Having acquired Russian air force support for the Stage I upgrade for the Su-30 and Su-27UB twin seat fighters, Irkutsk Aviation Industrial Association (IAPO) is speeding up work on Stage II follow-on package with intent to begin fly-tests on the first thus upgraded aircraft in autumn. Work on the project began in 1999 under IAPO initiative, now involving 0KB Sukhoi, Aerospace Equipment Consortium and MoD research institutes.

The Su-30KN and Su-27UBM, as the Su-30 interceptors and Su-27UB training fighters are designated after Stage I upgrade, regain the Su-27’s original avionics set, including RLPK-27 radar and SUV-27 weapons control system, and additionally get a «by-pass channel» strap-on package containing Baget-55 processor and MVK digital computer with data exchange capability using MIL-1553B multiplex databus. This enables additional modes for the radar, including ground mapping (through use of synthesized aperture) and selection of moving ground targets. The Su-30KN have the same cockpit instruments as original Su-30, except for a single liquid-crystal MFI-55 (5х5 in) MFD that replaces a standard cathode-ray display in each cockpit. Stage I enables the Su-30 to fire X-31A, X-31P and X-29T air-to-surface missiles and KAB-500 guided bombs. It also adds R-77/RVV-AE missile to the list of its air-to-air weapons.

Stage II applies to the aircraft that underwent Stage I upgrade. It enhances their air-to-air capability through replacing the RLPK-27’s original slotted antenna with a phased-array one featuring digital beam control (electronic scanning). The upgraded radar has 50% greater acquisition range, while providing track-while-scan and multi-target shooting capability with R-77, R-27 and R-73 air-to-air missiles. The new antenna, designated Pero, was developed on the base of the technologies first tried on the MiG-31’s Zaslon radar. So far two experimental Pero units have been assembled.

Stage II aircraft will feature a «glass» cockpit meeting HOTAS (hands-on-throttle-and-stick) conception, with three MFI-68 (6х8″) liquid-crystal color displays and two MFI-55s (5х5″) replacing dial instruments in each of the cockpits. Flight Test and Research Institute (LII) is evaluating the required next-generation crew station technologies on the Su-30 side number 597, whose forward cockpit features three MFI-68s and two data-input devices with built-in screens.

IAPO has begun conversion of a Su-30K into the Su-30KN Stage II specimen with intent to begin flight tests this autumn and have a preliminary report on the aircraft by the year-end. A full-scale mockup of the Su-30KN Stage II crew station is to be displayed at MAKS’2001. According to IAPO spokesman. Stage II modernization will permit Russian air force to keep its twin-seat Flankers up to date throughout their remaining operational lifetime. The company hopes not only to win orders for upgrade of the in-service machines, but also sell newly built Su-30KN to both local and foreign customers.