Letov Š-20

The Letov Š-20 was a fighter aircraft produced in Czechoslovakia during the 1920s.

Design and development
The Letov Š-20 was a conventional, single-bay biplane with unstaggered wings braced by N-struts. In overall appearance, it greatly resembled contemporary SPAD fighters. The fuselage and empennage were of welded steel tube construction and covered in fabric. The wings had a tubular metal spar but were otherwise wooden, and also fabric-skinned.

The Czechoslovakian Air Force bought 105 machines, and 10 examples were produced for Lithuania under the designation Š-20L. These remained in service until 1936 and 1935 respectively.

Operational history
An Š-20 placed second in the single-engine category of the national President of the Republic air race in 1925, but fared better the following year. In the 1926 race, an Š-20 not only won this category but also set a new national airspeed record of 234 km/h (146 mph). This record was short-lived, however, since the prize for the fastest circuit was also won in an Š-20, and this raised the record to 245 km/h (153 mph).

A single prototype of an unarmed advanced trainer version was built as the Š-21, but this did not sell.

Variants

 * Š-20 - initial production version
 * Š-20M - revised version with slimmed down rear fuselage (main production version for Czechoslovakia)
 * Š-20L - export version for Lithuania (8 built)
 * Š-20R - version with further revisions to fuselage (1 built)
 * Š-20J - version with Walter-built Bristol Jupiter engine
 * Š-21 - trainer version with Hispano-Suiza 8Aa engine (1 built)