 While the aircraft maintains a strong superficial resemblance to the Su @-@ 27 , the airframe , avionics , propulsion and weapons systems of the Su @-@ 35 have been thoroughly overhauled . Technological advancements have produced more compact and lighter hardware , such as the radar , shifting the centre of gravity to the aircraft 's rear . These improvements removed the need for canards and saw the abandonment of the " tandem triplane " featured on several Su @-@ 27 derivatives . Also omitted was the Su @-@ 27 's dorsal airbrake , which was replaced by differential deflection of the vertical stabilizers . Other aerodynamic refinements include a height reduction of the vertical stabilizers , a smaller aft @-@ cockpit hump , and shorter rearward @-@ projecting " sting " . 
