Sukhoi Su-9


The Sukhoi Su-9 was a single-engine, all-weather, missile-armed interceptor aircraft 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 "Fitter", 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 "Fishpot-C" 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 unmanned aerial vehicles. It was replaced by the upgraded Su-11 and the much-superior Su-15 "Flagon" and MiG-25 "Foxbat".
The combat record of the "Fishpot", if any, is unknown. It is possible that it was involved in the interception of reconnaissance missions whose details remain classified, but nothing is publicly admitted.
It was reported that a Su-9 was involved in the interception of Francis Gary Powers' U-2 on Soviet territory on 1 May 1960. A newly manufactured Su-9 which was in transit flight happened to be near Powers' U-2. The Su-9 was unarmed and was directed to ram the U-2. One ramming attempt was made and the Su-9 missed the U-2, primarily due to large difference in the speed of the two planes. No further ramming attempt was made due to Su-9's lack of fuel.
Its pilot, Captain Igor Mentyukov later claimed that his slipstream had caused the U-2 to break apart. He discounts the official version that the U-2 was shot down by an SA-2 missile, saying that Captain Powers could not have survived such a hit.
On September 4, 1959 a modified Su-9 piloted by Vladimir Sergeievitch Ilyushin set a new world record for absolute height, at 28,852 m. In November of the same year Ilyushin set several new sustained speed/altitude records in the same aircraft. This record was later broken on 6 December 1959 by Commander Lawrence E. Flint, Jr., who performed a zoom climb to a world record of 98,557 ft while piloting an F4H-1 Phantom.

Design

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.
The Su-9 was developed from earlier work on a developmental aircraft designated T-3, to which the Su-9 was very nearly identical. Internally at Sukhoi, the Su-9 was known as the T-43.
The delta wing of the Su-9 was adopted because of its lower drag in the supersonic flight regime. 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. 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 radar in the shock cone and was armed with four K-5 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. 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.
The Su-9 has been frequently mistaken for the MiG-21 due to the many similarities in design. The primary distinguishing factors are size and the Su-9's bubble canopy.

Variants

;T-405
;Su-9
;Su-9U
;T-431
;Sukhoi Su-11

Operators