De Schelde S.21

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The '''De Schelde S.21''' was a proposed Dutch fighter of the late 1930s and early 1940s. It was a single-seat, single-engined, pusher monoplane. A single prototype was under construction in 1940, but work was abandoned due to the German invasion.

==Design and development== The Dutch shipbuilding company NV Koninklijke Maatschappij De Schelde of Vlissingen entered the aviation business in 1935, when it recruited most of the technical staff, including Chief Designer T. E. Slot, of Pander & Son, which had failed in 1934. Early designs built by De Schelde were the De Schelde Scheldemusch, a lightweight single-seater pusher biplane powered by a {{convert|40|hp|kW}} Praga B engine, and the Scheldemeeuw, a flying boat version of the Scheldemusch.<ref name="aifeb74 p73-4">Beeling ''Air International'' December 2015, pp. 73–74.</ref> In 1938, Slot started design work on two more advanced types which also followed Slot's preferred pusher configuration, the De Schelde S.20, a light cabin monoplane, and the S.21, a single-seat fighter, with construction of prototypes for both types beginning in early 1939.<ref name="aifeb74 p74">Beeling ''Air International'' December 2015, p. 74.</ref>

The S.21 was a low-wing cantilever monoplane of all-metal construction. It featured an inverted gull wing, with the aircraft's tail carried on twin booms.<ref name="greenv3 p98">Green 1961, p. 98.</ref> The compact fuselage nacelle carried the pilot, engine and the aircraft's armament. The pilot sat in a heavily glazed cockpit in the nose of the nacelle, with the engine, a Daimler-Benz DB 600Ga liquid-cooled inverted V12 engine rated at {{cvt|1050|hp}} for takeoff and at {{cvt|920|hp}} at {{cvt|4000|m}}, driving a three-bladed propeller was situated immediately behind the pilot. Slot recognized that to allow the pilot to bail out from the aircraft, the propeller would have to be jettisoned. A mechanism for doing this had yet to be decided on when work on the aircraft stopped.<ref name="aifeb74 p74"/> The engine was cooled by a radiator in the nose of the aircraft below the cockpit.<ref name="aifeb74 p74"/> A nosewheel undercarriage was fitted.<ref name="greenv3 p98"/>

Its armament consisted of a single Madsen 23 mm cannon on a flexible mount in the nose, together with four 7.9 mm FN-Browning machine guns in the side of the nacelle. The cannon was intended to be fixed during air-to-air combat, and during ground strafing operations, it would be released and aimed manually by the pilot, with an automatic stabilizing system controlling the aircraft's ailerons and elevators to aid the pilot in keeping control of the aircraft while busy aiming and firing the cannon.<ref name="aifen74 p75">Beeling ''Air International'' December 2015, p. 75.</ref><ref>{{cite book|title=FM30-35: Military intelligence: Identification of German aircraft|year=1942|publisher=United States War Department|pages=10–11|url=https://books.google.com/books?id=VdAsAAAAIAAJ&q=focke+wulf+fw+198&pg=PA10}}</ref>

The prototype S.21 was almost complete when Germany invaded the Netherlands in May 1940, with the De Schelde factory and the prototype S.21 being seized by German troops. Development was abandoned, with the prototype being tested to destruction at Utrecht.<ref name="aifen74 p75"/> Although abandoned, artist impressions of the S.21 were presented in the wartime aviation press as the fictional '''Focke-Wulf Fw 198'''.<ref name="greenv3 p98"/><ref name="aifen74 p75"/>

==Specifications (Performance estimated)== 3-way drawing of the De Schelde S.21|thumb|300px|right {{Aircraft specs |ref=Dutch Digression <ref name="aifeb74 p74-5">Beeling ''Air International'' December 2015, pp. 74–75.</ref> |prime units?=met  |genhide=

|max speed kmh=590 |max speed mph= |max speed kts= |max speed note=at {{convert|4000|m|ft}} |cruise speed kmh=520 |cruise speed mph= |cruise speed kts= |cruise speed note= |stall speed kmh= |stall speed mph= |stall speed kts= |stall speed note= |never exceed speed kmh= |never exceed speed mph= |never exceed speed kts= |never exceed speed note= |range km= |range miles= |range nmi= |range note= |combat range km= |combat range miles= |combat range nmi= |combat range note= |ferry range km= |ferry range miles= |ferry range nmi= |ferry range note= |endurance= |ceiling m=10000 |ceiling ft= |ceiling note= |g limits= |roll rate= |glide ratio= |climb rate ms= |climb rate ftmin= |climb rate note= |time to altitude= |lift to drag= |wing loading kg/m2= |wing loading lb/sqft= |wing loading note= |fuel consumption kg/km= |fuel consumption lb/mi= |power/mass= |thrust/weight=

|avionics= }}

==References== === Notes === {{reflist}} === Bibliography === * {{cite magazine|last=Beeling|first=M.|title=Dutch Digression|magazine=Air Enthusiast International|date=February 1974|volume=6|issue=2|pages=69–75}} * {{cite book|last=Green|first=William|title=War Planes of the Second World War: Volume Three Fighters|year=1961|publisher=Macdonald|location=London}}

==External links== * [http://www.airwar.ru/enc/fww2/s21.html S.21] (in Russian)

Category:Single-engined pusher aircraft Scheldemusch Category:Inverted gull-wing aircraft Category:Low-wing aircraft Category:Twin-boom aircraft Category:Single-engined piston aircraft