The Sukhoi Su-57 (Russian: Сухой Су-57; NATO reporting name: Felon) is a twin-engine stealth multirole fighter aircraft developed by Sukhoi. It is the product of the PAK FA (Russian: ПАК ФА, prospective aeronautical complex of front-line aviation) programme, which was initiated in 1999 as a more modern and affordable alternative to the MFI (Mikoyan Project 1.44/1.42). Sukhoi's internal designation for the aircraft is T-50. The Su-57 is the first aircraft in Russian military service designed with stealth technology and is intended to be the basis for a family of stealth combat aircraft.
