Stampe SV-4B

The SV-4B is the Belgian version of the Stampe et Vertongen SV-4 training biplane with a de Havilland Gipsy Major engine, and the one that served Belgian military aviation both before and after the Second World War. According to the French Wikipedia, it left the Stampe et Vertongen works at Deurne, near Antwerp, in July 1937 as a derivative of the 1933 SV-4 conceived by the pilot and industrialist Jean Stampe. It differed in its symmetrical, positively swept wings, each fitted with ailerons, and in its 130 hp (97 kW) inverted Gipsy Major I. AeroVFR explains that the greater span and the ailerons on both planes led to the SV-4B designation; the Dutch Wikipedia gives another reading of the letter: the 'b' stood for 'bis', after Jean Stampe came back from France with an order for thirty aircraft.

The military competition and the pre-war figures do not agree between sources. The French Wikipedia places in 1937 the victory in the Belgian military aviation trainer competition and an order for 30 aircraft; avionslegendaires.net describes a 1939 competition won with 300 aircraft ordered; AeroVFR holds that the 1937 aircraft won the competition but was not produced because of a stall judged too sharp and a difficult landing, which led to a longer fuselage and sweep on both wings. When war broke out, according to the French Wikipedia, only 20 had been assembled at Deurne; the English Wikipedia puts at 35 the aircraft built before the company was closed during the war, and avionslegendaires.net at 30 those built for Belgium. Shown in France in 1939, the type led to a licence for Farman, but the French production that eventually materialised was the Renault-engined SV-4C, which is not part of this variant.

The most famous SV-4B is OO-ATD. The Stampe en Vertongen Museum in Antwerp records that it was the fourth SV-4b to leave Deurne, that it was registered on 13 February 1939 and that on 7 March it became the property of Baron Thierry d'Huart, who lived at the Ter Block castle in Overijse, near Brussels. After the capitulation, the sergeant pilots Michel Donnet and Léon Divoy, who had fought in the eighteen-day campaign of May 1940, spent months preparing the aircraft — kept in a small hangar while German troops occupied the castle — assembling, among other things, an instrument panel and gathering petrol in small quantities. A first attempt on 19 May 1941 failed when the engine would not start. On the night of 4 to 5 July 1941, with Divoy at the controls (the aircraft had dual controls and Donnet assisted him), they took off with a cold engine and a tailwind less than 200 metres from the castle, on a heading of 300. After a night flight of more than three hours they landed in a field near Clacton-on-Sea, Essex, and walked to the police station at Thorpe-le-Soken. According to the English Wikipedia, the aircraft was camouflaged and marked 'J7777', served with Nos. 24 and 510 Squadrons RAF as MX457 and was returned to its owner in 1945. The museum adds that it was displayed in the Cinquantenaire Park in Brussels on 20 July 1945, that Stampe et Renard checked and demilitarised it on 15 March 1948, that in 1957 it was re-registered OO-ATO and that it was destroyed on 7 July 1960 in an orchard near Virton. Donnet rose to lieutenant general; Divoy was taken prisoner in 1942.

After the war, Jean Stampe and the engineer Alfred Renard founded Stampe et Renard at Evere, which built the 65 SV-4Bs of the Belgian Air Force; the English Wikipedia places that production between 1948 and 1955, and the French one gives a total of 95 SV-4Bs built in Belgium. These aircraft received a sliding canopy over the cockpit — 'heresy' for purists of the open biplane, according to the Amicale du Bourget — and more powerful engines, the Gipsy Major X or the Blackburn Cirrus Major III of 145 hp (108 kW according to the English Wikipedia). One documented example is OO-ROR, construction number 1161: it first flew on 6 January 1949 with Jean Stampe at the controls, was delivered to the Air Force on 10 February, served as V-19 with the Elementary Training School at Gossoncourt and with the 'Les Manchots' display team, famous for its mirror formation with one aircraft inverted above another, and was written off in 1970. Instructors of the Belgian Air Force flying school such as Commandant Jean Feyten and Lieutenant Paul Christiaens shone with the Stampe at international air shows from 1965 to 1970. Aviationsmilitaires.net also credits seven SV-4Bs to the Belgian Congo air arm. The last SV-4B of the Belgian Air Force was retired in 1975, replaced by the SF-260 according to AeroVFR; today OO-BPL (construction number 1194) wears the exact colour scheme of OO-ATD.