|First flight||25 December 1958|
|Primary user||Soviet Air Forces|
|Produced||1962 - 1965|
|Developed from||Sukhoi Su-9|
Design and development 
The Su-11 was an upgraded version of the Sukhoi Su-9 ('Fishpot') interceptor, which had been developed in parallel with the OKB's swept wing Su-7 fighter bomber. Recognizing the Su-9's fundamental limitations, Sukhoi began work on the Su-11, which first flew in 1961 as the T-47 prototype.
The Su-11 shared the Su-9's delta wing, swept tailplanes and cigar-shaped fuselage, as well as the circular nose intake, but had a longer nose to accommodate the more powerful 'Oryol' (Eagle; NATO reporting name 'Skip Spin') radar set. A more powerful Lyulka AL-7F-1 turbojet was installed, providing 9.8 kN (2,210 lbf) more afterburning thrust for improved climb rate and high-altitude performance (and to compensate for increased weight). The Su-11 can be distinguished from the Su-9 by the external fuel pipes atop the fuselage, aft of the cockpit.
The Su-9's beam-riding K-5 missiles were replaced by a pair of R-98 (AA-3 'Anab') weapons, usually one R-98MR semi-active radar homing and one R-98MT infrared guided. Like many interceptors of the period, it had no cannon.
A conversion trainer version, the Su-11U 'Maiden,' was also developed. Similar to the Su-9U, it had full armament and radar systems for training purposes. Because the second seat further reduced its already marginal fuel capacity, it was not really intended for combat use.
Operational history 
Even with the superior radar, the Su-11 remained heavily dependent on ground control interception (GCI) to vector its pilot onto targets. It had no capability against low-flying aircraft either, and Sukhoi OKB considered the Su-11 to be a misfire, much inferior to the far more formidable Su-15 ('Flagon'). Nevertheless a few examples remained operational until early 1980s. The last Su-11s left front-line service around 1983.
Specifications (Su-11-8M) 
- Crew: One
- Length: 18.29 m (60 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 weight: 9,000 kg (20,000 lb)
- Loaded weight: 13,600 kg (30,000 lb)
- Powerplant: 1 × Lyulka AL-7F-1 turbojet, 96 kN (21,164 lbf)
- Maximum speed: Mach 2.2, 2340 km/h (1454.01 mph) at 11,000 m (36,000 ft)
- Combat: 500 km (312 mi)
- Ferry: 1,125 km (703 mi)
- Service ceiling: 17,000 m (55,760 ft)
- Rate of climb: 136.7 m/s (27,000 ft/min)
- Wing loading: 400 kg/m² (82 lb/ft²)
- Thrust/weight: 0.71
See also 
- Related development
- Aircraft of comparable role, configuration and era
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