The Koolhoven F.K.47 was a 1930s one-off two seat biplane designed and built in the

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

for an individual customer as a

sport Sport pertains to any form of Competition, competitive physical activity or game that aims to use, maintain, or improve physical ability and Skill, skills while providing enjoyment to participants and, in some cases, entertainment to specta ...

and touring aircraft.

Design and development

The F.K.47 was specifically built for H.L. Jonker Roelants as a sports tourer and registered in his name in June 1933. It had much in common with the early version of the

Koolhoven F.K.46 The Koolhoven F.K.46 was a 1930s Netherlands, Dutch training biplane designed and built by Koolhoven. The F.K.46 was a two-seat biplane with a fixed tailwheel landing gear and tandem open cockpits. The prototype first flew in 1933, powered by a C ...

sport and training aircraft, which first flew four months later. Both were two seat, single bay biplanes, with equal span, unswept wings of constant

chord Chord may refer to: * Chord (music), an aggregate of musical pitches sounded simultaneously ** Guitar chord a chord played on a guitar, which has a particular tuning * Chord (geometry), a line segment joining two points on a curve * Chord ( ...

and strong stagger, braced with N-form struts. The upper wing of the F.K.47 was held above the

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...

primarily by a pair of short, outward leaning N-form

cabane strut In aeronautics, bracing comprises additional structural members which stiffen the functional airframe to give it rigidity and strength under load. Bracing may be applied both internally and externally, and may take the form of strut, which act in ...

s to the upper fuselage

longeron In engineering, a longeron and stringer is the load-bearing component of a framework. The term is commonly used in connection with aircraft fuselages and automobile chassis. Longerons are used in conjunction with stringers to form structural ...

s. There was a shallow rounded cut-out in the trailing edge of this wing to enhance the upward view from the forward cockpit. The F.K.47 was powered by a 130 hp (97 kW) de Havilland Gipsy Major air-cooled inverted inline engine, driving a two blade

propeller A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon ...

. The fuselage had a rounded decking with the forward cockpit placed under the upper wing trailing edge and the aft one just behind the lower wing edge. Both cockpits were open. Aft, the

fin A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. Fin ...

was quadrant-shaped with a vertical

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally aircraft, air or watercraft, water). On an aircraft the rudder is used primarily to ...

. The undercarriage was conventional, with the mainwheels on

cantilever A cantilever is a rigid structural element that extends horizontally and is supported at only one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a canti ...

tube, faired legs, assisted by a tailwheel.

Operational history

At least some of Roelant's flights around

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

in the sole F.K.47, ''PH-EJR'', ended badly. An early trip to the

Dolomites The Dolomites ( it, Dolomiti ; Ladin: ''Dolomites''; german: Dolomiten ; vec, Dołomiti : fur, Dolomitis), also known as the Dolomite Mountains, Dolomite Alps or Dolomitic Alps, are a mountain range located in northeastern Italy. They form par ...

in July 1933 ended prematurely with engine failure over

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

. Three years later, flying between

Rotterdam Rotterdam ( , , , lit. ''The Dam on the River Rotte'') is the second largest city and municipality in the Netherlands. It is in the province of South Holland, part of the North Sea mouth of the Rhine–Meuse–Scheldt delta, via the ''"N ...

and

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but off course he landed at a military field where tensions had been raised by the recent

German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ger ...

occupation of the

Rhineland The Rhineland (german: Rheinland; french: Rhénanie; nl, Rijnland; ksh, Rhingland; Latinised name: ''Rhenania'') is a loosely defined area of Western Germany along the Rhine, chiefly its middle section. Term Historically, the Rhinelands ...

. He and his aircraft were briefly held under guard. He continued to use it until 1939 when it was destroyed.

Specifications

References

{{Koolhoven aircraft FK.47 1930s Dutch sport aircraft Biplanes Aircraft first flown in 1933 Single-engined tractor aircraft