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 Samudree Baaj project was initiated in 2006 by the Indian Navy, as part of the long historic plan to provide the Indian Navy with a fully capable aircraft carrier. This plan had been initiated in 1989, when India announced a plan to replace its ageing British-built aircraft carriers, INS Vikrant and INS Viraat (ex-HMS Hermes), with two new 28,000-ton Air Defence Ships (ADS) that would operate the BAe Sea Harrier aircraft. The first vessel was to replace Vikrant, which was set to decommission in early 1997. Construction of the ADS was to start at the Cochin Shipyard (CSL) in 1993 after the Indian Naval Design Organisation had translated this design study into a production model. Following the 1991 economic crisis, the plans for construction of the vessels were put on hold indefinitely.

In 1999, then-Defence Minister George Fernandes revived the project and sanctioned the construction of the Project “71 ADS”. By that time, given the ageing Sea Harrier fleet, the letter of intent called for a carrier that would carry more modern jet fighters. In 2001, CSL released a graphic illustration showing a 32,000-ton STOBAR (Short Take-Off But Arrested Recovery) design with a pronounced ski jump. The aircraft carrier project finally received formal government approval in January 2003. By then, design updates called for a 37,500-ton carrier to operate the MiG-29K. India opted for a three-carrier fleet consisting of one carrier battle group stationed on each seaboard, and a third carrier held in reserve, in order to continuously protect both its flanks, to protect economic interests and mercantile traffic, and to provide humanitarian platforms in times of disasters, since a carrier can provide a self-generating supply of fresh water, medical assistance or engineering expertise to populations in need for assistance.

In August 2006, then-Chief of the Naval Staff, Admiral Arun Prakash stated that the designation for the vessel had been changed from Air Defence Ship (ADS) to Indigenous Aircraft Carrier (IAC). The euphemistic ADS had been adopted in planning stages to ward off concerns about a naval build-up. Final revisions to the design increased the displacement of the carrier from 37,500 tons to over 40,000 tons. The length of the ship also increased from 252 metres (827 ft) to 262 metres (860 ft).

It was at this time that, beyond the MiG-29K, primarily a carrier-capable trainer and also a light (and less costly) strike aircraft would be needed. With the running production of the Hawk Mk. 132 for the Indian Air Force and BAE Systems’ connection and experience to the USA and McDonnell/Boeing’s adaptation of the Hawk as the US Navy’s carrier-capable T-45 trainer, HAL was instructed to develop a suitable aircraft family on the Hawk’s basis for the new carriers.

HAL’s Samudree Baaj is a fully carrier-capable version of the British Aerospace Hawk Mk. The Hawk had not originally been designed to perform carrier operations, so that numerous modifications were required, such as the extensive strengthening of the airframe to withstand the excessive forces imposed by the stresses involved in catapult launches and high sink-rate landings, both scenarios being routine in aircraft carrier operations.

The aerodynamic changes of the aircraft, which were mutually developed by HAL and BAE Systems, included improvements to the low-speed handling characteristics and a reduction in the approach speed. Most notable amongst the changes made to the Hawk's design were extended flaps for better low-speed handling, along with the addition of spoilers on the wings to reduce lift and strakes on the fuselage which improved airflow and stabilizer efficiency.

Other, less obvious modifications included a reinforced airframe, the adoption of a more robust and widened landing gear, complete with a catapult tow bar attachment to the oleo strut of the new two-wheel nose gear design, and an arresting hook. The tail fin was extended by 1 foot (12 in, 30.5 cm) to compensate for the loss of the Hawk’s ventral stabilizing strakes. To make room for the arrester hook, the original ventral air brake was split and re-located to the flanks, similar to the USN’s T-45 trainer.

At the time of the Samudree Baaj’s design, the exact catapult arrangement and capacity on board of India’s new carriers was not clear yet – even more so, since the MiG-29K and its powerful engines might have made a catapult obsolete. Therefore, the Samudree Baaj was designed to be operable either with a ski jump ramp (in the style of the Russian Kiev class carriers, of which India had purchased one as INS Vikramaditya) or with only minimal launch support within the projected STOBAR concept, which included a relatively short-stroke steam catapult and a similarly short, undampened arrester gear.

By 2009 the basic airframe had been defined and four prototypes were built for two versions: the Mk. 101 trainer, which was basically a navalized version of the land-based Mk. 132 with almost the same mission equipment, and the Mk. 201, a single-seater. Two airframes of each type were built and the first Samudree Baaj flight took place in early 2011. The Indian government ordered 30 trainers and 15 attack aircraft, to be delivered with the first new Indian carrier, INS Vikrant, in late 2017.

The Samudree Baaj Mk. 201 was developed from the basic navalized Hawk airframe as a light multirole fighter with a small visual signature and high maneuverability, but high combat efficiency and capable of both strike and point defense missions. It differed from the trainer through a completely new forward fuselage whereby the forward cockpit area, which normally housed the trainee, was replaced by an electronics bay for avionics and onboard systems, including a fire control computer, a LINS 300 ring laser gyroscope inertial navigation system and a lightweight (145 kg) multimode, coherent, pulse-Doppler I band airborne radar. This multimode radar was developed from the Ferranti Blue Fox radar and capable of airborne interception and air-to-surface strike roles over water and land, with look-down/shoot-down and look-up modes. It had ten air-to-surface and ten air-to-ground modes for navigation and weapon aiming purposes.

A ventral fairing behind the radome carried a laser rangefinder and a forward-looking infrared (FLIR). Mid-air refueling was also possible, through a detachable (but fixed) probe. GPS navigation or modern night-flight systems were integrated, too.

Like the trainer, the Mk. 201 had a total of seven weapon hardpoints (1 ventral, four underwing and a pair of wing tip launch rails), but the more sophisticated avionics suite allowed a wider range of ordnance to be carried and deployed, which included radar-guided AAMs for BVR strokes and smart weapons and guided missiles – especially the Sea Eagle and AGM-84 “Harpoon” anti-ship missiles in the Indian Navy’s arsenal. For the maritime strike role and as a support for ASW missions, the Samudree Baaj Mk. 201 could even deploy Sting Ray homing torpedoes.

Furthermore, a pair of 30mm (1.18 in) ADEN machine cannon with 150 RPG were housed in a shallow fairing under the cockpit. The self-protection systems include a BAE SkyGuardian 200 RWR and automatic Vinten chaff/flare dispensers located above the engine exhaust.

The Samudree Baaj project was highly ambitious, so that it does not wonder that there were many delays and teething troubles. Beyond the complex avionics integration this included the maritime adaptation of the Adour engine, which eventually led to the uprated Adour Mk. 871-1N, which, as a side benefit, also offered about 10% more power.

However, in parallel, INS Vikrant also ran into delays: In July 2012, The Times of India reported that construction of Vikrant has been delayed by three years, and the ship would be ready for commissioning by 2018. Later, in November 2012, Indian English-language news channel NDTV reported that cost of the aircraft carrier had increased, and the delivery has been delayed by at least five years and is expected to be with the Indian Navy only after 2018 as against the scheduled date of delivery of 2014. Work then commenced for the next stage of construction, which included the installation of the integrated propulsion system, the superstructure, the upper decks, the cabling, sensors and weapons. Vikrant was eventually undocked on 10 June 2015 after the completion of structural work. Cabling, piping, heat and ventilation works were to be completed by 2017; sea trials would begin thereafter. In December 2019, it was reported that the engines on board the ship were switched on and in November 2020, only the basin trials of the aircraft carrier were completed.

By that time, the first Samudree Baaj aircraft had been delivered to Indian Navy 300 squadron, and even though only based at land at Hansa Air Station, flight training and military operations commenced. In the meantime, the start of Vikrant's trials had initially been scheduled to begin on 12 March 2020, but further construction delays caused that to be moved back to April. With the COVID-19 crisis, the navy explained that trials were unlikely to begin before September/October. During the Navy Day press meeting in December 2019, Navy Chief Admiral Karambir Singh said Vikrant would be fully operational before the end of 2022. The COVID-19 pandemic had already pushed that back to 2023 and further delays appeared possible.

Firing such a heavy weapon caused a lot fo problems, which were severe even if the gun was mounted on a ship or on land. To compensate for such a large-caliber gun’s recoil and to make firing a 14 in shell (which alone weighed around almost 700 kg/1.550 lb, plus the charge) from a relatively light airframe feasible, the respective gun had to be as light as possible and avoid any recoil, which would easily tear an aircraft – even a bomber – apart upon firing. Therefore, the Gerät 104 was designed as a recoilless cannon. Its firing system involved venting the same amount of the weapon's propellant gas for its round to the rear of the launch tube (which was open at both ends), in the same fashion as a rocket launcher. This created a forward directed momentum which was nearly equal to the rearward momentum (recoil) imparted to the system by accelerating the projectile itself. The balance thus created did not leave much net momentum to be imparted to the weapon's mounting or the carrying airframe in the form of felt recoil. A further share of the recoil induced by the moving round itself could be compensated by a muzzle brake which re-directed a part of the firing gases backwards. Since recoil had been mostly negated, a heavy and complex recoil damping mechanism was not necessary – even though the weapon itself was huge and heavy.

Work on the "Münchhausen" device (a secret project handle after a fictional German nobleman created by the German writer Rudolf Erich Raspe in the late 18th century who reputedly had ridden on a cannonball between enemy frontlines), was done by Rheinmetall-Borsig and lasted until 1941. The first test of a prototype weapon was conducted on 9th of September 1940 in Unterlüss with a satisfactory result, even though the weapon was only mounted onto an open rack and not integrated into an airframe yet. At that time, potential carriers were the Ju 88, the Dornier Do 217 and the new Junkers Ju 288. Even though the system’s efficacy was doubted, the prospect of delivering a single, fatal blow to an important , armored arget superseded any doubts at the RLM, and the project was greenlit in early 1942 for the next stage: the integration of the Sondergerät 104 into an existing airframe. The Ju 88 and its successor, the Ju 188, turned out to be too light and lacked carrying capacity for the complete, loaded weapon, and the favored Ju 288 was never produced, so that only the Dornier Do 217 or the bigger He 177 remained as a suitable carriers. The Do 217 was eventually chosen because it had the biggest payload and the airframe was proven and readily available.

After calculations had verified that the designed 14 in rifle would have effectively no recoil, preliminary tests with dumm airframes were carried out. After ground trials with a Do 217 E day bomber to check recoil and blast effects on the airframe, the development and production of a limited Nullserie (pre-production series) of the dedicated Do 217 F variant for field tests and eventual operational use against British sea and land targets was ordered in April 1942.

The resulting Do 217 F-0 was based on the late “E” bomber variant and powered by a pair of BMW 801 radial engines. It was, however, heavily modified for its unique weapon and the highly specialized mission profile: upon arriving at the zone of operation at high altitude, the aircraft would initiate a dive with an angle of attack between 50° and 80° from the horizontal, firing the SG 104 at an altitude between 6,000 and 2,000 meters. The flight time of the projectile could range from 16.0 seconds for a shot from an altitude of 6,000 meters at a 50° angle to just 4.4 seconds for a shot from 2.000 meters at an almost vertical 80° angle. Muzzle velocity of the SG 104 was only 300 m/s, but, prior to impact, the effective velocity of the projectile was projected to range between 449 and 468 m/s (1,616 to 1,674 km/h). Together with the round's weight of roughly 700 kg (1.550 lb) and a hardened tip, this would still ensure a high penetration potential.

The operational Sondergerät 104 had an empty mass of 2.780 kg (6,123 lb) and its complete 14 inch double cartridge weighed around 1.600 kg (3,525 lb). The loaded mass of the weapon was 4,237 kg, stretching the limits of the Do 217’s load capacity to the maximum, so that some armor and less vital pieces of equipment were deleted. Crew and defensive armament were reduced to a minimum.

Even though there had been plans to integrate the wepaon into the airframe (on the Ju 288), the Gerät 104 was on the Do 217 F-0 mounted externally and occupied the whole space under the aircraft, precluding any use of the bomb bay. The latter was occupied by the Gerät 104’s complex mount, which extended to the outside under a streamlined fairing and held the weapon at a distance from the airframe. Between the mount’s struts inside of the fuselage, an additional fuel tank for balance reasons was added, too.

The gun’s center, where the heavy round was carried, was positioned under the aircraft’s center of gravity, so that the gun barrel markedly protruded from under the aircraft’s nose. To make enough space, the Do 217 Es bomb aimer’s ventral gondola and his rearward-facing defensive position under the cockpit were omitted and faired over. The nose section was also totally different: the original extensive glazing (the so-called “Kampfkopf”) was replaced by a smaller, conventional canopy, similar to the later Do 217 J and N night fighter versions, together with a solid nose - the original glass panels would have easily shattered upon firing the gun, esp. in a steep high-speed dive. A "Lotfernrohr" bomb aiming device was still installed in a streamlined and protected fairing, though, so that the navigator could guide the pilot during the approach to the target and during the attack run.

To stabilize the heavy aircraft during its attack and to time- and safely pull out of the dive, a massive mechanical dive brake was mounted at the extended tail tip, which unfolded with four "petals". A charecteristic stabilizing dorsal strake was added between the twin fins, too.

The ventral area behind the gun’s rear-facing muzzle received additional metal plating and blast guiding vanes, after trials in late 1940 had revealed that firing the SG 104 could easily damage the Do 217’s tail structure, esp. all of the tail surfaces’ rudders and the fins’ lower ends in particular. Due to all this extra weight, the Do 217 F-0’s defensive armament consisted only of a single 13 mm MG 131 machine gun in a manually operated dorsal position behind the cockpit cabin, which offered space for a crew of three. A fixed 15 mm MG 151 autocannon was mounted in the nose, too, a weapon with a long barrel for extended range and accuracy. It was not an offensive weapon, though, rather intended as an aiming aid for the SG 104 because it was loaded with tracer bullets: during the final phase of the attack dive, the pilot kept firing the MG 151, and the bullet trail showed if he was on target to fire the SG 104 when the right altitude/range had been reached.

The first Do 217 F-0 was flown and tested in late 1943, and after some detail changes the type was cleared for a limited production run of ten aircraft in January 1944. The first operational machine was delivered to a dedicated testing commando, the Erprobungskommando 104 “Münchhausen”, also known as “Sonderkommando Münchhausen” or simply “E-Staffel 104”. The unit was based at Bordeaux/Merignac and directly attached to the KG 40's as a staff flight. At that time, KG 40 operated Do 217 and He 177 bombers and frequently flew reconnaissance and anti-shipping missions over the Atlantic west of France, up to the British west and southern coast, equipped with experimental Henschel Hs 293 glide bombs.

Initial flights confirmed that the Do 217 airframe was burdened with the SG 104 to its limits, the already rather sluggish aircraft (the Do 217 had generally a high wing loading and was not easy to fly) lost anything that was left of what could be called agility. It needed an experienced pilot to handle it safely, esp. during start and landing. It is no wonder that two Do 217 F-0s suffered ground accidents during the first two weeks of operations, but the machines could be repaired, resume the test program and carry out attack missions.

However, during one of the first test shots with the weapon, one Do 217 F-0 lost its complete tail section though the gun blast, and the aircraft crashed into the Bay of Biscay, killing the complete crew.

On 4th or April 1944 the first "hot" attack against an enemy ship was executed in the Celtic Sea off of Brest, against a convoy of 20 ships homeward bound from Gibraltar. The attack was not successful, though, the shot missing its target, and the German bomber was attacked and heavily damaged by British Bristol Beaufighters that had been deployed to protect the ships. The Do 217F-0 eventually crashed and sank into the Atlantic before it could reach land again.

A couple of days later, on 10th of April, the first attempt to attack and destroy a land target was undertaken: two Do 217 F-0s took off to attack Bouldnor Battery, an armored British artillery position located on the Isle of Wight. One machine had to abort the attack due to oil leakages, the second Do 217 F-0 eventually reached its target and made a shallow attack run, but heavy fog obscured the location and the otherwise successful shot missed the fortification. Upon return to its home base the aircraft was intercepted by RAF fighters over the Channel and heavily damaged, even though German fighters deployed from France came to the rescue, fought the British attackers off and escorted the limping Do 217 F-0 back to its home base.

These events revealed that the overall SG 104 concept was generally feasible, but also showed that the Do 217 F-0 was very vulnerable without air superiority or a suitable escort, so that new tactics had to be developed. One consequence was that further Do 217 F-0 deployments were now supported by V/KG 40, the Luftwaffe's only long range maritime fighter unit. These escorts consisted of Junkers Ju 88C-6s, which were capable of keeping up with the Do 217 F-0 and fend of intercepting RAF Coastal Command’s Beaufighters and later also Mosquitos.

In the meantime, tests with the SG 104 progressed and several modifications were tested on different EKdo 104's Do 217 F-0s. One major upgrade was a further strengthening of the tail section, which added another 200 kg (440 lb) to the aircraft's dry weight. Furthermore, at least three aircraft were outfitted with additional dive brakes under the outer wings, so that the dive could be better controlled and intercepted. these aircraft, however, lost their plumbed underwing hardpoints, but these were only ever used for drop tanks during transfer flights - a loaded SG 104 precluded any other ordnance. On two other aircraft the SG 104 was modified to test different muzzle brakes and deflectors for the rear-facing opening, so that the gun blast was more effectively guided away from the airframe to prevent instability and structural damage. For instance, one machine was equipped with a bifurcated blast deflector that directed the rearward gasses partly sideways, away from the fuselage.

These tests did not last long, though. During the Allied Normandy landings in June 1944 E-Staffel 104 was hastily thrown into action and made several poorly-prepared attack runs against Allied support ships. The biggest success was a full hit and the resulting sinking of the Norwegian destroyer HNoMS Svenner (G03) by "1A+BA" at dawn on 6th of June, off Sword, one of the Allied landing zones. Other targets were engaged, too, but only with little effect. This involvement, however, led to the loss of three Do 217 F-0s within just two days and four more heavily damaged aircraft – leaving only two of EKdo 104's Do 217 F-0s operational.

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 Saab B31 was originally developed as a straightforward tactical bomber replacement for the Saab 18, called the Saab B31, which would carry its free-fall ordnance internally in a bomb bay. The Saab B31 had a streamlined, drop-shaped fuselage. A crew of two were envisioned, the pilot and a navigator/bomb aimer. They would sit in separate cabins, a generously glazed nose section with an optical bombsight and a navigational/bomb aiming radar in a shallow blister underneath, and in a fighter-type cockpit on top of the hull, respectively. Swept wings were planned that would offer a good compromise between speed benefits and range/lift. Due to the aircraft’s size and weight, two de Havilland Ghost engines were required, but integrating these bulky centrifugal flow engines with a relatively large diameter turned out to be a design challenge.

Several layouts were evaluated, including engines buried in the rear fuselage with side air intakes, or engines mounted in wing root fairings with individual exhausts at the wings’ trailing edge. Eventually the Saab B31’s powerplants were directly mounted in nacelles under slightly swept (20°) shoulder wings, what made access and maintenance easy and kept the fuselage free for a huge fuel capacity, a generous bomb bay, and a conventional tricycle main landing gear. The latter’s tread width was quite narrow, though, which might have caused handling problems, so that during the bomber’s design refinements the landing gear arrangement was radically changed into a tandem layout. It eventually comprised of two main struts featuring large low-pressure twin wheels, supported by small outrigger wheels that semi-retracted into fairings under the bulbous engine nacelles. While unusual, this arrangement had the side benefit that the bomb bay could be lengthened and the fuel capacity in the fuselage could be increased without a center of gravity shift, with the rear/main landing gear strut well placed further aft, well behind the aircraft’s center of gravity. This, however, prevented normal rotation upon take-off, so that the front strut was lengthened to provide the aircraft with an imminent positive angle of attack while rolling, giving the Saab B31 a distinctive nose-up stance on the ground.

The enlarged bomb bay could hold up to four free-fall 340 kg bombs, the B31’s primary weapon. Additional ordinance, typically two further single bombs of up to 500 kg caliber, pods with unguided missiles, or drop tanks to extend range, could be carried on a pair of hard points outside of the engine nacelles. The maximum total payload was 2.400 kg. No offensive or defensive guns were carried, the B31 was supposed to rely only on speed and agility. Large air brakes on the aircraft’s flanks were introduced to prevent the exceeding of the B31’s design speed limit of Mach 0.9 in a dive, and they also helped to slow down the aircraft upon landing. To reduce the landing run length further a brake parachute was housed in an extended teardrop fairing on the fin that also held the swept horizontal stabilizers.

Overall, the Saab B31 reminded vaguely of the Soviet Yak-120/25 (NATO code Flashlight A) and of the French Sud-Ouest SO.4050 Vautour, which were both under development at the same time. Beyond the original tactical bomber role that was supposed to supersede the Swedish B 18, the Saab B31 was also intended to fulfill night/all-weather reconnaissance missions, outfitted with a camera and sensor pallet in the bomb bay and flash bombs on the wing hardpoints. Furthermore, the aircraft was proposed to become, in a second step, the basis for a jet-powered long-range all-weather fighter, a type of aircraft that was direly needed by Flygvapnet during the late Forties. The situation was so severe and urgent that the Swedish Air Force did not want to wait for a J31 development and had to procure sixty radar-equipped de Havilland Mosquito NF.30 night fighters from Great Britain as a hasty stopgap solution – a totally outdated model in the late Forties, but it was the best and only readily available off-the-rack solution.

In parallel, both engine and aircraft technology underwent dramatic developments and literally made leaps: In December 1948, an initial contract for the design and mockup of Saab's newly proposed P.1150 design was issued, a modern swept-wing design that already represented the next, transonic fighter aircraft generation. The resulting aircraft would become the Saab 32 ‘Lansen’ and it literally overtook the B31’s intended role as the Saab 18 bomber and attack aircraft replacement. However, a modern all-weather fighter with long range and a powerful radar was still not on the horizon, and, consequently, the Saab B31’s original bomber/reconnaissance version was dropped completely in favor of an optimized interceptor derivative with a powerful on-board radar: the J31. This was, however, also just a stopgap solution until an all-weather fighter version of the favored Saab 32 would be ready for service, so that a single aircraft type would take over multiple military roles and therewith simplify production, maintenance and logistics.

From that point on the Saab B31 was re-designed and optimized for a principal fighter role, with an attack capability as a secondary capability. However, due to its bomber origins and its intended mission profile the J31 was not intended to be a typical sleek and nimble dogfighter (that was the contemporary Saab 29’s role as a day fighter, even though a radar-equipped version of the Tunnan was on Saab’s drawing boards, too, yet not realized because compact systems were not available), but rather as a standoff night fighter which would loiter on station and patrol the air space, search for targets and then identify and engage them.

The bomber’s large air brakes were a welcome feature to position the approaching fighter behind a potential slower target, which were primarily relatively cumbersome bombers that would come in at medium to high altitude and at subsonic speed. This mission profile heavily influenced the J31 design and also set boundaries that were later hard to overcome and develop the aircraft’s potential further. While the light bomber basis would meet the required demands concerning range, speed and limited agility, the obligatory radar and its periphery to fulfill the N/AW fighter mission led to a major re-design of the forward fuselage. A large radar dish under a solid nose radome now occupied the formerly glazed nose section, and the radar operator was placed together with the pilot in a new pressurized side-by-side cockpit under a common canopy. A large and relatively flat forward windshield was used; while not conducive to high-speed flight, it provided distortion-free external visibility, something that was particularly valued for a night fighter at that time. Both pilot and navigator/radar operator had full steering equipment, what also made a dedicated trainer version unnecessary. Both sticks were extendable so that more force could be exerted upon it by the pilot as a fallback measure in the event of a hydraulic failure. Bleed air from the engines was used to de-ice the wings’ and tail surfaces’ leading edges and the engines’ air intakes, so that the aircraft could operate even in harsh climatic conditions.

Radar and fire control system for the J31 were created and produced by Ericsson and called “Gryning” (= Dawn). The system was quite advanced for the time even though complex: a combination of three different radars, each performing separate functions. The system comprised a search radar, a tracking radar, both located in the nose under a huge mutual radome, and a tail warning radar with a separate, smaller antenna. The search radar covered the front hemisphere and could detect aircraft at distances up to 35 kilometres (about 20 miles) away while the tracking radar could achieve a weapons lock up to 4 km (2.5 miles) away. Additionally, the Gryning system had a limited look-down capability, being able to detect aircraft that flew underneath the J31 at an altitude of down to 800 m (2.600 ft). The tail-mounted surveillance radar was effective up to 15 km (almost 10 miles) away. The complexity of this vacuum tube-based radar system, produced before the advent of semiconductor electronics, required a lot of internal space and intensive maintenance to keep it operating properly – and it would have been much too big or heavy to fit into the more modern but also more slender Saab 32 airframe.

The armament was changed, too. While the B31 bomber was intended to carry no guns at all the fighter derivative was now armed with four 20 mm cannon in the lower nose, plus two retractable unguided air-to-air missile racks in the former bomb bay in tandem, carrying a total of 96 projectiles, which were supposed to be fired singly, short bursts or in one or more massive salvoes against bomber formations, covering a huge field of fire and ensuring a takedown even with a single hit. This core armament was complemented by a pair of underwing hardpoints outside of the engine nacelles which could carry pods with further 18 unguided missiles each, iron bombs of up to 500 kg calibre for a secondary attack capability, or 570 l drop tanks to extend the J31’s range and loiter time.

An initial order for three prototypes was placed by the Swedish government, and on 16 October 1950, the first J31, even though still lacking the radar, conducted its maiden flight. The flight test program proceeded relatively smoothly, but the performance was rather poor for a fighter. More powerful engines were required, but choices for Saab were very limited. The use of the Saab 29’s indigenous afterburner variant of the Ghost (which was by then license-produced in Sweden as the Svenska Flygmotor RM2) was deemed inefficient for the large aircraft, so that attempts were made to improve the Ghost’s dry thrust for the J31 without an increased fuel consumption through reheat. This new indigenous engine variant became the RM2F (“förstärkt” = “powered-up”), which provided 5,400 lbf (24.02 kN) of thrust with water-alcohol injection instead of the RM2’s original dry 5,000 lbf (22 kN) maximum thrust. The tank for the required water-alcohol mixture was carried in the rear half of the former bomb bay and replaced one of the unguided missile racks. These were hardly ever used operationally, though, and soon completely removed, replaced by a second water-alcohol tank, which gave the aircraft enough endurance of 30 minutes at the increased thrust output level.

A follow-on order for six pre-production aircraft was soon received, which were still equipped with the weaker original RM2 and designated J31A. These machines were delivered to F 1 Västmanland Flygflottilj at Hässlö air base in Central Sweden, which just had been converted from a bomber to a night fighter unit, having been equipped with the J 30 Mosquitos. There the J31 was evaluated against the J30 until early 1951 and deemed superior in almost every aspect. With these satisfactory results, a full production order for 54 more aircraft was placed in mid-1951. These machines were now outfitted with more powerful RM2F engines and other refinements and designated J31B. This became the type’s operational main variant. All were delivered to F 1 where they were exclusively operated and gradually replaced the J 30s. In service the J31 received the unofficial nickname “Val” (= Whale), due to its bulky yet streamlined shape, but it was officially never adopted.

During regular maintenance in the following two years, the six early J31As received the stronger RM2F, together with the second water-alcohol tank as well as some avionics updates and were accordingly re-designated J31Bs. Further updates included wipers for the windscreen (a serious issue esp. at slow speed and while taxiing) and two smaller brake parachutes instead of the single large original one.

All J31s were delivered in a natural metal finish and retained it throughout their career; only two machines ever received camouflage during trials, but this measure was deemed unnecessary for the aircraft due to their role. Some aircraft of F 1’s 3rd squadron and operated by the unit’s staff flight had the aircrafts’ fins painted in dark green, though, to improve the contrast to the tactical code letters’ colour, yellow or white, respectively. The J31s’ radomes were made from fiberglass and originally tinted in opaque black. During maintenance and after damage, however, some machines received newly produced replacement fairings which were untinted/semi-transparent.

The only major update the J31B received was rolled out starting in 1958, when the IR-guided Rb24 (AIM-9B Sidewinder AAM) was introduced in the Swedish Air Force. Together with the J29 Tunnan fighters the J31s were outfitted to carry launch rails on the wing hardpoints – even though only a single pair could be carried in total. This, however, markedly improved the type’s combat efficiency, and it would take until the Saab 35F in 1965 with its Rb27/28 Falcon missiles to introduce more capable guided anti-aircraft missiles. Since the Rb24s extended the J31’s weapon range considerably, a potential gun upgrade with 30 mm cannons was not executed and Saab’s resources rather allocated into the Saab 32’s development.

Even though the J31B was a capable night and all-weather fighter for its time, it was limited due to its outdated weaponry and quickly superseded by advancing radar, engine and aerodynamic technologies. It did its job but lacked development and performance potential – and it was a large and complicated aircraft that required lots of maintenance. However, the J31 turned out to be a very stable and robust weapon platform, and it was quite popular among the crews because of the spacious cockpit, even though the field of view on the ground was very limited, due to the tall landing gear front leg, and several J31s were involved in taxiing accidents. Due to its twin engines and radar intercept operator, pilots gained more confidence on long missions in the remote northern areas of. Sweden, esp. on mission over open water.

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.