Letov S-31

The Letov Š-31 was a fighter aircraft produced in Czechoslovakia in the early 1930s in a number of variants. All of the aircraft had metal tubular framing and fabric covering with a metal engine cowling.

The first flight of the definitive and highly altered Š.231 version was on March 17, 1933. After testing at the Czechoslovak flight facility at Prague-Lethany, modifications were undertaken to improve the machine’s performance. It entered production the following year and began equipping Czech fighter units in June 1936. The machines however did not remain in front line fighter status with the Czechoslovak Air Force until the German occupation of Czechoslovakia in 1939. The sole Š.331 and 22 out of 24 produced Š.231s were sold to representatives of the Spanish Republican government. Reports of their combat record in Spanish Civil War are vague, but at least three machines survived the war and were used by victorious Nationalists. The operational performance and ultimate fate of the Š.331 is unrecorded.

Letov S-31
Class Aircraft
Type Fighter
Manufacturer Letov Kbely
Origin Czechoslovakia
Country Name Origin Year
Czechoslovakia 1929
Country Name Operational Year Retirement Year
Czechoslovakia View
Spain View
Slovakia View
ManufacturerName Production From Production To Quantity
Letov Kbely View

Role fighter
Manufacturer Letov
First flight 1929
Primary users Czechoslovak Air Force
Spanish Republican Air Force

General characteristics

  • Crew: 1
  • Length: 7.80 m (25 feet 7 inches)
  • Wingspan: 10.06 m (33 feet 0 inches)
  • Height: 3.00 m (9 feet 10 inches)
  • Empty weight: 1,280 kg (2,822 pounds)
  • Loaded weight: 1,770 kg (3,902 pounds)
  • Powerplant: 1 × Walter Bristol Mercury V-S2, 9-cylinder, air-cooled radial piston engine, 412 kW (560 hp)


  • Maximum speed: 348 km/h at 5,000 m (216 mph at 16,405 feet)
  • Range: 450 km (280 miles)
  • Service ceiling: 7,800 m (25,590 feet)


  • Guns: Two fixed forward-firing 7.7 mm (0.303 inch) machine guns mounted in fuselage nose, one similar weapon in pod beneath each lower wing,
  • Bombs: Six small bombs at hard points beneath lower wings

End notes