Avro 547

The Avro 547 was a prototype triplane airliner developed in Britain after the First World War, using components from the successful Avro 504 with an extra set of wings and a new deep fuselage housing a fully enclosed cabin for four passengers, while the pilot sat in an open cockpit offset to port. The first prototype had a 160 hp Beardmore engine and flew well, with characteristics like the 504. The second, substantially modified to compete in a British Air Ministry competition and fitted with a 240 hp Siddeley Puma as the 547A, turned out slow and unstable. Qantas bought the first prototype in November 1920 for 2,798 pounds, but it proved utterly unsuited to outback conditions and was quickly decommissioned.