Helping hand

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Despite certain expectations that Sukhoi would display both of its newest products — the Superjet 100 regional jet and the Su-35 multirole fighter — at Le Bourget this year, the Russian aircraft maker has decided to celebrate the 100th anniversary of the Paris Air Show only with its major civil product. Nevertheless, this does not mean that the Su-35 program has been overshadowed by the first successes of the Superjet 100 project. Quite the reverse — the Su-35 program has recently received a serious financial boost with the Russian Air Force finally deciding to purchase the aircraft as an interim solution until the fifth-generation fighter enters service.
Sukhoi had lobbied for this solution for several years, all the while developing the Su-35 on its own. The purchase decision was announced by Russian Prime Minister Vladimir Putin during his visit to Sukhoi’s main assembly facility in Komsomolsk-on-Amur in the beginning of May. There he was shown a Su-35 prototype — as well as the prototype of the Sukhoi T-50 design developed to meet the air force’s next-generation fighter program, known as PAK FA (the Russian acronym for Future Aircraft System of Frontline Aviation).
"We have decided to place additional orders with the [Sukhoi] facility," Putin said after his visit to Komsomolsk-on-Amur. "Until 2105 it will deliver 60 new combat aircraft to the Russian Armed Forces." A source at Russia’s United Aircraft Corporation, a merger of domestic fixed-wing aircraft manufacturers that also includes Sukhoi, explained to Russia & CIS Observer that this figure includes 48 Su-35 airframes. It will enable the air force to fully re-equip two fighter regiments. The rest will be a mix of Su-27SM single-seat fighters and Su-30MK2 twin-seat aircraft, said the source. The deliveries of Su-35s to the air force should be completed by 2015 while other modifications will be handed over by 2011-12.
The single-seat Su-35 — also referred to as the Su-27SM2 by the Russian military — combines the proven Su-27 airframe with completely new onboard equipment, as well as the company’s modernization solution for existing Flankers and some developments for the future T-50 fifth-generation fighter. The first prototype was demonstrated at the MAKS 2007 air show, with the NIIP Irbis passive electronically scanned array already fitted on the aircraft. The Su-35 is powered by a pair of experimental NPO Saturn 117S engines, a further derivative of the Al-31 powerplant. Compared to its predecessor, the 117S has two more tons of thrust (to 14.5 tons) and a FADEC control system. Its swiveling nozzles are identical to those used on the Al-31FM modification that powers Su-30MKI fighters.
Sukhoi designers have also made a serious step forward in developing equivalents of certain foreign-made onboard components previously used in the Su-35 program. For example, the aircraft’s cockpit simulator demonstrated at the Paris Air Show in 2007 had a control stick made by the French company Thales. When presenting the first prototype a year later, Su-35 program director Igor Dyomin stressed that the aircraft had only Russian-made equipment. Among these newly developed components for the Su-35 he also mentioned an IR radiation detector and a new optical radar station.
The flight tests started with the first Su-35 prototype taking off on February 19, 2008. In October the same year the second prototype made its maiden flight. To date, both aircraft have made over 100 flights. Sukhoi has reported that during the first year of testing it managed to confirm the aircraft’s stability parameters and check the integrated control system, various subsystems and navigation equipment. One more prototype completed static trials to achieve marginal conditions for the confirmation of the aircraft’s flight performance.
This year Sukhoi was planning to use the third aircraft for flight trials to bring the total number of test flights to 150-160. Unfortunately, the third prototype missed its chance to take off as it was destroyed during taxi trials at the end of April 2009. Nevertheless, the company has confirmed that the development schedule remains unchanged and that this year it plans to complete the static trials and begin testing the super-agility mode on the flying prototypes.
During the first test flights the Su-35 unexpectedly demonstrated supercruise speed, i.e. a supersonic speed at the highest thrust settings without the use of the afterburner — one of the distinct features of a next-generation fighter. This became possible thanks to the use of the more powerful 117S engines, combined with a lighter airframe incorporating composite elements, and more advanced onboard equipment. "We didn’t expect such a result and were surprised at it," — Igor Dyomin confessed at the time. He also confirmed that the aircraft had reached supercruise speed twice, at the altitudes of 5,000 and 11,000 meters. "It went supersonic and continued to speed up," Dyomin said, adding that Sukhoi would continue assessing the parameters achieved and testing the aircraft at supercruise settings at various altitudes and missions, including flights with combat loads.
The order from the Russian Air Force gives Sukhoi significant financial support and will enable it to ensure a workload for its Komsomolsk-on-Amur manufacturing site, which has suspended large-scale Flanker production since the completion of a series of Chinese orders in the early 2000s. Sukhoi CEO Mikhail Pogosyan expects to sell up to 200 aircraft through 2020 and, besides the domestic orders, hopes to find foreign customers in South East Asia, Africa, the Middle East and Latin America. However, the Su-35, which was initially promoted as Sukhoi’s exclusive export product, has not met with any success on the foreign markets yet. It failed to make the short list for the Brazilian Air Force’s fighter competition. A Sukhoi source complained to Russia & CIS Observer that the Brazilian choice had been affected by political reasons; on the other hand, the tender’s offset requirements were categorized as unrealistic by the Russian side.
The domestic procurement of the Su-35 will help Sukhoi to finish the development of the T-50. The first flight of Russia’s fifth-generation fighter is expected by the end of 2009. At any rate, Russian Air Force Commander Col-Gen Alexander Zelin in December 2008 expressed his hope to see the first flying T-50 prototype ready by the Air Force Day, which is celebrated on August 12. Members of the Russian government miss no chance to assert that the PAK FA program faces no delays. Vladimir Putin was no exception when he confirmed, after his visit to Komsomolsk-on-Amur, that the Sukhoi facility was actively working to develop the fifth-generation fighter. "The work is on schedule. I saw it myself," said the Russian prime minister.
Earlier Sukhoi and government officials said that the PAK FA would enter service with the Russian Air Force in 2015. Now, with the decision to purchase the Su-35 in that year, it looks like Sukhoi is taking more time to complete the development of its fifth-generation fighter than initialy planned.