There were three prototypes of this Avro 529 development built, the third model not having any engines, they were the Avro 533A Manchester Mk1 and the Avro 533A Manchester MkII. The original Mk1 was designed to take the ABC Dragonfly engine, but when this was not forthcoming the plane was fitted with 2 x 400 h.p Liberty engines thus making the Mk II fly first. The Dragonfly engines arrived eventually, but as we know elsewhere these just did not make the grade. The result being that the performance was far below expectations and Avro decided to cut their losses and abandoned the project. A passenger version the Avro 537 was still born.