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A simulation of the Avro Canada MX 1794 undergoing a secret test flight accompanied by a USAF chase plane. Bill Rose A photomontage showing a completed prototype Avro Canada MX 1794 fitted with a high-visibility cockpit canopy for preliminary testing. Bill Rose not match a properly designed swept wing at supersonic speeds. They also advised the Wright-Patterson project office that the I/d ratio at low subsonic speeds would be unsat- isfactory. The USAF seems to have accepted this but felt that the astonishing thrust/weight ratio of the Project 1794 aircraft more than compen- sated for any deficiencies. By the end of that month, wind tunnel testing had switched to NACA’s Ames facility in California and Project 1794 seemed to be back on course. On 11th October 1956, during a presenta- tion to the US Navy at the Pentagon, Admiral Russell was advised that a Project 1794 pro- totype would be completed by January 1957. Then the programme was quietly dropped ... or so we are told! Despite the obvious disin- formation and intentional confusion gener- ated by the multiple use of designations for the same programme, there are documents which show ongoing discussion of a ramjet- powered flying disc as late as March 1959. Meanwhile, another project known as PV.704 was getting under way and this briefly used the title Project 1794, which then became Performance Research System Nr 453L and finally WS-606A. A simulation of the Avro Canada MX 1794 undergoing a secret test flight accompanied by a USAF chase plane. Bill Rose A photomontage showing a completed prototype Avro Canada MX 1794 fitted with a high-visibility cockpit canopy for preliminary testing. Bill Rose ai emerged from the initial studies. The first, called Configuration A, was a single-seat air- craft with a completely circular wing, married to a compact tailless fuselage. Power was provided by six side-by-side Armstrong Sid- deley Viper jet engines and a central RFGT fed by large over-wing air intakes. The radial flow ducted fan was intended to provide full VTOL, although it was later realised that the aircraft’s endurance could be substantially improved by using a rolling take-off. This was called Ground Effect Take- off (GETO) and calculations suggested it would increase the mission range by 35%. The WS-606A had a length of 37ft (11.28m) and the circular wing spanned 29ft (8.84m). A minor variant of this design shows the same aircraft with four turbojets instead of six, but otherwise it appears virtually the same. WS-606A Configuration A was expected to attain Mach 4 at an altitude of 95,000ft (28.953m), which was far in excess of the most advanced combat aircraft then under development. The second version of the WS-606A air- craft, known as Configuration B, was approx- imately the same size but used a different propulsion system layout. This comprised two unspecified Pratt & Whitney jet engines coupled to a RFGT located in the centre of the circular wing. This system was expected to provide a total thrust of 55,000 Ib (244kN). Air for the engines was drawn through a nose inlet fitted with a conical centre-body and the fuselage looked slightly reminiscent of the CF-105 Arrow. This version of WS-606A car- ried a pilot and a navigator. Three sets of dou- ble wheels supported the aircraft and ground clearance would have been absolutely mini- mal, with just a few inches to spare. Gross weight was calculated at 65,000 Ib (29,483kg). As research continued more realistic esti- mates started to emerge; these indicated a maximum speed of Mach 2.5, a ceiling of 65,000ft (19.812m), a combat radius of 800 miles (1,287km) and a ferry range of 3,300 miles (5,310km). By the time the design had been revised as Configuration B, the perfor- WS-606A In addition to developing the USAF’s MX 1794, the SPG were also working on a broadly sim- ilar proposal for the RCAF called Private Ven- ture 704 (PV.704). By 1955 the USAF and CIA were looking for a successor to the high-alti- tude Lockheed U-2 spyplane and PV.704 caught their attention. This design seemed to promise the kind of performance the USAF sought for its next-generation spyplane. Essentially, PV.704 was a variant of MX 1794 with a totally different cockpit that took the form of a central dome with viewing ports for the pilot. After carefully examining this alter- native concept, various design changes were suggested and the dome-shaped cockpit was replaced with a fuselage section containing extra engines for level flight and additional storage space. This revision clearly won favour with the Pentagon, who made substantial black bud- get funding available for further development and renamed PV.704 as Weapons System 606A (WS-606A). Two versions of WS-606A 71 Ea Canada’s Cold War Saucers