The MIP Smyk, MIP from the initials of its Polish designers with Smyk meaning Brat or Kid, was an aerodynamically refined motor glider designed and built at Warsaw Technical University from 1935.

Design and development

The Smyk was designed by three students of the Warsaw Technical University, Ludwig Moczarski, Jan Idźkowski and Jerzy Ploszajski, as a diploma project. Their objective was a low-power motor glider with the lowest possible drag. The result was a wooden,

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

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 ...

with a retractable undercarriage, powered by a Scott Flying Squirrel AS-2 inverted, air-cooled, twin-cylinder,

two-stroke A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes of the piston, one up and one down, in one revolution of the crankshaft in contrast to a four-stroke engine which re ...

engine. Its one piece, tapered wing, which had an

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 7.7, contained a

plywood Plywood is a composite material manufactured from thin layers, or "plies", of wood veneer that have been stacked and glued together. It is an engineered wood from the family of manufactured boards, which include plywood, medium-density fibreboa ...

covered

torsion box A torsion box consists of two thin layers of material (skins) on either side of a lightweight core, usually a grid of beams. It is designed to resist torsion under an applied load. A hollow core door is probably the most common example of a torsio ...

from the main spar around the

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 ...

. Behind the torsion box the wing was fabric covered. An auxiliary rear spar carried long span, tapered

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 ...

. The wing's deepened, wholly ply-covered centre-section blended wing roots into the upper fuselage. The Smyk's cockpit was immediately ahead of the wing main spar within a reinforced cut-out in the torsion box, its rear-hinged transparency closely following the wing profile. The Squirrel engine was conventionally cowled in the nose, with a fuel tank in the centre of the wing behind the main spar. The central part of the fuselage was an oval section,

-covered, semi-

monocoque Monocoque ( ), also called structural skin, is a structural system in which loads are supported by an object's external skin, in a manner similar to an egg shell. The word ''monocoque'' is a French term for "single shell". First used for boats, ...

structure but the rear fuselage was aluminum-covered for easy inspection of the rear control surface cabling. Its

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. F ...

was a ply-covered integral part of the fuselage and carried a fabric covered

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, airship, or other vehicle that moves through a fluid medium (usually air or water). On an airplane, the rudder is used primarily to counter adverse yaw ...

; the tapered, blunt-tipped, cantilever horizontal tail with inset

elevators An elevator (American English) or lift (English in the Commonwealth of Nations, Commonwealth English) is a machine that vertically transports people or freight between levels. They are typically powered by electric motors that drive tracti ...

was mounted at mid-fuselage. The Smyk's unusual retractable undercarriage had two independent short, vertical legs, with compressed rubber shock absorbers and large, low-pressure tyres. Each leg top was rigidly mounted on a V-strut hinged at slight angles to both the longitudinal and vertical axes of the fuselage on a bulkhead-mounted internal frame. When the legs were lifted with a chain system the hinge geometry, combined with a folding stiffening strut, placed the wheels within the fuselage and parallel to its sides. There were two pairs of undercarriage doors, the rear one only open whilst the legs were in motion. The tailskid was a fixed, laminated spring. The Smyk's first flight was on 1 October 1937, piloted by Aleksander Onoskyo, and testing continued through 1938-9. The Squirrel engine was heavier than specified but nonetheless the aircraft handled well and had a maximum speed of . A differential

elevator An elevator (American English) or lift (Commonwealth English) is a machine that vertically transports people or freight between levels. They are typically powered by electric motors that drive traction cables and counterweight systems suc ...

linkage produced precise control input and the usual range of aerobatic manoeuvres, apart from the roll, was available. Some minor modifications were made as a result of these development flights, perhaps the most effective being a high quality repaint, which raised the maximum speed by . Since the expensive and heavy retractable undercarriage only increased the maximum speed by , it was decided that a second, two-seat Smyk, with a span reduction and powered by a Saroléa Albatros

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 ...

, should have a fixed undercarriage. Its partially complete airframe was destroyed during the

German invasion of Poland The invasion of Poland, also known as the September Campaign, Polish Campaign, and Polish Defensive War of 1939 (1 September – 6 October 1939), was a joint attack on the Second Polish Republic, Republic of Poland by Nazi Germany, the Slovak R ...

in 1939.

Specifications

Note

References

{{reflist, refs= {{cite journal , date=11 February 1943 , title=The M.I.P. Smyk, journal=

Flight Flight or flying is the motion (physics), motion of an Physical object, object through an atmosphere, or through the vacuum of Outer space, space, without contacting any planetary surface. This can be achieved by generating aerodynamic lift ass ...

, volume=XLIII , issue=1731 , pages=152–4 , url= https://www.flightglobal.com/pdfarchive/view/1943/1943%20-%200380.html {{cite book, title=Polish Aircraft 1893-1939, last=Cynk, first=Jerzy, year=1971, publisher=Putnam Publishing, location=London, isbn=0-370-00085-4, pag
646-8
url-access=registration, url=https://archive.org/details/polishaircraft1800cynk/page/646 {{cite book , title= British Piston Aero-engines and their Aircraft, last=Lumsden, first=Alec, year=1994, publisher=Airlife , location=Shrewsbury , isbn=1-85310294-6 , page=226 Motor gliders 1930s Polish sport aircraft Aircraft first flown in 1937 Shoulder-wing aircraft Single-engined tractor aircraft Aircraft with retractable conventional landing gear Single-engined piston aircraft