In early 2002 Sukhoi was chosen as prime contractor for the planned Russian 5th-generation fighter is named the PAK FA [ Perspektivnyi Aviatsionnyi Kompleks Frontovoi Aviatsyi - Future Air complex for Tactical Air Forces]. This intermediate category twin-engined fighter was to be larger than a MiG-29 and smaller than a Su-27. The new fighter was said meant to be about the same size as the US F-35 JSF, with a primary air superiority mission and ground attack and reconnaissance being secondary missions.
The aircraft was to feature a long and extended combat radius, supersonic cruise speed, low radar cross section, supermaneuverability, and the ability to make short takeoffs and landings.
Although T-50 specifications still classified, fragmentary information on its engines imply that this heavy-duty fighter will have a take-off weight of over 30 metric tons and can be close in dimension to the well-known Sukhoi Su-27 Flanker. The new fighter's exterior was designed using Stealth technology, also called LO technology (low observable technology).
