 Other than the different engines, there were few differences between the two types, other than the Mk I having a slightly reduced lower wing surface, and enlarged tailfin and rudder to correct control problems indicated in testing.Flight testing also indicated a lower performance than anticipated which resulted in Avro reconsidering the type's further trials, and eventually led to the abandoning of the third prototype, which was never fitted with engines.In March 1919, Avro proposed a passenger airliner, the Avro 537, that would be adapted from the earlier bomber version.