Letov S-4


1st Flight 1922

Crew: 1

Length: 6.58 m (21 ft 7 in)

Wingspan: 8 m (26 ft 3 in)

Height: 2.62 m (8 ft 7 in)

Wing area: 15.9 m2 (171 sq ft)

Empty weight: 673 kg (1,484 lb)

Gross weight: 980 kg (2,161 lb)

Powerplant: × Hispano-Suiza 8Ba V-8 water-cooled piston engine, 160 kW (220 hp)

Propellers: 2-bladed wooden fixed pitch propeller


Maximum speed: 232 km/h (144 mph, 125 kn)

Service ceiling: 6,200 m (20,300 ft)

Time to altitude: 3,000 m (9,800 ft) in 9.3 minutes

Wing loading: 61.5 kg/m2 (12.6 lb/sq ft)

Power/mass: 0.16 kW/kg (0.1 hp/lb)


Guns: 2 x synchronized 7.7 mm (0.303 in) Vickers machine-guns


The Š-4 was first created in 1922 as an intended successor to the SPAD S.VII and S.XIII, in service with the newly created Czechoslovak Air Force.

It first flew in 1922, with fabric-covered wooden wings and a metal fuselage and tail.

The Czechoslovak Air Force ordered 20 Š-4s in 1922 and these were delivered in early 1923.

The plane lived out the 1920s as a fighter and trainer, but by 1927 difficulties were being experienced due to the low manufacturing quality of the Š-4.

As a result, all remaining Š-4s were upgraded to Š-4a trainer aircraft in 1928.

20 aircraft were built.



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