Almost ready for flight

The first flight of the PAK FA (T-50) tactical fighter, the fifth-generation replacement for Russia’s Su-27 fleet, was officially postponed for a few months compared to the previous expectation, but the government and military officials assure that the development is under way. In August both Gen Col Alexander Zelin, Commander of the Russian Air Force, and Mikhail Pogosyan, head of Sukhoi jet maker that is a lead contractor under PAK FA program, said the new aircraft will make its first flight by the end of the year. The previous deadline announced by Zelin at the end of 2008 was this year’s Air Force Day, celebrated on 12 August. Now the Commander confirmed that one prototype, assembled at Sukhoi’s KnAAPO facility in Komsomolsk-on-Amur, has already been delivered to Moscow and started static tests. The flying prototype is expected to be rolled out in November.
Although the PAK FA program is kept classified, some details about the future aircraft were revealed during MAKS 2009 air show, held in Zhukovsky in August. Alexander Zelin told that the first prototype will start flight testing powered by a pair of NPO Saturn 117S engines. These powerplants, a further modification of AL-31 engines uprated to 14.5 ton thrust are now installed at the new Su-35 multirole fighters. He explained that the initial prototypes of new engine for T-50 are being designed at the moment by NPO Saturn and MMPP Salyut companies.
More progress is reported on T-50’s avionics suite being developed by Avionica Concern. The company’s head Givi Djanjgava explained that two avionics kits for T-50 are ready and they include six-processor computer, visualization tools and flight instrument system. The suite will be installed at T-50’s first flying prototype in September while now the company is working on the software package for the first flight. According to Djanjgava, the new avionics will give T-50 network-centric capabilities, enable it to use new weapons and make the pilot’s work easier with graphic indication.
At MAKS 2009 air show Tikhomirov’s NIIP unveiled a full-scale active phased array antenna, it develops for T-50. Unlike the other Russian AESA radar – Zhuk-AE developed by Phazotron-NIIR for MiG-35 fighter, in Tikhomirov’s antenna the transmit/receive (T/R) modules are hidden inside the array. Anatoly Sinany, Tikhomirov’s chief designer, told Russia & CIS Observer that T-50 AESA radar will have 1,500 T/R modules, produced by Iztok company from Fryazino, near Moscow.
Now the first prototype of T-50’s X-band radar is passing a bench tests. According to NIIP, the second prototype for ground testing is to be assembled by the end of this year. The AESA radar for the first T-50 flying prototype is expected to be ready only in mid-2010.
Besides X-band radar, Tikhomirov’s NIIP also showed an L-band active phased array that is believed to be installed on the leading edge-flaps of the future aircraft. This L-band radar should also be installed at Su-35 fighter.
So it looks like the first flight ‘postponement’ doesn’t indicate a delay in the overall program. Previously, Sukhoi and state officials have said 2015 will be the year the fifth-generation fighter enters service with the Russian Air Force. In June Sukhoi’s Pogosyan reported that T-50s will be procured by the Air Force in parallel with the Su-35s. At MAKS 2009 Sukhoi and the Air Force signed a contract on delivery of 48 Su-35 that should be completed by 2015. This might imply that the next-generation T-50 design will be subjected to protracted testing before the military gets a final product with the required performance.
The Air Force Commander also mentioned the two-seat version of T-50 which he tentatively named as T-50UB (Uchebno-boevoy, combat trainer). Zelin explained that this modification will be developed jointly with the Indians. India joined PAK FA program in 2007, when it was assumed that Sukhoi and Hindustan Aeronautics (HAL) would develop a fifth-generation fighter for the Indian Air Force on a parity basis.