Letov Š-18

{{Expand Czech|topic=transp|Letov Š-18|date=April 2020}}

{{Infobox aircraft

|name=Letov Š-18

|image=Letov Smolik.jpg

|caption=

|type=Primary trainer

|manufacturer=Letov Kbely

|designer=Alois Smolík

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|introduction=

|retired=

|status=

|primary_user=Czechoslovakian Air Force

|more_users=Finnish Air Force

|produced=

|number_built=

|program cost=

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|developed_from=

|variants=

}}

The Letov Š-18 was a Czechoslovak single-engined, two-seat biplane trainer. It was designed by Alois Smolík at Letov Kbely. The Š-18 first flew in 1925.

The aircraft was quite successful and sold well, both to private pilots and to flying clubs. Apart from the basic variant, there was also still the type Š-118, which was equipped with a Walter NZ 85 engine (85 hp, 63 KW). Some machines were exported to Bulgaria. The Czechoslovakian Air Force used the type 1925 to 1930 as a beginner trainer aircraft.

A complete reconstruction of the fuselage led to the Š-218, which had a steel tube frame and was equipped with a {{convert|120|hp|kW|abbr=on}} Walter NZ 120 engine. The first flight of this type took place in 1926.

In 1929, one Š-218 Smolik was presented at Helsinki International Air Show. The Finnish Air Force showed interest in the type and purchased it in March 1930. Nine more were soon ordered along with the manufacturing license. The nine aircraft ordered from Czechoslovakia arrived at Finland in June–July 1931. The Finnish State Aircraft Factory manufactured 29 slightly modified aircraft in three series. The first ten (powered by {{convert|145|hp|kW|abbr=on}} Walter Mars engines) were ready in 1933, the second series of ten aircraft (powered by {{convert|162|hp|kW|abbr=on}} Walter Gemma engines) were ready in 1935, and nine more (powered by {{convert|150|hp|kW|abbr=on}} Bramo Sh 14) were in 1936.Listemann & Ritaranta 2012, pp. 181–182 The Finnish version could develop a maximum speed of 155 km/h (83 knots, 96 mph). The type was in service with the Finnish Air Force as a primary trainer between 1930 - 1945.{{cite web |last=Perttula |first=Pentti |title=Backwoods Landing Strip: Finnish Air Force Aircraft |url=http://www.sci.fi/~ambush/faf/fafincolor.html |date= |publisher= |accessdate=2009-06-28 }}{{dead link|date=December 2017 |bot=InternetArchiveBot |fix-attempted=yes }} One aircraft is still preserved at the Finnish Aviation Museum in Vantaa and one replica is being built in Finland (as of 2005).