biplane

Biplane combines the Latin prefix bi- (two) with the French word plan (flat surface, plane), from Latin planus (flat, level). The word was first used in French aeronautical circles in the 1870s and 1880s to describe a flying machine with two parallel wings, one above the other. Octave Chanute, a French-born American engineer, used the term in his 1894 book Progress in Flying Machines. The Wright brothers' 1903 Flyer was a biplane.

The biplane design was not arbitrary. Two shorter wings braced together with struts and wires were structurally stronger than one long wing, given the materials available in 1903 — wood, fabric, and wire. The biplane could be lighter and more rigid than a monoplane of equal wingspan. This engineering advantage dominated aviation from 1903 through World War I, when biplanes like the Sopwith Camel and Fokker Dr.I fought over the Western Front.

The word biplane became synonymous with early aviation itself. Between the wars, barnstormers flew biplanes across rural America, performing aerobatics and selling rides. The de Havilland Tiger Moth, a biplane trainer, taught a generation of World War II pilots to fly. But metal construction and stressed-skin monoplane designs — pioneered by Hugo Junkers in 1915 — gradually made the second wing unnecessary. By 1940, military biplanes were obsolete.

The last biplanes in regular service were agricultural crop dusters, and even those have mostly converted to monoplanes. The word biplane now evokes nostalgia: open cockpits, leather helmets, barnstorming over wheat fields. It is a word for a technology that worked because of its era's limitations, and died when those limitations were overcome.