MOSCOW (Sputnik) — So far the prototypes of the aircraft have been equipped with the so-called Izdeliye 117 — an engine of the "first stage," which has already been put into production, while the engine of the "second stage" is being developed.
"Testing of T-50 aircraft with the next-generation engine, which was initially created for this aircraft, will start in the near future," Korotkov said.
Russian Sukhoi T-50 (PAK FA) is the fifth-generation stealth fighter. It is a single-seat, twin-engine multirole jet fighter designed for air superiority and attack roles. The first flight of the aircraft took place in 2010.