The first 504 arrived in 1913. They were the basis for five night-fighter squadrons.
The Avro 504 was a First World War biplane aircraft made by the Avro aircraft company and under licence by others. Production during the war totalled 8,970 and continued for almost 20 years, making it the most-produced aircraft of any kind that served in any military capacity during the First World War. More than 10,000 were built from 1913 until production ended in 1932.
The 504 was the first British aeroplane to strafe troops on the ground as well as the first British aircraft to make a bombing raid over Germany.It was also the first Allied aeroplane to be downed by enemy anti-aircraft fire.
This 504K was at RAF London and is restored from two other planes, the wings came a Avro 548A.
The 504K was a training version of the 504 produced in 1918.