Kömyn valtakunta: MIRAGE - The Fairies wear combat boots

The story of the Mirage begins within the Korean War. The Soviet MiG-15 fighters wiped the sky clear of the straight-winged Lockheed F-80 Shooting Stars, and even the well-performing swept-wing F-86 Sabres were mingled in a hard dog-fight against lighter, more nimble MiGs. The Sabres were equipped with state-on-of-the-art technology oh the 1940’s, such as radar-guided leading computer gunsights, hydraulic servo flight controls among others. All in all, this equipment among with according fuel load, made the 8-ton Sabre two tons heavier than the MiG-15, but the engine power was not enough to equalize the field. The Sabre pilots felt being outmaneuvered and outclimbed by the MiGs.

In the West the MiG-15 was a horrible hangover. The pilots hungered for more speed, more power, more performance. In the USA, this development lead to the F-104 Starfighter, a fighter almost too performing to handle. Another way to adhere the same problem is to reduce the weight of the aircraft, which in turn reduces the required engine power- This is a vicious cycle, as powerful engines are large and heavy, and thus require a large wing surface to carry them, and as powerful engines inhale vast amounts of fuel, also the fuel load has to be large and yet carried by the ever larger wing. This weight needs larger landing and heavier landing gears to carry the weight on ground, and eventually all this mass will require more engine power, and so the cycle will go on and on.

By counteracting the cycle, the aircraft will do the opposite on the drawing board. This became a trend in the early 1950’s, and thus was created a flock combat aircraft light as fairies: the A-4 Skyhawk for the US Navy, the British Folland Gnat, the Italian Fiat G.91 and the French Mirage.

But the Mirage’s story was laid by the French government. They saw that the development of fighter jets was aiming past the two-Mach mark. The Soviet Union was developing both her fighter and bomber jets at an advancing speed, and the French, ashamed by the initial loss, but yet emerging on the winning side of the Second World War, had to counter this threat by aircraft of similar performance, or better. And thus the company founded by Marcel Dassault in 1929 answered to the government’s wishes in the year of the Dragon 1952.

The government required a supersonic interceptor to deflect the threat of Soviet long-range Tupolev bombers- The Dassault company was at the time producing sub-to-transonic Mystère-family fighter jets for the French Air Force, so the following product was baptized MD 550 Mystère-Delta, owing to its delta wing. The design was at first supposed to use two Turbomeca Gazibo turbojets, but the prototype was eventually powered by twin Armstrong Siddeley Vipers instead. The engine was quite primitive single-shaft axial-flow turbojet of only 12 kN of thrust, but similarly of quite light structure at only 250 kg.

MD.550 Mystère-Delta. Photo: Dassault

With these little muscles the MD 550 prototype was able to reach Mach 0,95 during her preliminary test series in July 1955. After some fine tuning, she could reach Mach 1,3 on level flight. The advantages of the delta wing were apparent. With this design, a low cross-section relative to the lifting wing area could be achieved. In addition, both in trans- to supersonic speed the compressive resistance forces grow roughly at the rate of the wingspan, which makes a highly swept wing – such as a delta wing – very advantageous for a fighter jet. In addition, the large wing area of the delta wing allows a large wing tank to be inserted even in a relatively thin wing cross-section, which produces more range with minimal to no penalty in aerodynamic resistance.

Thus the Mystère-Delta’s wing was tapered to traumatic 60 degrees, and the wing hat length-to-thickness ratio of an athletic 5 %. Originally the vertical stabilizer was also of a delta design, but soon altered for a F-tail to smooth the aircraft. The Viper turbojets were upgraded with afterburners and longer jetpipes for dash speed, and the intakes redesigned to be smaller to improve supersonic performance.

After these changes the Mystère-Delta weighed just 3610 kg. It really was a light fighter, and all the reformations were large enough in total to justify renaming of the design: she was now on the Mirage I.
But Mirage was still underpowered for her anticipated mission, the interception of Soviet heavy, soon supersonic bombers laden with nuclear bombs. The small aircraft was nimble, but lacked the power. The French Air Force needed more performance. Thus Dassault proposed an upgraded version, the Mirage II, with more powerful Gasizibo engines, but this small improvement in performance didn’t receive much applause from the Air Force. Dassault thus designed a much more radical revision, the Mirage III.

Mirage III. Phtoto: Dassault

She was much more than an enlarged Mirage I. As fighter jets were on more dire need of speed than ever, Dassault designed servo-controlled shock cones for the air intakes, as the Starfighter had. In addition, the delta winged structure was redesigned according to the newly discovered area rule, that when approaching transonic speeds, the airflow will occasionally actually exceeding the speed of sound. This is due to the fact that the airflow must always run past the wing profile, and all exceedings of the sound barrier will result in large air wave – the sound barrier itself. This will increase the resistance of the airflow significantly, and the speed in which point any wing will encounter this is called the critical Mach number for the said wing profile. To reduce the number of these shock waves, and their intensity, the changes in the cross-section of the aircraft are designed to be as smooth as possible, and thus the Mirage was redesigned with a wasp-hull.

Consequently the wing sweep is very steep, as the speed of overflying air is dominated by the normal component of the flow. By sweeping the wing, this flow can be accelerated, which in turn, increases the speed at which the flow would be transonic – partially subsonic, partially supersonic. A delta wing is naturally steep, and thus fit for this purpose like elbow grease for anal sex.

The new approach needed discarding the small turbojets designed originally for missiles, and Dassault dropped Hermann Östrich into the engine bay. He was a former engineer of BMW, having designed the BMW 003 jet engine, one of two types ever to enter mass production on Nazi Germany, The French forces made him an offer after he had refused one by the Americans, and the French forces relocated him at the former Dornier production facility on Rickenbach, French-occupied Germany.

Östrich gathered around 200 engineers and developers from BMW:s jet engine project, and employed them at his workshop, Atelier Technique Aéronautique Rickenbach, colloquially known as ATAR.
The BMW 003 formed the basis for the ATAR family – though the design was so thoroughly reworked and redesigned so many times, that only the concept roughly remained. In Nazi Germany nickel was in short supply, and thus all the high-temperature alloys were scarce to the designers and manufacture. This is why the BMW 003 had hollow stamped-steel turbine blades, so a pressurized airflow could cool them. Now, after the war, the designers had access to nickel alloys and state-of-the-art tools, and could substitute the internally air-cooled blades with much thinner, more efficient ones. Östrich’s team used the BMW 003 design as their basis, but the resulting ATAR 09 had little more in common than the axial-flow design.

ATAR 09 had more blades and stages. The inflowing air was forced by a nine-stage compressor into an annular combustor, which fed a two-stage turbine. The compressor is of a magnesium-alloy, save for the first stage, which is made of steel in case of foreign object damage. This 1400 kg beast could burst 42 kN dry, 59 kN with reheat.

Mirage III C. Photo: Wikipedia

With these powers invested, the Mirage III climbed for her maiden flight on 17 November 1956. The French Air Force, Armée de l'Air, was impressed. The design had now the much needed performance, so during the test flight program, a pre-series of 10 Mirage IIIA aircraft was ordered in April 1957.
As Mirage was showing the anticipated performance, the AdA made additional requirements to add multi-role capabilities to the design. This resulted in enlarging the wings even further and the fuselage growing nearly by two meters. The pre-series Mirage IIIA also received a Cyrano Ibis radar, more sophisticated avionics and a brake chute. The intake cones were also improved with automatic control system. In October 1958 Mirage IIIA was recorded by radar flying Mach 2,2 – the first European aircraft achieving the past Mach 2 mark, despite the empty weight now reaching 5900 kg. If this wasn’t enough, the Mirage could be fitted with a SEPR booster rocket unit.

The pre-production was soon followed by the Mirage IIIC (C for Chasseur, Fighter in French), a fully operational all-weather interceptor model. Now yet again lengthened by half a meter, the Mirage IIIC featured hardpoints for missiles and twin 30 mm DEFA revolver cannons. The gun barrels were located under the intakes, which could result in gunblast reaching the intake, reducing oxygen partial pressure in the combustion chamber, and thus choking the engine. This was rectified by adding an automatic gun mode to the engine controls, which temporarily reduced the fuel flow when the guns were fired, thus keeping the combustion in stochiometric balance. The Mirage entered service in AdA in July 1961, year of the ox.

Isreaeli Mirage III CJ. The J-model receives outer winf hardpoints, bringing the total to five. The front side of this aircraft is covered with air victory markings. Photo: Wikipedia

The Mirage was soon to be baptized in war, in the Six-Day War of 1967. Israel had countered the MiG-19 and MiG-21 purchased of Syria and Egypt by placing an order of 72 Mirage IIICJ interceptors, of which 65 had been delivered before the war. The Mirage played a key role in suppressing the Egyptian Air Force in a surprise attack early in the war.

In dogfight the Mirage proved to be more than her weight in gold, tearing 48 enemy fighters from the sky, including 23 of the feared Soviet-made state-of-the art MiG-21 interceptors, with only a loss of five of their own.

The Israelis had received a fully intact MiG-21 by a Iraqi defector during operation Diamond in August 1966, and inspected and tested the aircraft with care before handing it over to the United States. The MiG was a close match to the Mirage, but the Mirage had a more sophisticated radar – the one on MiG-21F series was more of a radio rangefinder for leading-computing gunsights than a true air combat radar. The Mirage also had a somewhat primitive Cyrano radar system, but it had far more capabilities in detection and could even illuminate target for a single Matra R.530 semi-active radar homing missile carried in the center pylon. The missile performed poorly against maneuvering targets such as fighters, having originally designed to shoot down heavy bombers laden with gravity nuclear bombs from a distance.

The main armament of the MiG-21 had similar difficulties, though. The K-13 (NATO reporting name AA-2 ATOLL) was a reverse-engineered copy of the American AIM-9B Sidewinder infrared homing missile, both only capable to seek to the hot exhaust of enemy aircraft, and thus only useful when fired from behind of the target. The MiG-21 F-13 and FL carried hardpoints for two of these missiles, while the Israeli CJ export version of the Mirage had four hardpoints for functionally similar, but lesser-performing Israeli Shafrir-1 missiles (and were thus later equipped with US-made AIM-9B instead). In missile combat, the two aircraft had roughly similar performance, as the kill probability of early air-to-air missiles was relatively low to begin with.

In dogfighting withing gun range, the Mirage had the edge. The MiG-21 F-13 had a single 30 mm NR-30 cannon with only 60 shells, which would run out in two seconds of gunfire. The Mirage had twin 30 mm DEFA cannons, with 125 shells each, lasting for 7 seconds – and thus allowing for several more bursts at the enemy, a significant advantage in dogfight. The MiG-21 FL version didn’t have a gun at all, instead carrying a larger radar antenna and thus better detection range.

The Mirage fire control system used her Cyrano radar to measure the range to the enemy and computed the firing solution accordingly in a leading gunsight. The system was prone to ground clutter, as were all radars of the 1960’s, and was proven nearly useless an a fats maneuvering dogfight. The manufacturer Thomson-CSF responded to this insight with a simple override switchboard with two switches: one switch engaged the system was zeroed at 250 meters, the another engaged for 600 meters, and with both engaged at 400 meters.

Australian Mirage IIIO's. Photo: Wikipedia

All in all, of the 23 MiG-21s the Mirages tore from the sky, 22 were shot down with gunfire. Conversely, of the 5 Mirages lost, three were shot down by a Atoll missile. The Israelis had assumed the tactic to close the range in as soon as possible and engage in brutal close-quarters dogfight, as this gave them the advantage of Mirages larger ammunition supply and lesser wing loading, which allowed for higher performance in a turn relative to the MiG, which in turn had better climb rate (7100 m/min against Mirages 5000) and thrust-to-weight ratio (0,69 vs 0,59). Accordingly, the Mirages were unable to intercept pre-war MiG recon flights over Israel, as they traveled the 160 km routes in less that six minutes at Mach 1,5 at 18 000 m altitude, and the Mirages on Quick Reaction Alert duty required five minutes from runway to reach this altitude, flying at Mach 1,3 and traveled only 60 km on map. The MiGs were outside the reach of their missiles, save for the guns.

But the Mirage proved to be a sturdy workhorse: Pilot Ezza Dotan’s Mirage was hit in dogfight
by a K-13 missile, which exploded right under the belly of his jet. The engine was swept with shrapnel, but was able to provide enough power for him to turn against the enemy, breaking their formation and for him to disengage by a sharp turn straight downwards, able to evade the confused enemy in his crippled but flyworthy plane. During the descent, the engine eventually flamed out, but Dotan managed to glide to base, where the maintenance crew hastily repaired the Mirage and replaced the heroic ATAR engine unit with a fresh one. Two days later, the same Mirage engaged dogfight again.

Dotan's Mirage III after the hit. Photo: Osprey publishing.

Israel had another way to form the future for the Mirage. They made a request for a simplified version Mirage 5 for interdiction use with less avionics (as the East Mediterranean weather was usually clear), especially the radar which was an expensive piece of equipment, but pilots wouldn’t need them in a ground strike role. Dassault yet again stretched the fuselage by 30 cm for more fuel, and as the radar was omitted, avionics could be relocated to it’s place, further increasing the range, and the SEPR booster rocket was replaced with a fixed fuel tank (in most other models, this tank was optional to the rocket). This simplified design offered an 32 % increase in fuel load, and a total of 14 bombs could be carried, in a less expensive frame. Israel placed an order of 50 aircraft in April 1966.

The aircraft were still at the factory when the Six-Day War began, and as a result France placed Israel under arms embargo. The fresh aircraft rolling out from assembly line were assimilated to the AdA as Mirage 5F.

The embargo was ambiguous: France wa willing to deliver spare parts after the war, and e.g. Ernst Trost claims that 20 Mirage IIIs were flown by AdA directly to Israel, just prior to the war, and the French pilots returned by airliner the following day. It is not clear how the Israelis gained the blueprints and manufacturing details for the Mirage 5, but they did produce new planes from scratch as the IAI Nesher.
In Switzerland, a Sultzer engineer Alfred Frauenknacht had been responsible for destroying factory blueprints used in license production of Swiss Mirage IIIS. He burned waste paper instead, and smuggled the blueprints to Mossad agents. He was caught and sentenced to 4,5 years in prison in 1971, but this is only a part of the espionage scheme – the Swiss version of the Mirage was of Mirage III, type already at Israeli service, and Fraunknacht worked at Sulzer, the engine manufacturer, whereas the airframes themselves were produced by F+W Emmen.

In addition, the Nesher program went in a very rapid succession. The prototype was flown in September 1969, and the serial production aircraft deliveries began in November 1971 – quite a short time to reverse-engineer a supersonic fighter-bomber with all assorted manufacturing details and plans. There are some claims that when modifying the Israeli Mirage III’s to the more powerful J79 engine, the Rockwell staff was also seen assembling Mirage 5’s, and that the fuselages would actually have been imported by Aerospatiale from France and engines from Belgium by SABCA. There is no confirmed data, but it’s likely that the Israeli were not alone in their Nesher program, and France has notoriously been a willing supplier of military hardware with little questions asked.

The Mirage 5 was ultimately the most popular export variant of the Mirage family, selling 517 units to 11 customers, even though the French also developed a in-between model of the two main variants, the multi-role Mirage IIIE with less extra fuel but equipped with a a radar.

Mirage 5 showing her impressive ordnance load. Photo: Dassault

During the Falklands War in 1982 the Mirages experienced a fate similar to MiG-21’s nearly two decades earlier: they were torn from the sky. The Argentinian Air Force had a very limited operating window above the islands, as the main airport in Stanley had too short a runway for the delta-winged jets to operate (due to their steep delta wing the Mirage has a high stall speed, and thus landing and takeoff speeds, requiring a long runway), and were forced to fly in from continental air bases. The Mirage III interceptors were at the extreme of their endurance above the islands, having just minutes of time to maneuver into combat. They could not carry missiles, as their drag and weight would have consumed too much fuel, and had to engage the British Sea Harrier VTOL fighters with guns – with subsonic speed, as the very thin fuel reserve didn’t allow supersonic or even the use of afterburner. The very nimble Sea Harriers with their newly acquired AIM-9L all-aspect Sidewinder missiles had a huge advantage in close-range dogfight at slow speeds, and shot down a Mirage III and damaged another (which tried an emergency landing at Stanley, only to be accidentally shot down by Argentinian air defense) in this only fighter-to-fighter engagement of the war. The Royal Navy aircrews had trained against AdA Mirages just prior their deployment to the Falklands, and the results were overwhelming: when flying supersonic and carrying missiles, the Mirages were painstakingly at advantage against the subsonic Sea Harriers, able to fire their missiles at higher altitude and speed, and thus at greater range.

The Mirage 5 variants in other hand had larger fuel tanks and much more endurance than Mirage III variants, and engaged British fleet in many occasions among with smaller A-4 Skyhawk strike planes. Mirages scored many hits with unguided iron bombs to several ships, causing serious damage to the destroyer HMS Antrim and the frigate HMS Plymouth, and with Skyhawks sank the frigate HMS Ardent, in spite that the Argentine Air Force was surprised by the war initiated by the military Junta of Argentina. The pilots had no training in anti-shipping operations, and thus tended to release their bombs too close to their targets, unaware that their detonators didn’t have sufficient time to arm properly, ant the British sappers were able to disarm and dismantle many bombs that had hit directly, but found buried deep within ship hulls with their detonators still unarmed.

Argentinian Mirage 5. Photo: Wikipedia.

The Sea Harriers took their heavy toll on upon the oncoming Mirage 5 interdictors, shooting down 11 planes, but as the large numbers of hits and heavy losses to the Royal Navy ships indicate, the British didn’t enjoy air superiority during the campaign. The Argentinian pilots flew a large amount of sorties against the British forces and air defenses unescorted, approached against heavy anti-air fire at high speeds at very low altitude to release their weapons at the last minute. There was no question about the bravery of the Argentinian aircrews.

The Mirage was modified with enthusiasm on many parts of the world. Some regained Mirage 5’s air combat capabilities by retrofitting a radar, the Israeli Neshers had proprietary avionics, gunsights appropriate air combat and often carried air-to-air missiles, totalling over a hundred kills during the War of Attrition in the 70’s. The Nesher was developed into the IAI Kfir multirole version, with more powerful General Electric J79 of the Phantom II air superiority fighter also in service in Israel and added canard wings to increase lift.

IAI Kfir. Photo: Wikipedia

In South Africa, the Kfir was used as a basis for a further developed Atlas Cheetah upgrade for their Mirage III airframes, with advanced features such as a HUD and HOTAS controls in 1986. In France Dassault developed an upgraded version, Mirage 50, in 1969, which included an improved Cyrano IV radar and uprated ATAR 09K-50 engine of 50 kN dry and 70 kN reheat thrust.

During the 1970’s advancements in fighter technology were rapid, and the first generation Mirage family soon falling into obsolescence. More modern, heavier and outperforming multirole designs were succeeding her. Thus Dassault developed a cousin for the Mirage proper, the Mirage F1, which has relative mechanical and systems compatibility with the original Mirage, but is of a different, swept shoulder-wing design. Instead, in the early 1980s a true successor, the Mirage 2000 was put into service. The 2000 has a similar basic design as the original Mirage, but the aircraft is designed from scratch to be he definitive iteration of the Mirage family.

The Mirage was an effective interceptor to counter the Soviet bomber threat, and more than equal combatant to the feared MiG-21. Her service life and variant tree grew through the decades, and the Mirage 5P is still operated in Pakistani Air Force, more than half a century later. The Mirage was tossed into the boxing ring, toe to toe with her best rivals to fight of the rule of the air, the land and the sea.

In part due to efficient operators, in part due to high design quality the Mirage enjoys a reputation as one of the most successful fighters of the 20th century, and marked the capabilities if the light fighter design. Around a modest empty wight, powerful engine and a large delta wing was built a warbird light as a feather, but which stung like a bee.