The Caudron Type D was a French pre-

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single seat,

twin-boom A twin-boom aircraft has two longitudinal auxiliary spars, or “auxiliary booms” , that may contain ancillary components such as fuel tanks and/or provide a supporting structure for other items. Typically, twin tailbooms support the tail ...

tractor A tractor is an engineering vehicle specifically designed to deliver a high tractive effort (or torque) at slow speeds, for the purposes of hauling a Trailer (vehicle), trailer or machinery such as that used in agriculture, mining or constructio ...

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, a close but slightly smaller relative of the two seat Caudron Type C. More than a dozen were completed, one exported to the

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, where they may also have been licence-built, and three to

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

Design and development

In late 1911, W.H. Ewen acquired the right to supply Caudron aircraft in the

and in Ewen Aviation's 1913 catalogue the single seat Type D appears on the page labelled Type C; though the latter was a two-seater, the two types appear to have been closely related. Both were twin boom, tractor biplanes, which began with equal upper and lower spans but were later modified into

sesquiplane A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While a ...

s. Both were single-seaters, with engine and pilot in an inter-wing

nacelle A nacelle ( ) is a streamlined container for aircraft parts such as Aircraft engine, engines, fuel or equipment. When attached entirely outside the airframe, it is sometimes called a pod, in which case it is attached with a Hardpoint#Pylon, pylo ...

. In contrast to the Type C, the Type D was a little smaller and lighter and in its early months was powered by the low power () 3-cylinder Anzani

radial engine The radial engine is a reciprocating engine, reciprocating type internal combustion engine, internal combustion engine configuration in which the cylinder (engine), cylinders "radiate" outward from a central crankcase like the spokes of a wheel. ...

. After modification to a sesquiplane, the upper to lower span ratio of the Type D was smaller than that of the Type C. The Type D was a two-bay biplane with an inner bay only about half the width of the outer. Both two- spar fabric-covered wings had rectangular plans apart from angled tips. There was no stagger, so the two sets 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 ...

s were parallel and vertical. The upper wing overhang produced by the sesquiplane modification was supported by extra parallel pairs of outward leaning interplane struts. Wire bracing completed the structure. The rear spar was ahead of mid- chord, leaving the

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s in the rear part of the wing flexible and allowing

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. The nacelle was a simple, short, flat-sided structure. It was supported above the lower wing on two more pairs of interplane struts which passed within the nacelle. The Anzani engine was mounted uncowled at the front, with the pilot seated under the trailing edge. 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 ...

of the Type D was supported on a pair of girders arranged parallel to one another in plan. The upper girder members were attached to the upper wing spars at the tops of the innermost interplane struts and the lower ones ran under the lower wing, mounted on downward extensions of the inner interplane struts. The mounting was strengthened with two diagonal struts on each side, one from the base of the forward interplane strut to the upcurved tip of the lower member and the other from the rear interplane strut to the junction of the lower member and its first vertical cross member. Each of these lower members, which supported the aircraft on the ground as skids, carried twin, rubber sprung landing wheels. Behind the wing the upper and lower members converged to the rear; the drag on the lower members reduced the landing run. There were three vertical cross braces on each girder but the only lateral inter-girder cross-members were near the tail, though there was wire bracing. The broad chord

tailplane A tailplane, also known as a horizontal stabilizer, is a small lift (force), lifting surface located on the tail (empennage) behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed-wing aircraft such as helicopters ...

was mounted a little below the upper girder member with a pair of round-cornered rectangular

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 above it.

Operational history

The Type D first appeared in December 1911 and in total thirteen were built. Of these, one was sold in

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and three others to China, all sesquiplanes; the Chinese aircraft had the more powerful 6-cylinder Anzani radial engine. This engine was again mounted uncowled, showing its characteristic ring exhaust. One aircraft, originally the Type Abis, was modified into a Type D, retaining its

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 ...

7-cylinder rotary engine with an oil-deflecting cowling over the upper half, extending back over the front fuselage. A Type D powered by a larger

displacement Displacement may refer to: Physical sciences Mathematics and physics *Displacement (geometry), is the difference between the final and initial position of a point trajectory (for instance, the center of mass of a moving object). The actual path ...

6-cylinder Anzani, producing , was delivered from

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on 21 June 1912 by Guillaux to Mr Ramsay in

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. It had a longer nacelle which seated two, had curved, raised decking immediately ahead of the cockpit and was suspended between the innermost interplane struts, like the Type B rather than the Type C. Caudron referred to this version as the Type D2. With tanks for it had an endurance of three hours. A second Type D2 was constructed for Philippe Marty. It is not known how many aircraft were constructed in the United Kingdom by Ewen Aviation or its successor, British Caudron, nor the particular types built, though one was powered by a Anzani and used at Ewen's flying school. It was mostly flown by beginners on short, straight hops.

Specifications

Performance figures are for the Gnome rotary-engined variant.

References

{{Caudron aircraft 1910s French aircraft TD Twin-boom aircraft Rotary-engined aircraft Aircraft first flown in 1911 Single-engined tractor aircraft Aircraft with fixed conventional landing gear Biplanes