[Monochrome photograph of the Avro 503 prototype on Brighton Beach June 1913]
During early 1913 a second version of the Avro 501 was built and Roe fitted it with larger wings and a twin float undercarriage. In this form it became the Avro 503. It performed well and was sold to the German Government.
Several German companies made their own copies of the machine and these formed the basis for German seaplane development during the early part of the First World War.
AVRO 504 Prototype
[Monochrome photograph showing the Avro 504 prototype in its original form]
The Avro 504 was an improved version of the Avro 500 produced in carly 1913 fitted with a 70 hp (52 kW) Gnome rotary engine and staggered wings. First tests were carried out at Brooklands in July and the aeroplane made its public debut at Hendon on September 20th as an entrant in the Second Aerial Derby Flown by E. P. "Fred" Raynham. The 504 was placed fourth in the Derby with an average speed of 66.5 mph. (106 km/h).
The RNAS took over the prototype at the outbreak of War but unfortunately it was destroyed when the engine failed on the delivery flight.
[Monochrome photograph of the improved prototype in its final form as sponsored by the Daily Mail and taken around coastal resorts during early 1914]