Sukhoi T-50/PAK FA The highly classified Sukhoi T-50/PAK FA (Perspektivniy Aviacionniy Complex Frontovoi Aviacii – Perspective Aviation Complex for Front line Aviation) is being developed as a 5th generation multi-role fighter aircraft for service with the Russian Federation Air Force. Taking to the air in January 2010, in the form of the T-50 development aircraft, the PAK FA was born out of the LFI (Legikiy Frontovoy Istrebitel – Light Front line Fighter) program that emerged from the ashes of the cancelled Soviet era MFI (Mnogofunktsional’nyy Frontovoy Istrebitel – Multifunctional Front line Fighter) program to find a Su-27 heavy air superiority fighter replacement. Even five and a half years after its first flight, the T-50/PAK FA program, shrouded in secrecy, remains something of an enigma. What is clearly evident is that the aircraft possess the main traits expected to be embodied in a 5th generation air combat fighter; low-observability in the radio and electromagnetic wavebands, highly integrated sensors/avionics, the ability to supercruise and super-manoeuvrability. This volune covers the program from conception, detailing the previous MFI and LFI programs, to flight testing of the T-50 development aircraft. The T-50/PAK FA is described in detail, as are its various advanced systems, including powerplant, radar optoelectronics, electronic warfacre, navigation and weapons etc. All technical information about the aircraft, systems and weapons comes from manufacturers/developers documentation. There will be several occasions throughout this volume where certain words will be spelled in traditional English and United States English, for example ‘manoeuvrability’ (traditional English), ‘maneuvrability’ (United States English), as quoted passages from maufacturers documentation is used on several occasions. In regards to formal or informal writing, it has been deemed more appropriate to use the term 5th generation over the more formal fifth generation when referring to aircraft.