Known as the C.450-01 Coléoptère, this prototype was basically similar to the C.400 P.3, with a tilting ejection seat inside an enclosed cockpit, but was fitted with an annular wing to permit transition into horizontal flight. The airframe was built by the Nord company in its Chatillon-sous-Bagneux works.
Directional control at take-off and landing was by pneumatic deflection of the main jet efflux, directional control during normal horizontal flight was by four swiveling fins equally spaced around the rear end of the annular wing, while transitions from vertical to horizontal attitudes were eased by the use of two small retractable fins mounted on the sides of the fuselage nose.
Piloted by Auguste Morel, the C.450-01 made its first free vertical flight on May 6, 1959 at Melun-Villaroche. During the ninth flight on 25 July 1959, the pilot was making a transition from vertical to horizontal and achieved very limited tilting when flight control was lost at a very low altitude, reports vary from 49 to 246 ft (15 to 75 m). Morel ejected but was severely wounded, the crash marked the end of the "flying engine" program and the end of Morel's test pilot career.
Span onver fins: 14 ft 9.6 in (4.51 m)
Length: 26 ft 3.8 in (8.02 m)
Outside diameter: 10 ft 6 in (3.20 m)
Height: 7 ft 7.7 in (2.33 m)
Loaded weight: 6,614 lb (3000 kg)."