The Stampe et Vertongen SV.5 Tornado was a military trainer aircraft designed and built in Belgium in the 1930s.Taylor 1989, p.839''The Illustrated Encyclopedia of Aircraft'', p.2955 It saw service with the

Belgian Air Force The Belgian Air Component ( nl, Luchtcomponent, french: Composante air) is the air arm of the Belgian Armed Forces, and until January 2002 it was officially known as the Belgian Air Force ( nl, Belgische Luchtmacht; french: Force aérienne belg ...

Jouhaud 1999, p.85 and Latvian Air Force,Jouhaud 1999, p.84 and Latvian firm VEF purchased a production license, although it is uncertain whether it built any examples.

Design and development

The SV.5 was

Stampe et Vertongen Stampe et Vertongen was a Belgian aircraft manufacturer formed in 1922 and based at Antwerp. The company specialised in design and construction of primary trainers/tourers and advanced trainers. One of their products - the Stampe-Vertongen SV.4 - ...

's response to a 1933 requirement by the

for a two-seat training biplane with aerobatic capabilities. Jean Stampe directed designer George Ivanow to update the company's RSV.22 to meet the new specifications, but the resulting design was an entirely new aircraft with only a superficial resemblance to its predecessor. It was a conventional, single-bay biplane with staggered wings of unequal span.Jouhaud 1999, p.87 The pilot and instructor sat in open cockpits in tandem and the aircraft was powered by an

Armstrong Siddeley Serval The Armstrong Siddeley Serval was a British ten-cylinder aero engine developed by Armstrong Siddeley in the late 1920s. Following company tradition, the engine was named for the serval. Design and development The Serval was a ten-cylinder, do ...

radial engineJouhaud 1999, p.83 in the nose, enclosed in a Townend ring. The main units of the fixed undercarriage were divided and the tail was supported by a tailwheel. It could be equipped for bombing or gunnery training. Unlike earlier Stampe et Vertongen products, which had wooden structures, the SV.5 airframe was riveted together from steel tube in a method inspired by

Hawker Hawker or Hawkers may refer to: Places * Hawker, Australian Capital Territory, a suburb of Canberra * Hawker, South Australia, a town * Division of Hawker, an Electoral Division in South Australia * Hawker Island, Princess Elizabeth Land, Antarct ...

in the United Kingdom. The prototype first flew in September 1933, and on 16 October 1934, the Belgian Air Force evaluated it against five competitors: the Avro 626, Breda Ba.25, Fairey Fox III, LACAB T-7, and the Renard R-34. A sixth competitor, the

Caproni Ca.113 The Caproni Ca.113 was an advanced training biplane produced in Italy and Bulgaria in the early 1930s. Designed as a follow-on to the Ca.100, it was a more powerful and robust aircraft capable of aerobatics. It was a conventional design with two ...

, suffered an accident on arrival and was disqualified. The SV.5 outclassed all its rivals in the maintainability trials, and was less expensive than any of them. However, the Avro 626 was selected for political reasons. The SV.5 nevertheless found a customer in the Latvian Air Force, which was seeking a similar aircraft. When a study mission to Belgium confirmed the type's suitability, the Latvian government negotiated the purchase of ten examples in exchange for 5,700 tonnes of wheat. These machines were slightly different from the prototype, with a

NACA cowl The NACA cowling is a type of aerodynamic fairing used to streamline radial engines installed on airplanes. It was developed by Fred Weick of the National Advisory Committee for Aeronautics (NACA) in 1927. It was a major advance in aerodynamic ...

in place of the Townend ring, a redesigned horizontal stabiliser, and simplified main undercarriage. Germany would not permit the overflight of the aircraft, so in September 1936 they were shipped disassembled to

Riga Riga (; lv, Rīga , liv, Rīgõ) is the capital and largest city of Latvia and is home to 605,802 inhabitants which is a third of Latvia's population. The city lies on the Gulf of Riga at the mouth of the Daugava river where it meets the Ba ...

, where Jean Stampe oversaw their assembly by VEF. In the meantime, the Belgian Air Force finally placed an order for twenty SV.5s. Stampe et Vertongen delivered these between October 1936 and mid 1937.

Variants

Ivanow used the SV.5 as the basis for a family of follow-on designs with only minor variations: ;SV.6 :version with 260-kW (350-hp) Armstrong Siddeley Cheetah IX ;SV.7 :version with 378-kW (507-hp)

Pratt & Whitney Wasp Junior The Pratt & Whitney R-985 Wasp Junior is a series of nine-cylinder, air-cooled, radial aircraft engines built by the Pratt & Whitney Aircraft Company from the 1930s to the 1950s. These engines have a displacement of ; initial versions produced , ...

, also with spoilers under the upper wing ;SV.8 :version with 180-kW (240-hp)

Armstrong Siddeley Lynx The Armstrong Siddeley Lynx is a British seven-cylinder aero engine developed by Armstrong Siddeley. Testing began in 1920 and 6,000 had been produced by 1939. In Italy Alfa Romeo built a licensed version of this engine named the Alfa Romeo ...

IV ;SV.9 :SV.5 with metal, variable-pitch propeller, and upper wings moved 2 cm (1 in) rearward to improve centre of gravity Of these, only a single SV.9 was built. This aircraft was exported to Latvia, together with a license for production by VEF. Although rumours exist that VEF built examples of the type, this cannot be confirmed.

Operators

; *

(20) ; * Latvian Air Force (10)

Specifications (SV.5)

Notes

References

* * Gerdessen, Frederik. "Estonian Air Power 1918 – 1945". '' Air Enthusiast'', No. 18, April – July 1982. pp. 61–76. . * * {{Stampe et Vertongen aircraft 1930s Belgian military trainer aircraft Stampe et Vertongen aircraft Biplanes Single-engined tractor aircraft Aircraft first flown in 1933