enter image description here The compressor ejects compressed air from the gap at high speed. The red arrow represents the path of compressed air. It is lift that adjusts the speed of the compressed air to adjust the aircraft.

  • 1
    $\begingroup$ Have you make reshearch? $\endgroup$
    – L'aviateur
    Apr 26, 2020 at 13:37
  • $\begingroup$ @L'aviateur How does VZ-9 blow compressed air on its upper surface? $\endgroup$
    – enbin
    Apr 26, 2020 at 20:51
  • $\begingroup$ They realized that this physical phenomenon(coanda effect) could be used on his device to produce a more practical VTOL device. The flow should instead exit from the top of the device and be redirected downwards by a device similar to shutters. This mechanism should produce a lift all around the device allowing him to land flat and no longer standing as in Project Y $\endgroup$
    – L'aviateur
    Apr 27, 2020 at 7:20
  • $\begingroup$ lh3.googleusercontent.com/proxy/… $\endgroup$
    – L'aviateur
    Apr 27, 2020 at 7:34
  • $\begingroup$ @L'aviateur Air must be ejected at high speed, otherwise the lift is not enough. $\endgroup$
    – enbin
    Apr 27, 2020 at 9:50

1 Answer 1


This us the Avro-Canada VZ-9 .He focused on the " Coanda " effect capable of flying a possible flying saucer.

A.V. Roe (Avro) Aircraft Limited (later Avro Canada) based its design concept for the Avrocar on using the exhaust from turbojet engines to drive a circular “turborotor” which produced thrust. By directing this thrust downward, the turborotor would create a cushion of air (also known as “ground effect”) upon which the aircraft would float at low altitude. When the thrust was directed toward the rear, the aircraft would accelerate and gain altitude.

Each service had different requirements: the Army wanted to use it as a subsonic, all-terrain troop transport and reconnaissance craft, but the USAF wanted a VTOL aircraft that could hover below enemy radar then zoom up to supersonic speed. Avro’s designers believed they could satisfy both services, but these two sets of requirements differed too much.

Research data originally indicated that a circular wing might satisfy both the Army’s and Air Force’s requirements, and Avro built two small test vehicles to prove the concept.

Designated the VZ-9AV Avrocar (“VZ” stood for “experimental vertical flight,” “9” for the ninth concept proposal, and “AV” for Avro).

Tests with scale models at Wright-Patterson AFB, Ohio, indicated that the cushion of air under the Avrocar would become unstable just a few feet off the ground. The aircraft would be incapable of reaching supersonic speeds, but the testing went ahead to determine if a suitable aircraft could be developed for the Army. The first prototype was sent to NASA. There, wind tunnel tests proved that the aircraft had insufficient control for high speed flight and was aerodynamically unstable.The second Avrocar prototype underwent flight tests that validated the wind tunnel tests. If it flew more than three feet above the ground, the Avrocar displayed uncontrollable pitch and roll motions, which the Avro engineers called "hubcapping." The Avrocar could only reach a maximum speed of 35 mph, and all attempts to end the hubcapping failed. The project was cancelled in December 1961.

Edit: The 124-blade "turborotor" was placed in the center with the majority of the thrust flow directed straight down through an opening in the floor. Part of this flow was separated and redirected to operate the control system which ran around the outer periphery of the disc. Power for the rotor was generated by three reactors attached to the main structure. Each engine had its own fuel and oil tanks. The thrust deflection control system consisted of a large ring located around the main disc, with the flat part inside. The pilot's controls moved the ring in relation to the rest of the aircraft, affecting the air flow. The vertical lift could be increased by lowering the ring entirely. Tilting the ring resulted in asymmetric thrust for directional control.

Source :https://www.nationalmuseum.af.mil/Visit/Museum-Exhibits/Fact-Sheets/Display/Article/195801/avro-canada-vz-9av-avrocar/

So nothing is impossible but this concept turns out to be complex

  • 2
    $\begingroup$ The stability issues could be solved with a computer controller. Time to revive avrocar? $\endgroup$ Apr 26, 2020 at 9:23
  • 1
    $\begingroup$ good idea Maybe yes. $\endgroup$
    – L'aviateur
    Apr 26, 2020 at 9:24
  • $\begingroup$ but what would it be able to do that current aircraft and helicopters can't? The hovercraft has gone almost extinct because its niche is just too small to sustain an industry. $\endgroup$
    – Hobbes
    Apr 26, 2020 at 9:51
  • 1
    $\begingroup$ Yes this is a experimental aircraft :Although American public opinion lived in disproportionate fear of flying saucers, the US Army and the US Air Force teamed up to launch a program to study the flight possibilities of flying saucers , officially called "aircraft to lenticular wing so they search if it is better than aircraft and helicopter.this is the goal of experimental aircraft s $\endgroup$
    – L'aviateur
    Apr 26, 2020 at 10:12
  • $\begingroup$ @JohnDvorak The speed and direction of compressed air must be controlled by the computer. $\endgroup$
    – enbin
    Apr 26, 2020 at 14:00

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.