Aviation Naval Warfare Land Systems Small Arms By Flag By Year By Tag

Koolhoven F.K.55

1938 X-PLANE

Koolhoven F.K. 55 Stories

Before WW2 (1939-1945), the Dutch had a respectable aviation industry that produced some notable local design types. The Koolhoven F.K. 55 was a prototype modeled after a high-speed fighter, introduced in the second half of the 1930s.

The line ended with the construction of a single example, whose maiden flight took place on June 30, 1938, with the program ending by the end of the year.

Its design began in 1937 as a sleek, advanced fighter with a cockpit positioned forward of the wing main aircraft, which moved forward (and shoulders) in the center of the ship. The wingtips are rounded and the appendages appear straight. The rear wing is conventional, with one rear wing and two horizontal planes. The building is hybrid and consists of metal and wood. "Trailing" landing gear was introduced.

The engine of choice became an 860-horsepower Lorraine 12-hour "Petrel" V-12, driving a pair of twin-blade propeller assemblies in counter-rotating fashion. Since the cockpit is in the front of the fuselage, the engine is mounted behind the pilot (as detailed elsewhere on this page for the famous Bell P-39 "AiraCobra" fighter).

The finished aircraft was ready for its maiden flight in early 1938, with the appearance required of a high-performance aircraft. The fixed landing gear ushered in this milestone moment in design, with the aim of introducing a retractable system in later development. In practice, however, the design proved to be flawedthe 860 horsepower produced for the engine was just take-off power. Underpowered and expensive to overhaul, the aircraft project was eventually abandoned by Kurhoeven and went down in the history of military aviation.

In vain, engineers demanded the installation of a supercharged 1,200-horsepower Lorraine "Sterner" engine.

As designed, the F.K. 55 has a top speed of 317 mph, a cruising speed of nearly 280 mph, a range of up to 530 miles, and a rate of climb of 2,580 feet per minute (all figures estimated by Koolhoven). Proposed Weapon The plan was to mount a 20mm gun with a propeller hub and 4 x .303 machine guns, two on each wing. The P-39 has similar weapons, but has a more powerful 37mm automatic cannon in the nose.

Performance is also better: the Q model has a top speed of 600 km/h. Like the F.K. 55, it first flew in 1938 and has an excellent wartime record in subsequent global conflicts.