The Siskin was one of the first British fighters produced after the First World War. It was designed by Major F M Green to meet the RAF specification for a single seat machine powered by the new Dragonfly radial engine and first flew in May 1919. Whilst the aircraft gave a generally good performance and handled well, the Dragonfly proved not only unreliable but quite unable to provide the power expected. Green therefore decided to retrofit the Siddeley Jaguar engine and, at the same time, introduce an all-steel aircraft structure. The result, designated the Siskin III, took to the air on 7th May 1923 with six being delivered to the RAF for evaluation in January 1924.
Entry into productive service with No 41 squadron at RAF Northolt followed in May 1924. Armament as a fighter comprised 2 x .303in Vickers machine guns but provision was also made for the carriage of up to 4 x 20 lb bombs under the wings. A superb aerobatic machine, the Siskin was an invariable participant at RAF displays between 1925 and 1931; it was also successful in other disciplines, with a civil version, the Mk V, winning the King’s Cup Air Race in 1925 at a speed of more than 151 mph. Thirteen RAF squadrons operated the aircraft until its retirement in 1932 and a small number also saw service with Canada, Sweden and Estonia. Whilst some 470 machines were built in total, there are, sadly, no known survivors.
The Siskin equipped Nos 1 and 43 Squadrons at RAF Tangmere from 1927 and 1928 respectively, with a third unit, No 25 Squadron, collocated temporarily in 1929. It continued in service with both established squadrons until 1931 at which time it began to be replaced by the Fury.