Radioplane XKD4R

The Radioplane XKD4R, designated RP-70 by its manufacturer, was a target drone built by Northrop Corporation's Radioplane Division. Though never mass-produced, it served as the basis for the later AQM-38, which saw successful production.

This air-launched drone was powered by a single Aerojet solid-fuel rocket motor, with exhaust nozzles positioned at the wing's trailing edges. Its airframe was mostly molded plastic, and it used an unusual control setup: three canard fins at the front—one on top and one on each side of the fuselage—along with fixed horizontal fins at the rear. An autopilot guided the drone after launch, and a parachute deployed after roughly nine minutes of flight for recovery.

The XKD4R-1 first flew in January 1958 and underwent extensive testing by the U.S. Navy, typically launched from McDonnell F3H Demon fighters. While the RP-70 performed satisfactorily, it was not put into production. Instead, the improved RP-76 variant first flew in 1959 and was built for both the U.S. Air Force and Navy, eventually becoming the AQM-38 in 1962.