Coléoptère: A Plane Without Wings Was Scrapped After 9 Flights

Laelia Yang August 24, 2022 | 06:53

70 years ago, the Coleoptere vertical take-off and landing aircraft attracted attention as soon as it was launched with its unique shape but was scrapped after only 9 flights.

Plane Without Wings

In the late 1950’s French aerospace firm SNECMA developed a highly unconventional tail-sitting vertical take-off and landing (VTOL) aircraft with an annular wing.

The C.450 Coléoptère would be unlike any aircraft in the world. Unlike conventional airplanes, the Coléoptère would rest on its tail and use engine power alone to lift off the ground before transitioning to vertical flight, returning to land vertically once again on its tail. Its cylindrical wing promised greater efficiency over a conventional wing by eliminating wing-tip vortices. It would also be more compact, further reducing the space needed for vertical take-off and landings.

Known as the C.450-01 Coleoptere, this prototype was basically similar to the C.400 P.3 Atar Volant, with a tilting 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 the normal horizontal flight were 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.

Despite the prototype’s long and difficult development process, plagued with problems such as intense engine vibrations interfering with radio communications, the Coleoptere finally reached a flyable state. On the 17th of April, 1959, the Coleoptere achieved its first successful tethered flight. A few weeks later, on May 3rd, the Coleoptere was able to achieve its first free hover, lasting for three and a half minutes. However, a few months later, on July 25th, 1959, disaster struck.

For its ninth flight, the Coleoptere was supposed to take off, achieve an altitude of 2000 feet, transition from a vertical orientation to roughly a 36 degree orientation, and then return to a vertical orientation before hovering, and descending for a landing. Unfortunately, the Coleoptere was unable to establish a hover, and instead oscillated rapidly around all three axes as it plummeted towards the earth. These random rotations kept the pilot from ejecting until the craft was a mere 150 feet from the ground, and the pilot ended up being badly injured as a result.

Coléoptère Physical Features

WINGS - Annular wing of light alloy construction, comprising two skins and internal structure. Chord 3.0m.

FUSELAGE - Conventional light alloy structure. Retractable fore-planes on the nose.

TAIL UNIT - Cruciform fins and rudders of light alloy construction, mounted on the trailing edge of the wing, to provide directional control in all axes.

LANDING GEAR - Four oleo-pneumatic legs mounted on the trailing edge of the wing. Small catering wheels with rubber tires. Wheel track 2.95m.

POWER PLANT - One SNECMA Atar 101E.V turbojet (3,700kg of thrust) mounted aft of the cockpit in the fuselage. Integral fuel tanks with a total capacity of 700kg of fuel.

ACCOMMODATION - Pilot on tilting ejection seat in an enclosed cabin.