The VL Myrsky ("Storm") is a Finnish World War II fighter aircraft originally developed by Valtion lentokonetehdas for the Finnish Air Force. The models of the aircraft were Myrsky I, Myrsky II, and Myrsky III. It was designed by Edward Wegelius, Martti Vainio and Torsti Verkkola who worked at Valtion lentokonetehdas. The decision to start developing a new fighter for the Finnish Air Force was based on experience gained before the Winter War: in the "arms race" leading up to a war, smaller nations can have difficulty purchasing top-of-the-line fighters without a significant political cost. The Finnish Air Force requested preliminary proposals for a domestic fighter from State Aircraft Factory (Valtion Lentokonetehdas) in early 1939, before the Winter War. State Aircraft Factory prepared five alternative proposals by May 1939. After that, The Ministry of Defence ordered the fighter design from State Aircraft Factory in June 1939. The preliminary design was made by the aircraft-designer trio Arvo Ylinen (head of the design-bureau), Martti Vainio (aerodynamics), and Torsti Verkkola (structural design). Edward Wegelius was appointed head of the design department of the State Aircraft Factory when Ylinen later moved on to the Helsinki University of Technology in August 1940. VL did not appoint any main constructor to its products, such as the German aircraft manufacturers did. Due to difficulties obtaining duraluminium, the wings were made out of plywood and the fuselage was metal structure with a fabric and plywood skin. The planned Bristol Taurus III engine was not available due to war, so a Pratt & Whitney R-1830 (civil Twin Wasp) was chosen. Availability of this engine was also problematic, so the first prototype used an R-1830-S3C3-G, while later prototypes and production fighters used less-powerful SC3-Gs. Finland bought these engines from German war booty stocks. The first Myrsky prototype flew on 23 December 1941. The prototype was fully functional, but too heavy. After some modifications they soon had three new prototype aircraft. The test flights showed some structural problems during high-speed tests. All three prototypes were destroyed during test flights; two test pilots died, one was seriously injured. The culprit was found to be aeroelastic flutter, which was a poorly known phenomenon at the time. Resolving the flutter problem took almost a year. Series production started in autumn 1942 far before German deliveries of Messerschmitt Bf 109 had begun in 1943. The series production version was called the Myrsky II. 47 Myrsky IIs were built and together with the Myrsky I version and Myrsky prototype the production amounted to 51 in all. Although the aircraft met the specifications set for it, it did not fulfill all expectations due to structural problems. or operational history, click here. The Myrsky III was ordered in spring 1943, but none were built. Variants Myrsky Prototype, 1 built Myrsky I Preproduction aircraft, 3 built Myrsky II (Specifications below) Series-production aircraft, 47 built Myrsky III 10 being built but cancelled
