The Dutch aircraft concern of N.V. Koolhoven was established in 1926 and managed for itself a healthy resume of locally-designed and -developed aircraft heading into World War 2 (1939-1945). The company' s historical reach ended after May of 1940 as the Germans steamrolled towards Paris by way of The Netherlands and Belgium. Before its end, Koolhoven was able to deliver several notable designs of which one became the "F.K.56", a modern monoplane used for basic training. Only thirty-one of the type were completed and these went on to stock the air services of both The Netherlands and Belgium.
The F.K.56 carried its crew of two in tandem under a framed, fully-enclosed canopy. The engine was mounted at the front of the fuselage in the usual way and the wing mainplanes set low along the fuselage sides. To each wing was mounted a fixed main wheeled leg with a tailwheel seated under the aft section of the aircraft. The tail unit itself was traditional, utilizing a single vertical fin with mid-mounted horizontal planes. As a basic trainer, the aircraft's designated role was in introducing future aviators to the nuances of modern flight - so no armament was fitted.
Dimensions included a length of 7.8 meters, a wingspan of 11.5 meters, and a height of 2.3 meters. Empty weight was 1,060 kilograms against a Maximum Take-Off Weight (MTOW) of 1,600 kg. With power served through an American Wright "Whirlwind" R-975-E3 radial piston engine of 451 horsepower, the F.K.56 managed a maximum speed of 185 miles per hour, a range out to 500 miles, and a service ceiling of 24,000 feet.
First flight of a prototype form was recorded on June 30th, 1938. A second prototype followed that had a retractable undercarriage arrangement and third followed that with a revised wing mainplane and dual-control scheme. From the latter offering, the Dutch Army contracted for ten aircraft and the Belgians followed in February of 1940 with a twenty-strong order of their own. The type was available during the German invasion in 1940 but could do little to stave off their respective country's defeat - all ten were delivered to the Dutch before its fate was sealed while the Belgians had taken on seven of their twenty ordered.
With the end of the Koolhoven facility at Waalhaven Airport - destroyed by German bombs - and the conquering of The Netherlands and Belgium, the F.K.56 was no more.