In 1985 the approval was given for a naval variant of the Su-27 that would provide air superiority for its aircraft carriers. The new aircraft was designated Su-27 (K = Korabelny, Ship Borne) with a factory designation of T-10K which would later become Su-33, NATO Flanker D. Canards were added, strengthened frame and landing gear with a two-wheel nose gear. The drag chute was removed, a retractable tail hook added and wings, horizontal stabilizers and nose cone were made to fold. A retractable in-flight refueling probe was included on the port side.