 In 2003 , even as Russia aimed to export the Su @-@ 27M , Sukhoi launched a project to produce a fighter to bridge the gap between upgraded variants of the Su @-@ 27 and Su @-@ 30MK , and Russia 's fifth @-@ generation Sukhoi PAK FA . The project 's aim was a second modernization of the Su @-@ 27 airframe ( hence its classification as a " 4 + + generation fighter " ) by incorporating several characteristics that would be implemented on the PAK FA . Additionally , the aircraft was to be an alternative to the Su @-@ 30 family on the export market . The design phase was to take place until 2007 , when it would be available for sale . It was later reported that the programme was launched due to concerns that the PAK FA project would encounter funding shortages . The project 's in @-@ house designation is T @-@ <unk> ( <unk> <unk> , " Big Modernization " ) while the aircraft is marketed as the Su @-@ 35 . 
