A.Jackson Avro Aircraft since 1908 (Putnam)

Avro 541
  A projected twin-float fleet reconnaissance seaplane to RAF Type XXI, September 1919. It was envisaged as a folding wing sesquiplane powered by one 450 hp Napier Lion. Span 40 ft 0 in. Length 30 ft 0 in. Height 12 ft 10 in.

Avro 542
  Layout made in October 1919 for a passenger transport with one 450 hp Napier Lion engine.

Avro 550
  Reserved either for a projected three-seat reconnaissance triplane to Specification 37/22; or a 15-passenger European civil transport with three Rolls-Royce Condors to Specification 40/22.