The Avia 50-MP was a French

motor glider A motor glider is a fixed-wing aircraft that can be flown with or without engine power. The FAI Gliding Commission Sporting Code definition is: a fixed-wing aerodyne equipped with a means of propulsion (MoP), capable of sustained soaring flight ...

based on that of the Avia XV-A training

glider Glider may refer to: Aircraft and transport Aircraft * Glider (aircraft), heavier-than-air aircraft primarily intended for unpowered flight ** Glider (sailplane), a rigid-winged glider aircraft with an undercarriage, used in the sport of glidin ...

. First flown in 1934, it was intended to introduce pilots to motor-gliders.

Design and development

In 1933

Avia Avia Motors s.r.o. is a Czech automotive manufacturer. It was founded in 1919 as an aircraft maker, and diversified into trucks after 1945. As an aircraft maker it was notable for producing biplane fighter aircraft, especially the B-534. Avia ...

introduced two designs based on their earlier training gliders but fitted with low powered engines, placing them amongst the first

s. The Avia 50-MP (MP for moteur planeur or motor glider) was the more basic of the two and was a development of the Avia XV-A. The Avia 50-MP was a

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 ...

with a two piece

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 ...

of rectangular plan, with blunted tips and about 4.5° of sweep. Broad chord

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 filled about half the span. The roots were attached to a streamlined,

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 ...

mounted pillar, and each wing was braced from about half span to the lower fuselage with a pair of parallel

strut A strut is a structural component commonly found in engineering, aeronautics, architecture and anatomy. Struts generally work by resisting longitudinal compression, but they may also serve in tension. Human anatomy Part of the functionality o ...

s. The pillar also mounted the

pusher configuration In an aircraft with a pusher configuration (as opposed to a tractor configuration), the propeller(s) are mounted behind their respective engine(s). Since a pusher propeller is mounted behind the engine, the drive shaft is in compression in nor ...

Poinsard The Poinsard 25 hp or Mengin Type B is a small, two-cylinder, air-cooled, horizontally opposed aircraft engine built in France. it was manufactured by Établissements Pierre Mengin from a design by René Poinsard. Power was around 19 k ...

flat twin 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 ...

engine, its cylinders exposed for air-cooling and driving a two bladed

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 ...

just behind the wing

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. ...

. The pilot's single, 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 immediately in front of the wing-mounting pillar in an oval section forward fuselage similar to those of the motorless gliders. The position of the propeller disc just behind the wing required the rear fuselage to be rather shallow, so it was formed by four longerons with

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 ...

covering, resulting in a rectangular section. The empennage was conventional, with a triangular

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 ...

sitting on a low, raised step with a curved leading edge and carrying straight tapered, square tipped, unbalanced

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. The rear of the step mounted the rudder hinge bearing a tall, straight tapered and flat topped

balanced rudder Balanced rudders are used by both ships and aircraft. Both may indicate a portion of the rudder surface ahead of the hinge, placed to lower the control loads needed to turn the rudder. For aircraft the method can also be applied to elevators and ...

. The rudder extended to a rounded heel at the keel via cut-aways in the inner edges of the elevators. The Avia 50-MP landed on an under-fuselage skid fitted with two retractable wheels to facilitate ground handling. The earliest design had always included the possibility of an alternative wheeled

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 ...

and by June 1934, just a month after the first tests, it had been fitted. Each of the normal size wheels were mounted on a V-strut from mid-fuselage, with an axle to the central fuselage underside. The tail was protected by a small bumper. The first flight was piloted by Eric Nessler and took place on 17 May 1934. There are references to its activities in the French glider scene at least until 1938, when it was being used by the L'Air group.

Specifications

Notes

References

{{Ateliers vosgiens d'industrie aéronautique (Avia) aircraft Motor gliders 1930s French sailplanes Ateliers vosgiens d'industrie aéronautique (Avia) aircraft Aircraft first flown in 1934