Wearing civil registration F-ZXRM, applied for its state testing programme, the Mystere IVN taxies out for a flight. In May 1955 French aviatrix Jacqueline Auriol set a new women’s world air speed record in the machine - a matter of weeks before it was announced that there would no longer be separate records for men and women.

Again showing its “beard” intake to good effect, the Mystere IVN awaits another test flight. Note also the gun ports for the 30mm cannon recessed into the air intake. The 68mm rocket projectiles were to be housed in a retractable belly tray.

An early view of the MD.454 Mystere IVN.

Again only built as a single example, the Mystere IVN prototype, 01, comes into land after a test flight, the bulbous radar nose above the nose air intake being seen to good advantage. The DRAC-25 X-band radar suite was France’s first operational airborne radar detection system.

Mystere IVN поднялся в воздух 19 июля 1954 года. Двухместный всепогодный ночной вариант Mystere IVB - истребитель-перехватчик Mystere IVN - предлагалось вооружать двумя 30-мм пушками и 128 НАР.

The fitting of DRAA-3B Aladin radar equipment in an elongated nosecone gave the Mystere IVN a somewhat shrewish appearance. Fitted on a centreline mount beneath the fuselage is a Matra R-511 air-to-air missile, which worked in concert with the Aladin all-weather radar equipment. The first test firings of the R-511 were made in late 1956 and the missile entered production shortly afterwards, equipping the Armee de l’Air’s SNCASO Vautour squadrons.

Trailing its brake parachute, the Aladin-equipped Mystere IVN taxies in after a flight. Following its retirement as a testbed, the aircraft was withdrawn from use and put on static display outdoors at Aulnat, near Clermont-Ferrand, before being restored and displayed indoors at the Conservatoire Air et Espace d’Aquitaine in Bordeaux.

The Mystere IVN was used for extensive trials of Dassault’s Aida radar system, later fitted to the same company’s Etendard IVM, a navalised version of a land-based interceptor originally designed to an Armee de l’Air requirement. The gun ports are still visible here, but were faired over at some point during the trials programme.

Former wartime fighter pilot Gerard Muselli flew for the CEV and EPNER testpilots’ school before joining Dassault in the spring of 1952. Seen here in the Mystere IVN, he went on to perform test-pilot duties for the company’s Etendard and Mirage III and IV.

Dassault MD.454 Mystere IVN