.S. Air Force, U.S. Marine Corps, and U.S. Navy, as well as in the service of a number of other countries. In U.S. military service, the Bronco was operated until the early Nineties, and obsoleted USAF OV-10s were passed on to the Bureau of Alcohol, Tobacco, and Firearms for anti-drug operations. A number of OV-10As furthermore ended up in the hands of the California Department of Forestry (CDF) and were used for spotting fires and directing fire bombers onto hot spots.

This was not the end of the OV-10 in American military service, though: In 2012, the type gained new attention because of its unique qualities. A $20 million budget was allocated to activate an experimental USAF unit of two airworthy OV-10Gs, acquired from NASA and the State Department. These machines were retrofitted with military equipment and were, starting in May 2015, deployed overseas to support Operation “Inherent Resolve”, flying more than 120 combat sorties over 82 days over Iraq and Syria. Their concrete missions remained unclear, and it is speculated they provided close air support for Special Forces missions, esp. in confined urban environments where the Broncos’ loitering time and high agility at low speed and altitude made them highly effective and less vulnerable than helicopters.

Furthermore, these Broncos reputedly performed strikes with the experimental AGR-20A “Advanced Precision Kill Weapons System (APKWS)”, a Hydra 70-millimeter rocket with a laser-seeking head as guidance - developed for precision strikes against small urban targets with little collateral damage. The experiment ended satisfactorily, but the machines were retired again, and the small unit was dissolved.

However, the machines had shown their worth in asymmetric warfare, and the U.S. Air Force decided to invest in reactivating the OV-10 on a regular basis, despite the overhead cost of operating an additional aircraft type in relatively small numbers – but development and production of a similar new type would have caused much higher costs, with an uncertain time until an operational aircraft would be ready for service. Re-activating a proven design and updating an existing airframe appeared more efficient.

The result became the MV-10H, suitably christened “Super Bronco” but also known as “Black Pony”, after the program's internal name. This aircraft was derived from the official OV-10X proposal by Boeing from 2009 for the USAF's Light Attack/Armed Reconnaissance requirement. Initially, Boeing proposed to re-start OV-10 manufacture, but this was deemed uneconomical, due to the expected small production number of new serial aircraft, so the “Black Pony” program became a modernization project. In consequence, all airframes for the "new" MV-10Hs were recovered OV-10s of various types from the "boneyard" at Davis-Monthan Air Force Base in Arizona.

While the revamped aircraft would maintain much of its 1960s-vintage rugged external design, modernizations included a completely new, armored central fuselage with a highly modified cockpit section, ejection seats and a computerized glass cockpit. The “Black Pony” OV-10 had full dual controls, so that either crewmen could steer the aircraft while the other operated sensors and/or weapons. This feature would also improve survivability in case of incapacitation of a crew member as the result from a hit.

The cockpit armor protected the crew and many vital systems from 23mm shells and shrapnel (e. g. from MANPADS). The crew still sat in tandem under a common, generously glazed canopy with flat, bulletproof panels for reduced sun reflections, with the pilot in the front seat and an observer/WSO behind. The Bronco’s original cargo capacity and the rear door were retained, even though the extra armor and defensive measures like chaff/flare dispensers as well as an additional fuel cell in the central fuselage limited the capacity. However, it was still possible to carry and deploy personnel, e. g. small special ops teams of up to four when the aircraft flew in clean configuration.

Additional updates for the MV-10H included structural reinforcements for a higher AUW and higher g load maneuvers, similar to OV-10D+ standards. The landing gear was also reinforced, and the aircraft kept its ability to operate from short, improvised airstrips. A fixed refueling probe was added to improve range and loiter time.

Intelligence sensors and smart weapon capabilities included a FLIR sensor and a laser range finder/target designator, both mounted in a small turret on the aircraft’s nose. The MV-10H was also outfitted with a data link and the ability to carry an integrated targeting pod such as the Northrop Grumman LITENING or the Lockheed Martin Sniper Advanced Targeting Pod (ATP). Also included was the Remotely Operated Video Enhanced Receiver (ROVER) to provide live sensor data and video recordings to personnel on the ground.

To improve overall performance and to better cope with the higher empty weight of the modified aircraft as well as with operations under hot-and-high conditions, the engines were beefed up. The new General Electric CT7-9D turboprop engines improved the Bronco's performance considerably: top speed increased by 100 mph (160 km/h), the climb rate was tripled (a weak point of early OV-10s despite the type’s good STOL capability) and both take-off as well as landing run were almost halved. The new engines called for longer nacelles, and their circular diameter markedly differed from the former Garrett T76-G-420/421 turboprop engines. To better exploit the additional power and reduce the aircraft’s audio signature, reversible contraprops, each with eight fiberglass blades, were fitted. These allowed a reduced number of revolutions per minute, resulting in less noise from the blades and their tips, while the engine responsiveness was greatly improved. The CT7-9Ds’ exhausts were fitted with muzzlers/air mixers to further reduce the aircraft's noise and heat signature.

Another novel and striking feature was the addition of so-called “tip sails” to the wings: each wingtip was elongated with a small, cigar-shaped fairing, each carrying three staggered, small “feather blade” winglets. Reputedly, this installation contributed ~10% to the higher climb rate and improved lift/drag ratio by ~6%, improving range and loiter time, too.

Drawing from the Iraq experience as well as from the USMC’s NOGS test program with a converted OV-10D as a night/all-weather gunship/reconnaissance platform, the MV-10H received a heavier gun armament: the original four light machine guns that were only good for strafing unarmored targets were deleted and their space in the sponsons replaced by avionics. Instead, the aircraft was outfitted with a lightweight M197 three-barrel 20mm gatling gun in a chin turret. This could be fixed in a forward position at high speed or when carrying forward-firing ordnance under the stub wings, or it could be deployed to cover a wide field of fire under the aircraft when it was flying slower, being either slaved to the FLIR or to a helmet sighting auto targeting system.

The original seven hardpoints were retained (1x ventral, 2x under each sponson, and another pair under the outer wings), but the total ordnance load was slightly increased and an additional pair of launch rails for AIM-9 Sidewinders or other light AAMs under the wing tips were added – not only as a defensive measure, but also with an anti-helicopter role in mind; four more Sidewinders could be carried on twin launchers under the outer wings against aerial targets. Other guided weapons cleared for the MV-10H were the light laser-guided AGR-20A and AGM-119 Hellfire missiles, the Advanced Precision Kill Weapon System upgrade to the light Hydra 70 rockets, the new Laser Guided Zuni Rocket which had been cleared for service in 2010, TV-/IR-/laser-guided AGM-65 Maverick AGMs and AGM-122 Sidearm anti-radar missiles, plus a wide range of gun and missile pods, iron and cluster bombs, as well as ECM and flare/chaff pods, which were not only carried defensively, but also in order to disrupt enemy ground communication.

In this configuration, a contract for the conversion of twelve mothballed American Broncos to the new MV-10H standard was signed with Boeing in 2016, and the first MV-10H was handed over to the USAF in early 2018, with further deliveries lasting into early 2020. All machines were allocated to the newly founded 919th Special Operations Support Squadron at Duke Field (Florida). This unit was part of the 919th Special Operations Wing, an Air Reserve Component (ARC) of the United States Air Force. It was assigned to the Tenth Air Force of Air Force Reserve Command and an associate unit of the 1st Special Operations Wing, Air Force Special Operations Command (AFSOC). If mobilized the wing was gained by AFSOC (Air Force Special Operations Command) to support Special Tactics, the U.S. Air Force's special operations ground force. Similar in ability and employment to Marine Special Operations Command (MARSOC), U.S. Army Special Forces and U.S. Navy SEALs, Air Force Special Tactics personnel were typically the first to enter combat and often found themselves deep behind enemy lines in demanding, austere conditions, usually with little or no support.

M7 Aerosystems started on a blank sheet, even though Northrop-Grumman’s A-12 influence was clearly visible, and to a certain degree the aircraft shared the basic layout with the F-117A. The A-14 was tailored from the start to the ground attack role, and therefore a subsonic design. Measures to reduce radar cross-section included airframe shaping such as alignment of edges, fixed-geometry serpentine inlets that prevented line-of-sight of the engine faces from any exterior view, use of radar-absorbent material (RAM), and attention to detail such as hinges and maintenance covers that could provide a radar return. The A-14 was furthermore designed to have decreased radio emissions, infrared signature and acoustic signature as well as reduced visibility to the naked eye.

The resulting airframe was surprisingly large for an attack aircraft – in fact, it rather reminded of a tactical bomber in the F-111/Su-24 class than an alternative to the A-10. The A-14 consisted of a rhomboid-shaped BWB (blended-wing-and-body) with extended wing tips and only a moderate (35°) wing sweep, cambered leading edges, a jagged trailing edge and a protruding cockpit section which extended forward of the main body.

The majority of the A-14’s structure and surface were made out of a carbon-graphite composite material that is stronger than steel, lighter than aluminum, and absorbs a significant amount of radar energy. The central fuselage bulge ended in a short tail stinger with a pair of swept, canted fins as a butterfly tail, which also shrouded the engine’s hot efflux. The fins could have been omitted, thanks to the aerodynamically unstable aircraft’s fly-by-wire steering system, and they effectively increased the A-14’s radar signature as well as its visual profile, but the gain in safety in case of FBW failure or physical damage was regarded as a worthwhile trade-off. Due to its distinctive shape and profile, the A-14 quickly received the unofficial nickname “Squatina”, after the angel shark family.

The spacious and armored cockpit offered room for the crew of two (pilot and WSO or observer for FAC duties), seated side-by-side under a generous glazing, with a very good field of view forward and to the sides. The fuselage structure was constructed around a powerful cannon, the five-barrel GAU-12/U 25 mm ‘Equalizer’ gun, which was, compared with the A-10’s large GAU-8/A, overall much lighter and more compact, but with only little less firepower. It fired a new NATO series of 25 mm ammunition at up to 4.200 RPM. The gun itself was located under the cockpit tub, slightly set off to port side, and the front wheel well was offset to starboard to compensate, similar in arrangement to the A-10 or Su-25. The gun’s ammunition drum and a closed feeding belt system were located behind the cockpit in the aircraft’s center of gravity. An in-flight refueling receptor (for the USAF’s boom system) was located in the aircraft’s spine behind the cockpit, normally hidden under a flush cover.

Due to the gun installation in the fuselage, however, no single large weapon bay to minimize radar cross section and drag through external ordnance was incorporated, since this feature would have increased airframe size and overall weight. Instead, the A-14 received four, fully enclosed compartments between the wide main landing gear wells and legs. The bays could hold single iron bombs of up to 2.000 lb caliber each, up to four 500 lb bombs or CBUs, single laser-guided GBU-14 glide bombs, AGM-154 JSOW or GBU-31/38 JDAM glide bombs, AGM-65 Maverick guided missiles or B61 Mod 11 tactical nuclear weapons, as well as the B61 Mod 12 standoff variant, under development at that time). Retractable launch racks for defensive AIM-9 Sidewinder air-to-air missiles were available, too, and additional external pylons could be added, e.g. for oversize ordnance like AGM-158C Long Range Anti-Ship Missile (LRASM) or AGM-158 Joint Air to Surface Standoff Missile (JASSM), or drop tanks for ferry flights. The total in- and external ordnance load was 15,000 lb (6,800 kg).

The A-14 was designed with superior maneuverability at low speeds and altitude in mind and therefore featured a large wing area, with high wing aspect ratio on the outer wing sections, and large ailerons areas. The ailerons were placed at the far ends of the wings for greater rolling moment and were split, making them decelerons, so that they could also be used as air brakes in flight and upon landing.

This wing configuration promoted short takeoffs and landings, permitting operations from primitive forward airfields near front lines. The sturdy landing gear with low-pressure tires supported these tactics, and a retractable arrester hook, hidden by a flush cover under the tail sting, made it possible to use mobile arrested-recovery systems.

The leading edge of the wing had a honeycomb structure panel construction, providing strength with minimal weight; similar panels covered the flap shrouds, elevators, rudders and sections of the fins. The skin panels were integral with the stringers and were fabricated using computer-controlled machining, reducing production time and cost, and this construction made the panels more resistant to damage. The skin was not load-bearing, so damaged skin sections could be easily replaced in the field, with makeshift materials if necessary.

Power came from a pair of F412-GE-114 non-afterburning turbofans, engines that were originally developed for the A-12, but de-navalized and lightened for the A-14. These new engines had an output of 12,000 lbf (53 kN) each and were buried in blended fairings above the wing roots, with jagged intakes and hidden ducts. Flat exhausts on the wings’ upper surface minimized both radar and IR signatures.

Thanks to the generous internal fuel capacity in the wings and the fuselage, the A-14 was able to loiter and operate under 1,000 ft (300 m) ceilings for extended periods. It typically flew at a relatively low speed of 300 knots (350 mph; 560 km/h), which made it a better platform for the ground-attack role than fast fighter-bombers, which often have difficulty targeting small, slow-moving targets or executing more than just a single attack run on a selected target.

A mock-up was presented and tested in the wind tunnel and for radar cross-section in late 2008. The A-14’s exact radar cross-section (RCS) remained classified, but in 2009 M7 Aerosystems released information indicating it had an RCS (from certain angles) of −40 dBsm, equivalent to the radar reflection of a "steel marble". With this positive outcome and the effective design, M7 Aerosystems eventually received federal funding for the production of prototypes for an official DT&E (Demonstration Testing and Evaluation) program.

Three prototypes/pre-production aircraft were built in the course of 2010 and 2011, and the first YA-14 made its maiden flight on 10 May 2011. The DT&E started immediately, and the machines (a total of three flying prototypes were completed, plus two additional airframes for static tests) were gradually outfitted with mission avionics and other equipment. This included GPS positioning, an inertial navigation system, passive sensors to detect radar usage, a small, gyroscopically stabilized turret, mounted under the nose of the aircraft, containing a FLIR boresighted with a laser spot-tracker/designator, and an experimental 3-D laser scanning LIDAR in the nose as a radiation-less alternative to a navigation and tracking radar.

Soon after the DT&E program gained momentum in 2012, the situation changed for M7 Aerosystems when the US Air Force considered the F-35B STOVL variant as its favored replacement CAS aircraft, but concluded that the aircraft could not generate a sufficient number of sorties. However, the F-35 was established as the A-14’s primary rival and remained on the USAF’s agenda. For instance, at that time the USAF proposed disbanding five A-10 squadrons in its budget request to cut its fleet of 348 A-10s by 102 to lessen cuts to multi-mission aircraft in service that could replace the specialized attack aircraft.

In August 2013, Congress and the Air Force examined various proposals for an A-10 replacement, including the A-14, F-35 and the MQ-9 Reaper unmanned aerial vehicle, and, despite the A-14’s better qualities in the ground attack role, the F-35 came out as the overall winner, since it was the USAF’s favorite. Despite its complexity, the F-35 was – intended as a multi-role tri-service aircraft and also with the perspective of bigger international sales than the more specialized A-14 – regarded as the more versatile and, in the long run, more cost-efficient procurement option. This sealed the A-14’s fate and the F-35A entered service with U.S. Air Force F-35A in August 2016 (after the F-35B was introduced to the U.S. Marine Corps in July 2015). At that time, the U.S. planned to buy 2,456 F-35s through 2044, which would represent the bulk of the crewed tactical airpower of the U.S. Air Force, Navy, and Marine Corps for several decades.

The original TIEs were designed to attack in large numbers, overwhelming the enemy craft. The Imperials used so many that they came to be considered symbols of the Empire and its might. They were also very cheap to produce, reflecting the Imperial philosophy of quantity over quality.

However, a disadvantage of the fighter was its lack of deflector shields. In combat, pilots had to rely on the TIE/LN's maneuverability to avoid damage. The cockpit did incorporate crash webbing, a repulsorlift antigravity field, and a high-g shock seat to help protect the pilot, however these did next to nothing to help protect against enemy blaster fire.

Due to the lack of life-support systems, each TIE pilot had a fully sealed flight suit superior to their Rebel counterparts. The absence of a hyperdrive also rendered the light fighter totally dependent on carrier ships when deployed in enemy systems. TIE/LNs also lacked landing gear, another mass-reducing measure. While the ships were structurally capable of "sitting" on their wings, they were not designed to land or disembark their pilots without special support. On Imperial ships, TIEs were launched from racks in the hangar bays.

The high success rate of more advanced Rebel starfighters against standard Imperial TIE Fighters resulted in a mounting cost of replacing destroyed fighters and their pilots. That, combined with the realization that the inclusion of a hyperdrive would allow the fleet to be more flexible, caused the Imperial Navy to rethink its doctrine of using swarms of cheap craft instead of fewer high-quality ones, leading to the introduction of the TIE Advanced x1 and its successor, the TIE Avenger. The following TIE/D Defender as well as the heavy TIE Escort Fighter (or TIE/E) were touted as the next "logical advance" of the TIE Series—representing a shift in starfighter design from previous, expendable TIE models towards fast, well armed and protected designs, capable of hyperspace travel and long-term crew teams which gained experience and capabilities over time.

The TIE/E Escort, was a high-performance TIE Series starfighter developed for the Imperial Navy by Sienar Fleet Systems and it was introduced into service shortly before the Battle of Endor. It was a much heavier counterpart to the agile and TIE/D fighter, and more of an attack ship or even a light bomber than a true dogfighter. Its role were independent long range operations, and in order to reduce the work load and boost morale a crew of two was introduced (a pilot and a dedicated weapon systems officer/WSO). The primary duty profile included attack and escort task, but also reconnoiter missions. The TIE/E shared the general layout with the contemporary TIE/D fighter, but the cockpit section as well as the central power unit were much bigger, and the ship was considerably heavier.

The crew enjoyed – compared with previous TIE fighter designs – a spacious and now fully pressurized cockpit, so that no pressurized suits had to be worn anymore. The crew members sat in tandem under a large, clear canopy. The pilot in front had a very good field of view, while the WSO sat behind him, in a higher, staggered position with only a limited field of view. Both work stations had separate entries, though, and places could not be switched in flight: the pilot mounted the cockpit through a hatch on port side, while the WSO entered the rear compartment through a roof hatch.

In a departure from the design of previous TIE models, instead of two parallel wings to either side of the pilot module, the TIE Escort had three quadanium steel solar array wings mounted symmetrically around an aft section, which contained an I-s4d solar ionization reactor to store and convert solar energy collected from the wing panels. The inclusion of a third wing provided additional solar power to increase the ship's range and the ship's energy management system was designed to allow weapons and shields to be charged with minimum loss of power to the propulsion system.

Although it was based on the standard twin ion engine design, the TIE/E’s propulsion system was upgraded to the entirely new, powerful P-sz9.8 triple ion engine. This allowed the TIE/E a maximum acceleration of 4,220 G or 21 MGLT/s and a top speed of 144 MGLT, or 1,680 km/h in an atmosphere — almost 40 percent faster than a former standard TIE Fighter. With tractor beam recharge power (see below) redirected to the engines, the top speed could be increased to 180 MGLT in a dash.

In addition to the main thrusters located in the aft section, the TIE Escort's triple wing design allowed for three arrays of maneuvering jets and it featured an advanced F-s5x flight avionics system to process the pilot's instructions. Production models received a class 2, ND9 hyperdrive motivator, modified from the version developed for the TIE Avenger. The TIE/E also carried a Sienar N-s6 Navcon navigation computer with a ten-jump memory.

Special equipment included a small tractor beam projector, originally developed for the TIE Avenger, which could be easily fitted to the voluminous TIE Escort. Models produced by Ysanne Isard's production facility regularly carried such tractor beams and the technology found other uses, such as towing other damaged starfighters until they could achieve the required velocity to enter hyperspace. The tractor beam had limited range and could only be used for a short time before stopping to recharge, but it added new tactics, too. For instance, the beam allowed the TIE/E crews to temporarily inhibit the mobility of enemy fighters, making it easier to target them with the ship's other weapon systems, or prevent enemies from clear shots.

The TIE Escort’s weapons systems were primarily designed to engage bigger ships and armored or shielded targets, like armed freighters frequently used by the Alliance. Thanks to its complex weapon and sensor suite, it could also engage multiple enemy fighters at once. The sensors also allowed an effective attack of ground targets, so that atmospheric bombing was a potential mission for the TIE/E, too.

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The TIE Escort Fighter carried a formidable array of weaponry in two modular weapon bays that were mounted alongside the lower cabin. In standard configuration, the TIE/E had two L-s9.3 laser cannons and two NK-3 ion cannons. The laser and ion cannons could be set to fire separately or, if concentrated power was required, to fire-linked in either pairs or as a quartet.

The ship also featured two M-g-2 general-purpose warhead launchers, each of which could be equipped with a standard load of three proton torpedoes or four concussion missiles. Depending on the mission profile, the ship could be fitted with alternative warheads such as proton rockets, proton bombs, or magnetic pulse warheads.

Additionally, external stores could be carried under the fuselage, which included a conformal sensor pallet for reconnaissance missions or a cargo bay with a capacity for 500 kg (1.100 lb).

The ship's defenses were provided by a pair of forward and rear projecting Novaldex deflector shield generators—another advantage over former standard TIE models. The shields were designed to recharge more rapidly than in previous Imperial fighters and were nearly as powerful as those found on capital ships, so that the TIE/E could engage other ships head-on with a very high survivability. The fighters were not equipped with particle shields, though, relying on the reinforced titanium hull to absorb impacts from matter. Its hull and wings were among the strongest of any TIE series Starfighter yet.

The advanced starfighter attracted the attention of several other factions, and the Empire struggled to prevent the spread of the technology. The ship's high cost, together with political factors, kept it from achieving widespread use in the Empire, though, and units were assigned only to the most elite crews.

Two Klimov M-107 water-cooled Vee-12 engines, each with a. take-off power of 1 ,600 hp (1,193 kW) and a maximum design power of 1,500 hp (1,119 kW) at 5,500 m (18,045 ft), were mounted in the center fuse­lage in a staggered-tandem arrangement: the front engine was offset to starboard and of the rear one to port. Thus, the total power was increased but the drag was the same as for a single-engined aircraft, which was expected to increase fight speed consider­ably. Consequently, the project was internally designated 'I-2M107', literally "Article powered by two M107 engines".

Furthermore, the left cylinder bank of the front engine and the right cylinder bank of the rear engine were disposed vertically, so that each engine had one set of exhaust stubs on top of the fuselage and one on the fuselage side. Both engines drove a single three ­blade tractor propeller of 4.0 m (13 tt 2 in) diameter via parallel extension shafts and a common reduction gearbox. Both water radiators were located side by side in a chin housing, while the oil coolers were buried in the wings. The total fuel capacity of the four tanks arranged in the center fuselage was 1,113 litres (244.86 Imp. gal).

Because of the power plant arrangement and the large ground angle (necessary to give adequate ground clearance for the large propeller) the cockpit was offset to port and placed ahead of the wing leading edge to provide better forward visibility on take-off and landing. The cockpit was protected by a bulletproof windscreen, a front armor plate and an armored backrest; the armor weight totaled 70kg (154Ib).

The main landing gear units with 800 x 280 mm (31.5x11 in) wheels retracted inwards into the wing roots and the 400 x 150 mm (15.7 x 5.9 in) tail wheel retracted aft. The fighter's armament consisted of two wing-mounted 12.7-mm Berezin UBS machine-guns firing outside the propeller disc and a single 20-mm ShVAK cannon fir­ing through the propeller hub*.

A full-scale mock-up was inspected in December 1943, and with German long range bombers threatening the Western front line as well as the lack of a fast and powerful fighters to intercept them (the earlier MiG-5 had turned out to be a disappointment, and Mikoyan's I-211/221 family if high altitude fighters also suffered from serious technical problems at that time), OKB Suchoj received an immediate go-ahead for further development of the SuCh-1, how the I-2M107 was now officially called, since Vladimir A. Chizhevskiy took lead of the project.

In the course of 1944 three prototypes went through a fast development program. While the aircraft itself was easy to handle, overheating problems and trouble with the gearbox for the two engines could only partly be rectified - esp. the power transmission should remain the SuCh-1s Achilles Heel.

Anyway, the Su-5 was ready for service introduction towards late 1944, and the powerful type was exclusively to be used as an interceptor. Several improvements had been made, compared to the prototypes: now two slightly more powerful Klimov VK-107A engines were used, which were better suited for high altitude operations, and the chin-mounted water cooler was considerably enlarged. The oil coolers had been re-designed and they were now placed under the wing roots.

The wing span had been extended by 6' and a bigger (now 4.3m diameter!), four-bladed propeller was added in order to improve performance at high altitude. No pressurized cabin was installed, but the cockpit received an extended glazing for better all-round field of vision.

Armament had also been augmented: now a Nudelman N-23 23mm cannon was firing through the propeller hub, and the number of UBS machine-guns in the wings was increased to four.

As initial duty experience was gathered, it became quickly clear that the firepower had to be augmented, so that the propeller-hub-mounted 23mm cannon was quickly replaced by a Nudelman-Richter NR-37 37mm cannon, and the four wing-mounted UBS machine guns were replaced by two 20-mm ShVAK cannons or even two Nudelman N-23 23mm cannons - the latter became the production standard from March 1945 on, even though the type's designation did not change.

Experience also showed that the overheating problem had been cured, but the complicated gear box tended to malfunction, esp. when full power was called for in aerial combat: high G forces took their toll and damaged the bearings, even warping the extension shafts and structural parts, so that some SuCh-1 were literally torn apart in mid-air.

The high torque powers of the large propeller also took their toll on handling: starting and landing was described as "hazardous", esp. when the fuel tanks were empty or in cross winds.

Consequently, SuCh-1 pilots were warned to engage into any dogfight or enter close combat with single-engined enemy fighters, and just focus on large enemy aircraft.

On the other side, the SuCh-1's powerful cannon armament made it a deadly foe: a single hit with the NR-37 cannon could down an aircraft, and its top speed of roundabout 700 km/h (435 mph) was more than enough for the Luftwaffe's heavy bomber types like the He 177.

Several engine and armament experiments were undertaken. For instance, at least one SuCh-1 was outfitted with a Nudelman-Sooranov NS-45 45mm cannon firing through the propeller hub, even a 57mm cannon was envisaged. Furthermore, one airframe was prepared to carry two Charomskiy M-30V 12 cylinder diesel engines, in order to produce a heavy long-range escort fighter (internally called I-2M30V).

In order to minimize the torque problems a contraprop arrangement with two three-bladed propellers and a diameter of only 3.6m was under development.

Beckett and Rice developed a basic platform meeting these requirements, then attempted to build a fiberglass prototype in a garage. The effort produced enthusiastic supporters and an informal pamphlet describing the concept. W. H. Beckett, who had retired from the Marine Corps, went to work at North American Aviation to sell the aircraft.

The aircraft's design supported effective operations from forward bases. The OV-10 had a central nacelle containing a crew of two in tandem and space for cargo, and twin booms containing twin turboprop engines. The visually distinctive feature of the aircraft is the combination of the twin booms, with the horizontal stabilizer that connected them at the fin tips. The OV-10 could perform short takeoffs and landings, including on aircraft carriers and large-deck amphibious assault ships without using catapults or arresting wires. Further, the OV-10 was designed to take off and land on unimproved sites. Repairs could be made with ordinary tools. No ground equipment was required to start the engines. And, if necessary, the engines would operate on high-octane automobile fuel with only a slight loss of power.

The aircraft had responsive handling and could fly for up to 5½ hours with external fuel tanks. The cockpit had extremely good visibility for both pilot and co-pilot, provided by a wrap-around "greenhouse" that was wider than the fuselage. North American Rockwell custom ejection seats were standard, with many successful ejections during service. With the second seat removed, the OV-10 could carry 3,200 pounds (1,500 kg) of cargo, five paratroopers, or two litter patients and an attendant. Empty weight was 6,969 pounds (3,161 kg). Normal operating fueled weight with two crew was 9,908 pounds (4,494 kg). Maximum takeoff weight was 14,446 pounds (6,553 kg).

The bottom of the fuselage bore sponsons or "stub wings" that improved flight performance by decreasing aerodynamic drag underneath the fuselage. Normally, four 7.62 mm (.308 in) M60C machine guns were carried on the sponsons, accessed through large forward-opening hatches. The sponsons also had four racks to carry bombs, pods, or fuel. The wings outboard of the engines contained two additional hardpoints, one per side. Racked armament in the Vietnam War was usually seven-shot 2.75 in (70 mm) rocket pods with white phosphorus marker rounds or high-explosive rockets, or 5" (127 mm) four-shot Zuni rocket pods. Bombs, ADSIDS air-delivered/para-dropped unattended seismic sensors, Mk-6 battlefield illumination flares, and other stores were also carried.

Operational experience showed some weaknesses in the OV-10's design. It was significantly underpowered, which contributed to crashes in Vietnam in sloping terrain because the pilots could not climb fast enough. While specifications stated that the aircraft could reach 26,000 feet (7,900 m), in Vietnam the aircraft could reach only 18,000 feet (5,500 m). Also, no OV-10 pilot survived ditching the aircraft.

The OV-10 served in the U.S. Air Force, U.S. Marine Corps, and U.S. Navy, as well as in the service of a number of other countries. In U.S. military service, the Bronco was operated until the early Nineties, and obsoleted USAF OV-10s were passed on to the Bureau of Alcohol, Tobacco, and Firearms for anti-drug operations. A number of OV-10As furthermore ended up in the hands of the California Department of Forestry (CDF) and were used for spotting fires and directing fire bombers onto hot spots.

This was not the end of the OV-10 in American military service, though: In 2012, the type gained new attention because of its unique qualities. A $20 million budget was allocated to activate an experimental USAF unit of two airworthy OV-10Gs, acquired from NASA and the State Department. These machines were retrofitted with military equipment and were, starting in May 2015, deployed overseas to support Operation “Inherent Resolve”, flying more than 120 combat sorties over 82 days over Iraq and Syria. Their concrete missions remained unclear, and it is speculated they provided close air support for Special Forces missions, esp. in confined urban environments where the Broncos’ loitering time and high agility at low speed and altitude made them highly effective and less vulnerable than helicopters.

Furthermore, these Broncos reputedly performed strikes with the experimental AGR-20A “Advanced Precision Kill Weapons System (APKWS)”, a Hydra 70-millimeter rocket with a laser-seeking head as guidance - developed for precision strikes against small urban targets with little collateral damage. The experiment ended satisfactorily, but the machines were retired again, and the small unit was dissolved.

However, the machines had shown their worth in asymmetric warfare, and the U.S. Air Force decided to invest in reactivating the OV-10 on a regular basis, despite the overhead cost of operating an additional aircraft type in relatively small numbers – but development and production of a similar new type would have caused much higher costs, with an uncertain time until an operational aircraft would be ready for service. Re-activating a proven design and updating an existing airframe appeared more efficient.

The result became the MV-10H, suitably christened “Super Bronco” but also known as “Black Pony”, after the program's internal name. This aircraft was derived from the official OV-10X proposal by Boeing from 2009 for the USAF's Light Attack/Armed Reconnaissance requirement. Initially, Boeing proposed to re-start OV-10 manufacture, but this was deemed uneconomical, due to the expected small production number of new serial aircraft, so the “Black Pony” program became a modernization project. In consequence, all airframes for the "new" MV-10Hs were recovered OV-10s of various types from the "boneyard" at Davis-Monthan Air Force Base in Arizona.

While the revamped aircraft would maintain much of its 1960s-vintage rugged external design, modernizations included a completely new, armored central fuselage with a highly modified cockpit section, ejection seats and a computerized glass cockpit. The “Black Pony” OV-10 had full dual controls, so that either crewmen could steer the aircraft while the other operated sensors and/or weapons. This feature would also improve survivability in case of incapacitation of a crew member as the result from a hit.

The cockpit armor protected the crew and many vital systems from 23mm shells and shrapnel (e. g. from MANPADS). The crew still sat in tandem under a common, generously glazed canopy with flat, bulletproof panels for reduced sun reflections, with the pilot in the front seat and an observer/WSO behind. The Bronco’s original cargo capacity and the rear door were retained, even though the extra armor and defensive measures like chaff/flare dispensers as well as an additional fuel cell in the central fuselage limited the capacity. However, it was still possible to carry and deploy personnel, e. g. small special ops teams of up to four when the aircraft flew in clean configuration.

Additional updates for the MV-10H included structural reinforcements for a higher AUW and higher g load maneuvers, similar to OV-10D+ standards. The landing gear was also reinforced, and the aircraft kept its ability to operate from short, improvised airstrips. A fixed refueling probe was added to improve range and loiter time.

Intelligence sensors and smart weapon capabilities included a FLIR sensor and a laser range finder/target designator, both mounted in a small turret on the aircraft’s nose. The MV-10H was also outfitted with a data link and the ability to carry an integrated targeting pod such as the Northrop Grumman LITENING or the Lockheed Martin Sniper Advanced Targeting Pod (ATP). Also included was the Remotely Operated Video Enhanced Receiver (ROVER) to provide live sensor data and video recordings to personnel on the ground.

To improve overall performance and to better cope with the higher empty weight of the modified aircraft as well as with operations under hot-and-high conditions, the engines were beefed up. The new General Electric CT7-9D turboprop engines improved the Bronco's performance considerably: top speed increased by 100 mph (160 km/h), the climb rate was tripled (a weak point of early OV-10s despite the type’s good STOL capability) and both take-off as well as landing run were almost halved. The new engines called for longer nacelles, and their circular diameter markedly differed from the former Garrett T76-G-420/421 turboprop engines. To better exploit the additional power and reduce the aircraft’s audio signature, reversible contraprops, each with eight fiberglass blades, were fitted. These allowed a reduced number of revolutions per minute, resulting in less noise from the blades and their tips, while the engine responsiveness was greatly improved. The CT7-9Ds’ exhausts were fitted with muzzlers/air mixers to further reduce the aircraft's noise and heat signature.

Another novel and striking feature was the addition of so-called “tip sails” to the wings: each wingtip was elongated with a small, cigar-shaped fairing, each carrying three staggered, small “feather blade” winglets. Reputedly, this installation contributed ~10% to the higher climb rate and improved lift/drag ratio by ~6%, improving range and loiter time, too.

Drawing from the Iraq experience as well as from the USMC’s NOGS test program with a converted OV-10D as a night/all-weather gunship/reconnaissance platform, the MV-10H received a heavier gun armament: the original four light machine guns that were only good for strafing unarmored targets were deleted and their space in the sponsons replaced by avionics. Instead, the aircraft was outfitted with a lightweight M197 three-barrel 20mm gatling gun in a chin turret. This could be fixed in a forward position at high speed or when carrying forward-firing ordnance under the stub wings, or it could be deployed to cover a wide field of fire under the aircraft when it was flying slower, being either slaved to the FLIR or to a helmet sighting auto targeting system.

The original seven hardpoints were retained (1x ventral, 2x under each sponson, and another pair under the outer wings), but the total ordnance load was slightly increased and an additional pair of launch rails for AIM-9 Sidewinders or other light AAMs under the wing tips were added – not only as a defensive measure, but also with an anti-helicopter role in mind; four more Sidewinders could be carried on twin launchers under the outer wings against aerial targets. Other guided weapons cleared for the MV-10H were the light laser-guided AGR-20A and AGM-119 Hellfire missiles, the Advanced Precision Kill Weapon System upgrade to the light Hydra 70 rockets, the new Laser Guided Zuni Rocket which had been cleared for service in 2010, TV-/IR-/laser-guided AGM-65 Maverick AGMs and AGM-122 Sidearm anti-radar missiles, plus a wide range of gun and missile pods, iron and cluster bombs, as well as ECM and flare/chaff pods, which were not only carried defensively, but also in order to disrupt enemy ground communication.

In this configuration, a contract for the conversion of twelve mothballed American Broncos to the new MV-10H standard was signed with Boeing in 2016, and the first MV-10H was handed over to the USAF in early 2018, with further deliveries lasting into early 2020. All machines were allocated to the newly founded 919th Special Operations Support Squadron at Duke Field (Florida). This unit was part of the 919th Special Operations Wing, an Air Reserve Component (ARC) of the United States Air Force. It was assigned to the Tenth Air Force of Air Force Reserve Command and an associate unit of the 1st Special Operations Wing, Air Force Special Operations Command (AFSOC). If mobilized the wing was gained by AFSOC (Air Force Special Operations Command) to support Special Tactics, the U.S. Air Force's special operations ground force. Similar in ability and employment to Marine Special Operations Command (MARSOC), U.S. Army Special Forces and U.S. Navy SEALs, Air Force Special Tactics personnel were typically the first to enter combat and often found themselves deep behind enemy lines in demanding, austere conditions, usually with little or no support.

The specification for the aircraft followed the cancellation of the Air Ministry's 1942 E.24/43 supersonic research aircraft specification which had resulted in the Miles M.52 program. W.E.W. "Teddy" Petter, formerly chief designer at Westland Aircraft, was a keen early proponent of Britain's need to develop a supersonic fighter aircraft. In 1947, Petter approached the Ministry of Supply (MoS) with his proposal, and in response Specification ER.103 was issued for a single research aircraft, which was to be capable of flight at Mach 1.5 (1,593 km/h) and 50,000 ft (15,000 m).

Petter initiated a design proposal with F W "Freddie" Page leading the design and Ray Creasey responsible for the aerodynamics. As it was designed for Mach 1.5, it had a 40° swept wing to keep the leading edge clear of the Mach cone. To mount enough power into the airframe, two engines were installed, in an unusual, stacked layout and with a high tailplane This proposal was submitted in November 1948, and in January 1949 the project was designated P.1 by English Electric. On 29 March 1949 MoS granted approval to start the detailed design, develop wind tunnel models and build a full-size mock-up.

The design that had developed during 1948 evolved further during 1949 to further improve performance. To achieve Mach 2 the wing sweep was increased to 60° with the ailerons moved to the wingtips. In late 1949, low-speed wind tunnel tests showed that a vortex was generated by the wing which caused a large downwash on the initial high tailplane; this issue was solved by lowering the tail below the wing. Following the resignation of Petter, Page took over as design team leader for the P.1. In 1949, the Ministry of Supply had issued Specification F23/49, which expanded upon the scope of ER103 to include fighter-level manoeuvring. On 1 April 1950, English Electric received a contract for two flying airframes, as well as one static airframe, designated P.1.

The Royal Aircraft Establishment disagreed with Petter's choice of sweep angle (60 degrees) and the stacked engine layout, as well as the low tailplane position, was considered to be dangerous, too. To assess the effects of wing sweep and tailplane position on the stability and control of Petter's design Short Brothers were issued a contract, by the Ministry of Supply, to produce the Short SB.5 in mid-1950. This was a low-speed research aircraft that could test sweep angles from 50 to 69 degrees and tailplane positions high or low. Testing with the wings and tail set to the P.1 configuration started in January 1954 and confirmed this combination as the correct one. The proposed 60-degree wing sweep was retained, but the stacked engines had to give way to a more conventional configuration with two engines placed side-by-side in the tail, but still breathing through a mutual nose air intake.

From 1953 onward, the first three prototype aircraft were hand-built at Samlesbury. These aircraft had been assigned the aircraft serials WG760, WG763, and WG765 (the structural test airframe). The prototypes were powered by un-reheated Armstrong Siddeley Sapphire turbojets, as the selected Rolls-Royce Avon engines had fallen behind schedule due to their own development problems. Since there was not much space in the fuselage for fuel, the thin wings became the primary fuel tanks and since they also provided space for the stowed main undercarriage the fuel capacity was relatively small, giving the prototypes an extremely limited endurance. The narrow tires housed in the thin wings rapidly wore out if there was any crosswind component during take-off or landing. Outwardly, the prototypes looked very much like the production series, but they were distinguished by the rounded-triangular air intake with no center-body at the nose, short fin, and lack of operational equipment.

On 9 June 1952, it was decided that there would be a second phase of prototypes built to develop the aircraft toward achieving Mach 2.0 (2,450 km/h); these were designated P.1B while the initial three prototypes were retroactively reclassified as P.1A. P.1B was a significant improvement on P.1A. While it was similar in aerodynamics, structure and control systems, it incorporated extensive alterations to the forward fuselage, reheated Rolls Royce Avon R24R engines, a conical center body inlet cone, variable nozzle reheat and provision for weapons systems integrated with the ADC and AI.23 radar. Three P.1B prototypes were built, assigned serials XA847, XA853 and XA856.

In May 1954, WG760 and its support equipment were moved to RAF Boscombe Down for pre-flight ground taxi trials; on the morning of 4 August 1954, WG760 flew for the first time from Boscombe Down. One week later, WG760 officially achieved supersonic flight for the first time, having exceeded the speed of sound during its third flight. While WG760 had proven the P.1 design to be viable, it was plagued by directional stability problems and a dismal performance: Transonic drag was much higher than expected, and the aircraft was limited to Mach 0.98 (i.e. subsonic), with a ceiling of just 48,000 ft (14,630 m), far below the requirements.

To solve the problem and save the P.1, Petter embarked on a major redesign, incorporating the recently discovered area rule, while at the same time simplifying production and maintenance. The redesign entailed a new, narrower canopy, a revised air intake, a pair of stabilizing fins under the rear fuselage, and a shallow ventral fairing at the wings’ trailing edge that not only reduced the drag coefficient along the wing/fuselage intersection, it also provided space for additional fuel.

On 4 April 1957 the modified P.1B (XA847) made the first flight, immediately exceeding Mach 1. During the early flight trials of the P.1B, speeds in excess of 1,000 mph were achieved daily.

In late October 1958, the plane was officially presented. The event was celebrated in traditional style in a hangar at Royal Aircraft Establishment (RAE) Farnborough, with the prototype XA847 having the name ‘Skyspark’ freshly painted on the nose in front of the RAF Roundel, which almost covered it. A bottle of champagne was put beside the nose on a special rig which allowed the bottle to safely be smashed against the side of the aircraft.

On 25 November 1958 the P.1B XA847 reached Mach 2 for the first time. This made it the second Western European aircraft to reach Mach 2, the first one being the French Dassault Mirage III just over a month earlier on 24 October 1958

The first operational Skyspark, designated Skyspark F.1, was designed as a pure interceptor to defend the V Force airfields in conjunction with the "last ditch" Bristol Bloodhound missiles located either at the bomber airfield, e.g. at RAF Marham, or at dedicated missile sites near to the airfield, e.g. at RAF Woodhall Spa near the Vulcan station RAF Coningsby. The bomber airfields, along with the dispersal airfields, would be the highest priority targets in the UK for enemy nuclear weapons. To best perform this intercept mission, emphasis was placed on rate-of-climb, acceleration, and speed, rather than range – originally a radius of operation of only 150 miles (240 km) from the V bomber airfields was specified – and endurance. Armament consisted of a pair of 30 mm ADEN cannon in front of the cockpit, and two pylons for IR-guided de Havilland Firestreak air-to-air missiles were added to the lower fuselage flanks. These hardpoints could, alternatively, carry pods with unguided 55 mm air-to-air rockets. The Ferranti AI.23 onboard radar provided missile guidance and ranging, as well as search and track functions.

The next two Skyspark variants, the Skyspark F.1A and F.2, incorporated relatively minor design changes, but for the next variant, the Skyspark F.3, they were more extensive: The F.3 had higher thrust Rolls-Royce Avon 301R engines, a larger squared-off fin that improved directional stability at high speed further and a strengthened inlet cone allowing a service clearance to Mach 2.0 (2,450 km/h; the F.1, F.1A and F.2 were all limited to Mach 1.7 (2,083 km/h). An upgraded A.I.23B radar and new, radar-guided Red Top missiles offered a forward hemisphere attack capability, even though additional electronics meant that the ADEN guns had to be deleted – but they were not popular in their position in front of the windscreen, because the muzzle flash blinded the pilot upon firing. The new engines and fin made the F.3 the highest performance Skyspark yet, but this came at a steep price: higher fuel consumption, resulting in even shorter range. From this basis, a conversion trainer with a side-by-side cockpit, the T.4, was created.

The next interceptor variant was already in development, but there was a need for an interim solution to partially address the F.3's shortcomings, the F.3A. The F.3A introduced two major improvements: a larger, non-jettisonable, 610-imperial-gallon (2,800 L) ventral fuel tank, resulting in a much deeper and longer belly fairing, and a new, kinked, conically cambered wing leading edge. The conically cambered wing improved manoeuvrability, especially at higher altitudes, and it offered space for a slightly larger leading edge fuel tank, raising the total usable internal fuel by 716 imperial gallons (3,260 L). The enlarged ventral tank not only nearly doubled available fuel, it also provided space at its front end for a re-instated pair of 30 mm ADEN cannon with 120 RPG. Alternatively, a retractable pack with unguided 55 mm air-to-air rockets could be installed, or a set of cameras for reconnaissance missions. The F.3A also introduced an improved A.I.23B radar and the new IR-guided Red Top missile, which was much faster and had greater range and manoeuvrability than the Firestreak. Its improved infrared seeker enabled a wider range of engagement angles and offered a forward hemisphere attack capability that would allow the Skyspark to attack even faster bombers (like the new, supersonic Tupolev T-22 Blinder) through a collision-course approach.

Wings and the new belly tank were also immediately incorporated in a second trainer variant, the T.5.

The ultimate variant, the Skyspark F.6, was nearly identical to the F.3A, with the exception that it could carry two additional 260-imperial-gallon (1,200 L) ferry tanks on pylons over the wings. These tanks were jettisonable in an emergency and gave the F.6 a substantially improved deployment capability, even though their supersonic drag was so high that the extra fuel would only marginally raise the aircraft’s range when flying beyond the sound barrier for extended periods.

Finally, there was the Skyspark F.2A; it was an early production F.2 upgraded with the new cambered wing, the squared fin, and the 610 imperial gallons (2,800 L) ventral tank. However, the F.2A retained the old AI.23 radar, the IR-guided Firestreak missile and the earlier Avon 211R engines. Although the F.2A lacked the thrust of the later Skysparks, it had the longest tactical range of all variants, and was used for low-altitude interception over West Germany.

The first Skysparks to enter service with the RAF, three pre-production P.1Bs, arrived at RAF Coltishall in Norfolk on 23 December 1959, joining the Air Fighting Development Squadron (AFDS) of the Central Fighter Establishment, where they were used to clear the Skyspark for entry into service. The production Skyspark F.1 entered service with the AFDS in May 1960, allowing the unit to take part in the air defence exercise "Yeoman" later that month. The Skyspark F.1 entered frontline squadron service with 74 Squadron at Coltishall from 11 July 1960. This made the Skyspark the second Western European-built combat aircraft with true supersonic capability to enter service and the second fully supersonic aircraft to be deployed in Western Europe (the first one in both categories being the Swedish Saab 35 Draken on 8 March 1960 four months earlier).

The aircraft's radar and missiles proved to be effective, and pilots reported that the Skyspark was easy to fly. However, in the first few months of operation the aircraft's serviceability was extremely poor. This was due to the complexity of the aircraft systems and shortages of spares and ground support equipment. Even when the Skyspark was not grounded by technical faults, the RAF initially struggled to get more than 20 flying hours per aircraft per month compared with the 40 flying hours that English Electric believed could be achieved with proper support. In spite of these concerns, within six months of the Skyspark entering service, 74 Squadron was able to achieve 100 flying hours per aircraft.

Deliveries of the slightly improved Skyspark F.1A, with revised avionics and provision for an air-to-air refueling probe, allowed two more squadrons, 56 and 111 Squadron, both based at RAF Wattisham, to convert to the Skyspark in 1960–1961. The Skyspark F.1 was only ordered in limited numbers and served only for a short time; nonetheless, it was viewed as a significant step forward in Britain's air defence capabilities. Following their replacement from frontline duties by the introduction of successively improved Skyspark variants, the remaining F.1 aircraft were employed by the Skyspark Conversion Squadron.

The improved F.2 entered service with 19 Squadron at the end of 1962 and 92 Squadron in early 1963. Conversion of these two squadrons was aided by the of the two-seat T.4 and T.5 trainers (based on the F.3 and F.3A/F.6 fighters), which entered service with the Skyspark Conversion Squadron (later renamed 226 Operational Conversion Unit) in June 1962. While the OCU was the major user of the two-seater, small numbers were also allocated to the front-line fighter squadrons. More F.2s were produced than there were available squadron slots, so later production aircraft were stored for years before being used operationally; some of these Skyspark F.2s were converted to F.2As.

The F.3, with more powerful engines and the new Red Top missile was expected to be the definitive Skyspark, and at one time it was planned to equip ten squadrons, with the remaining two squadrons retaining the F.2. However, the F.3 also had only a short operational life and was withdrawn from service early due to defence cutbacks and the introduction of the even more capable and longer-range F.6, some of which were converted F.3s.

The introduction of the F.3 and F.6 allowed the RAF to progressively reequip squadrons operating aircraft such as the subsonic Gloster Javelin and retire these types during the mid-1960s. During the 1960s, as strategic awareness increased and a multitude of alternative fighter designs were developed by Warsaw Pact and NATO members, the Skyspark's range and firepower shortcomings became increasingly apparent. The transfer of McDonnell Douglas F-4 Phantom IIs from Royal Navy service enabled these much longer-ranged aircraft to be added to the RAF's interceptor force, alongside those withdrawn from Germany as they were replaced by SEPECAT Jaguars in the ground attack role.

The specification for the aircraft followed the cancellation of the Air Ministry's 1942 E.24/43 supersonic research aircraft specification which had resulted in the Miles M.52 program. W.E.W. "Teddy" Petter, formerly chief designer at Westland Aircraft, was a keen early proponent of Britain's need to develop a supersonic fighter aircraft. In 1947, Petter approached the Ministry of Supply (MoS) with his proposal, and in response Specification ER.103 was issued for a single research aircraft, which was to be capable of flight at Mach 1.5 (1,593 km/h) and 50,000 ft (15,000 m).

Petter initiated a design proposal with F W "Freddie" Page leading the design and Ray Creasey responsible for the aerodynamics. As it was designed for Mach 1.5, it had a 40° swept wing to keep the leading edge clear of the Mach cone. To mount enough power into the airframe, two engines were installed, in an unusual, stacked layout and with a high tailplane This proposal was submitted in November 1948, and in January 1949 the project was designated P.1 by English Electric. On 29 March 1949 MoS granted approval to start the detailed design, develop wind tunnel models and build a full-size mock-up.

The design that had developed during 1948 evolved further during 1949 to further improve performance. To achieve Mach 2 the wing sweep was increased to 60° with the ailerons moved to the wingtips. In late 1949, low-speed wind tunnel tests showed that a vortex was generated by the wing which caused a large downwash on the initial high tailplane; this issue was solved by lowering the tail below the wing. Following the resignation of Petter, Page took over as design team leader for the P.1. In 1949, the Ministry of Supply had issued Specification F23/49, which expanded upon the scope of ER103 to include fighter-level manoeuvring. On 1 April 1950, English Electric received a contract for two flying airframes, as well as one static airframe, designated P.1.

The Royal Aircraft Establishment disagreed with Petter's choice of sweep angle (60 degrees) and the stacked engine layout, as well as the low tailplane position, was considered to be dangerous, too. To assess the effects of wing sweep and tailplane position on the stability and control of Petter's design Short Brothers were issued a contract, by the Ministry of Supply, to produce the Short SB.5 in mid-1950. This was a low-speed research aircraft that could test sweep angles from 50 to 69 degrees and tailplane positions high or low. Testing with the wings and tail set to the P.1 configuration started in January 1954 and confirmed this combination as the correct one. The proposed 60-degree wing sweep was retained, but the stacked engines had to give way to a more conventional configuration with two engines placed side-by-side in the tail, but still breathing through a mutual nose air intake.

From 1953 onward, the first three prototype aircraft were hand-built at Samlesbury. These aircraft had been assigned the aircraft serials WG760, WG763, and WG765 (the structural test airframe). The prototypes were powered by un-reheated Armstrong Siddeley Sapphire turbojets, as the selected Rolls-Royce Avon engines had fallen behind schedule due to their own development problems. Since there was not much space in the fuselage for fuel, the thin wings became the primary fuel tanks and since they also provided space for the stowed main undercarriage the fuel capacity was relatively small, giving the prototypes an extremely limited endurance. The narrow tires housed in the thin wings rapidly wore out if there was any crosswind component during take-off or landing. Outwardly, the prototypes looked very much like the production series, but they were distinguished by the rounded-triangular air intake with no center-body at the nose, short fin, and lack of operational equipment.

On 9 June 1952, it was decided that there would be a second phase of prototypes built to develop the aircraft toward achieving Mach 2.0 (2,450 km/h); these were designated P.1B while the initial three prototypes were retroactively reclassified as P.1A. P.1B was a significant improvement on P.1A. While it was similar in aerodynamics, structure and control systems, it incorporated extensive alterations to the forward fuselage, reheated Rolls Royce Avon R24R engines, a conical center body inlet cone, variable nozzle reheat and provision for weapons systems integrated with the ADC and AI.23 radar. Three P.1B prototypes were built, assigned serials XA847, XA853 and XA856.

In May 1954, WG760 and its support equipment were moved to RAF Boscombe Down for pre-flight ground taxi trials; on the morning of 4 August 1954, WG760 flew for the first time from Boscombe Down. One week later, WG760 officially achieved supersonic flight for the first time, having exceeded the speed of sound during its third flight. While WG760 had proven the P.1 design to be viable, it was plagued by directional stability problems and a dismal performance: Transonic drag was much higher than expected, and the aircraft was limited to Mach 0.98 (i.e. subsonic), with a ceiling of just 48,000 ft (14,630 m), far below the requirements.

To solve the problem and save the P.1, Petter embarked on a major redesign, incorporating the recently discovered area rule, while at the same time simplifying production and maintenance. The redesign entailed a new, narrower canopy, a revised air intake, a pair of stabilizing fins under the rear fuselage, and a shallow ventral fairing at the wings’ trailing edge that not only reduced the drag coefficient along the wing/fuselage intersection, it also provided space for additional fuel.

On 4 April 1957 the modified P.1B (XA847) made the first flight, immediately exceeding Mach 1. During the early flight trials of the P.1B, speeds in excess of 1,000 mph were achieved daily.

In late October 1958, the plane was officially presented. The event was celebrated in traditional style in a hangar at Royal Aircraft Establishment (RAE) Farnborough, with the prototype XA847 having the name ‘Skyspark’ freshly painted on the nose in front of the RAF Roundel, which almost covered it. A bottle of champagne was put beside the nose on a special rig which allowed the bottle to safely be smashed against the side of the aircraft.

On 25 November 1958 the P.1B XA847 reached Mach 2 for the first time. This made it the second Western European aircraft to reach Mach 2, the first one being the French Dassault Mirage III just over a month earlier on 24 October 1958

The first operational Skyspark, designated Skyspark F.1, was designed as a pure interceptor to defend the V Force airfields in conjunction with the "last ditch" Bristol Bloodhound missiles located either at the bomber airfield, e.g. at RAF Marham, or at dedicated missile sites near to the airfield, e.g. at RAF Woodhall Spa near the Vulcan station RAF Coningsby. The bomber airfields, along with the dispersal airfields, would be the highest priority targets in the UK for enemy nuclear weapons. To best perform this intercept mission, emphasis was placed on rate-of-climb, acceleration, and speed, rather than range – originally a radius of operation of only 150 miles (240 km) from the V bomber airfields was specified – and endurance. Armament consisted of a pair of 30 mm ADEN cannon in front of the cockpit, and two pylons for IR-guided de Havilland Firestreak air-to-air missiles were added to the lower fuselage flanks. These hardpoints could, alternatively, carry pods with unguided 55 mm air-to-air rockets. The Ferranti AI.23 onboard radar provided missile guidance and ranging, as well as search and track functions.

The next two Skyspark variants, the Skyspark F.1A and F.2, incorporated relatively minor design changes, but for the next variant, the Skyspark F.3, they were more extensive: The F.3 had higher thrust Rolls-Royce Avon 301R engines, a larger squared-off fin that improved directional stability at high speed further and a strengthened inlet cone allowing a service clearance to Mach 2.0 (2,450 km/h; the F.1, F.1A and F.2 were all limited to Mach 1.7 (2,083 km/h). An upgraded A.I.23B radar and new, radar-guided Red Top missiles offered a forward hemisphere attack capability, even though additional electronics meant that the ADEN guns had to be deleted – but they were not popular in their position in front of the windscreen, because the muzzle flash blinded the pilot upon firing. The new engines and fin made the F.3 the highest performance Skyspark yet, but this came at a steep price: higher fuel consumption, resulting in even shorter range. From this basis, a conversion trainer with a side-by-side cockpit, the T.4, was created.

The next interceptor variant was already in development, but there was a need for an interim solution to partially address the F.3's shortcomings, the F.3A. The F.3A introduced two major improvements: a larger, non-jettisonable, 610-imperial-gallon (2,800 L) ventral fuel tank, resulting in a much deeper and longer belly fairing, and a new, kinked, conically cambered wing leading edge. The conically cambered wing improved manoeuvrability, especially at higher altitudes, and it offered space for a slightly larger leading edge fuel tank, raising the total usable internal fuel by 716 imperial gallons (3,260 L). The enlarged ventral tank not only nearly doubled available fuel, it also provided space at its front end for a re-instated pair of 30 mm ADEN cannon with 120 RPG. Alternatively, a retractable pack with unguided 55 mm air-to-air rockets could be installed, or a set of cameras for reconnaissance missions. The F.3A also introduced an improved A.I.23B radar and the new IR-guided Red Top missile, which was much faster and had greater range and manoeuvrability than the Firestreak. Its improved infrared seeker enabled a wider range of engagement angles and offered a forward hemisphere attack capability that would allow the Skyspark to attack even faster bombers (like the new, supersonic Tupolev T-22 Blinder) through a collision-course approach.

Wings and the new belly tank were also immediately incorporated in a second trainer variant, the T.5.

The ultimate variant, the Skyspark F.6, was nearly identical to the F.3A, with the exception that it could carry two additional 260-imperial-gallon (1,200 L) ferry tanks on pylons over the wings. These tanks were jettisonable in an emergency and gave the F.6 a substantially improved deployment capability, even though their supersonic drag was so high that the extra fuel would only marginally raise the aircraft’s range when flying beyond the sound barrier for extended periods.

Finally, there was the Skyspark F.2A; it was an early production F.2 upgraded with the new cambered wing, the squared fin, and the 610 imperial gallons (2,800 L) ventral tank. However, the F.2A retained the old AI.23 radar, the IR-guided Firestreak missile and the earlier Avon 211R engines. Although the F.2A lacked the thrust of the later Skysparks, it had the longest tactical range of all variants, and was used for low-altitude interception over West Germany.

The first Skysparks to enter service with the RAF, three pre-production P.1Bs, arrived at RAF Coltishall in Norfolk on 23 December 1959, joining the Air Fighting Development Squadron (AFDS) of the Central Fighter Establishment, where they were used to clear the Skyspark for entry into service. The production Skyspark F.1 entered service with the AFDS in May 1960, allowing the unit to take part in the air defence exercise "Yeoman" later that month. The Skyspark F.1 entered frontline squadron service with 74 Squadron at Coltishall from 11 July 1960. This made the Skyspark the second Western European-built combat aircraft with true supersonic capability to enter service and the second fully supersonic aircraft to be deployed in Western Europe (the first one in both categories being the Swedish Saab 35 Draken on 8 March 1960 four months earlier).

The aircraft's radar and missiles proved to be effective, and pilots reported that the Skyspark was easy to fly. However, in the first few months of operation the aircraft's serviceability was extremely poor. This was due to the complexity of the aircraft systems and shortages of spares and ground support equipment. Even when the Skyspark was not grounded by technical faults, the RAF initially struggled to get more than 20 flying hours per aircraft per month compared with the 40 flying hours that English Electric believed could be achieved with proper support. In spite of these concerns, within six months of the Skyspark entering service, 74 Squadron was able to achieve 100 flying hours per aircraft.

Deliveries of the slightly improved Skyspark F.1A, with revised avionics and provision for an air-to-air refueling probe, allowed two more squadrons, 56 and 111 Squadron, both based at RAF Wattisham, to convert to the Skyspark in 1960–1961. The Skyspark F.1 was only ordered in limited numbers and served only for a short time; nonetheless, it was viewed as a significant step forward in Britain's air defence capabilities. Following their replacement from frontline duties by the introduction of successively improved Skyspark variants, the remaining F.1 aircraft were employed by the Skyspark Conversion Squadron.

The improved F.2 entered service with 19 Squadron at the end of 1962 and 92 Squadron in early 1963. Conversion of these two squadrons was aided by the of the two-seat T.4 and T.5 trainers (based on the F.3 and F.3A/F.6 fighters), which entered service with the Skyspark Conversion Squadron (later renamed 226 Operational Conversion Unit) in June 1962. While the OCU was the major user of the two-seater, small numbers were also allocated to the front-line fighter squadrons. More F.2s were produced than there were available squadron slots, so later production aircraft were stored for years before being used operationally; some of these Skyspark F.2s were converted to F.2As.

The F.3, with more powerful engines and the new Red Top missile was expected to be the definitive Skyspark, and at one time it was planned to equip ten squadrons, with the remaining two squadrons retaining the F.2. However, the F.3 also had only a short operational life and was withdrawn from service early due to defence cutbacks and the introduction of the even more capable and longer-range F.6, some of which were converted F.3s.

The introduction of the F.3 and F.6 allowed the RAF to progressively reequip squadrons operating aircraft such as the subsonic Gloster Javelin and retire these types during the mid-1960s. During the 1960s, as strategic awareness increased and a multitude of alternative fighter designs were developed by Warsaw Pact and NATO members, the Skyspark's range and firepower shortcomings became increasingly apparent. The transfer of McDonnell Douglas F-4 Phantom IIs from Royal Navy service enabled these much longer-ranged aircraft to be added to the RAF's interceptor force, alongside those withdrawn from Germany as they were replaced by SEPECAT Jaguars in the ground attack role.

The specification for the aircraft followed the cancellation of the Air Ministry's 1942 E.24/43 supersonic research aircraft specification which had resulted in the Miles M.52 program. W.E.W. "Teddy" Petter, formerly chief designer at Westland Aircraft, was a keen early proponent of Britain's need to develop a supersonic fighter aircraft. In 1947, Petter approached the Ministry of Supply (MoS) with his proposal, and in response Specification ER.103 was issued for a single research aircraft, which was to be capable of flight at Mach 1.5 (1,593 km/h) and 50,000 ft (15,000 m).

Petter initiated a design proposal with F W "Freddie" Page leading the design and Ray Creasey responsible for the aerodynamics. As it was designed for Mach 1.5, it had a 40° swept wing to keep the leading edge clear of the Mach cone. To mount enough power into the airframe, two engines were installed, in an unusual, stacked layout and with a high tailplane This proposal was submitted in November 1948, and in January 1949 the project was designated P.1 by English Electric. On 29 March 1949 MoS granted approval to start the detailed design, develop wind tunnel models and build a full-size mock-up.

The design that had developed during 1948 evolved further during 1949 to further improve performance. To achieve Mach 2 the wing sweep was increased to 60° with the ailerons moved to the wingtips. In late 1949, low-speed wind tunnel tests showed that a vortex was generated by the wing which caused a large downwash on the initial high tailplane; this issue was solved by lowering the tail below the wing. Following the resignation of Petter, Page took over as design team leader for the P.1. In 1949, the Ministry of Supply had issued Specification F23/49, which expanded upon the scope of ER103 to include fighter-level manoeuvring. On 1 April 1950, English Electric received a contract for two flying airframes, as well as one static airframe, designated P.1.

The Royal Aircraft Establishment disagreed with Petter's choice of sweep angle (60 degrees) and the stacked engine layout, as well as the low tailplane position, was considered to be dangerous, too. To assess the effects of wing sweep and tailplane position on the stability and control of Petter's design Short Brothers were issued a contract, by the Ministry of Supply, to produce the Short SB.5 in mid-1950. This was a low-speed research aircraft that could test sweep angles from 50 to 69 degrees and tailplane positions high or low. Testing with the wings and tail set to the P.1 configuration started in January 1954 and confirmed this combination as the correct one. The proposed 60-degree wing sweep was retained, but the stacked engines had to give way to a more conventional configuration with two engines placed side-by-side in the tail, but still breathing through a mutual nose air intake.

From 1953 onward, the first three prototype aircraft were hand-built at Samlesbury. These aircraft had been assigned the aircraft serials WG760, WG763, and WG765 (the structural test airframe). The prototypes were powered by un-reheated Armstrong Siddeley Sapphire turbojets, as the selected Rolls-Royce Avon engines had fallen behind schedule due to their own development problems. Since there was not much space in the fuselage for fuel, the thin wings became the primary fuel tanks and since they also provided space for the stowed main undercarriage the fuel capacity was relatively small, giving the prototypes an extremely limited endurance. The narrow tires housed in the thin wings rapidly wore out if there was any crosswind component during take-off or landing. Outwardly, the prototypes looked very much like the production series, but they were distinguished by the rounded-triangular air intake with no center-body at the nose, short fin, and lack of operational equipment.

On 9 June 1952, it was decided that there would be a second phase of prototypes built to develop the aircraft toward achieving Mach 2.0 (2,450 km/h); these were designated P.1B while the initial three prototypes were retroactively reclassified as P.1A. P.1B was a significant improvement on P.1A. While it was similar in aerodynamics, structure and control systems, it incorporated extensive alterations to the forward fuselage, reheated Rolls Royce Avon R24R engines, a conical center body inlet cone, variable nozzle reheat and provision for weapons systems integrated with the ADC and AI.23 radar. Three P.1B prototypes were built, assigned serials XA847, XA853 and XA856.

In May 1954, WG760 and its support equipment were moved to RAF Boscombe Down for pre-flight ground taxi trials; on the morning of 4 August 1954, WG760 flew for the first time from Boscombe Down. One week later, WG760 officially achieved supersonic flight for the first time, having exceeded the speed of sound during its third flight. While WG760 had proven the P.1 design to be viable, it was plagued by directional stability problems and a dismal performance: Transonic drag was much higher than expected, and the aircraft was limited to Mach 0.98 (i.e. subsonic), with a ceiling of just 48,000 ft (14,630 m), far below the requirements.

To solve the problem and save the P.1, Petter embarked on a major redesign, incorporating the recently discovered area rule, while at the same time simplifying production and maintenance. The redesign entailed a new, narrower canopy, a revised air intake, a pair of stabilizing fins under the rear fuselage, and a shallow ventral fairing at the wings’ trailing edge that not only reduced the drag coefficient along the wing/fuselage intersection, it also provided space for additional fuel.

On 4 April 1957 the modified P.1B (XA847) made the first flight, immediately exceeding Mach 1. During the early flight trials of the P.1B, speeds in excess of 1,000 mph were achieved daily.

In late October 1958, the plane was officially presented. The event was celebrated in traditional style in a hangar at Royal Aircraft Establishment (RAE) Farnborough, with the prototype XA847 having the name ‘Skyspark’ freshly painted on the nose in front of the RAF Roundel, which almost covered it. A bottle of champagne was put beside the nose on a special rig which allowed the bottle to safely be smashed against the side of the aircraft.

On 25 November 1958 the P.1B XA847 reached Mach 2 for the first time. This made it the second Western European aircraft to reach Mach 2, the first one being the French Dassault Mirage III just over a month earlier on 24 October 1958

The first operational Skyspark, designated Skyspark F.1, was designed as a pure interceptor to defend the V Force airfields in conjunction with the "last ditch" Bristol Bloodhound missiles located either at the bomber airfield, e.g. at RAF Marham, or at dedicated missile sites near to the airfield, e.g. at RAF Woodhall Spa near the Vulcan station RAF Coningsby. The bomber airfields, along with the dispersal airfields, would be the highest priority targets in the UK for enemy nuclear weapons. To best perform this intercept mission, emphasis was placed on rate-of-climb, acceleration, and speed, rather than range – originally a radius of operation of only 150 miles (240 km) from the V bomber airfields was specified – and endurance. Armament consisted of a pair of 30 mm ADEN cannon in front of the cockpit, and two pylons for IR-guided de Havilland Firestreak air-to-air missiles were added to the lower fuselage flanks. These hardpoints could, alternatively, carry pods with unguided 55 mm air-to-air rockets. The Ferranti AI.23 onboard radar provided missile guidance and ranging, as well as search and track functions.

The next two Skyspark variants, the Skyspark F.1A and F.2, incorporated relatively minor design changes, but for the next variant, the Skyspark F.3, they were more extensive: The F.3 had higher thrust Rolls-Royce Avon 301R engines, a larger squared-off fin that improved directional stability at high speed further and a strengthened inlet cone allowing a service clearance to Mach 2.0 (2,450 km/h; the F.1, F.1A and F.2 were all limited to Mach 1.7 (2,083 km/h). An upgraded A.I.23B radar and new, radar-guided Red Top missiles offered a forward hemisphere attack capability, even though additional electronics meant that the ADEN guns had to be deleted – but they were not popular in their position in front of the windscreen, because the muzzle flash blinded the pilot upon firing. The new engines and fin made the F.3 the highest performance Skyspark yet, but this came at a steep price: higher fuel consumption, resulting in even shorter range. From this basis, a conversion trainer with a side-by-side cockpit, the T.4, was created.

The next interceptor variant was already in development, but there was a need for an interim solution to partially address the F.3's shortcomings, the F.3A. The F.3A introduced two major improvements: a larger, non-jettisonable, 610-imperial-gallon (2,800 L) ventral fuel tank, resulting in a much deeper and longer belly fairing, and a new, kinked, conically cambered wing leading edge. The conically cambered wing improved manoeuvrability, especially at higher altitudes, and it offered space for a slightly larger leading edge fuel tank, raising the total usable internal fuel by 716 imperial gallons (3,260 L). The enlarged ventral tank not only nearly doubled available fuel, it also provided space at its front end for a re-instated pair of 30 mm ADEN cannon with 120 RPG. Alternatively, a retractable pack with unguided 55 mm air-to-air rockets could be installed, or a set of cameras for reconnaissance missions. The F.3A also introduced an improved A.I.23B radar and the new IR-guided Red Top missile, which was much faster and had greater range and manoeuvrability than the Firestreak. Its improved infrared seeker enabled a wider range of engagement angles and offered a forward hemisphere attack capability that would allow the Skyspark to attack even faster bombers (like the new, supersonic Tupolev T-22 Blinder) through a collision-course approach.

Wings and the new belly tank were also immediately incorporated in a second trainer variant, the T.5.

The ultimate variant, the Skyspark F.6, was nearly identical to the F.3A, with the exception that it could carry two additional 260-imperial-gallon (1,200 L) ferry tanks on pylons over the wings. These tanks were jettisonable in an emergency and gave the F.6 a substantially improved deployment capability, even though their supersonic drag was so high that the extra fuel would only marginally raise the aircraft’s range when flying beyond the sound barrier for extended periods.

Finally, there was the Skyspark F.2A; it was an early production F.2 upgraded with the new cambered wing, the squared fin, and the 610 imperial gallons (2,800 L) ventral tank. However, the F.2A retained the old AI.23 radar, the IR-guided Firestreak missile and the earlier Avon 211R engines. Although the F.2A lacked the thrust of the later Skysparks, it had the longest tactical range of all variants, and was used for low-altitude interception over West Germany.

The first Skysparks to enter service with the RAF, three pre-production P.1Bs, arrived at RAF Coltishall in Norfolk on 23 December 1959, joining the Air Fighting Development Squadron (AFDS) of the Central Fighter Establishment, where they were used to clear the Skyspark for entry into service. The production Skyspark F.1 entered service with the AFDS in May 1960, allowing the unit to take part in the air defence exercise "Yeoman" later that month. The Skyspark F.1 entered frontline squadron service with 74 Squadron at Coltishall from 11 July 1960. This made the Skyspark the second Western European-built combat aircraft with true supersonic capability to enter service and the second fully supersonic aircraft to be deployed in Western Europe (the first one in both categories being the Swedish Saab 35 Draken on 8 March 1960 four months earlier).

The aircraft's radar and missiles proved to be effective, and pilots reported that the Skyspark was easy to fly. However, in the first few months of operation the aircraft's serviceability was extremely poor. This was due to the complexity of the aircraft systems and shortages of spares and ground support equipment. Even when the Skyspark was not grounded by technical faults, the RAF initially struggled to get more than 20 flying hours per aircraft per month compared with the 40 flying hours that English Electric believed could be achieved with proper support. In spite of these concerns, within six months of the Skyspark entering service, 74 Squadron was able to achieve 100 flying hours per aircraft.

Deliveries of the slightly improved Skyspark F.1A, with revised avionics and provision for an air-to-air refueling probe, allowed two more squadrons, 56 and 111 Squadron, both based at RAF Wattisham, to convert to the Skyspark in 1960–1961. The Skyspark F.1 was only ordered in limited numbers and served only for a short time; nonetheless, it was viewed as a significant step forward in Britain's air defence capabilities. Following their replacement from frontline duties by the introduction of successively improved Skyspark variants, the remaining F.1 aircraft were employed by the Skyspark Conversion Squadron.

The improved F.2 entered service with 19 Squadron at the end of 1962 and 92 Squadron in early 1963. Conversion of these two squadrons was aided by the of the two-seat T.4 and T.5 trainers (based on the F.3 and F.3A/F.6 fighters), which entered service with the Skyspark Conversion Squadron (later renamed 226 Operational Conversion Unit) in June 1962. While the OCU was the major user of the two-seater, small numbers were also allocated to the front-line fighter squadrons. More F.2s were produced than there were available squadron slots, so later production aircraft were stored for years before being used operationally; some of these Skyspark F.2s were converted to F.2As.

The F.3, with more powerful engines and the new Red Top missile was expected to be the definitive Skyspark, and at one time it was planned to equip ten squadrons, with the remaining two squadrons retaining the F.2. However, the F.3 also had only a short operational life and was withdrawn from service early due to defence cutbacks and the introduction of the even more capable and longer-range F.6, some of which were converted F.3s.

The introduction of the F.3 and F.6 allowed the RAF to progressively reequip squadrons operating aircraft such as the subsonic Gloster Javelin and retire these types during the mid-1960s. During the 1960s, as strategic awareness increased and a multitude of alternative fighter designs were developed by Warsaw Pact and NATO members, the Skyspark's range and firepower shortcomings became increasingly apparent. The transfer of McDonnell Douglas F-4 Phantom IIs from Royal Navy service enabled these much longer-ranged aircraft to be added to the RAF's interceptor force, alongside those withdrawn from Germany as they were replaced by SEPECAT Jaguars in the ground attack role.

The G-79 project comprised a total of four different layouts and engine arrangements for a single seat fighter aircraft. G-79A and B were traditional tail sitters, but both featured mixed propulsion for an enhanced performance: G-79A was powered by an R-2800 radial engine and a Rolls Royce Derwent VI jet booster in the tail, fed by a pair of dorsal air intakes behind the cockpit. The G-79B was a similar aircraft, but its primary engine was a General Electric TG-100 turboprop in a more slender nose section. Even though both designs were big aircraft, initial calculations indicated a performance that would be superior to the Grumman F8F Bearcat, which had been designed as a thoroughbred interceptor.

The other two designs were pure jet fighters, both with a tricycle landing gear. G-79C had a layout reminiscent of the Gloster Meteor and was powered by two Derwent VI engines in bulky wing nacelles, and G-79D was finally an overall smaller and lighter aircraft, similar in its outlines to the early Vought F6U Pirate, and powered by a single Nene in the rear fuselage, fed by air intakes in the wing roots.

Since the operation of jet-powered aircraft from carriers was terra incognita for the US Navy, and early turbojets thirsty and slow to react to throttle input, BuAer decided to develop two of Grumman's G-79 designs into prototypes for real life evaluation: one of the conservative designs, as a kind of safe route, and one of the more modern jets.

From the mixed propulsion designs, the turboprop-powered G-79B was chosen (becoming the XF9F-1 'JetCat'), since it was expected to offer a higher performance and development potential than the radial-powered 'A'. From the pure jet designs the G-79D was chosen, because of its simplicity and compact size, and designated XF9F-2 'Panther'.

The first JetCat prototype made its maiden flight on 26 October 1947, but it was only a short airfield circuit since the TG-100 turpoprop failed to deliver full power and the jet booster had not been installed yet. The prototype Panther, piloted by test pilot Corky Meyer, first flew on 21 November 1947 without major problems.

In the wake of the two aircrafts' test program, several modifications and improvements were made. This included an equal armament of four 20mm guns (mounted in the outer, foldable wings on the JetCat and, respectively, in the Panther’s nose). Furthermore, both aircraft were soon armed with underwing HVAR air-to-ground rockets and bombs, and the JetCat even received an underfuselage pylon for the potential carriage of an airborne torpedo. Since there was insufficient space within the foldable wings and the fuselage in both aircraft for the thirsty jet’s fuel, permanently mounted wingtip fuel tanks were added on both aircraft, which incidentally improved the fighters' rate of roll. Both F9F types were cleared for flight from aircraft carriers in September 1949.

The F9F-1 was soon re-engined with an Allison T38 turboprop, which was much more reliable than the TF-100 (in the meantime re-designated XT31) and delivered a slightly higher power output. Another change was made for the booster: the bulky Derwent VI engine from the prototype stage was replaced by a much more compact Westinghouse J34 turbojet, which not only delivered slightly more thrust, it also used up much less internal space which was used for radio and navigation equipment, a life raft and a relocated oil tank. Due to a resulting CG shift towards the nose, the fuselage fuel cell layout had to be revised. As a consequence, the cockpit was moved 3’ backwards, slightly impairing the pilot’s field of view, but it was still superior to the contemporary Vought F4U.

Despite the engine improvements, though, the F9F-1 attained markedly less top speed than the F9F-2. On the other side, it had a better rate of climb and slow speed handling characteristics, could carry more ordnance and offered a considerably bigger range and extended loiter time. The F9F-2 was more agile, though, and more of the nimble dogfighter the US Navy was originally looking for. Its simplicity with just a single engine was appealing, too.

The Panther was eventually favored as the USN's first operational jet day fighter and put into production, but the F9F-1 showed much potential as a fast fighter bomber. Through pressure from the USMC, who was looking for a replacement for its F7F heavy Tigercat fighters, a production order for 50 JetCats was eventually placed, later augmented to 82 aircraft because the US Navy also recognized the type’s potential as a fast, ship-borne multi-role fighter. Further interest came in 1949 from Australia, when the country’s government was looking for a - possibly locally-built in license - replacement for the outdated Mustang Mk 23 and De Havilland Vampire then operated by the Royal Australian Air Force (RAAF). Both Grumman designs were potential contenders, rivalling with the domestic CAC CA-23 fighter development.

The Grumman Panther became the most widely used U.S. Navy jet fighter of the Korean War, flying 78,000 sorties and scoring the first air-to-air kill by the U.S. Navy in the war, the downing of a North Korean Yakovlev Yak-9 fighter. Being rugged aircraft, F9F-2s, -3s and -5s were able to sustain operations, even in the face of intense anti-aircraft fire. The pilots also appreciated the Panther’s air conditioned cockpit, which was a welcome change from the humid environment of piston-powered aircraft.

The F9F-1 did fare less glamorous. Compared with the prototypes, the T38 turboprop's power output could be enhanced on service aircraft, but not on a significant level. The aircraft's original, rather sluggish response to throttle input and its low-speed handling were improved through an eight-blade contraprop, which, as a side benefit, countered torque problems during starts and landings on carriers.

The JetCat’s mixed powerplant installation remained capricious, though, and the second engine and its fuel meant a permanent weight penalty. The aircraft's complexity turned out to be a real weak point during the type's deployment to front line airfields in the Korean War, overall readiness was – compared with conservative types like the F4U and also the F9F-2, low. Despite the turboprop improvements, the jet booster remained necessary for carrier starts and vital in order to take on the MiG-15 or post-war piston engine types of Soviet origin like the Lavochkin La-9 and -11 or the Yakowlev Yak-9.

Frequent encounters with these opponents over Korea confirmed that the F9F-1 was not a “naturally born” dogfighter, but rather fell into the escort fighter or attack aircraft class. In order to broaden the type's duty spectrum, a small number of USMC and USN F9F-1s was modified in field workshops with an APS-6 type radar equipment from F4U-4N night fighters. Similar to the Corsair, the radar dish was carried in a streamlined pod under the outer starboard wing. The guns received flame dampers, and these converted machines, re-designated F9F-1N, were used with mild success as night and all-weather fighters.

To make the purchase easier, Ernst Heinkel and Bücker started Svenska Aero in Lidingö in 1921. The contract on the aircraft was transferred from Caspar to Svenska Aero. Heinkel and some German assembly workers temporarily moved to Lidingö to assemble the aircraft. During 1922 to 1923, the company moved into a former shipyard in Skärsätra on Lidingö since the company had received additional orders from the navy's air force. The parts for those aircraft were made in Sweden by Svenska Aero but assembled by TDS. In 1928, the navy ordered four J 4 (Heinkel HD 19) as a fighter with pontoons. That delivery came to be the last licens- built aircraft by Svenska Aero. In the mid-1920s, Svenska Aero created their own design department to be able to make their own aircraft models. Sven Blomberg, earlier employed by Heinkel Flugzeugwerke, was hired as head of design. In 1930, he was joined by Anders Johan Andersson from Messerschmitt. Despite that, Svenska Aero designed and made several different models on their own.

One of them was the model SA-16, a direct response to the Swedish Air Force and Navy’s interest in the new dive bomber tactics, which had become popular in Germany since the mid-Thirties and had spawned several specialized aircraft, the Junkers Ju 87 being the best-known type. The Flygvapnet (Swedish Air Force) had already conducted dive bombing trials with Hawker Hart (B 4) biplanes, but only with mixed results. Diving towards the target simplified the bomb's trajectory and allowed the pilot to keep visual contact throughout the bomb run. This allowed attacks on point targets and ships, which were difficult to attack with conventional level bombers, even en masse. While accuracy was increased through bombing runs at almost vertical dive, the aircraft were not suited for this kind of operations – structurally, and through the way the bombs were dropped.

Therefore, Svenska Aero was tasked to develop an indigenous dedicated dive bomber, primarily intended to attack ships, and with a secondary role as reconnaissance aircraft – a mission profile quite similar to American ship-based “SB” aircraft of the time. Having learnt from the tests with the Hawker Harts, the SA-16 was a very robust monoplane, resulting in an almost archaic look. It was a single-engine all-metal cantilever monoplane with a fixed undercarriage and carried a two-person crew. The main construction material was duralumin, and the external coverings were made of duralumin sheeting, bolts and parts that were required to take heavy stress were made of steel. The wings were of so-called “double-wing” construction, which gave the SA-16 considerable advantage on take-off; even at a shallow angle, large lift forces were created through the airfoil, reducing take-off and landing runs. Retractable perforated air brakes were mounted under the wings’ leading edges. The fully closed “greenhouse cabin” offered space for a crew of two in tandem, with the pilot in front and a navigator/radio operator/observer/gunner behind. To provide the rear-facing machine gun with an increased field of fire, the stabilizers were of limited span but deeper to compensate for the loss of surface, what resulted in unusual proportions. As a side benefit, the short stabilizers had, compared with a wider standard layout, increased structural integrity. Power came from an air-cooled Bristol Mercury XII nine-cylinder radial engine with 880 hp (660 kW), built by Nohab in Sweden.

Internal armament consisted of two fixed forward-firing 8 mm (0.315 in) Flygplanskulspruta Ksp m/22F (M1919 Browning AN/M2) machine guns in the wings outside of the propeller disc. A third machine gun of the same type was available in the rear cockpit on a flexible mount as defensive weapon. A total of 700 kg (1,500 lb) of bombs could be carried externally. On the fuselage centerline, a swing arm could hold bombs of up to 500 kg (1.100 lb) caliber and deploy them outside of the propeller arc when released in a, additional racks under the outer wings could hold bombs of up to 250 kg (550 lb) caliber each or clusters of smaller bombs, e. g. four 50 (110 lb) or six 12 kg (26 ½ lb) bombs.

Flight testing of the first SA-16 prototype began on 14 August 1936. The aircraft could take off in 250 m (820 ft) and climb to 1,875 m (6,152 ft) in eight minutes with a 250 kg (550 lb) bomb load, and its cruising speed was 250 km/h (160 mph). This was less than expected, and pilots also complained that navigation and powerplant instruments were cluttered and not easy to read, especially in combat. To withstand strong forces during a dive, heavy plating, along with brackets riveted to the frame and longeron, was added to the fuselage. Despite this, pilots praised the aircraft's handling qualities and strong airframe. These problems were quickly resolved, but subsequent testing and progress still fell short of the designers’ hopes. With some refinements the machine's speed was increased to 274 km/h (170 mph) at ground level and 319 km/h 319 km/h (198 mph, 172 kn) at 3,650 m (11,980 ft), while maintaining its good handling ability.

Since the Swedish Air Force was in dire need for a dive bomber, the SA-16 was accepted into service as the B 9 – even though it was clear that it was only a stopgap solution on the way to a more capable light bomber with dive attack capabilities. This eventually became the Saab 17, which was initiated in 1938 as a request from the Flygvapnet to replace its fleet of dive bombers of American origin, the B 5 (Northrop A-17), the B 6 (Seversky A8V1) and the obsolete Fokker S 6 (C.Ve) sesquiplane, after the deal with Fokker to procure the two-engine twin-boom G.I as a standardized type failed due to the German invasion of the Netherlands. The B 9 dive bomber would subsequently be replaced by the more modern and capable B 17 in the long run, too, which made its first flight on 18 May 1940 and was introduced to frontline units in March 1942. Until then, 93 SA-16s had been produced between 1937 and 1939. When the B 17 became available, the slow B 9 was quickly retired from the attack role. Plans to upgrade the aircraft with a stronger 14 cylinder engine (a Piaggio P.XIbis R.C.40D with 790 kW/1,060 hp) were not carried out, as it was felt that the design lacked further development potential in an offensive role.