A Brief History of the Avro 504K
First flown in 1913, the Avro 504K was to become one of the most famous aircraft of all time. It started its long career in 1914, when 3 504As, of the Royal Naval Air Service, bombed the German Zeppelin sheds in the first planned raid in aerial warfare. The Avro 504K was one of the first aeroplane types used to strafe troops on the ground. It also had the unenviable distinction of being the first Entente aeroplane to be downed by enemy anti-aircraft fire.
In the winter of 1917–18, converted 504Js and 504Ks were given to Home Defence squadrons of the RFC to replace the ageing B.E.2cs. These aircraft were modified as single-seaters, armed with a Lewis gun above the wing on a Foster mounting, and powered by 100 hp (75 kW) Gnome or 110 hp (80 kW), with around 226 still being used as fighters at the end of World War I
Though it was soon obsolete as a front-line aircraft, it came into its own as a trainer, with thousands being built during the war, the major production types being the 504J and the mass produced 504K. Around 8,000 Avro 504s had been produced by the end of the war in 1918.
Whilst the aircraft stayed in RAF service after the war, large numbers of surplus aircraft were available for sale, both for civil and military use. More than 300 504Ks were placed on the civil register in Britain. Used for training, pleasure flying, banner towing and even barnstorming exhibitions. Civil 504s continued flying in large numbers until well into the 1930s when aircraft like the DH Tiger moth replaced it.
The 504N, which had a radial engine and a redesigned undercarriage, was produced in 1925 and was chosen by the RAF to replace the 504K. Used to equip the RAF’s five training schools, a total or 592 504Ns were produced between 1925 and 1932. The 504N was also used by the armed forces of Belgium, Brazil, Chile, Denmark, Greece, Thailand and South Africa, with licensed production taking place in Denmark, Belgium, Canada and Japan. The Soviet Union produced a copy of Avro 504K under the designation U-1.
The Avro 504 was finally replaced in 1933 by the Avro Tutor, ending the career of this truly remarkable aircraft.