The Letov Š-3 was a single-seat, single-engine

parasol 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 ...

fighter aircraft Fighter aircraft are fixed-wing military aircraft designed primarily for air-to-air combat. In military conflict, the role of fighter aircraft is to establish air superiority of the battlespace. Domination of the airspace above a battlefield ...

designed and built in

Czechoslovakia , rue, Чеськословеньско, , yi, טשעכאסלאוואקיי, , common_name = Czechoslovakia , life_span = 1918–19391945–1992 , p1 = Austria-Hungary , image_p1 ...

in the early 1920s. Only one was completed and flown, its makers preferring to develop a

biplane A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While ...

fighter.

Design and development

The Letov Š-3, originally known as the Letov Š.B1, was the first original fighter design from Letov, the start of a line designed by Alois Šmolik. It had a wooden

and a metal-framed

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 ...

and

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 ...

, and was powered by a six-cylinder water-cooled in-line

BMW IIIa BMW IIIa was an inline six-cylinder SOHC valvetrain, water-cooled aircraft engine, the first-ever engine produced by Bayerische Flugzeugwerke AG, who, at the time, were exclusively an aircraft engine manufacturer. Its success laid the foundatio ...

engine. The wing was only slightly tapered, being almost rectangular and with a cutout in 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. ...

over the

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 ...

to improve the pilot's field of view. Short-span

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 were mounted far outboard. On each side there were two pairs 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 bracing the wing to the fuselage; both pairs were mounted on the lower fuselage but one pair met the wing at about 60% span, the other at 30%. Each outer strut had a

jury strut In aeronautics, bracing comprises additional structural members which stiffen the functional airframe to give it rigidity and strength under load. Bracing may be applied both internally and externally, and may take the form of strut, which act in c ...

at right angles which met the top of its inboard equivalent at the wing. The Š-3's upright inline engine was completely enclosed within a

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 ...

, with its top just below the pilot's eye line. It drove a two-blade

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 ...

with a domed

spinner Technology *Spinner (aeronautics), the aerodynamic cone at the hub of an aircraft propeller * Spinner (cell culture), laboratory equipment for cultivating plant or mammalian cells * Spinner (computing), a graphical widget in a GUI * Spinner (MIT Med ...

. The BMW was cooled with Lamblin cylindrical

radiators 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 ...

placed between the undercarriage legs, though a diagram shows it with narrow, fuselage-hugging (cheek) radiators. The oval cross-section fuselage tapered rearwards behind the cockpit to a straight tapered

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 divided

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 with a cutout for

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 ...

movement; the latter was mounted on a circular-edged

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 had its bottom cropped for elevator clearance. The Š-3 had a fixed, single-axle

conventional undercarriage Conventional landing gear, or tailwheel-type landing gear, is an aircraft undercarriage consisting of two main wheels forward of the center of gravity and a small wheel or skid to support the tail.Crane, Dale: ''Dictionary of Aeronautical Term ...

, with mainwheels on cross-braced V-struts. The first prototype was destroyed late in 1921 by a factory fire before its first flight, but the second flew early the next year. It took part in the International Meeting at Zurich in 1922 with modest success but the Military Aircraft Works decided to concentrate its efforts on the

Letov Š-4 The Letov Š-4 was a Czechoslovak single-bay, unstaggered biplane fighter and trainer in the 1920s. Production history The Š-4 was first created in 1922 as an intended successor to the Société Pour L'Aviation et ses Dérivés, SPAD SPAD S.VII, ...

, and development of the Š-3 ended.

Specifications

References

{{DEFAULTSORT:Letov S-3 Parasol-wing aircraft 1920s Czechoslovakian fighter aircraft Single-engined tractor aircraft Š-3