Editing Avro Canada (section)

===Supersonic Avrodynes===

In 1952, Avro Chief Designer John Frost selected a group of eight engineers and draftsmen to create the Avro '''Special Projects Group'''.  In its intense exploration of radical aeronautical design ideas and development of new technology, as well as security, the SPG resembled Lockheed's "Skunk Works".<ref>Zuk 2001, p. 41.</ref>  Initial projects included research and development work on a series of "[[flying saucer]]"-like vehicles. The only design that materialized beyond mock-up was the VZ-9-AV Avrocar, funded entirely by the U.S. military from 1956.<ref name="Frontiers"/>

* '''Project Y1:  "the Spade"'''
[[File:Project Y mockup colour.jpg|thumb|right|Project Y mock-up in the Experimental Flight Hangar c. 1954.]]
Design reports from early 1952 outlined key features of a new gas turbine propelled engine and disc-shaped vehicle:  an inner disc with central eye intake with an outer, counter-rotating disc, with rear-directed thrust nozzles, later refined  to include controlling the aeroplane by [[thrust vectoring]] and stabilizing the vehicle by having the large engine rotor act as a gyroscope.<ref>Zuk 2001, pp. 41–43.</ref> The aircraft was designed for vertical take-off and landing which was thought to be hazardous and required an electronic flight-stabilization system, then not-yet available. Financed largely by Avro, the Canadian government deemed these problems too expensive to finance beyond an initial funding of $400,000. A USAF-led delegation to Avro in December 1953 gave Avro the opportunity to discuss their projects, but Y-1 was not deemed worthy of financing.

* '''Project Y2'''
In mid-1954, Frost proposed "Project Y-2:  Flat Vertical Take-Off Gyroplane" in response to requests by the US Air Force and US Navy for "vertical rising point-defense fighters".<ref>Whitcomb 2002, p. 100.</ref>  In late 1954, the USAF purchased the development rights to this saucer-shaped VTOL vehicle powered by more conventional engines than, and designed to avoid many of the problems with, the Y-1. The USAF designated it '''Project MX-1794''' and studies of the Avro saucer designs '''Project Silver Bug'''.  Through 1958, Avro spent $2.5 million and the USAF $5.4 million funding the project.  Numerous models were constructed and wind-tunnel testing was undertaken at MIT and Wright Patterson Air Force Base (where Roswell UFO studies were reportedly undertaken).

The design included eight [[Armstrong Siddeley Viper]] turbojet engines, a very large centre rotor/impeller with Lundstrom compressor turbines, with the cockpit mounted in the top/centre. Control was achieved through eight small exhausts at the outer edge, directed either through the top or bottom, in addition to the main turbine exhaust through the bottom/centre of the craft.  A multi-engine test rig was built and tested in 1956, resulting in powerful thrust and a great deal of noise, and vibration.  One Special Projects Group member reported that the prototype was secretly removed by the US Navy for further testing in California.<ref>Whitcomb 2002, p. 104.</ref>

Avro also decided to internally fund development of a radial-flow gas turbine engine vehicle, designated '''PV-704''', which proposed no central impeller or exhaust, but rather a large spinning turbo-disc directing all thrust to the outer rim.  Funding enabled continued development but was insufficient for a prototype.

In 1957, the USAF provided additional funding to extend the project, by then highly classified and designated as '''Weapon System 606A'''.  The concept developed was for a circular-winged, supersonic aircraft. Over 1,000 hours of wind-tunnel testing were performed.  Drawings developed by Avro show an aircraft that appears to be a merging of flying saucer with more conventional fuselage shapes, in other words a tailless aircraft with circular wings (when viewed from above or below).