The Koolhoven Heidevogel was one of the first

Dutch Dutch or Nederlands commonly refers to: * Something of, from, or related to the Netherlands ** Dutch people as an ethnic group () ** Dutch nationality law, history and regulations of Dutch citizenship () ** Dutch language () * In specific terms, i ...

aircraft, an improvement of the popular

Farman Farman Aviation Works () was a French aircraft company founded and run by the brothers Richard, Henri, and Maurice Farman. They designed and constructed aircraft and engines from 1908 until 1936; during the French nationalization and rational ...

type.

Development

Frits Koolhoven began as car dealer and racing driver but his entry into aviation came in partnership with Henri Wijnmalen whose uncle was the Verwey in the motor car manufacturing business, Verwey and Lugard. An aviation department of the latter developed, with Koolhoven dominant in the factory and Wijnmalen running the flying school. The Heidevogel (Heathbird or Heatherbird) was one of several pioneer aircraft based on the

Farman III The Farman III, also known as the Henry Farman 1909 biplane, was an early French aircraft designed and built by Henry Farman in 1909. Its design was widely imitated, so much so that aircraft of similar layout were generally referred to as being ...

and generally known as "Farman types", though it had several modifications to the wings,

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, airship, or other vehicle that moves through a fluid medium (usually air or water). On an airplane, the rudder is used primarily to counter adverse yaw ...

s and accommodation. It was a multi-bay, unequal span biplane with no stagger and wings of constant chord, braced with pairs of parallel

interplane 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 struts, which act in ...

Ailerons An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement around ...

provided lateral control. The

empennage The empennage ( or ), also known as the tail or tail assembly, is a structure at the rear of an aircraft that provides stability during flight, in a way similar to the feathers on an arrow.Crane, Dale: ''Dictionary of Aeronautical Terms, third ed ...

was supported by an open frame

fuselage The fuselage (; from the French language, French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds Aircrew, crew, passengers, or cargo. In single-engine aircraft, it will usually contain an Aircraft engine, engine as wel ...

with longitudinal upper and lower pairs of

longeron In engineering, a longeron or stringer is a 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 fram ...

s or booms, each side braced with four vertical

strut A strut is a structural component commonly found in engineering, aeronautics, architecture and anatomy. Struts generally work by resisting longitudinal compression, but they may also serve in tension. A stay is sometimes used as a synonym for ...

pairs. At the rear, fixed and almost square horizontal tailplanes stretched between the upper and the lower pairs of booms. A pair of

trapezoidal In geometry, a trapezoid () in North American English, or trapezium () in British English, is a quadrilateral that has at least one pair of parallel sides. The parallel sides are called the ''bases'' of the trapezoid. The other two sides are ...

rudders were hinged on the last two verticals, assisted by another central one further forward. The

elevator An elevator (American English) or lift (Commonwealth English) is a machine that vertically transports people or freight between levels. They are typically powered by electric motors that drive traction cables and counterweight systems suc ...

was all moving and mounted ahead of the wings on a pair of vertically converging booms with vertical cross braces. In Farman types the pilot sat over the wing, completely exposed, with the 37 kW (50 hp) seven cylinder

Gnome Omega The Gnome 7 Omega (commonly called the Gnome 50 hp) is a French seven-cylinder, air-cooled aero engine produced by Gnome et Rhône. It was shown at the Paris Aero Salon held in December 1908 and was first flown in 1909. It was the world's ...

rotary engine The rotary engine is an early type of internal combustion engine, usually designed with an odd number of cylinders per row in a radial configuration. The engine's crankshaft remained stationary in operation, while the entire crankcase and its ...

behind him in

pusher configuration In aeronautical and naval engineering, pusher configuration is the term used to describe a drivetrain of air- or watercraft with propulsion device(s) after the engine(s). This is in contrast to the more conventional tractor configuration, wh ...

; Koolhoven added a pod or gondola, its flat sides curving together to a sharp edge at the front. The

undercarriage Undercarriage is the part of a moving vehicle that is underneath the main body of the vehicle. The term originally applied to this part of a horse-drawn carriage, and usage has since broadened to include: *The landing gear of an aircraft. *The ch ...

consisted on each side of a pair of wheels on either side of a skid, curved up at the front. Each skid was mounted on two vertical struts attached below the wing at the bases of the innermost interplane struts and laterally braced with an inner diagonal strut to the wing underside. A long, curved tailskid was fixed just ahead of the leading edge of the tailplane.

Operational history

Both Koolhoven and Wijnmalen flew the Heidevogel throughout 1911 but Verwey and Lugard went bankrupt at the end of the year.

Specifications

References

{{Koolhoven aircraft 1910s Dutch aircraft Heidevogel Biplanes Single-engined pusher aircraft Aircraft first flown in 1911 Rotary-engined aircraft