Built for the Admiralty early in 1916, the Avro 519 single seat biplane appears to have been fitted with the same wing structure as the 510, redesigned for folding and rigged with decreased gap. An enlarged version of a central skid undercarriage replaced the floats and the radiator was above and behind the engine which blocked the pilot's forward view. A large fin and rudder of the type used on the Avro 504B was also fitted.
An elongated secondary structure on top formed a streamlined headrest.
Four prototypes were built, comprising two Avro 519s for the R.N.A.S. and two Avro 519A two-seaters for the RFC. The RFC aircraft were fitted with a Vee strut undercarriage with no skid, and photographs taken by test pilot Capt. F. T. Courtney suggest that all four were delivered to Farnborough for tests during or before May 1916. It is said that neither the R.N.A.S. nor the R.F.C. considered them strong enough for the 150hp engine, and their rate of climb was poor. No hint of their career or ultimate fate remains.
Engine: 1 x 150hp Sunbeam Nubian
Wingspan: 19.20 m / 63 ft 0 in
Max. speed: 122 km/h / 76 mph