This is a one sexy plane. image - Aircraft Lovers Group

Designed by TE Slot for the Dutch firm De Schelde, the S.21 was a single seat fighter which reached the advanced prototype stage. Construction commenced early in 1939. Slot believed that, with all the weight concentrated on the fighter's CG. the S.21 would make an excellent gun platform and offer a degree of manoeuvrability comparable with, if not superior to, that of more orthodox single-seat fighter configurations.
Not only was it intended to take on the interceptor role, low-level ground attack was also envisaged. A 23mm Madsen cannon was to be fixed for the interceptor role and flexible for ground attack role. This being achieved by an automatic stabilising system whereby the pilot only had to adjust the rudder while operating the flexible cannon mode. Other armament included four 7.9mm FN-Browning machine guns.
Estimated maximum speed of 367mph at 13,125ft, and a maximum continuous cruise of 323mph was "feasible".
Unfortunately, no opportunity to confirm these calculations was to present itself. The prototype was in final assembly in May 1940 when the Wehrmacht occupied the De Schelde factory. the airframe was transported to Utrecht where it was tested to destruction in the Zerlegebetrieb (Analysis Department).
This Dutch fighter was, however, to gain a brief claim to fame after its demise as, for a time, artist's impressions of the warplane were widely disseminated under the label "Focke-Wulf 198"!