SNECMA C.450-01 Coleoptere

1959

Back to the Virtual Aircraft Museum
  VTOL RESEARCH AIRCRAFTVirtual Aircraft Museum / France / SNECMA  

SNECMA C.450-01 Coleoptere

Following tests of the Atar Volant, which have proved the ability of a vertically-mounted turbojet to raise a VTOL aircraft safely from the ground, of accelerating it in vertical flight to a speed where it can become airborne like a conventional aircraft, and of returning it to the ground in a vertical descent, SNECMA built a prototype research aircraft around this type of power plant. The actual power-unit used was the Atar 101 E.5V fitted with jet deflection nozzle and rated at 3,700kg of thrust.

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

The C.450-01 made its first free vertical flight on May 6, 1959 at Melun-Villaroche. On July 25, during transition from vertical to horizontal flight control was lost at an altitude of about 75m and the Coleoptere crashed and was destroyed. The pilot, Auguste Morel, ejected successfully and was unhurt.

It was stated afterwards that the accident occurred when the intended programme of flight tests concerning inclination had been carried out successfully, and that neither the jet control stabilisation system nor the annular wing aerodynamic formula was the cause of the crash.

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 nose.

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

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

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

ACCOMMODATION - Pilot on tilting ejection seat in enclosed cabin.

FACTS AND FIGURES

© A special mechanism was needed to rotate the seat so that the pilot was in a more-or-less natural position most of the time.

© Auxiliary intake doors supplied the engine with the airflow it needed during vertical flight.

© Extra windows in the lower nose helped the pilot align the aircraft and judge height during landing.

© Although looking like a giant ducted fan engine, the main 'body' of the Coleoptere was in fact an annular wing.

SNECMA C.450-01 Coleoptere

Specification 
 CREW1
 WEIGHTS
  Take-off weight3000 kg6614 lb
 DIMENSIONS
  Wingspan4.51 m15 ft 10 in
  Length8.02 m26 ft 4 in
 PERFORMANCE
  Max. speed800 km/h497 mph
  Ceiling3000 m9850 ft

3-View 
SNECMA C.450-01 ColeoptereA three-view drawing (642 x 1012)

Comments
robert, e-mail, 03.11.2014 13:34

it works they just have put a pane in the floor so the pilot can see for take-off and landing.i used the letterbox wing on a rc model and it works like this ring wing.

reply

jakas, e-mail, 23.09.2012 16:59

dobra maszyna!

reply

Noname, e-mail, 31.03.2020 10:24

Another failed tailsitter, post-dating Lockheed,

reply

Centurion13, e-mail, 03.07.2009 03:02

I wonder - would the high-speed avionic computers used today allow such a craft to work? It is an impractical question, mind you. Such aircraft are no longer desired. But I bet it could be done....

reply

leo rudnicki, e-mail, 05.05.2009 21:05

Another failed tailsitter, post-dating Lockheed, Convair and Ryan failures.

reply

David, e-mail, 11.11.2008 05:00

When you consider the transition manouevre for landing it would be extremely unlikely to work. You would have to be near vertical and above stall speed, and then reverse. That is why the test pilots pulled the plug and refused to fly it.

reply

Aero-Fox, 17.03.2008 17:13

Undoubtedly one of the craziest aircraft I've ever seen.
Regardless, a great idea that should have worked.

reply

Do you have any comments?

Name    E-mail


All the World's Rotorcraft

All rhe World's Rotorcraft AVIATION TOP 100 - www.avitop.com Avitop.com