The Caudron C.68 was a two-seat

French French may refer to: * Something of, from, or related to France ** French language, which originated in France ** French people, a nation and ethnic group ** French cuisine, cooking traditions and practices Arts and media * The French (band), ...

training Training is teaching, or developing in oneself or others, any skills and knowledge or fitness that relate to specific useful competencies. Training has specific goals of improving one's capability, capacity, productivity and performance. I ...

and touring aircraft, built in the early 1920s, which attracted interest at the time because of its simple and fast wing folding arrangement. Only a few were produced.

Design and development

Apart from its folding wings, the C.68 was a conventional single bay biplane with rectangular plan wings of similar span, mounted without stagger.

Aileron 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 aroun ...

s were fitted only on the upper wings. The outer

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 in parallel pairs and the upper wing was supported over the

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 ...

on four upright

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 struts, which act in ...

s. The forward pair of these were unusual in extending down to the lower fuselage

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 and in being split vertically; the inner halves linked the centre section and fuselage and the outer halves were extra interplane struts. To fold the wings a short section of the centre section

trailing edge The trailing edge of an aerodynamic surface such as a wing is its rear edge, where the airflow separated by the leading edge meets.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 521. Aviation Supplies & Academics, 1997. ...

was folded back to make room for the part of the upper wing aft of its hinge and the lower, outer, normally concealed part of the cabane/interplane strut swung out of its slot in the fuselage. The rear part of the lower wing cleared the fuselage underside. The aileron cables ran within the wing and did not need to be disconnected for folding thanks to wires that prevented them slackening. The C.68 was powered by a

Anzani 6-cylinder Alessandro Anzani developed the first two-row radial from his earlier 3- cylinder Y engine by merging two onto the same crankshaft with a common crankweb. Development By December 1909 Anzani had a 3-cylinder air-cooled true radial engine runn ...

two row

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. ...

, mounted without a

cowling A cowling (or cowl) is the removable covering of a vehicle's engine, most often found on automobiles, motorcycles, airplanes, and on outboard boat motors. On airplanes, cowlings are used to reduce drag and to cool the engine. On boats, cowlings ...

and driving a two blade

propeller A propeller (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 a working flu ...

. Behind the engine the fuselage was flat sided, though the underside had a curved profile and there was curved upper decking. It had two open

cockpit A cockpit or flight deck is the area, on the front part of an aircraft, spacecraft, or submersible, from which a pilot controls the vehicle. The cockpit of an aircraft contains flight instruments on an instrument panel, and the controls th ...

s, one under the wing and the second just aft of the trailing edge. The C.68's

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. F ...

was triangular and broad, carrying a vertical edged unbalanced rudder which extended down to the keel. Its

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 on top of the fuselage with its

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 ...

s notched to allow rudder movement. It had a tailskid undercarriage with its mainwheels on a single long axle sprung on two V-form struts from the lower fuselage longerons. Folding and deploying the wings was straightforward and rapid, taking less than four minutes. Folding began by pinning on a tailskid extension to keep the lower wings off the ground. This extension could also link the folded C.68 behind a car for towing. The C.68's folded width was less than its height. The C.68 was first flown in 1922 and was on display at the 1922 Paris Salon, which opened on 15 December. Another C.68 was flown to Paris by Becheler who landed it in front of the Grand Palais on 16 December 1922, then gave a demonstration of its folding wings. Four C.68s appeared on the French Civil Register. In total six C.68s were built, of which a single example survives ad is in airworthy condition.

Specifications

References

{{Caudron aircraft C.068 1920s French sport aircraft Single-engined tractor aircraft Biplanes Aircraft first flown in 1922