 In March 2012 , the Russian media reported that the two countries were in final contract negotiations for 48 Su @-@ 35s ; the remaining obstacle is reportedly Moscow 's demand that Beijing guarantee proper licensing for its Su @-@ 35 production . China denied this deal because it did not want the Su @-@ 35 , but only shown slight interest in its 117S engine ; at the 2012 Zhuhai Air Show Russia approached China with its 117S engine in a failed attempt to sell Su @-@ 35 . 
