10/31/2010. Designed by Alois Šmolík, the two-seat Š-18 was a state of the art Czechoslovakian biplane trainer of the mid-1920s. Of all-wooden construction, covered with fabric, the Š-18, nick-named Komár (Mosquito) was powered by a 60 hp Walter NZ-60 five-cylinder air-cooled radial engine. It first flew in 1925 and was used by the Czechoslovakian AF, flight clubs and individuals, while a number were exported to Bulgaria. Re-engined in 1926 with an 85 hp Walter NZ-85 seven-cylinder air-cooled radial, the aircraft was designated Š-118.
Also in 1926 appeared the similar Š-218, nicknamed Velký Komár (Big Mosquito), which had a steel tube fuselage and was powered by an 120 hp Walter NZ-120 nine-cylinder air-cooled radial engine. In 1929 the Š-218 was used on a promotional flight to the Baltic States, Poland and Finland, where it was demonstrated by Captain Hamšík at the Helsinki International Air Show. The aircraft remained in Finland for further testing and was bought by the Finnish AF in March 1930, and received the s/n SM-127.
An additional nine aircraft were ordered from Letov, these arrived at the Kauhava Aviation School in May-June, 1931, and were serialed SM-128 to SM-136. The Valtion Lentokonetehdas (State Aircraft Factory) obtained a production license and built an additional 29 aircraft. Designated Letov Š-218 Smolik and powered by a license-built 145 hp Brandenburgische Motorenwerke (Bramo) Sh 14 A4 seven-cylinder air-cooled radial engine, these were delivered between 1933 and 1936, serialed SM-137 to SM-165. The last Finnish AF Š-218 was withdrawn from use in 1945.
Two aircraft still exist, this one at Prague (shown also in these site files photos: 1 2), and another, coded SM-153, in the Finnish Aviation Museum at Helsinki-Vantaa airport.