The Sukhoi Su-57 ( Russian : ????? ??-57; NATO code : Felon ) is a fifth-generation fighter jet developed by Sukhoi for the Russian Air Force . Previously this fighter jet was named PAK-FA ( Russian : ??? ??; short for: ????????????? ??????????? ???????? ????????? ???????/frontline air force prospective aeronautical complex). This fighter is planned to replace the MiG-29 Fulcrum and Su-27 Flanker fighter jetson the Russian air defense system. In addition, the Su-57 was also used as the basis for the Sukhoi HAL FGFA project which aims to develop fighter jets for the needs of the Indian Air Force, but the Sukhoi HAL FGFA project has been completed after India was disappointed with Russia in the project.