This was originally the third SO.6020, intended as a photo reconnaissance aircraft, but it was completed as the experimental mixed-power SO.6025 with its Nene jet engine augmented by a SEPR 25 booster rocket in the rear of the underbelly fairing. It first flew on 28 December 1949 but the rocket motor, running on highly toxic fluorine and nitric acid, was not ignited in flight until June 1952. The SO.6025 became the first European aircraft to break the sound barrier in horizontal flight in December 1953, piloted by André Turcat. It was later dumped at the Suippes shooting range, but its remains are now on display at Ailes Anciennes Toulouse. Photo from: Sud-Ouest

The second prototype of the Espadon (swordfish) jet fighter, seen on display here well before its first flight on 16 September 1949. The small aft ventral air intake turned out to be ineffective. Other intake arrangements were tested, but the Espadon failed to qualify for operational service. Fitted with an auxiliary rocket motor, the third prototype F-WFRG exceeded Mach 1 in level flight in 1953. Photo by: Dmitri Kessel / Life

First of four prototypes of a proposed fighter. SNCASO photo. Photo from: Civil Aviation Historical Society, Melbourne, Australia

The only existing airframe remains of this aircraft type preserved within "Ailes anciennes de Toulouse" museum. Only 4 prototypes were built between 1948 and 1953. This plane is however a piece of French aviation history. It was the first supersonic European aircraft in level flight in December 1953.

Only four prototypes of this late-1940s French interceptor were built, and only this one survives. This was the third prototype SO.6020, which was modified as an SO.6025 (and hence re-serialled as 01).