Bristol drew up three possible designs to meet F7/30 (the Type 127 and 128 are basically the same aircraft with different engines) powered by either the Air Ministry's favoured R-R Goshawk of the company's own Mercury radial. A high priority in the specification was for the aircraft to provide the pilot with a good field of view and it was suggested that pusher and/or monoplane layouts should be considered. They were also looking for innovation and not just a continuation of existing design philosophy. As a consequence Bristol's simple fixed undercarriage, braced monoplane designs were rejected. The Type 123 biplane, which was hardly original in style, was completely redesigned and approved for construction, although it remained conservative. The all-new Type 133 was then designed as the company's prefered solution to the specification, and constructed as a private venture. It probably came closest to what the Air Ministry were hoping for.