The Caudron C.37 was a French three-engined

biplane 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 ...

passenger transport, built in 1920. It could carry six passengers.

Design and development

Between 1919 and 1922 Caudron built a series of multi-engined civil passenger transport biplanes of similar design but increasing size and engine power, the C.33, C.37, C.39, C.43 and C.61. The C.37 was the first

trimotor A trimotor is an aircraft powered by three engines and represents a compromise between complexity and safety and was often a result of the limited power of the engines available to the designer. Many trimotors were designed and built in the 1920s ...

in this series. The C.37 was a three bay biplane with fabric-covered, rectangular-plan wings mounted without stagger. The lower wing had dihedral outboard of the engines, and the upper carried the

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 around ...

s, which were not balanced as they were on the later aircraft. The wings were joined by vertical pairs of

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 strut, which act in ...

s, the forward members attached near the

leading edge The leading edge of an airfoil surface such as a wing is its foremost edge and is therefore the part which first meets the oncoming air.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 305. Aviation Supplies & Academics, ...

s, and the centre section was supported by similar, shorter

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 from the upper

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 ...

. Each inner bay was defined by two close pairs of leaning interplane struts, supporting an

Le Rhône 9C The Le Rhône 9C is a nine-cylinder rotary aircraft engine produced in France by '' Société des Moteurs Le Rhône'' / Gnome et Rhône. Also known as the Le Rhône 80 hp in a reference to its nominal power rating, the engine was ...

nine-cylinder

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 i ...

about halfway between the wings. Each wing-mounted engine was in a long, tapered

cowling A cowling 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 are a cove ...

, open at the rear. There was a third cowled Le Rhône in the nose. The airliner could fly on only two engines when carrying six passengers. Behind the engine the

was flat-sided, with a wide, open

cockpit A cockpit or flight deck is the area, usually near the front of an aircraft or spacecraft, from which a Pilot in command, pilot controls the aircraft. The cockpit of an aircraft contains flight instruments on an instrument panel, and the ...

with its windscreen immediately under the upper

. With a useful load of the C.37 was capable of carrying six passengers, though it is not certain if windows or seats were fitted. Behind the wings the fuselage tapered gently to a broad, triangular

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 ...

which carried a vertical-edged

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 ...

that reached down to the keel. The

tailplane A tailplane, also known as a horizontal stabiliser, is a small 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 and gyroplane ...

was mounted on top of the fuselage so its

elevator An elevator or lift is a wire rope, cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or deck (building), decks of a building, watercraft, ...

s had a notch for rudder movement. The C.37 had a fixed tailskid undercarriage. There were pairs of main wheels mounted on single axles attached at their centre to a longitudinal bar held under the engine at each end on short, forward-raked V-struts. To prevent nose-overs, there was a fifth wheel mounted under the nose.

Specifications

References

{{Caudron aircraft C.037 1920s French airliners Biplanes Trimotors