Sud-Ouest Espadon

The Sud-Ouest SO.6020 Espadon (en: Swordfish) was a post-war prototype French interceptor designed and built by SNCASO. Only four aircraft were built and the type did not go into production.

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.^[1] The unarmed first prototype S.O.6020.01 first flew on 12 November 1948.^[1] 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.^[1] 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.^[1]

The first prototype was modified for research use and had two wingtip-mounted Turbomeca Marbore turbojets fitted.^[1] 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.^[1] 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.^[1]

Variants

S.O.6020-01

Nene-powered prototype first flown on 12 November 1948, later fitted with two wingtip-mounted Turbomeca Marbore turbojets.^[1]

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.^[1]

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.^[1]

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^[1]

S.O.6025

The third prototype fitted with a SEPR 25 auxiliary liquid-fuel rocket beneath the fuselage.^[1]

S.O.6026

The second prototype also modified with a SEPR 251 rocket engine.^[1]

Specificarions (SO.6021)

Data from The Complete Book of Fighters^[2]

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

• Endurance: 2.5 hours
• Rate of climb: 27 m/s (5,300 ft/min)

Armament

• Guns: 6x 20 mm (0.787 in) cannon
  

or 2x 30 mm (1.181 in) DEFA cannon

References

Notes

Bibliography