Melun-Villaroche, 28 September 1952. Kostia Rozanoff, Dassault’s chief test pilot, lifts a silver prototype off the runway and stays aloft for 25 minutes. In level flight the new jet touches Mach 0.92, comfortably beyond what its designers had hoped for. The aircraft is the Dassault Mystère IV, and France has just caught up with the swept-wing age.

Seven years earlier the country had no modern fighter industry worth the name. By the end of the decade the Mystère IV was flying with three air forces, wearing the colours of the Patrouille de France, and going to war over the Sinai and the Punjab. It was, in the words of Wikipedia’s summary, the first transonic aircraft to enter service with the French Air Force.

It also carried an unusual secret for a symbol of French revival: most of the French fleet was paid for by Washington.

From Hurricane to Mystery

The family begins with the Dassault MD.450 Ouragan, French for hurricane. Marcel Dassault, back from Buchenwald and determined to rebuild French aviation, launched it as a private venture; its prototype first flew on 28 February 1949, again with Rozanoff at the controls. Dassault’s own history calls it the Air Force’s first jet designed and produced in France. The story of the man himself is told in our profile of Marcel Dassault.

The Ouragan was a straight-winged machine, already being overtaken by swept-wing designs when it reached squadrons in 1952. Dassault’s answer was pure evolution: keep the Ouragan’s fuselage, add a thinner wing swept back at 30 degrees, and call it the Mystère. The production Mystère IIC equipped the French Air Force from 1954, 150 of them, but it was an interim type and never fought.

The Mystère IV was something else. It looked like its predecessor, yet Dassault describes a genuinely new aircraft: a wing swept to 38 degrees instead of 30, a thinner profile, and a contract, signed on 2 August 1951, for a fighter capable of reaching Mach 1 in a dive.

Twenty-Five Minutes Over Melun

The prototype, Mystère IV 01, flew on a British Rolls-Royce Tay engine. That 25-minute first flight in September 1952 delivered more speed than predicted, and the new jet later went supersonic in a dive, a feat that would become routine for its pilots. Early production aircraft kept the Tay, while most of the fleet received the Hispano-Suiza Verdon, a French-built derivative of the same engine.

The armament was blunt and effective: two 30 mm DEFA revolver cannon with 150 rounds each, plus around a tonne of bombs, rockets or drop tanks on four underwing points. This was a fighter that could also hit the ground hard, and that double personality would define its war record.

A former French fighter pilot recalls going supersonic in the Mystère IV (in French), from the Conservatoire de l’Air et de l’Espace d’Aquitaine.

Paid For in Dollars

Here the Cold War enters the hangar. According to Dassault’s own history, a US Air Force delegation including Chuck Yeager evaluated French combat aircraft in December 1952. In April 1953 came the decisive order: more than 220 Mystère IVs for the French Air Force, bought by the United States under its Offshore Procurement programme. Dassault’s history describes the batch simply as a gift to the French Air Force.

It was a very European arrangement of the 1950s: American money, a French airframe, a British-designed engine built under licence. Production ran from 1954 to 1958, and the type reached the 12th Fighter Wing at Cambrai in May 1955. Accounts of the total differ slightly, with 411 in Dassault’s count and 421 in other references, of which roughly 240 went to the French Air Force.

The new jet was soon at war. In 1956 French Mystère squadrons deployed to Israel during the Suez crisis, and the aircraft stayed in French service for decades, finishing its career as a training mount. Its successor in the Dassault family, the Super Mystère, would follow it into French service.

The Golden Age of the Patrouille de France

For many French enthusiasts the Mystère IV means one thing: the aerobatic team. Dassault notes that the first aerobatic team on the type was trained at Cambrai, and twelve Mystères flew over the Champs-Élysées for Bastille Day on 14 July 1955.

The Patrouille de France flew the Mystère IVA from 1957 until the end of 1963, first with the 2nd Fighter Wing at Dijon and then with the 7th at Nancy. Budget cuts disbanded the team in January 1964, and it was reborn weeks later on the far gentler Fouga Magister.

The team’s Mystère years still look astonishing on film: tight formations of swept-wing jets, close to the crowd, with none of the safety distances of a modern display.

Archive footage of the Patrouille de France displaying its Mystère IV jets in 1961.

Israel: First Swept Wings Over the Sinai

In the Middle East the Mystère arrived just in time. The Israeli Air Force switched an order for Mystère IIs to the Mystère IV, and on 11 April 1956 the first four landed at Hazor, announcing themselves with a sonic boom. They reformed 101 Squadron, and 61 aircraft were eventually delivered. When fighting began on 29 October 1956, only about a third had arrived.

On 30 October, Israeli Mystères met MiG-15 of the Egyptian Air Force over the Mitla Pass and shot one down, the type’s first kill. The next day a pair of Mystères was credited with four Egyptian de Havilland Vampires. Israel lost one Mystère, to ground fire. The wider campaign is covered in our account of the Suez air war.

By June 1967 the Mystère had been pushed into ground attack by newer Super Mystères and Mirages. Two squadrons, around 35 aircraft, flew it in the Six-Day War, striking Egyptian air bases in Operation Focus and then supporting troops on three fronts. Israeli accounts credit Mystère pilots with three aircraft shot down, two MiG-17 and a Jordanian Cacciatore di Hawker, for the loss of seven or eight Mystères depending on the source. The type left Israeli service in the early 1970s.

India: Low and Fast to Sargodha

IL Aeronautica militare indiana took about 110 Mystère IVAs from 1957 and used them as fighter-bombers. Air Marshal Philip Rajkumar, who joined No. 1 “Tigers” Squadron at Adampur in 1964, remembered his first taste of the jet’s speed.

In the 1965 war the Mystères, often with Folland Gnats covering them, flew close support against armour and artillery. On 7 September No. 1 Squadron raided Sargodha, the most important base of the Aeronautica militare pakistana. India claimed six aircraft destroyed on the ground; Pakistan admitted losing a single F-86 Sabre.

When the dawn strike missed its target, Rajkumar flew in the four-ship daylight attack that followed, racing home at what he estimated was no more than 50 feet.

That morning Squadron Leader A. B. Devayya did not return. He was shot down by an Caccia stellare F-104 flown by Flight Lieutenant Amjad Hussain, and the Starfighter crashed too; its pilot ejected. In 1980 Pakistan acknowledged losing an F-104 in combat with a Mystère that day, and in 1988 Devayya received a posthumous Maha Vir Chakra. In 1971 Nos. 3 and 31 Squadrons still flew the Mystère on the western front, operating from Sirsa.

A Bridge to the Mirage

The Mystère IV never became a dogfighting legend, and its record is better told in sorties than in kills. Its real importance was industrial. It taught Dassault to build a swept-wing fighter in numbers, to sell it abroad and to support it in war, the lessons that made the Mirage III possible a few years later.

It also cost Dassault dearly. Kostia Rozanoff, who had flown the first Ouragan and the first Mystère IV, was killed in 1954 during a low-level pass in a Mystère IV B, the afterburning development that gave way to the Super Mystère.

French aviation magazine Aerobuzz retraces the Mystère IV and its place in the French Air Force (in French).

Today Mystère IVAs survive in museums from Le Bourget to Tucson, several of them in Britain. Look closely at one and you see the whole French post-war story in a single airframe: an Ouragan’s bones, a British engine, American money, and the swept wing that carried France into the jet age.

Sources: Dassault Aviation (Mystère IV, Mystère II, Ouragan and Kostia Rozanoff histories), This Day in Aviation, Jewish Virtual Library (IAF aircraft inventory), Bharat Rakshak (Philip Rajkumar, “Tigers Over Sargodha”; Sirsa’s War), Aeromorning, flugzeuginfo.net, Wikipedia (Dassault Mystère IV, Dassault Mystère, Dassault Ouragan, Patrouille de France)