Even while the AVRO CF100 "Canuck" all weather fighter was still in design and production, AVRO was looking ahead and submitted some ideas to the RCAF.

With the "Cold War" on there was a requirement for a supersonic replacement of the CF100 to meet the ever changing Soviet threat.

The RCAF in April 1953  issued Air 7-3: Design Studies of Prototype Supersonic, All-weather, Interceptor Aircraft.

On 31 Aug 1955, the RCAF issued Air 7-4 Issue 3: Specification for Supersonic All-weather Interceptor Aircraft Type CF105.

The major requirements of Air 7-4 were:

          a. Combat speed of Mach 1.5;
          b. Ceiling of 60,000 feet;
          c. An active radius of 200 NM;
          d. Climb to 50,000 feet in 5 minutes; and
          e. Maneuverability of a 2 G turn at 50,000 feet at Mach 1.5 while maintaining
              speed and altitude

Air 7-4 was twenty-six (26) pages in length.