Complex sentence: The Avro Canada CF-103 as a twin-engine swept-wing transonic fighter, which was proposed as a replacement of the CF-100 but the RCAF placed no orders and cancelled the program in 1951 while at the mock-up stage.
Split into simpler sentences: The Avro Canada CF-103 was a twin-engine swept-wing capable of transonic speeds. It was proposed as a replacement of the CF-100 but the RCAF placed no orders and cancelled the program in 1951 while at the mock-up stage.