Sud Ouest Espadon

Design and development

The single-seat interceptor was a cantilever mid-wing monoplane powered by a 5000lb thrust Rolls Royce Nene engine licence-built by Hispano-Suiza. The unarmed first prototype S.O.6020.01 first flew on 12 November 1948. The second prototype S.O.6020-02 had a revised fin and air inlets and was fitted with six cannon. It first flew on 30 December 1949. The first prototype was later modified to the same configuration. The third prototype S.O.6020-03 was modified with an auxiliary 14.71 kN (3,307 lbf) SEPR 25 liquid-fuel rocket engine beneath the fuselage and was re-designated S.O.6025.

The first prototype was modified for research use and had two wingtip-mounted Turbomeca Marbore turbojets fitted. The second aircraft also had a 14.71 kN (3,307 lbf) SEPR 25 rocket engine fitted in the rear fuselage underneath the tail pipe and was re-designated as the S.O.6026. The proposed production variant, the S.O.6021 first flew on 3 June 1950, it had a lighter-weight structure and a revised cockpit with an ejection seat.

Variants

S.O.6020-01

Nene-powered prototype first flown on 12 November 1948, later fitted with two wingtip-mounted Turbomeca Marbore turbojets.

S.O.6020-02

Second prototype first flown 30 December 1949, later modified with the addition of a 14.71 kN (3,307 lbf) SEPR 25 rocket engine and re-designated S.O.6026.

S.O.6020-03

Third prototype, modified before first flight as the S.O.6025 also with a SEPR 25 auxiliary liquid-fuel rocket beneath the fuselage.

S.O.6021

The proposed production aircraft based on the S.O.6020-03, but with a lighter-weight structure, ejection seat, smaller pressurised cockpit and hydraulically boosted flying controls. The sole prototype was first flown on 3 June 1950

S.O.6025

The third prototype fitted with a SEPR 25 auxiliary liquid-fuel rocket beneath the fuselage.

S.O.6026

The second prototype also modified with a SEPR 251 rocket engine. and first flown on 4 January 1952.

Specificarions (SO.6021)

Data from The Complete Book of Fighters

General characteristics

Crew: 1

Length: 15 m (49 ft 3 in)

Wingspan: 10.6 m (34 ft 9 in)

Height: 4.72 m (15 ft 6 in)

Wing area: 26.5 m² (285 sq ft)

Empty weight: 4,750 kg (10,472 lb)

Gross weight: 6,870 kg (15,146 lb)

Powerplant: 1 × Rolls-Royce Nene centrifugal compressor turbojet engine, 22 kN (5,000 lbf) thrust

Performance

Maximum speed: 967 km/h; 522 kn (601 mph)

Endurance: 2.5 hours

Rate of climb: 27 m/s (5,300 ft/min)

Armament

Guns: 6x 20 mm (0.787 in) cannon