Koolhoven F.K.45
The Koolhoven F.K.45 was an aerobatic biplane built to the requirements of one pilot who flew it at airshows in the mid-1930s. Only one was built.
Design and development
The F.K.45 was the result of a 1931 order from René Paulhan, a French test pilot with Nieuport-Delage, for a light aerobatic aircraft. It was first flown in February 1932, though not delivered to Paulhan for two more years. It was a single bay biplane, with equal span, unswept wings of constant chord and strong stagger, braced with N-form struts and flying wires. Ailerons were mounted on both upper and lower wings. The upper wing of the F.K.45 was held above the fuselage by a pair of short, outward leaning N-form cabane struts to the upper fuselage longerons. The single seat cockpit, set in an opening in the otherwise continuous, rounded fuselage decking, was under the wing trailing edge where a rectangular cut-out enhanced visibility. Its tailplane was mounted on top of the fuselage; the fin was quadrant shaped and the straight edged rudder extended down to the keel.The F.k.45 was powered by a 115 hp Cirrus-Hermes IIB four cylinder inverted air-cooled inline, which drove a two blade propeller. Its undercarriage was of the fixed, conventional type, with the mainwheels on axles forming an inverted V and attached to the central fuselage underside. The main legs, with shock absorbers, were mounted on the upper longerons. There was a small tailwheel.