The T-50/Su-57 prototype first flew on January 29, 2010 and as of March 2018 there are 10 Su-57 prototypes and were renamed Felons that year. This is Russia's first stealth aircraft and was designed to cope with the F-22 and F-35. The Su-57 is made from extensive use of composite material and radar absorbing material (RAM). The original AL-41F-1 engine is under powered and will be replaced by an Izdelie 30 which is under development. The Felon has super maneuverability, super-cruise, thrust-vectoring nozzles. Russia ordered 76 Su-57s. Within Sukhoi the aircraft was designated as T-50 and is the first Russian aircraft to use stealth technology. Su-57 Bort 056 was the sixth flying prototype completing its maiden flight on April 17, 2016. With all the structural changes made increased the normal aircraft take-off weight to 55,000 pounds. The early Su-57 program was fraught was problems, mission control systems and accidents delaying the first production aircraft from 2015 to 2020. Apparently a carrier based variant is being considered.