The Sukhoi Su-27 (Russian: Сухой Су-27) is a twin-engine supermanoeuverable fighter aircraft designed by Sukhoi. It was intended as a direct competitor for the large American fourth generation fighters, with 3,530-kilometre (1,910 nmi) range, heavy armament, sophisticated avionics and high manoeuvrability. The Su-27 most often flies air superiority missions, but is able to perform almost all combat operations.
There are several related developments of the Su-27 design. The Su-30 is a two-seat, dual-role fighter for all-weather, air-to-air and air-to-surface deep interdiction missions. The Su-33 is a navy fleet defence interceptor for use on aircraft carriers. Further versions include the side-by-side 2-seat Su-34 strike variant and the Su-35 improved air defence fighter.
- T-10: Initial prototype configuration.
- T-10S: Improved prototype configuration, more similar to production spec.
- P-42: Special version built to beat climb time records. The aircraft had all armament, radar and paint removed, which reduced weight to 14,100 kg. It also had improved engines. Similar to the American F-15 Streak Eagle project.
- Su-27: Pre-production series built in small numbers with AL-31 engine.
- Su-27S: Initial production single-seater with improved AL-31F engine. The "T10P"
- Su-27P: Standard version but without air-to-ground weapons control system and wiring and assigned to Soviet Air Defence Forces units.
- Su-27UB: Initial production two-seat operational conversion trainer.
- Su-27SK: Export Su-27S single-seater
- Su-27UBK: Export Su-27UB two-seater.
- Su-27K: Carrier-based single-seater with folding wings, high-lift devices, and arresting gear, built in small numbers. They followed the "T10K" prototypes and demonstrators.
- Su-27M: Improved demonstrators for an advanced single-seat multi-role Su-27S derivative. These also included a two-seat "Su-35UB" demonstrator.
- Su-27PD: Single-seat demonstrator with improvements such as inflight refueling probe.
- Su-27PU: Two-seat version of the Su-27P interceptor, designed to support with tactical data other single-seat Su-27P, MiG-31 and other interceptor aircraft in PVO service. Later prototypes renamed Su-30 by Russia, and modified into a multi-role fighter mainly for export market, moving away from the original purpose of the aircraft.
- Su-32: Two-seat dedicated long-range strike variant with side-by-side seating in "platypus" nose. Prototype of Su-32FN and Su-34.
- Su-27SM: Mid-life upgraded Soviet Su-27S, featuring technology evaluated in the Su-27M demonstrators.
- Su-27SKM: Single-seat multi-role fighter for export. It is a derivative of the Su-27SK but includes upgrades such as advanced cockpit, more sophisticated self-defense electronic countermeasures (ECM) and an in-flight refueling system.
- Su-27UBM: Comparable upgraded Su-27UB two-seater.
- Su-27SM2: 4+ gen block upgrade for Russian Su-27, featuring some technology of the Su-35BM; it includes Irbis-E radar, and upgraded engines and avionics.
- Su-27SM3: The same as the Su-27SM but is built new rather than a mid-life upgrade.
- Su-KUB: Essentially an Su-27K carrier-based twin-seater with a side-by-side cockpit, for use as a naval carrier trainer or multi-role aircraft.