VL Pyörremyrsky (Hurricane) is a Finnish fighter designed by Valtion lentokonetehdas (VL, State Aircraft Factory) during World War II. Only one was built. It was also known as VMT Pyörremyrsky, after VL was merged with other factories to form the Valtion Metallitehdas in 1946.
By 1942 it was becoming clear that the VL Myrsky would not match contemporary Soviet fighters by the time it would become operational, and thus the idea of equipping the Myrsky with a V12 engine was raised. It was not possible, so a new aircraft was created by Torsti Verkkola. On 26 November 1942 the Finnish Air Force ordered two prototypes, to be finished by May 1944. A cheaper version with smaller wings and lighter armament, called Puuska, was also planned but never built.
Pyörremyrsky was intended to match the Messerschmitt Bf 109G's performance, and was mainly built out of wood, since metal was scarce. The Pyörremyrsky was equipped with the Bf 109's Daimler-Benz DB 605A-1 engine and propeller, and thus the Pyörremyrsky was nicknamed "Puumersu" (Wooden Messerschmitt), even though it was an original design. Since the Messerschmitt was criticized for its narrow landing gear, the Pyörremyrsky's landing gear was made wider.
As the tide of the war turned, the shortage of time and resources forced VL to deprioritize the Pyörremyrsky, and eventually the second prototype was dropped. The Continuation War ended in September 1944 and the entire war in May 1945, and thus the Pyörremyrsky was no longer needed. The prototype, PM-1, was finished anyway, and first flew on 21 November 1945 in Härmälä, flown by Esko Halme. A piece of the engine cowling fell off and exhaust fumes entered the cockpit, forcing Halme to land prematurely after 25 minutes.
PM-1 flew only 34 times, for 27 hours in total. The last flight was on 22 July 1947, although PM-1 wasn't officially retired until 1 April 1953.
The Pyörremyrsky was regarded as a potent design. It was more agile than the Bf 109G and could also outclimb it. The prototype had minor issues with stability, the flaps and the rudder that could have been ironed out, but the poor glue used in the joints could have caused serious problems, like in VL Myrsky. Pyörremyrsky's wing profile was later reused in the Valmet Vihuri trainer.
- PM-1 is on display at the Finnish Air Force Museum in Tikkakoski. It was restored in 1970-1972.
- Crew: One
- Length: 9.13 m (29 ft 11 in)
- Wingspan: 10.38 m (34 ft 1 in)
- Height: 3.89 m (12 ft 9 in)
- Wing area: 19.00 m² (204.5 ft²)
- Empty weight: 2,619 kg (5,774 lb)
- Loaded weight: 3,310 kg (7,297 lb)
- Max. takeoff weight: 3,310 kg (7,300 lb)
- Powerplant: 1 × Daimler-Benz DB 605AC V-12, 1,100 kW (1,475 hp)
- Maximum speed: 620 km/h (385 mph)
- Service ceiling: 11,250 m (36,900 ft)
- Rate of climb: 18.5 m/s (3,640 ft/min)
- Wing loading: 174 kg/ m² (35.7 lb sq ft)
- 2 × 12.7 mm LKK/42 machine guns with 300 rounds (not fitted)
- 1 × 20 mm MG 151/20 with 200 rounds (not fitted)
- 4 × 50 kg or 100 kg bombs (not fitted)