Sukhoi’s T-50 fifth-generation fighter program has made significant strides since the first aircraft (T-50-1) flew at the Knaapo factory’s airfield back in January 2010. The most important recent milestone is the first flight of the second aircraft (T-50-2), which is now scheduled to join T-50-1 in flight trials.

Aircraft T-50-3 is currently in final assembly and is due to fly later this year in a configuration representative of the initial production version. Components of T-50-4 are advanced, and this aircraft is intended to fly in the full operational configuration, depending on the outcome of ongoing trials. T-50-5 and T-50-6 are due to fly some time next year.

T-50-2 conducted its first flight at Knaapo on March 3 this year, in a sortie lasting just under an hour. It subsequently flew three more times in the next two days, and in early April was shipped to Zhukovskiy.

Compared with T-50-1, the T-50-2 has some notable differences, including what appears to be some real sensor systems in place of T-50-1’s representative fairings, a new single-piece canopy and a generally higher standard of surface finish.

Engine and Radar Developments

As of last week T-50-2 had yet to fly again at the Zhukovskiy test facility, possibly because it was being fitted with new engines. T-50-1 flew with the NPO Saturn AL-41F1 engine, also known as Izdeliye 117, an advanced derivative of the engine that powers the Su-35. In addition to flying in the T-50, the AL-41F1 had undertaken 32 flights by March this year in an Su-27M testbed.

Saturn’s AL-41F1 was originally seen as the initial power- plant, pending development by the Lyulka-Saturn research-and-development center and MMPP Salyut of a more powerful and more advanced engine, identified as Izdeliye 129. The new engine is expected to feature rectangular low-observable nozzles. However, Lyulka-Saturn CEO Victor Chepkin recently spoke of an interim powerplant, dubbed Type 30, offering 15 to 25 percent more thrust than the AL-41F1 and which may have benefitted from Salyut’s input.

Chepkin stated that fifth-generation engine development is ahead of schedule, and also alluded to the fact that the Type 30 is ready for flight in the T-50. It may therefore be installed in T-50-2, accounting for the delay in its return to flight.
NIIP Tikhomirov is to supply the AESA radar for the T-50 program, based on the back end of the passive e-scan Irbis radar used in the Su-35S. Three active e-scan units have been built for testing. The first has undergone an exhaustive series of ground tests and NIIP Tikohomirov is happy that it meets requirements, including adequate cooling. The second of the radars is planned for installation in T-50-3, while the third radar is scheduled to be mounted in T-50-4 in a production-representative configuration.

Russian and Indian Requirements

Last year Russian Prime Minister Vladimir Putin demanded that the T-50 be ready for operational evaluation and initial training at the Lipetsk academy in 2013, and enter operational service in 2015. Judging by other current fighter programs, that timescale would appear to be optimistic, having already slipped by a few months (T-50-2 was due to fly in November 2010). The Russian government has signaled its intentions to order 10 from 2012, and then 60 after 2016, with a total requirement of around 200.

India has signed up to co-develop a version for its air force known as the FGFA (fifth-generation fighter aircraft), which will be a two-seat variant. After several years of negotiation, the initial design contract was signed last December. HAL has negotiated a 25-percent share in the design and development of this version, including software and mission computer, cockpit displays, navigation systems and countermeasures.

India requires around 200 two-seat FGFAs, but before that date it will take 50 single-seaters similar to Russia’s T-50. Initial operations for the Indian aircraft are slated for 2017.

Vietnam has also shown considerable interest in the T-50, as have a number of other air forces.