Gloster Gauntlet The British Gloster Gauntlet was a single - seat , biplane fighter of the RAF designed and built by Gloster Aircraft in the 1930s . It was the last RAF fighter to have an open cockpit and the penultimate biplane fighter in service . Design and development . The Gloster S . S . 18 first flew in January 1929 . The Gauntlet was a development of the Gloster S . S . 19B design , which originally mounted six machine guns ( i . e . four in the wings and two in the fuselage ) . The original S . S . 19 prototype being re - engined with a Bristol Mercury VIS engine , first flying in this form in 1933 . On testing the S . S . 19 , the Air Ministry placed an order for 24 aircraft in September 1933 , to be named the " Gauntlet " . This initial order was followed up with orders for the revised Gauntlet Mk . II . This new model used a revised construction method based on that used by Hawker following Hawker ' s takeover of Gloster , as this was much easier to build and repair than Gloster ' s welded structure . A total of 204 Mk IIs were produced in the UK . Operational history . The Gauntlet Mk . I first entered service with No 19 Squadron at RAF Duxford in May 1935 . The Gauntlet proved successful and popular in operational service , being faster than the aircraft it replaced , the Bristol Bulldog to form the main part of the RAF ' s fighter strength . The Gauntlet was the fastest aircraft in the RAF from 1935 to 1937 . The Gauntlet Mk II entered service with 56 Squadron and 111 Squadron in May 1936 , a further six squadrons being re - equipped with the Gauntlet by the end of the year . At the height of its career , the Gauntlet equipped a total of 14 Squadrons of RAF Fighter Command . No . 32 ( The Royal ) Squadron RAF Gauntlets were used in early trials of ground direction of fighters by radar . As more advanced fighters , such as the Gloster Gladiator , Hawker Hurricane and Supermarine Spitfire started to re - equip the Gauntlet squadrons in 1936 and 1937 , the Gauntlets were passed on to freshly formed units as their first equipment to allow then to gain training before receiving more modern fighters . Gauntlets were also shipped to the Middle East , equipping three RAF squadrons . All home based Gauntlet squadrons had re - equipped with more modern fighters by the start of the Second World War , but remained in service in the Middle East for longer , with a flight of Gauntlets remaining in service with No . 3 Sqn RAAF in the Middle East when Italy declared war in 1940 . These were briefly used for ground attack operations against the Italians before being retired from operations owing to maintenance problems . Gauntlets continued in use for meteorological flights until 1943 . Seventeen Gauntlets IIs were licence produced in Denmark , while 25 ex - RAF machines were supplied by South Africa as support to Finland in 1940 as a result of the Winter War . Already obsolete , they were used as advanced trainers by the Finns . The Finnish nickname for the Gauntlet was " Kotletti " ( literally " cutlet " ) . Survivors . As of 2008 , the only airworthy Mk II in the world , " GT - 400 " , is registered in Finland where it spends its summers in Kymi Airfield Aviation Museum near Kotka .