The Peyret-Mauboussin PM X, PM 4 or Mauboussin M.10 was a low power, single-seat,

high wing A monoplane is a fixed-wing aircraft A fixed-wing aircraft is a heavier-than-air aircraft, such as an airplane, which is capable of flight using aerodynamic lift. Fixed-wing aircraft are distinct from rotary-wing aircraft (in which a r ...

cantilever A cantilever is a rigid structural element that extends horizontally and is unsupported at one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a cantilev ...

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 wings. A monoplane has inherently the highest efficiency and lowest drag of any wing con ...

. Only one was built but it set several records in the under class both as a landplane and a

floatplane A floatplane is a type of seaplane with one or more slender floats mounted under the fuselage to provide buoyancy. By contrast, a flying boat uses its fuselage for buoyancy. Either type of seaplane may also have landing gear suitable for land, ...

Design and development

The Peyret-Mauboussin PM X was the first of three designs to come from the firm formed by Pierre Mauboussin and Louis Peyret in 1928. It was designed to be as simple, inexpensive and cheap to run as possible to encourage more people to fly and was originally intended to compete at the September 1928

Orly Orly () is a commune in the southern suburbs of Paris, Île-de-France. It is located from the center of Paris. The name of Orly came from Latin ''Aureliacum'', "the villa of Aurelius". Orly Airport partially lies on the territory of the c ...

International Lightplane Competition (''Concourse d'avions légere'') but was not completed in time. It had a one-piece wing, straight-tapered in plan out to elliptical tips and mounted on top of 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 ...

. It also tapered outwards in thickness, with a horizontal lower surface, and had reflexed camber or double curvature. Its

aspect ratio The aspect ratio of a geometry, geometric shape is the ratio of its sizes in different dimensions. For example, the aspect ratio of a rectangle is the ratio of its longer side to its shorter side—the ratio of width to height, when the rectangl ...

of 10 was high for the period. Structurally, the all-wooden wing was built around two box spars,

ribs The rib cage or thoracic cage is an endoskeletal enclosure in the thorax of most vertebrates that comprises the ribs, vertebral column and sternum, which protect the vital organs of the thoracic cavity, such as the heart, lungs and great vessels ...

and three-ply skin. There were narrow- chord, full-span

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 roll (or movement around ...

, each divided into two parts, the outer section conventional and the inner serving as a camber-changing flap. The PM X was powered by a

ABC Scorpion II The ABC Scorpion is a 30 hp (22 kW) two-cylinder aero engine designed by British engineer Granville Bradshaw for use in light aircraft. The engine was built by ABC Motors Limited and first ran in 1921.Gunston 1989, p.9. Variants ; ...

flat-twin engine A flat-twin engine is a two-cylinder internal combustion engine with the cylinders on opposite sides of the crankshaft. The most common type of flat-twin engine is the boxer-twin engine, where both pistons move inwards and outwards at the same ti ...

, mounted in the nose with its

cylinder head In a piston engine, the cylinder head sits above the cylinders, forming the roof of the combustion chamber. In sidevalve engines the head is a simple plate of metal containing the spark plugs and possibly heat dissipation fins. In more modern ...

s exposed for cooling. Its fuel tanks were in the wing. The fuselage was a strikingly short, flat-sided, rectangular section structure, formed by four

spruce A spruce is a tree of the genus ''Picea'' ( ), a genus of about 40 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal ecosystem, boreal (taiga) regions of the Northern hemisphere. ''Picea'' ...

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 double ply covered, with the pilot's enclosed cabin under the wing

leading edge The leading edge is the part of the wing that first contacts the air;Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 305. Aviation Supplies & Academics, 1997. alternatively it is the foremost edge of an airfoil sectio ...

; the PM X's tapered nose gave him a good forward view. Behind him there was a luggage space, capable of accommodating a passenger seat. Access to the cabin was via a port-side door. Behind the cabin the fuselage tapered markedly to a vertical tail, the shape of which became a Mauboussin trademark. It was tall, strongly straight-tapered to a rounded tip and carried a deep unbalanced rudder. The horizontal tail was also strongly straight-tapered, with an unbalanced one-piece elevator and mounted on the fuselage underside, clear of the bottom of the rudder. Its

landing gear Landing gear is the undercarriage of an aircraft or spacecraft that is used for taxiing, takeoff or landing. For aircraft, it is generally needed for all three of these. It was also formerly called ''alighting gear'' by some manufacturers, s ...

was fixed and conventional, with mainwheels on split, cranked axles mounted on a central inverted strut-pyramid from the lower fuselage

s. There were rearward drag struts to the longerons as well as rubber cord shock absorbing struts. The undercarriage track was . The PM X had a short, castering tailskid.

Operational history

The PM X was first flown on 7 December 1928, piloted by Charles Fauvel. In September 1929, flying from

le Bourget Le Bourget () is a commune in the northeastern suburbs of Paris, France. It is located from the center of Paris. The commune features Le Bourget Airport, which in turn hosts the Musée de l'Air et de l'Espace (Air and Space Museum). A very ...

, he began to set a series of world records for light aircraft in the under empty weight 4th category. On 4 September he covered at and the following day reached an altitude of . On the 6 September he covered on a closed circuit and on the 10th flew a straight line record of . A year later he extended the circuit record to and added a duration record of 12 h 3 m. The M.10 was then modified into a

seaplane A seaplane is a powered fixed-wing aircraft capable of takeoff, taking off and water landing, landing (alighting) on water.Gunston, "The Cambridge Aerospace Dictionary", 2009. Seaplanes are usually divided into two categories based on their tech ...

(''Hydravion'' in French), equipped with a pair of floats. Renamed the H.10, it first flew on 23 November 1930 and set more records in its new class. It was withdrawn from use after an accident on 24 October 1932.

Variants

;M.10: Original PM X, as described. ;M.10bis:Alternative designation for the H.10 floatplane ;H.10: M.10 converted to

Specifications (M.10, landplane)

Notes

References

{{Mauboussin aircraft Peyret aircraft Mauboussin aircraft 1920s French sport aircraft High-wing aircraft Single-engined tractor aircraft Aircraft first flown in 1928