Primary
gliders are a category of
aircraft
An aircraft ( aircraft) is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or the Lift (force), dynamic lift of an airfoil, or, i ...
that enjoyed worldwide popularity during the 1920s and 1930s as people strove for simple and inexpensive ways to learn to fly.
[Schweizer, Paul A: ''Wings Like Eagles, The Story of Soaring in the United States'', pages 14-22. Smithsonian Institution Press, 1988. ]
Constructed of
wood
Wood is a structural tissue/material found as xylem in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulosic fibers that are strong in tension and embedded in a matrix of lignin t ...
,
metal
A metal () is a material that, when polished or fractured, shows a lustrous appearance, and conducts electrical resistivity and conductivity, electricity and thermal conductivity, heat relatively well. These properties are all associated wit ...
cables and
cloth
Textile is an umbrella term that includes various fiber-based materials, including fibers, yarns, filaments, threads, and different types of fabric. At first, the word "textiles" only referred to woven fabrics. However, weaving is n ...
, primary gliders were very light and easy to fly. They generally had no
cockpit
A cockpit or flight deck is the area, on the front part of an aircraft, spacecraft, or submersible, from which a pilot controls the vehicle.
The cockpit of an aircraft contains flight instruments on an instrument panel, and the controls th ...
and no instruments.
Operations
Primary gliders were generally launched by
bungee cord
file:Bungee Cord PICT6882a.jpg, Bungee cords equipped with metal hooks
A bungee cord (sometimes spelled bungie; also known as a shock cord or an ocky strap) is an elastomer, elastic cord composed of one or more elastic strands forming a core, usua ...
, whereby a rubber rope was arranged in a "V" with the glider at the apex. The ends of the rope were pulled by hand to launch the glider from a slope. Primaries were also launched by
auto-tow and auto-bungee tow. Ramp launching from cliffs was also attempted successfully.
Modern primaries
Modern versions of primary gliders are still built, but, while they are much like the originals in appearance, they are usually constructed with
composites and safety enhancements.
Types
Examples include:
References
*
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