During the early days of the Cold War, the U.S. military sought new ways of delivering a nuclear warhead to a target. One platform to do that, the Navaho surface-to-surface cruise missile, utilized the North American Aviation (NAA) RTV-A-5 (Research Test Vehicle, Air Force). Also known as the X-10, the turbojet-powered aircraft was used to test the flight characteristics and guidance, navigation, and control systems for the planned SM-64 Navaho.

Named after the Navaho Nation, the Navaho was intended to be a supersonic intercontinental cruise missile that could be capable of delivering a nuclear weapon to the targets within the Soviet Union from bases within the continental United States while cruising at Mach 3 at 60,000 feet.

X-10: A Testing Platform with Big Goals 

North American built 13 X-10s, ten of which were used in test flights, with the first of those occurred in October 1953. The X-10 was powered by two Westinghouse XJ40 engines of 10,000 lbs. thrust each (with afterburner), which allowed for a maximum speed of 1,300 mph with a range of 400 miles and a ceiling of 45,000 feet. The test prototype was unique in that it could take off and land on a conventional runway, while it also featured an all-moving canard and delta-wing configuration that was designed to be similar to the planned Navaho cruise stage.

It was equipped with an autopilot for automatic, stable flight while it was controlled by a radio-command guidance system via an AN/ARW-56 on-board receiver and an AN/ARW-55 transmitter in the ground control station.

The X-10 proved to be quite a high-performance aircraft for its time, and it has been noted that for a brief period it was actually the fastest turbojet-powered aircraft flown and could reach speeds of Mach 2.05.

The program proved successful and continued through November 1956 – when the significantly less successful tests of the XSM-65 Navaho began. All of the first ten of the Navaho launches ended in failure, while the next two flights lasted just around four and a half minutes. A bigger issue was that by the time the program was reaching the test stage, the first Atlas Intercontinental Ballistic Missile (ICBM) began flight tests, and showed great promise. As a result, the Navaho program was canceled and with it, the X-10 program ended as well.

Over the course of the test flights, several of the X-10s were lost in landing flights, while three surplus X-10s were launched as high-speed, high-altitude target drones as part of the XB-70 program as targets for the surface-to-air missiles (SAMs) then in development. Two of the three crashed, and of the original 13 X-10s built, the only remaining one is now in the collection of the National Museum of the United States Air Force at Wright Patterson Air Force Base in Dayton, Ohio.

Peter Suciu is a Michigan-based writer who has contributed to more than four dozen magazines, newspapers and websites. He regularly writes about military small arms, and is the author of several books on military headgear including A Gallery of Military Headdress, which is available on Amazon.com.