 In total , 15 airworthy Su @-@ 35s ( Su @-@ 27M ) were produced , including an Su @-@ 35UB two @-@ seat prototype , along with two static test prototypes . The Su @-@ 35UB , powered by two modified AL @-@ 31FPs with thrust @-@ vectoring nozzles , made its first flight on 7 August 2000 . It was demonstrated to South Korea during that country 's F @-@ X replacement fighter tender , before becoming an avionics testbed . The original Su @-@ 35 never entered serial production due to a lack of funding , and the VVS continued to use its Su @-@ 27 fleet . The Su @-@ 35 's automatic control of canards and the Su @-@ 37 's thrust @-@ vectoring technology were applied to the Sukhoi Su @-@ 30MKI . One of the Su @-@ 35s , T10M @-@ 10 , served as a testbed for the Saturn 117 ( AL @-@ 41F1 ) engine intended for Russia 's upcoming PAK FA fifth @-@ generation jet fighter . 
