The Dewoitine 14 was a mid-1920s

French French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with Franc ...

civil transport, capable of carrying mixture of passengers and freight. The sole example was used in commercial trials.

Design and development

Dewoitine aircraft, gliders and ultralights apart, had generally been metal-framed but the all-wood D.14 was an exception. Designed as a civil transport, it could carry up to six passengers or a mixture of passengers and freight. It was a

high wing A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

monoplane with a two part, straight-edged, unswept wing 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 ( ...

out to angled tips. Each half-wing was built around two

spars The United States Coast Guard (USCG) Women's Reserve, also known as the SPARS (SPARS was the acronym for "Semper Paratus—Always Ready"), was the women's branch of the United States Coast Guard Reserve. It was established by the United States ...

and was fabric covered. On each side a pair of faired struts braced the spars to the lower

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 ...

longerons 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 ...

. Its overhung ailerons were aerodynamically balanced. The D.14 was powered by a

Lorraine 12E Courlis The Lorraine 12E Courlis was a W-12 (broad arrow) aero engine produced by the French company Lorraine-Dietrich during the 1920s and 1930s. Variants ;12E: ;12Eb: ;12Ebr: ;12Ed: ;12Edr: ;12Ee: ;12Ew:The standard Eb fitted with a supplementary s ...

W12 engine A W12 engine is a twelve-cylinder piston engine where three banks of four cylinders are arranged in a W configuration around a common crankshaft. W12 engines with three banks of four cylinders were used by several aircraft engines from 1917 unti ...

, water-cooled with a pair of Lamblin

radiator Radiators are heat exchangers used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are constructed to function in cars, buildings, and electronics. A radiator is always a ...

s. Part of the fuel was in wing tanks and part in the fuselage. The engine was enclosed under a closely fitted cowling which followed the three banks of cylinders. Behind the engine the fuselage had a rectangular cross-section defined by four longerons. The pilot's 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 ...

, offset to port, was in the wing

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, ...

. The central, windowed part of the fuselage contained passengers and freight and was divided into three compartments. The forward one, under the wing, could either be given over to freight or contain two passenger seats. A central compartment provided four seats and the rearmost contained a toilet and had separate entry doors to the cabin and a baggage hold. 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 conventional with a swept, straight-edged

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 ...

mounted on top of the fuselage and a 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 ...

. Both

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 ...

and

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, ...

were balanced, the latter with overhung tips like those of the ailerons. The D.14 had conventional, fixed

landing gear Landing gear is the undercarriage of an aircraft or spacecraft that is used for takeoff or landing. For aircraft it is generally needed for both. It was also formerly called ''alighting gear'' by some manufacturers, such as the Glenn L. Martin ...

. A pair of V-struts, splayed slightly outwards, were attached to the lower fuselage longerons and supported a rigid axle, with the mainwheels apart. The forward components of the V-struts were telescopic, with shock absorbers and coil springs inside their streamlined fairings.

Operational history

The D.14 first appeared in public, still unflown, at the Paris Aero Salon held in December 1924. In January it was at Villacoublay, with trials scheduled to begin in the week starting 20 January. It had flown by 4 February 1925. In December 1925 the D.14 was about to start commercial trials with CIDNA, fitted with a Farman 12We W-12 engine. The following May it was tested at Toussus-le-Noble, its performance reported as "much improved" because the geared-down Farman engine had allowed a larger diameter propeller to be fitted. In August 1926 it was at Villacoublay, still with this engine, now reported as delivering .

Specifications

References

{{Dewoitine aircraft 1920s French airliners D.14 High-wing aircraft Single-engined tractor aircraft Aircraft first flown in 1925