Avro 548

The Avro 548 was a civil trainer aircraft built in Britain by Avro after World War I, designed extensively from the Avro 504 military aircraft but with an inline engine and a third seat. The prototype, designated 545, first flew with a Curtiss OX-5 V-8 engine, which proved impractical for the civil market because of its weight and cooling complexity, so an air-cooled Renault engine was used and the 548 designation applied. Aircraft were usually customised for their buyers and some were retrofitted war-surplus 504s, with many used as civil trainers. The 548A took an 120 hp ADC Airdisco engine that greatly improved performance, Latvia and Portugal each bought two in 1924, and a cabin version, the 553, was never built.