Complex sentence: Even before the prototype of the CF-100 had flown, Avro Canada was conducting studies of potential advanced variations of the aircraft, as the RCAF was seeking an interceptor with greater high-speed performance.
Split into simpler sentences: Even before the prototype of the CF-100 had flown, Avro Canada was conducting studies of potential advanced variations of the aircraft. The RCAF was seeking an interceptor with greater high-speed performance.