Canard controls Supermaneuverability

the f-15 active in flight; design modified f-15 eagle vectored thrust , canards.

a canard elevator control surface placed forward of wings. sometimes, b-1b, used stabilize flexible portions of fuselage or provide minute attitude changes, used supplement or full replacement of tail-mounted stabilators.

the theory behind canards sole elevator surface no elevator configuration aft of wings satisfactory maneuvering purposes; airflow on wings creates turbulence, small, , affects elevators placed directly behind wings. placement below wings (common on many fighters) exposes elevators greater turbulence under-wing ordnance. original solution such problems, t-tail, has been largely discredited being prone dangerous deep stalls . other solutions v-tail place combination rudder-elevator surfaces out of wings airflow, reduce effectiveness of control surface in pure pitch , yaw axes.

as supplement traditional elevators, canards vastly increase control surface area, , increase critical angle of attack of wings canard directs air more directly toward leading edge of wing. can designed operate independently (i.e. counter-rotate), acting ailerons.

canards not requirement, , can have disadvantages including reduced pilot visibility, increased mechanical complexity , fragility, , increased radar signature. f-22, example, not incorporate canards, stealth reasons. production su-35 omits canards. many technology demonstrators , maneuverability testbeds such f-15 s/mtd incorporated canards, when production aircraft based on did not. production fighters eurofighter typhoon, dassault rafale , saab gripen use delta-wing configuration canard surfaces, while variants of su-27 including su-30, su-30mki, su-33 , su-37 use canards supplement traditional tail-mounted elevators.