Koolhoven FK23 aircraft as exhibited at Aviodrome, Lelystad, Holland. In World War I, the Dutchman Frits Koolhoven worked in England as a designer for British aircraft factories. In 1918 it was by BAT in London. After a number of precursors, he designed the BAT FK 23 Bantam with the new ABC Wasp radial engine of 170 hp. It was a very small aircraft whose expectations were very high. German aircraft with a similar power were no less than 50% heavier. This unit was a prototype series of 12 pieces ordered. In the summer of 1918 the first three aircraft were delivered to the Royal Air Force. In many test flights the aircraft proved to be satisfactory. Weak points were the then new radial engine which was very noisy and had to be replaced regularly. The ABC factory worked on an improved version. The allied air forces were on the verge of choosing this hunter to their standard. At the end of the war, however, all contracts were terminated. The RAF had finished two aircraft, the other aircraft continued ownership of the factory. Koolhoven tried to find buyers for the Bantams by participating in numerous demonstrations and air races.