The Letov ST-4 Aztek ( en,

Aztec The Aztecs () were a Mesoamerican culture that flourished in central Mexico in the post-classic period from 1300 to 1521. The Aztec people included different ethnic groups of central Mexico, particularly those groups who spoke the Nahuatl ...

) is a

Czech Czech may refer to: * Anything from or related to the Czech Republic, a country in Europe ** Czech language ** Czechs, the people of the area ** Czech culture ** Czech cuisine * One of three mythical brothers, Lech, Czech, and Rus' Places * Czech, ...

microlight aircraft Ultralight aviation (called microlight aviation in some countries) is the flying of lightweight, 1- or 2-seat fixed-wing aircraft. Some countries differentiate between weight-shift control and Aircraft flight control system, conventional three-a ...

that was designed and produced by

Letov Kbely Letov is an aircraft company located in Letňany, Prague, Czech Republic. It is the oldest aircraft company in the region. History Letov was founded in 1918 by the Czechoslovak Ministry of Defense to repair World War I trophy planes. The first i ...

of Prague - Letňany, in the 1990s. When it was available, the aircraft was supplied as a complete ready-to-fly aircraft, or as a kit for amateur construction.Purdy, Don: ''AeroCrafter - Homebuilt Aircraft Sourcebook, Fifth Edition'', page 195. BAI Communications, 15 July 1998. In January 2014, the ST-4 was no longer listed as a product of the company.

Design and development

The aircraft was designed to comply with the Fédération Aéronautique Internationale

microlight Ultralight aviation (called microlight aviation in some countries) is the flying of lightweight, 1- or 2-seat fixed-wing aircraft. Some countries differentiate between weight-shift control and conventional three-axis control aircraft with aile ...

category, including the category's maximum gross weight of . The ST-4 Aztek features a strut-braced

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 co ...

, a two-seats-in-

side-by-side configuration Tandem, or in tandem, is an arrangement in which a team of machines, animals or people are lined up one behind another, all facing in the same direction. The original use of the term in English was in ''tandem harness'', which is used for two ...

enclosed cockpit, fixed

tricycle landing gear Tricycle gear is a type of aircraft undercarriage, or ''landing gear'', arranged in a tricycle fashion. The tricycle arrangement has a single nose wheel in the front, and two or more main wheels slightly aft of the center of gravity. Tricycle g ...

with

wheel pants An aircraft fairing is a structure whose primary function is to produce a smooth outline and reduce drag.Crane, Dale: ''Dictionary of Aeronautical Terms, Third Edition'', page 206. Aviation Supplies & Academics Inc, Newcastle Washington, 1997. ...

, a small tailskid and a single engine in

tractor configuration In aviation, the term tractor configuration refers to an aircraft constructed in the standard configuration with its engine mounted with the propeller in front of it so that the aircraft is "pulled" through the air. Oppositely, the pusher co ...

. The aircraft is made from

aluminum Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It ha ...

tubing with fairings made from

fibreglass Fiberglass (American English) or fibreglass (Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass clo ...

and its flying surfaces are covered in

Dacron Polyethylene terephthalate (or poly(ethylene terephthalate), PET, PETE, or the obsolete PETP or PET-P), is the most common thermoplastic polymer resin of the polyester family and is used in fibres for clothing, containers for liquids and foo ...

sailcloth. Its span wing mounts flaps and has a wing area of . The wings are supported by V-struts with

jury struts 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 ...

and the

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 e ...

is cable-braced. The acceptable power range is and the standard engine used is the

Rotax 503 The Rotax 503 is a , inline 2-cylinder, two-stroke aircraft engine, built by BRP-Rotax GmbH & Co. KG of Austria for use in ultralight aircraft.Raisner, William: ''LEAF catlog'', pages 6-105. Leading Edge Airfoils, 1995. As of 2011 the Rot ...

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 (up and down movements) of the piston during one power cycle, this power cycle being completed in one revolution of ...

powerplant. The engine is mounted high above the cockpit on the front end of the aluminum tube that acts as the tailboom. The ST-4 Aztek has a typical empty weight of and a gross weight of , giving a useful load of . With full fuel of the payload for pilot, passenger and baggage is . The manufacturer estimated the construction time from the supplied kit as 80 hours.

Operational history

By 1998 the company reported that 26 kits had been sold, and that 15 aircraft were completed and flying.

Specifications (ST-4 Aztek)

References

External links

{{Letov aircraft ST-4 Aztek 1990s Czech and Czechoslovakian sport aircraft 1990s Czech and Czechoslovakian ultralight aircraft 1990s Czech and Czechoslovakian civil utility aircraft Single-engined tractor aircraft High-wing aircraft Homebuilt aircraft