The EKR (Eksperimentalnaya Krylataya Raketa, or experimental winged rocket) was a Soviet intermediate range cruise missile designed by the Korolev design bureau based on B. Chertok's elaboration of the German R-13 cruise missile design. The EKR as designed by Korolev would have been a Mach 3 ramjet, accelerated to supersonic cruise speed by an R-11 rocket booster. Smaller than the missile proposed by the Germans, it would have had a range of 730 km with a flight time of 927 seconds, a lift to drag ratio of 2.51, and a wing area of 3.31 m².