The F.K.48 was a high-wing cantilever monoplane of conventional design with twin engines carried in nacelles on the leading edges.

Usually fitted with fixed, tailwheel undercarriage, a floatplane version was also developed.

Three examples were purchased by the Dutch Army, but only one of these was ever delivered, the other two were destroyed before completion when the Koolhoven factory was bombed by Germany on 10 May 1940.

The Finnish Coast Guard (Merivartiolaitos) ordered two examples with floats and powered by Hirth engines.

[1] Data from N.V. Koolhoven-Vliegtuigen (1934-1940.,[1] Airwar:Koolhoven FK-49[2]General characteristics Performance