The Sukhoi Su-57 T-50 was developed under the iPerspektivniy Aviacionniy Complex Frontovoi Aviaciii Perspective Aviation Complex for Frontline Aviation program to field a fifth generation multifunctionalmultidimensional strike fighter for service with the Russia Federation Aerospace Forces from the third decade of the twenty first century. Taking to the air in January 2010, the T-50 prototype emerged from the LFI iLegikiy Frontovoi Istrebitel i- Light Frontline Fighter program that rose from the ashes of the cancelled Soviet era MFI iMnogofunktsional'nyy Frontovoi Istrebiteli - Multifunctional Frontline Fighter program aimed at fielding a Sukhoi Su-27 heavy air superiority fighter replacement.brThis volume, which builds upon and advances the work conducted on the 2015 volume, covers the Su-57 program from conception of the MFI and LFI programs from the early 1980's and 1990's, to flight testing of the T-50 development and pre-series aircraft and initial service deliveries of series air