The Dupuy D-40 was a French built, low powered

monoplane 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 ...

designed for touring abroad. The only example was used for an uncompleted journey to

Saigon , population_density_km2 = 4,292 , population_density_metro_km2 = 697.2 , population_demonym = Saigonese , blank_name = GRP (Nominal) , blank_info = 2019 , blank1_name = – Total , blank1_ ...

Design and development

The D-40 was designed and built by Roger Dupuy, with the assistance of the Provençal Aero Club, to be a robust aircraft fit for flights over large bodies of water and unfamiliar lands. It had a mostly wooden structure and was

plywood Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured ...

covered. It was a monoplane with a thick section, three part wing. Its inner section was rectangular in plan, only occupying 20% of the span and without dihedral. The outer sections were

trapezoidal A quadrilateral with at least one pair of parallel sides is called a trapezoid () in American and Canadian English. In British and other forms of English, it is called a trapezium (). A trapezoid is necessarily a convex quadrilateral in Eucli ...

out to briefly blunted tips and initially had 11.24° of dihedral. There were plans for further optimization of the dihedral angle during flight testing, though it is not known if it was changed.

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 Flight dynamics, roll (or ...

occupied about 35% of the

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. ...

s. There were six span-wise members on both the tops and bottoms of the wings, the forward pair forming the rear of a ply covered

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, ...

box

spar SPAR, originally DESPAR, styled as DE SPAR, is a Dutch multinational that provides branding, supplies and support services for independently owned and operated food retail stores. It was founded in the Netherlands in 1932, by Adriaan van Well, ...

and the third and fourth pairs defining a second box spar around mid-wing. A layer of fabric, easily doped and smoothed was stretched over the ply skin, a technique widely used at the time. Each wing was braced 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 ...

longeron 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 ...

s by V-struts rooted on the two wing spars at about 30% span. The fuselage of the D-40 was built around four

s and divided into eight sections; the forward section was aluminium framed and covered as it housed the small diameter, nine cylinder

Salmson 9AD Between 1920 and 1951 the Société des Moteurs Salmson in France developed and built a series of widely used air-cooled aircraft engines.Gunston 1986, p. 158. Design and development After their successful water-cooled radial engines, developed ...

radial engine The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is ca ...

. In photographs the engine was uncowled though early plans show a

Townend ring A Townend ring is a narrow- chord cowling ring fitted around the cylinders of an aircraft radial engine to reduce drag and improve cooling. Development The Townend ring was the invention of Dr. Hubert Townend of the British National Physica ...

-type

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 ...

; it was mounted as high as possible to provide

propeller A propeller (colloquially 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 ...

clearance on rough landing sites. Behind it the underside fell away rapidly to maximum depth at the wing; overall it was deep, flat sided and bottomed, with rounded decking. The longerons were

ash Ash or ashes are the solid remnants of fires. Specifically, ''ash'' refers to all non-aqueous, non- gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash ...

in the more highly stressed forward and tail sections, with

spruce A spruce is a tree of the genus ''Picea'' (), a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal (taiga) regions of the Earth. ''Picea'' is the sole genus in the subfami ...

elsewhere. Its single seat, 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 ...

was over the wing trailing edge, with a small windscreen and long, faired headrest. The D-40 had 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 ...

and trapezoidal

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 ...

, the latter hinged forward of the one-piece, blunt tipped, rectangular

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 ...

and with the rectangular

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, ...

hinged behind its trailing edge. Its fixed

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 ...

had its main wheels mounted without axles, with a track of . On each side a V-strut, with the hub at its vertex, was hinged at about 45° to the vertical from the lower fuselage longerons. A vertical bungee strut acted as a

shock absorber A shock absorber or damper is a mechanical or hydraulic device designed to absorb and damp shock impulses. It does this by converting the kinetic energy of the shock into another form of energy (typically heat) which is then dissipated. Most sh ...

, placing the wheel below the joint between centre and outer wing panels. Its tailskid was of the steel

leaf spring A leaf spring is a simple form of spring commonly used for the suspension in wheeled vehicles. Originally called a ''laminated'' or ''carriage spring'', and sometimes referred to as a semi-elliptical spring, elliptical spring, or cart spring, it ...

type.

Operational history

The exact date of the Dupuy D-40's first flight is not known but it was before the first week in January 1933. It received its ''certificat de navagbilité'' around the beginning of August 1933 after several modifications, particularly to the cockpit, had been made. Homologation trials, flown by Joseph Chartoire, were complete by early December. A year before, René Lefèvre had flown from

Paris Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. S ...

to Saigon, departing on 18 December 1932 and taking only 10 days, 7 hours and 50 minutes in a Peyret-Mauboussin PM XI aircraft with a low power Salmson engine similar to that of the D-40. Chartoire had planned a repeat of that flight on its anniversary, though he left Paris on 14 January and, after travelling largely over French colonies or territories, arrived in

Gabès Gabès (, ; ar, قابس, ), also spelled Cabès, Cabes, Kabes, Gabbs and Gaps, is the capital city of the Gabès Governorate in Tunisia. It is located on the coast of the Gulf of Gabès. With a population of 152,921, Gabès is the 6th largest ...

where he damaged his hand in the propeller. He stayed at

Damascus )), is an adjective which means "spacious". , motto = , image_flag = Flag of Damascus.svg , image_seal = Emblem of Damascus.svg , seal_type = Seal , map_caption = , ...

from 19 to 29 January to recover, then flew to

Beirut Beirut, french: Beyrouth is the capital and largest city of Lebanon. , Greater Beirut has a population of 2.5 million, which makes it the third-largest city in the Levant region. The city is situated on a peninsula at the midpoint o ...

. For uncertain reasons, he abandoned his flight and the D-40 to continue his travels but when he returned to Beirut the D-40 had been destroyed there. Only one D-40 was completed though Dupuy had hopes of marketing the aircraft. The cost, with a Salmson engine, was FF40,000; a lowered powered

Anzani Anzani was an engine manufacturer founded by the Italian Alessandro Anzani (1877–1956), which produced proprietary engines for aircraft, cars, boats, and motorcycles in factories in Britain, France and Italy. Overview From his native Italy, An ...

was offered as an alternative at FF28,000.

Specifications (Salmson engine)

References

{{reflist, refs= {{cite journal, date=5 January 1933 , title=De Paris à Saigon ... , journal=Les Ailes, issue=603 , pages=9, url=http://gallica.bnf.fr/ark:/12148/bpt6k6556830j/f13 {{cite journal, date=5 January 1933 , title=Le monoplace de tourisme Dupuy D-40 à moteur Salmson 40 CV , journal=Les Ailes, issue=603 , pages=1, url=http://gallica.bnf.fr/ark:/12148/bpt6k6556830j/f5 {{cite journal, date=5 January 1933 , first=Roger, last=Dupuy, title=Le monoplace de sport Dupuy D-40, journal=Les Ailes, issue=603 , pages=3–4, url=http://gallica.bnf.fr/ark:/12148/bpt6k6556830j/f7 {{cite journal, date=10 August 1933 , title=Notules Techniques, journal=Les Ailes, issue=634 , pages=4, url=http://gallica.bnf.fr/ark:/12148/bpt6k65568613/f4 {{cite journal, date=14 December 1933 , title=Notules Techniques, journal=Les Ailes, issue=652 , pages=3, url=http://gallica.bnf.fr/ark:/12148/bpt6k6556879s/f3 {{cite journal, date=1 March 1934, title=Voyages - Joseph Chartoire, journal=Les Ailes, issue=663 , pages=15, url=http://gallica.bnf.fr/ark:/12148/bpt6k65760288/f15 1930s French sport aircraft Aircraft first flown in 1932