Fairchild Republic A-10 Thunderbolt II: The 'Warthog' Ground Attack Aircraft

By Peter C. Smith

A comprehensive account of the origins, design, and history of the A-10A Warthog: “Highly recommended.” —AMPS Indianapolis

Includes photos

The Fairchild-Republic A-10A Close Support aircraft has become a legend over its long front line life. Known as the Warthog due to her unusual appearance, this little aircraft has built up an awesome reputation in the specialized ground-attack role, where her accuracy and deadliness are widely recognized as the best of their kind.

Hard lessons from World War II, which were reinforced by the bitter experience of the Vietnam War two decades later, showed it was both impracticable and cost-inefficient to use supersonic fighter jets in the close air support mission. A requirement was therefore drawn up for a plane capable of carrying a heavy and varied load of ordnance, which had good endurance and unprecedented maneuverability and could survive heavy ground fire—thus the A-10 was born. But by the time it came into service its role had changed to that of a tank-buster in the defense of Western Europe in the face of the overwhelming numbers of Soviet battle armor.

With her straight wing, twin tails, and turbine engines mounted high on her rear fuselage, this single-seat aircraft certainly presented a unique appearance. But all these features served a vital role, as Peter C. Smith explains in this highly detailed study.

Although the Warthog’s expected missions on the plains of Germany did not materialize, she did destroy hundreds of Soviet-built tanks during the Gulf wars. The A-10 has also flown almost continuous missions over the Balkans, against the Taliban in Afghanistan, and ISIS in Iraq and Syria. This beautifully illustrated and comprehensive volume brings the A-10’s incredible story right up to date.

• Language: English
• Publisher: Open Road Integrated Media
• Release date: Jan 31, 2021
• ISBN: 9781526759276

Book preview

Chapter 1

Varying Origins

Close Air Support, Anti-Tank, COIN, LARA

The A-10A Thunderbolt II earned itself a formidable reputation as the tank-busting aircraft par excellence during the Gulf War. This was no hyped-up accolade; the facts speak for themselves. Although ‘Warthogs’ (as the A-10A has been affectionately and universally known almost since its inception) formed but a small fraction of the combined United Nations’ aerial armada that pounded Saddam Hussein’s massive tank force, the A-10A was credited with the bulk of the actual tank ‘kills’ by a very wide margin.

Yet the A-10A was not originally conceived as a totally dedicated tank-killing aircraft and, from its earliest inception, forced upon an extremely reluctant Air Force by the needs of the army on the ground and the army’s determination to see those needs satisfied, its role changed according to circumstances as it metamorphasized into the supreme armour-destroyer that we know today.

In fact, it can be said that there were three strands of history that influenced thought and which ultimately led to the A-10A ending up as a destroyer of tanks and armoured vehicles. These were (1) Immediate: with the urgent requirement by the army for a specially-designed close support aircraft following their experiences during the Vietnam War which forced them to adopt the semi-obsolete Navy AD Skyraider pistonengine aircraft as the A-1 because their own policies and neglect of this facet of air power had led to a paucity of suitable machines for the job. The Skyraider could carry an enormous total and range of ordnance and could loiter in the battle zone, but with improved AAA from enemy forces and the introduction of SAMs, such aircraft were proving vulnerable to ground defences. What was required was a ground-attack aircraft with the armoured protection of another Second World War aircraft, the Soviet Il-2 or Shturmovik. A modern equivalent, with the combined qualities of the AD and the Il-2, was thought to be the solution. (2) Generic: via the precision of the North American A-36 Apache dive-bomber, which was highly accurate, and via the Republic-linked name of original P-47D Thunderbolt fighter aircraft, also of the Second World War, which adopted both dive-bombing with bombs and low-level attacks with rockets to strike at German tanks and was thus thought a suitable precedent. (3) Historic: via the examples of the specialized and totally dedicated aircraft and weapons developed by the Junkers company and others for the German Air Force from the First World War on, and especially those designed to combat the self-same threat posed by tens of thousands of heavily-armoured Soviet tanks during the Second World War, the exact same threat that hung like a nightmare over all NATO defence planning more than thirty years later (see Diagram 1).

Diagram 1: Influences on design of A10A

(1) Immediate: Douglas AD Skyraider + Ilyushin Il-2 Shturmovik

(2) Generic: North American A-36 Apache - Republic P-47D Thunderbolt

(3) Historic: Junkers JI and CLI - Junkers 87 G Panzerknacker

Let us examine each facet of influence in turn and in detail.

(1) The role of close support had long been an area of acute controversy in the US Air Force. Even in the 1930s, while the US Navy was specializing in the dive-bomber as its main air weapon, the USAAF shunned the concept and preferred the low-level ‘Attack’ concept, also favoured by the RAF at that time. When the US eventually became embroiled in the Second World War its land forces came up against the German Junkers Ju 87 Stukas in North Africa and found themselves stopped dead by them on several occasions. There was much recrimination at the time ¹ and the only available aircraft the USAAF had to carry out the Close Air Support (CAS) role, Curtiss P-40 fighters armed with under-wing bombs, proved totally inadequate and inefficient for this role.

The introduction in 1943 of the North American A-36, an Alison-engine prototype of the Mustang fighter fitted with Vultee dive brakes, proved more valuable, and this aircraft was both fast and accurate. It served very satisfactorily at Sicily, Salerno and Anzio in 1943–44 and in Burma and China in the same period, but only 500 had been built and once they had been used up, the USAAF was forced back to fighter-bombers for CAS once more.

Although a special study into Tactical Air Power was set up post-war, the introduction of the jet aircraft again produced argument and counter-argument and during the next major incident, the Korean War, there was again an acute lack of suitable aircraft for this duty. Once more, there was much bitterness between the army, who wanted Marine-type air support that was heavy, accurate and sustainable, and the Air Force jet pilots, who simply wanted to dogfight with MiGs and not get involved in ground-attack other than quick ‘in-bash-out’-type operations, which proved both inaccurate and meaningless. This lesson had to be re-learned in the Korean War in the early 1950s and was promptly forgotten, or more truly buried, by a strategical bomber-dominated Air Force hierarchy who still despised the Close Air Support role.

Again the arguments were vented and re-vented but the sum total was that when the Vietnam War became a full shooting war for the Americans, the most reliable aircraft to support troops on the ground proved itself to be the same old slow, reliable but accurate and enduring Douglas AD Skyraider that the US Navy and Marine Corps had used in Korea a decade or more earlier, for which there was still no US Air Force equivalent.

The deep studies into Counter Insurgency (COIN) aircraft came up with various answers, none of which was a satisfactory one. In the end, following the lead of the Vietnamese Air Force (VNAF), the US Air Force was forced to adopt retired US Navy ‘Spads’, refit and refurbish them and use them in the Ground Support role themselves as nothing else proved suitable. This was obviously not a satisfactory outcome for the USAF, but with the army calling for an aircraft that could deliver varied and sustainable ordnance and loiter over the battle zone, only the Able Dog filled the bill, even though she was to become increasingly vulnerable as time went on. So badly did the army want such an aircraft and so powerless was the Air Force to supply it, that serious consideration was given by the former service to buying, training and utilizing their own aircraft to do the job. This naturally raised hackles and alarm in the Air Force, who considered CAS ‘their job’, having been assigned the task when they gained independence from the army in 1948 under the Key West Agreement, even though they had refused to produce any specialized warplanes to carry it out. They were forced into a hasty re-think on policy.

Close Air Support was defined by the USAF in 1974 thus: ‘Air attacks against hostile targets which are in close proximity to friendly forces and which required detailed integration of each air mission with the fire and movement of those forces.’² This definition still holds good today of course, but even back then how to best provide such aerial firepower on the battlefield and, equally controversial, who was to provide it, was subject of the same bitter debate. Then, as now, it turned into a ‘war of attrition’ for steadily reducing funding in the aftermath of the disastrous outcome of the Vietnam War and enormous acrimony between the USAF (who did not want the job but did not want to relinquish any fixed-wing aircraft), and the US army (who deemed the mission absolutely vital and were therefore prepared to conduct it themselves). The army made repeated attempts to have its say on CAS but was repeatedly thwarted by the USAF throughout the 1950s, 1960s and onward.

The expeditious use of the North American T-28D trainer converted for use as a light ground-attack aircraft was considered, following the lead of the French in Algeria with the Fennec, but of course they faced little or no ground opposition and were thus able to operate almost freely. Initially the same conditions may have been relevant against the Viet Cong, but as the Soviet Union increasingly supplied them, and later the North Vietnamese regular army forces engaged with sophisticated 12.7mm-calibre multi-barrel AAA and Surface-to-Air Missile (SAM) systems, the vulnerability of such makeshift types rapidly increased. This increased firepower by the Communist forces brought about the early termination of the projected Light Armed Reconnaissance Aircraft (LARA) project, which had called for a relatively unsophisticated aircraft able to operate with all three services (Air Force, Marine Corps and Navy) as well as the Vietnamese. Although such an aircraft did eventually appear, the Rockwell OV-10 Bronco, it was used more as a Forward Air Control (FAC) aircraft for this reason. Another solution had to be found and another interim measure was adopted.

The French had also used their own Douglas Skyraiders in the CAS role, and the Vietnamese Air Force was also supplied with this aircraft by America. It proved a great success, so much so that the USAF eventually adopted the A-1 Skyraider themselves.

The establishment of 1 Fighter Squadron (Commando) FS(C) at Bien Hoa airfield significantly escalated American intervention in South-East Asia. Originally three American Skyraider squadrons were planned in order to give the necessary ‘stiffening’ of the VNAF units. The first detachment, 1 FS(C), commanded by Lieutenant Commander John M. Porter (later relieved by Lieutenant Commander William R. Eichelberger), was based at Bien Hoa from 8 July 1963 as part of 34 Tactical Group, their A-1Es Skyraider arriving there on 1 May 1964.

Re-designated 1 Air Commando Squadron, Composite, this unit became part of 6251 Tactical Fighter Wing on 8 July 1965, before moving into 3 Tactical Fighter Wing on 21 November 1965 and then, by 8 March 1966, 14 Air Commando Wing. Their duties soon expanded from the training of VNAF pilots to much more active participation in the war, flying psychological warfare, photo reconnaissance missions and, eventually, full combat bomber missions.

On 15 August 1967, this unit was re-designated as 1 Air Commando Squadron, Fighter, commanded by Lieutenant Commander James R. Hildreth, and was once more re-organized to become part of 56 Air Commando Wing on 20 December 1967. This wing was soon re-designated as 56 Special Operations Wing and, on 15 August 1967, was re-designated 1 Special Operations Squadron, with Lieutenant Commander John A. Saffell Jr. taking command on 20 December 1967. On 5 January 1966, 1 Air Commando began operations from Pleiku Air Base.

A-1J Skyraider (Bu. 142028) from USS Intrepid, of VA-176 over Vietnamese waters in 1966. (US Navy National Museum of Naval Aviation Pensacola, Florida)

From their success, a second USAF Skyraider squadron, 6 Air Commando, was established at England Air Force Base as part of 1 Air Commando Wing. From August 1967, the initial duties of the pilots of this squadron were to fly A-1H and A-1J Skyraiders from Davis-Monthan air base over to the US Navy facility at Quonset Point, Rhode Island for them to be refurbished and then fly them back to England AFB. Eventually fourteen pilots, commanded by Lieutenant Commander Repp, initiated a full re-training programme which continued until February 1968. On completion of this they transferred, via the Survival School at Clark AFB, to Pleiku, Vietnam. Under the command of Commander Wallace A. Ford, they had an establishment strength of 25 pilots with 135 airmen. In mid-March, the squadron’s twenty aircraft were unloaded at Cam Ranh Bay from the escort carrier transport ship and the squadron commenced operations.³

The Skyraider had enormous load-carrying capability and staying power but, with growing Communist AAA and SAM power, she proved more and more vulnerable to ground defences. Extra protection for both pilot and powerplant were necessary to give some degree of immunity in such a dangerous role. A powerful precedent for this type of flying armoured box had been set during the Second World War by the Soviet Union, who, developing strong anti-aircraft defences of their own, had seen the need early on.

The most famous development of the Soviet approach to low-level air attack and ground strafing had been the development and use of the Ilyushin Il-2 Shturmovik aircraft, which had received wide publicity in the West at that time.⁴ The Il-2 was indeed a formidable weapon of air warfare for, although of standard construction and lacking any outstanding performance like its contemporary, the Petlyakov Pe-2 dive-bomber, which was faster than many fighters, the Shturmovik was immensely strong and rugged, able to take considerable punishment and also to operate efficiently at low level. Its origins dated back to the unsatisfactory performance of the Nyeman R-10 and Sukhoi Su-2, which led in turn to an extremely specialized aircraft being demanded to fulfil the ground-attack role, the BSh-2, Bronirovanny Shturmovik (which can be translated as Armoured Assault).

As envisaged, the BSh-2 was to incorporate the heaviest possible armour protection, simplicity and toughness of construction, with the largest possible engine to haul it through the sky and carry into action a heavy forward-firing machine-gun armament of four ShKAS 7.62mm guns mounted in the wings, along with unguided rocket-projectiles like the RS-82 and the later RBS-82 and ROFS-132, exclusively for ground-attack work. High performance, rear gun protection and all other considerations went by the board in order to concentrate on this principal mission.

Ilyushin took up the challenge and came up with a single-engine, the AM-38 in-line rated at 1,600hp, which was originally a twin-seat design that seemed to fit the bill. Basically of standard metal construction with regard to the outer portions of the aircraft, nose, tail, rear fuselage and wings, the core of the Il-2 was virtually an armoured box that encased the vitals of the machine, the pilot’s area (Stalin having insisted the design be altered from a two-seater to a single-seater to economize on space), the engine compartment, the fuel tanks and the radiators. This ‘box’ was built of 7mm thick armour plate, which increased to a maximum of 12mm behind the pilot, the most vulnerable area as there was now no rear gunner.

By the time the Il-2 entered service, the strafing potential had been considerably enhanced by the adoption of two ShVAK 20mm cannon, with 100 rounds per gun, in place of two of the wing-mounted machine guns, with up to eight RS-82 rockets being carried on under-wing racks. The aircraft had an internal bomb-bay but, by utilizing the under-wing capacity in place of rockets, up to 1,320lb of bombs could be taken into battle. The speed was of course limited, some 270 mph being about the best, but this was not deemed essential, nor was the range – a mere 370 to 450 miles at most – for what was a totally dedicated tactical aircraft.

When the Soviet Union was invaded by Germany in June 1941, only a small number of Shturmoviks were available and their first taste of action was on 26 June 1941 when 4 Shturmovoi Aviapolk (ShAP or Ground Attack Air Regiment) went into action over the Berezina River. With an established strength of sixty-five aircraft, this former medium bomb unit was thrown into battle with little or no conversion training for either aircrew or ground-support complement and suffered horrendous losses, being reduced to a mere three aircraft after just seven weeks’ operations.

Nonetheless, as time went on, they proved invaluable and tactics improved as numbers and expertise rose. The famous ‘Circle of Death’ shallow dive approach, which replaced the low-level attack and which was introduced later in the war, quickly proved a most successful way of decimating German Panzer columns. The striking power of the Il-2 was much increased by the substitution of the VY, a high-velocity 20mm cannon which could open most German tanks with ease. The re-introduction of the rear gunner also gave a better measure of defence from German fighters attacking from behind, while the fitting of the more powerful 1,750hp AM-38F was another step forward during 1942, which resulted in the Il-2m3 sub-type. With the evacuation of many aircraft factories to safety beyond the Ural Mountains and with Stalin’s force and power behind it, actual production numbers soared. Relatively simple in construction, Shturmoviks were turned out, like the T-34 tank, in enormous numbers as the war went on, and by 1945 the Il-2 represented one-third of the entire Soviet warplane production!

With improved armament, improved power, improved tactics and overwhelming numbers, the Shturmovik dominated Close Air Support operations on the Eastern Front between 1943 and 1945 and earned itself a legendary reputation. Little wonder then, that almost a quarter of a century later American designers should look hard at just what made this aircraft so outstanding.

(2) North American A-36 Apache

This aircraft was the dive-bomber version of the North American P-51 Mustang long-range fighter and was developed ahead of that famous aircraft. Indeed, had it not been for the A-36, the introduction of the P-51 would have been much delayed.⁵ Of clean-cut design, the A-36 could carry a single 500lb bomb externally beneath her wings and used the same top and bottom opening dive-brakes mounted on the wings that was to be a feature of the Vultee Vengeance. Only 500 A-36 machines were built and they were used by three Air Groups of the United States Army Air Force in North Africa, Sicily and Italy as well as in the South-East Asia area in 1942–44.

(3) Republic P-47 Thunderbolt

The Hog’s official name was a red herring, the Republic division of the Fairchild Corporation giving rise to the historical but not very original dubbing of the aircraft by unimaginative Air Force officers as the Thunderbolt II in a kind of tribute to the Second World War long-range fighter, the Republic P-47 Thunderbolt. This original Thunderbolt was a heavy, single-engined fighter aircraft designed to escort Boeing B-17 Fortresses to Berlin but, due to its great strength and power, it was pressed into service in 1944–45 as a makeshift ground-attack aircraft armed with both bombs and rockets for European ground-support operations following the Normandy landings. As such, it substituted for the true ‘Attack’-type aircraft and acted as a dive-bomber due to lack of suitable machines for that role also, as all the most successful North American A-36 Apache dive-bombers, only 500 having been built in total, had been used up.

The main American contribution to the land war in Europe was made by the 9th Air Force, initially based on airfields in the UK. This outfit worked in conjunction with the British 2nd Tactical Air Force (which used Hawker Typhoons equipped with rockets and bombs (‘BombPhoons’) in a similar manner to fulfil one of their main directives, i.e. direct and indirect close support by fighter-bombers of the armies in the field. This was after the decision had been taken to confine long-range bomber fighter protection to the North American P-51 Mustang and turn the more rugged and strong P-47D into a ground-strafer and dive-bomber. The first dive-bombing mission was conducted by P-47Ds on 15 March 1944 by the 366th Fighter Group against St. Valery airfield. (Of course, having totally rejected the whole dive-bomber concept earlier in the war, the realization that the most accurate delivery of bombs was in fact achieved by this method could have caused red faces in both the USAAF and the RAF, but they called it ‘Vertical Bombing’ instead, and thus saved face both then and since!)

In April 1944, two Tactical Air Commands were established to support the US 1st and 3rd Armies respectively, once they had got ashore in Normandy. At first the P-47Ds carried relatively ineffectual payloads of 250lb bombs, but loading quickly escalated and soon combinations of 500lb bombs and 23lb fragmentation bombs were being carried on racks under the fuselage, and then 1,000lb bombs were found perfectly feasible for the Thunderbolt. Under the wings two 500lb bombs could be carried. When the V-2 rocket attacks on London commenced, their small launch sites proved difficult for conventional bombers to take out and the RAF was forced to resort to dive-bombing in order to suppress them. Having no dive-bombers (other than the Vultee Vengeance in Burma, which they were desperate to be rid of despite its success, and troops on the ground pleading for it to be retained), they had to equip Spitfire fighters with bomb racks and use them in the dive-bomber role.⁶

By June 1944 and the Normandy invasion, the USAAF had built up the IX and XIX Tactical Air Commands considerably and there were no fewer than twenty-one squadrons of P47Ds in the former and fifteen in the latter in time for operations. Other Allied Air Forces had been similarly equipped, the RAF having sixteen squadrons so fitted (as Thunderbolt IIs) in the Far East by the end of the war, while the Free French Armée de l’Air also had several of their Groups de Chasse supplied with the P-47D to perform the same role and these took part in the further invasion of Southern France and operations in that theatre in the autumn and winter of 1944, as well as units belonging to the Air Forces of Brazil (who used them in Italy 1944–45), Mexico and the USSR.

The Republic P-47D Thunderbolt featured greater armour protection for the pilot as befitted its new role of ground-attacker and the wings were also strengthened to carry the bomb loads demanded in this new operation, but apart from a few other refinements like the introduction of a bubble cockpit canopy and later improvements in engine power and range, this variant was similar to the standard production model. It was, for its day, a very large fighter aircraft, built around a single enormous radial engine, the Pratt & Whitney R-2800-21 and -63. Armed with up to eight 0.50 calibre machine guns as an interceptor, it could eventually tote up to 2,000lb worth of bombs into action and had range enough to strike at all Northern European targets.

The P-47D was one classic example of a high-performance fighter aircraft having the strength and power to make the successful conversion into a fighter-bomber, the other being its British contemporary, the Hawker Typhoon. Both aircraft received high acclaim as tank-busters in battles like Mortain, Falaise and such – the P-47D with bombs, the Typhoon with rockets – but those claims failed to stand up to detailed and expert scrutiny on the ground subsequent to the battles that established that reputation. However, if they were not in reality as successful as claimed at the time, their ‘legend’ had by that time been established and has lasted to this day, with little things like facts not tarnishing the image very much!

Originally built at Farmingdale, Long Island, the ‘Jug’ (as this monster was affectionately known) was built in such huge numbers that production had to be sub-contracted out to a new plant at Evansville, Indiana and to Curtiss-Wright at their Buffalo plant to satisfy demand. Nonetheless, it was as ‘Farmingdale’s Finest’ that the P-47D was associated and it was, therefore, an almost inevitable choice of name for a tank-busting successor, which also had been converted from one role, Close Air Support, to a more specialized anti-tank aircraft. One might have wished for more originality, but the logic of the choice that was made is clear enough. Fortunately – or maybe not – the pilots who flew the new aircraft were to come up with their own very original name for the A-10A; one that, if far from flattering, at least has earned an undying and lasting place in aviation history, and it is surely as the Warthog that this aircraft will forever be known!

In summary then, the success of the P-47 against German armour during the break-out from the beachheads and the Falaise Gap battle and the subsequent pursuit across Northern Europe gave rise to propaganda and media hype which portrayed the P-47 as a first-class tank-busting aircraft and this, in turn, influenced subsequent post-war decisions to form the Tactical Air Force in 1947, and further affected policy adopted by the Air Force once it had won its independence from the army the same year.

If the Skyraider had formed the working basis from which the original A-10A concept had been developed, then surely a far more relevant precedent than the P-47D was to be found when examining the historic influence. Until the advent of the Thunderbolt II on the scene, no aircraft had come closer to satisfactorily fulfilling that role than the Junkers Ju 87G, a variant of the famed Stuka dive-bomber, equipped with underwing cannon firing tungsten-tipped shells that could penetrate the tough hides of even the Soviet T-34, the main battle-tank of the Eastern Front during the Second World War.

This precedent has been totally ignored by modern historians, one indeed dismissing the Junkers Ju 87 with the usual bland statement that ‘…the Royal Air Force found its measure and defeated it.’⁷ The RAF undoubtedly defeated the Ju 87 in the Battle of Britain when it was incorrectly used as a strategic weapon, but it never defeated the Stuka in the preceding Battle of France which saw the ejection of all British forces from Europe in a matter of a few weeks, nor did it defeat it in the subsequent campaigns in the Balkans and hardly ever, if at all, did the RAF encounter the Gustav version, which fought almost all its battles on the Eastern Front where it created havoc among Soviet tank columns following its introduction in mid-1943. By ignoring the Ju 87G completely, such writers give a very one-sided view of the influence this aircraft had on the A-10A’s final and most famous combat role.

Yet even the Ju 87G had a more distant antecedent, dating back, in fact, to the First World War. This grim conflict had seen the introduction, by the British army, of the tank itself to break the hideous stalemate of trench warfare on the Western Front. Although of course primitive and slow by subsequent standards, the tank was successful when utilized correctly and spread fear among the German infantry. Antidotes were urgently required, and one was the introduction of specially-armoured aircraft which could make low-level attacks in the face of AA fire. Both the Germans and the British produced such aircraft, and these can also be considered as the great-grandfathers of the A-10A.

The British answer was the Sopwith Salamander, a typical biplane of the period but designed from the outset as a ground-attack machine, and thus from the engine compartment to the pilot’s area she was given some armour protection (although proof against small-arms fire only). This aircraft appeared too late to take part in any fighting, but the concept was sound enough. The Germans, whose need to protect themselves from the British tanks was more pressing and immediate, did rather better. As early as 1916, at Verdun, their scout aircraft had been employed in the ground-strafing role (Schlachtstaffeln units) with Halberstadt and Hannoverna aircraft. However, the Germans had also foreseen the need to provide a specialist aircraft for this role, and the Junkers company developed the JI and the CLI which incorporated both armour protection and offensive capability against land forces in addition to their normal machine guns in the form of bundles of grenades. Here was the germ of close support made manifest.

One pioneer in the art of using aircraft to destroy or at least disable or halt tanks was Oberleutnant Robert Ritter von Greim. He was serving with the 34 (Bavarian) Jagdstaffel and, on 1 March 1918, during the final great German offensive on the Western Front, he and his wingman Vizefeldwebel Putz, attacked a British tank column, strafing them from 600 metres and successfully breaking up their attack. It was the first tank-busting success in aviation history. Von Greim was awarded the Pour le Mérite for his action and laid the foundations on which the Luftwaffe of two decades later was built. Whole-hearted, unreserved support for the army was the Luftwaffe’s forte and gave them the blitzkrieg victories of 1939–41. Their attitude contrasted totally with that of the Allies who were very reluctant to commit aircraft to direct support of troops on the ground and, indeed, had built hardly any aircraft capable of doing so.

While machine-gun strafing might have been enough to strip tracks off the tanks of the British and French armies, and even penetrate the armour of some of the light tanks deployed by these forces, such methods proved useless against the armoured monsters encountered on the Eastern Front when Hitler took up cudgels against the Communist hordes of Stalin in June 1941. It was quickly found that such monsters as the T-35B heavy tank with 50mm armour plate, the KV-1A heavy tank with 77mm thick armour and even the far more numerous T-34/76A main battle-tank with sloping armour up to 45mm thick needed far greater penetrating power than this and a solution was hastily sought.

The answer was found in the conversion of the 37mm Flak 18 (or Bord Kannone 3.7cm) cannon, an anti-aircraft gun designed in the First World War which, much improved, entered service with the Luftwaffe⁸ in 1933 as the Fla 18/36/37. Although its slow traverse made it unsuitable in its design role, under test it was found eminently suitable for conversion to use as an anti-tank weapon. With a muzzle velocity of 2,820ft per second (855m per second) this weapon fired a Minengranatpatrone 18, 3lb (1.4kg) tungsten-cored, armour-piercing explosive shell, which had the ability to penetrate Soviet tank armour 60mm thick at an impact angle of 60 degrees at a distance of 100m. Upgraded versions were developed that were capable of piercing 120mm thick armour plating.

The weight of this weapon was 270kg and it had an overall length of 3,620mm. Each barrel was 6ft in length and was fitted with streamlined pods to help with the aerodynamics and also protect the breech mechanism. An air intake was fitted in a bulbous cowling with a circular frontal aperture above the gun pod for the gun’s hydraulic oil heater. The automatically-fed, six-round clips of shells were loaded into horizontal trays which extended from either side of the gun. They had folding-down hinged caps to take the clips. The rounds carried were 14.5in in length with a maximum diameter of 1.9in. As well as the pointed-nose armour-piercing rounds, alternate loadings could include blunt-tipped rounds, Brandsprenggandatpatrone (incendiary) self-destructing tracer rounds which only ignited if a hit was scored on a truck’s fuel tank, or the Sprenggranatpatrone 18 (high-explosive) round of self-destructing tracer for soft-skinned targets.

Various aircraft were trial-fitted with a variety of anti-tank weapons to see which was the most suitable and stable weapons platform for them. Among the aircraft finally equipped were the Junkers Ju 88P twin-engined bomber, which carried a hand-loaded 75mm KwK 39 gun under the fuselage, the Bf 110G.2R/1 and four twin-engined fighters (Zerstorer) which carried a single BK 37mm cannon, also beneath the fuselage, and the Hs 129B-2/R4 twin-engined ground-attack aircraft which had previously carried two 20mm MG151/20 cannon. Results varied and, in the end, the large Ju 88 proved unsuitable in this role and took heavy losses.

One of the trial aircraft thus fitted in December 1942 was a Ju 87D Stuka which had two of these awesome weapons slung beneath each wing outboard of her fixed undercarriage legs. Experimental test-firings against captured Soviet tanks by selected Stuka pilots gave good overall results and the idea was taken to the battlefield for more practical experiments in real action conditions. In February 1943, the Versuchverband für Panzerkämpfung (Experimental Tank-fighting Unit) was formed. It was led by Oberstleutnant Otto Weiss with Hauptmann Hans-Karl Stepp of the Erprobungsstelle as his second-in-command and experienced pilots were selected to take these aircraft into combat.

Major Hans-Ulrich Rudel – Tank Killer Supreme. (Franz Selinger)

Although it was found that the already slow Stuka was made even slower and slightly less manoeuvrable with these cannon emplaced, despite the fact that all extraneous equipment for their specialized role such as dive brakes, conventional bomb racks and the like, was stripped in compensation, along with the Hs 129B-2, these were the aircraft selected to equip the new Panzerjäger unit on the Eastern Front. They first saw combat at the huge tank battle of Kursk in July 1943 (Operation Zitadelle). They performed well, especially when concentrated as one force under the command of Hauptmann Hans-Ulrich Rudel and scored many victories. With conventional Stukas dropping bombs to suppress the flak defences, the Gustavs attacked the Soviet tanks, mainly from the rear or sides where their armour was thinner, and knocked out a great number.

Like most skills, the art of tank-busting was one that had to be acquired. Some pilots, like Rudel himself, proved naturally adept at it, and by the end of the war he had personally ‘killed’ more than 500 tanks. Others were almost as proficient, but not all proved so skilful. Nonetheless, the Ju 87G was, without doubt, the tank-smasher supreme and each dive-bomber group included one Panzerjäger Staffel on its establishment from then on until the end of the war.⁹

At the end of the war Rudel, among others, flew his intact unit to surrender to the Americans and was subsequently interrogated. He thought his captors might be interested in knowing just how his slow Ju87s had been so successful in knocking out so many Soviet tanks; after all, it was patently obvious to him that they would be next for Stalin’s attention. Instead he was listened to with complete scepticism and his claims were dismissed as Nazi propaganda! To Western airmen speed was everything, and they could not conceive of sacrificing mph for accuracy.¹⁰ They totally believed that such an inherently inaccurate weapon as an unguided rocket projectile could be fired from a high-speed Thunderbolt or Typhoon and hit such a small target as a moving tank, but they refused to credit that cannon-fire from a slow-moving Ju 87 could achieve the same or indeed far better results. That attitude was not to change for many years.¹¹

Chapter 2

Army Needs versus Air Force Doctrine (AAFSS)

The army’s Advanced Aerial Fire Support System (AAFSS) originated in 1964 and continued for seven years. However, well before this date, the army had, as noted, frequently expressed its dissatisfaction with the CAS provided to it by the USAF, whose main concern was, as always, high-altitude dogfighting, and whose aircraft were becoming ever faster, larger and less able to operate ‘down in the mud’ where the army wanted to see them. As early as the late 1950s, the army Aviation Combat Development Agency (ACDA) began to work with the Test Board to see if it was possible for the army to operate its own fixed-wing air support, more suited to its needs.

The parameters were obvious: such an aircraft must be able to operate mainly in the low-level environment over the immediate battlefield, be able to deliver a wide variety of ordnance accurately, must be able to take off and land from primitive and short landing strips, must be of rugged and tough construction to withstand such operations at a high level of intensity and must be simple to fly and maintain. Looking around at what was available ‘off-the-shelf’, the ACDA decided that one aircraft fitted that profile: the Cessna T-37A (USAF version of the 318).

Cessna T-37A

Nicknamed ‘Tweetybird’ by its pilots (due to its bulbous dual side-by-side cockpit and rounded forward fuselage which resembled the canary in the Warner Brothers cartoon), this was a twin-engined jet trainer built in Kansas. Accordingly, Project ‘Long Arm’ was set up and three of these little aircraft (56-3464, 56-3465 and 56-3466) were obtained on loan from the USAF in 1958 and flown to Fort Rucker for a one-year trial period. This trio was given army markings.

The Cessna T-37A had two Continental 920lb s.t. J9-T-9 turbojets, which gave it a maximum speed of 408 mph and a cruising speed of 368 mph. Wingspan was 33ft 10in, wing area 184 sq ft, with a fuselage length of 29ft 4in and a height of 9ft 5in. The aircraft had a range of 796 miles, adequate for the army’s needs, and a service ceiling of 39,200ft. No armament was, of course, carried but the Cessna was quite capable of being converted to a CAS role with the installation of cannon and underwing racks for bombs and rockets, which was state-of-the-art for the 1950s. It was certainly easy to fly and proved very manoeuvrable at low level. Whether it would have proven itself tough enough for the role envisaged is more doubtful. Nonetheless, the trials were deemed a success and the army declared the Cessna to be ideal, with the ACDA and the Army Aviation Board both recommending large procurement.

The army’s enthusiasm, not for the last time, aroused the Air Force’s jealousy. Quick to act at any hint or suspicion that any facet of its recently-acquired independence should be taken from it, whether it was interested in that facet or not, the USAF quickly moved to have the army’s idea quashed outright. The three T-37As were therefore returned to the USAF in 1959 and there the matter ended, for the time being.

The lessons of the Vietnam War proved that the army had been right and the Air Force wrong on this score, and the hasty adoption by the USAF of the former Navy Skyraider as the A-1 had merely reinforced, by the example of its success, that such an aircraft was a necessity. This led the army to try again. In the meantime, however, a new contender had arrived on the scene.

Appearance of the Northrop N-156F

The Northrop N-156F came about as a result of a detailed study by the parent company of the needs of the main Free World Defence groups, NATO and SEATO, for an affordable lightweight supersonic fighter, conducted as long ago as 1954. Sophisticated interceptors were, even then, getting ever larger and more complex and already passing out of the price range of most countries in these alliances. As a result of tours by Northrop representatives in 1955, they came up with a design for such an aircraft, powered by a pair of General Electric J85 turbojets, originally developed to power the GAM-72 Green Quail decoy drone. The criterion for ‘Cold War’ and Communist worldwide guerrilla tactics against democratic governments was versatility and so the Northrop design could operate from short runways, makeshift airstrips in jungles and rough terrain, close to the action, and from escort carriers for basic maritime and convoy protection duties. This ubiquitous design was the N-156F.

With the finalization of the design came a two-seater advance trainer version, the N-156T. Such a concept seemed an ideal solution and much confidence was expressed in its future. The two jets of the propulsion plant were located close together in the rear fuselage, being fed by two lateral air intakes on the underside of the fuselage, with the all-flying horizontal tail mounted below the engines, low on the fuselage itself. Fuselage design accorded to the Area Rule with a narrow cross-section in the area of the wing, which resulted in a near constant cross-section to facilitate airflow over the whole aircraft. The N-156 had very thin wings, with no dihedral or angle of incidence. These wings were swept back 24 degrees at quarter-chord and were fitted with a leading-edge extension (LEX) at each wing root. Each wing was fitted with sealed-Hap ailerons, hydraulically-powered, located at mid-span and had single-slotted, light alloy flaps inboard of them. The continuous-hinge flaps along the leading edges were of full-depth honeycomb build.

The N-156F was equipped with removable wingtip fuel tanks, also area-ruled, equipped with leading edge slats and trailing edge flaps. Armament for this lightweight interceptor comprised a pair of upper nose-mounted M39 20mm cannon, and an AIM-9L Sidewinder ‘point-and-shoot’ missiles could be carried on stations located at both wing-tips. Underwing pylons could accommodate conventional free-falling bombs and other weapons.

Despite its advanced design, relative cheapness and potential, the N-156 received two sharp setbacks almost immediately. The Air Force, obsessed as always with higher, faster, bigger fighters, rejected the whole concept, although it did condescend to take the trainer version, which became the T-38 Talon. The US Navy also turned the project down flat. The decision had been made to scrap the 100 or so Second World War-built escort carriers and not replace them; this left no home base for a naval version to work from, for the Navy was equally obsessed with big, high-performance machines for its giant new Forrestal-class carriers then on the stocks.

However, if two of the American armed forces saw no need for a lightweight fighter, Northrop still entertained hopes that its less affluent allies might still be interested. On 25 February 1958, Northrop took the decision to continue with the F-156F as a private venture, but took advantage of the T-38 contract to help offset design costs. The Air Force belatedly came to realize the low-cost benefit to its allies and, after inspecting a mock-up in 1958, ordered one static test airframe and three prototypes under the designation of the F-156T Freedom Fighter.

Northrop F-5. (Smithsonian Institute)

On 30 July 1959, the first N-156F made its maiden flight. It was powered by two 2,100lb s.t. General Electric non-afterburning YJ85-GE turbojets, later to be replaced by the 2,500lb s.t. dry and 3,850lb s.t. afterburning J85-GE-5 powerplant.

Further disappointment followed when Northrop approached European aircraft manufacturers with the aim of licence-building the N-156F for NATO. Fairey in England, Fokker in the Netherlands, Fiat in Italy and SABC in Belgium were all approached, and the talk was of worldwide sales of 4,000 aircraft. Alas, this all came to nothing, the Lockheed F-104 Starfighter being the final choice for many of these nations. In addition, US Air Force interest again waned after the second prototype had taken to the air, bringing about the third prototype being placed ‘on hold’ pending further thought on the subject.

The breakthrough came on 25 April 1962, when the Department of Defense (DoD) stated that the N-156F had been selected as the fighter for the Military Assistance Program (MAP) for supply to both NATO and SEATO allies. American serial numbers were to be allocated as the USAF was the purchasing agency for the whole program and was also made responsible for the training of allied aircrew at Williams AFB, Arizona. On 9 August 1962, the N-156F became the F-5A Freedom Fighter and was eventually to see service all over the globe, with licence-built versions being produced in Canada, South Korea, Spain, Switzerland and Taiwan in addition to US-built machines and by June 1972, when production ceased, some 1,871 of various marks had been produced by Northrop with a further 776 licence-built. They served with

Reviews for Fairchild Republic A-10 Thunderbolt II

[John Kelley · Rating: 5 out of 5 stars]

Outstanding review of a truly remarkable aircraft.
There are MANY who appreciate the dedication and expertise it takes to keep these sweethearts flying Thank You!