This article describes the supersonic Su-9 "Fishpot". For the earlier subsonic interceptor, see Sukhoi Su-9 (1946).

The Sukhoi Su-9 (NATO reporting name Fishpot) was a single-engine, all-weather, missile-armed interceptor developed by the Soviet Union.

Development

The Su-9 emerged from aerodynamic studies by TsAGI, the Soviet aerodynamic center, during the Korean War, which devised several optimum aerodynamic configurations for jet fighters. The design first flew in 1956 as the T-405 prototype. The Su-9 was developed at the same time as the Su-7, and both were first seen by the West at the Tushino Aviation Day on 24 June 1956, where the Su-9 was dubbed Fitter-B. It entered service in 1959.

Total production of the Su-9 was about 1,100 aircraft. It is believed that at least some Su-9s were upgraded to Su-11 form. None were exported to any of the USSR's client states nor to the Warsaw Pact nations. Remaining Su-9s and later Su-11s were retired during the 1970s. Some were retained as test vehicles or converted to remote-piloted vehicles for use as drones. It was replaced by the upgraded Su-11 and the much-superior Su-15 and MiG-25.

The combat record of the 'Fishpot,' if any, is unknown. It is possible that it was involved in the interception (or even shoot-down) of reconnaissance missions whose details remain classified, but nothing is publicly admitted.

On September 4 1962 a modified Su-9 (designated T-431 by the bureau) piloted by Vladimir Sergeievitch Ilyushin set a new world record for absolute height, at 28,852 m (94,658 ft). In November of the same year Ilyushin set several new sustained speed/altitude records in the same aircraft.

Description

The Su-9's fuselage and tail surfaces resembled those of the Su-7, but unlike the swept wing of that aircraft, the 'Fishpot' used a 53° delta wing with conventional slab tailplanes . It shared Sukhoi features like the rear-fuselage air brakes as well as the Su-7's Lyulka AL-7 turbojet engine and nose intake. The translating shock cone contains the radar set. (Another delta-wing aircraft, with a chin-mounted intake and larger radome, was flown at the same time, but did not enter production.)

The delta wing of the Su-9 was adopted because of its lower drag in the supersonic flight regimen. Its greater volume also allowed a very modest increase in fuel capacity compared to the Su-7. The Su-9 was capable of Mach 1.8 at altitude, or about Mach 1.14 with missiles. Its fuel fraction remained minimal, however, and operational radius was limited. Furthermore, rotation speeds were even higher than the Su-7, which was already high at 360 km/h (225 mph). Unlike the Su-7, which had very heavy controls but docile handling characteristics, the 'Fishpot' had light and responsive controls, but was very unforgiving of pilot error.

The Su-9 had primitive R1L (NATO reporting name 'High Fix') radar in the shock cone and was armed with four K-5 (AA-1 'Alkali') beam-riding air-to-air missiles. Like all beam-riders, the K-5 was so limited as to be nearly useless for air-to-air combat. Unlike the Su-7 and later Su-15, no Su-9 carried cannon armament, although two fuselage pylons were reserved for the carriage of drop tanks.

A two-seat trainer version, designated Su-9U, was also produced in limited numbers (about 50 aircraft). It received the NATO reporting name 'Maiden.' It had a full armament and radar system with displays in both cockpits, allowing trainees to practice all aspects of the interception mission, but because the second seat further reduced the already meager fuel fraction, it was not truly combat-capable.

Specifications (Su-9)

General characteristics

• Crew: one, pilot
• Length: 17.37 m (57 ft 0 in)
• Wingspan: 8.43 m (27 ft 8 in)
• Height: 4.88 m (16 ft 0 in)
• Wing area: 34 m² (366 ft²)
• Empty: 8,620 kg (19,000 lb)
• Loaded: 12,250 kg (27,000 lb)
• Maximum takeoff: 13,500 kg (29,700 lb)
• Powerplant: 1x Lyulka AL-7 , 90 kN (19,840 lbf)

Performance

• Maximum speed: Mach 2.0
• Range: 1,125 km (340 miles)
• Service ceiling: 16,760 m (55,000 ft)
• Rate of climb: 8,200 m/min (27,000 ft/min)
• Wing loading: 383 kg/m² (74 lb/ft²)
• Thrust-to-weight: 7.3 N/kg (0.73 lbf/lb)

Armament

• 4x K-5 (AA-1 'Alkali') air-to-air missiles

Related content

Related development: Sukhoi Su-7 - Sukhoi Su-11

Comparable aircraft: McDonnell F-101B Voodoo - Convair F-102 Delta Dagger - English Electric Lightning

Designation sequence: Su-7 - Su-9 - Su-10 - Su-11 - Su-15

See also:

• List of military aircraft of the Soviet Union and the CIS