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

fighter aircraft Fighter aircraft (early on also ''pursuit aircraft'') are military aircraft designed primarily for air-to-air combat. In military conflict, the role of fighter aircraft is to establish air supremacy, air superiority of the battlespace. Domina ...

designed and built in

Czechoslovakia Czechoslovakia ( ; Czech language, Czech and , ''Česko-Slovensko'') was a landlocked country in Central Europe, created in 1918, when it declared its independence from Austria-Hungary. In 1938, after the Munich Agreement, the Sudetenland beca ...

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 parasol wing and a metal-framed

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 ...

and empennage, and was powered by a six-cylinder water-cooled in-line BMW IIIa 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 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 aroun ...

s were mounted far outboard. On each side there were two pairs of parallel struts 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 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, with its top just below the pilot's eye line. It drove a two-blade

propeller A propeller (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 a working flu ...

with a domed spinner. The BMW was cooled with Lamblin cylindrical radiators 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 stabilizer, is a small lift (force), 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 divided elevators with a cutout for

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 ...

movement; the latter was mounted on a circular-edged fin and had its bottom cropped for elevator clearance. The Š-3 had a fixed, single-axle conventional undercarriage, 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, and development of the Š-3 ended.

Specifications

References

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