Preparing for service

The Russian Air Force plans to receive its first Sukhoi T-50 fifth-generation fighters in 2012-2016. It could be a pre-production batch of six to 10 aircraft, Vladimir Popovkin, deputy defense minister on armaments, said in June. The production of this batch will be launched in 2012 after the new fighter gets a preliminary approval from the military. Most of the trials should be completed by 2015, while serial production is to start in 2016. At the first stage the Air Force may order more than 50 aircraft, said Popovkin.
The T-50 has been in development by the Sukhoi company under the PAK FA (Perspektivny Aviatsionny Kompleks Frontovoy Aviatsii, or Future Tactical Aviation Aircraft System) program since 2002. The new aircraft is intended to replace the Russian Air Force’s Su-27 fighters. T-50 is definitely shaped for stealth with its chined forward fuselage, planform edge alignment, internal weapons bays and small vertical tails. According to Sukhoi, the aircraft’s fuselage is 30% made of composites, while its shape and special coating will allow the T-50 to demonstrate an unprecedented small radar cross section in the radar, optical and infrared ranges.
The first T-50 prototype made its maiden flight in January 2010. By mid-June the aircraft had made 16 flights. The second prototype is expected to join the test program this year while two more test airframes will be ready in 2010. "The task for the first two aircraft is to test aerodynamics, stability and controllability while the 3rd and 4th aircraft will be fitted with onboard equipment required by the customer," explains Sukhoi head Mikhail Pogosyan, adding that the aircraft subsystems like an AESA radar are being developed simultaneously.
The X-band AESA radar for the T-50 is being developed by the Tikhomorov NIIP design bureau. Its antenna, first unveiled at the Moscow MAKS exhibition in August 2009, has 1,500 transmit-receive modules. Besides the X-band radar, NIIP is also working on an L-band active phased array that will be installed on the T-50’s leading-edge flaps.
The first T-50 prototype is powered by a pair of NPO Saturn 117M engines, an improved modification of the 117S powerplant installed on Sukhoi Su-35 fighters. The 117M has a new FADEC system and a thrust reportedly increased from 14.5 to 15 tons. This engine, initially planned as a temporary solution, will now power the first production aircraft as well. "We think that this engine will meet the requirements at the initial stage of the aircraft’s operation", says Pogosyan, adding that development of a second-stage engine may be launched in 2011.
The testing of the T-50’s onboard equipment and weapons trials will start after 2012, and will involve aircraft from the pre-production batch. "The size of the pre-production batch will depend on the progress with prototype testing while these aircraft should speed up the trials," says Popovkin. The weapons trials will be conducted by the Air Force at the 929th flight-test center in Akhtubinsk. "We would like to complete the testing by 2015 in order to start deliveries of production aircraft from 2016," the deputy defense minister adds.
The Russian government in June disclosed the cost of the PAK FA program. When inspecting the T-50 prototype in Zhukovsky, Prime Minister Vladimir Putin said that 30 billion rubles (about $970 million) had already been spent on the aircraft’s development, and that another 30 billion was required to finish the program. But the PAK FA program is a top defense priority for the Russian authorities, and receives 100% funding annually.
The T-50 is expected to stay in service for 30-35 years. Sukhoi currently focuses on the single-seat version, but long-term plans include the development of a two-seat PAK FA version, dubbed T-50UB, that will also serve as a basis for the Indian Air Force’s prospective FGFA fighter. Russia and India signed an intergovernmental agreement on 2007 to jointly develop this aircraft, but a relevant contract between India’s HAL corporation and Sukhoi is still being discussed.