The X-10 on display in Dayton, Ohio. via
In a few months, history’s fastest drone and the only missile-style vehicle to receive an “X” designation will celebrate its 60th birthday. The X-10, one of the less well-known x-planes, made its maiden flight at Edwards Air Force Base in California on October 14, 1953.
Eight years earlier, the way wars were fought was about to change. The Second World War had just ended and one of it’s most notable weapons was the Nazi V-2 missile. Missiles were the weapon of the future, and the United States military wasn’t going to be left behind. In October of 1945, the U.S. Army Technical Service Command asked aeronautic corporations throughout the country to submit proposals for guided missiles. One response came from North American Aviation for a missile called MX-770, which was subsequently renamed Navaho.
Navaho was intended to be an interim strategic weapon, something the U.S. armed forces could use while the country’s first generation of Intercontinental Ballistic Missiles (ICBMs) came of age. The Navaho was designed to launch piggy back style on a booster rocket to an altitude of 50,000 feet. At that point in its flight, some two minutes after launch, the Navaho’s ramjet engines could power up and take over the remainder of the flight; the spent booster would fall away. This launch style made the Navaho more similar to the Nazi V-1 than the V-2, but this American missile would double the distance and payload capacity of its German predecessors.
But testing a missile is delicate business; it needs to be checked out in flight before going into mass production. That’s where the X-10 comes in. It was a proof on concept vehicle built to support the Navaho program. It was a drone with the same shape, aerodynamic qualities, guidance system, and control system that the Navaho missile would have. The only thing missing was the ramjet engines; when the X-10 was built, they were still under development.
The X-10 looked like a missile more than an aircraft. While some drones have a bump on the top where a cockpit would typically sit, the X-10 was sleek and flat all the way to the tail. It was 71 feet long with a 28 foot 2-inch wingspan. The pair of rear wings gave the cylindrical body a slight delta shape while the two movable forward wings added aerodynamic stability in transonic and supersonic flight (that is, flying through the so-called “sounds barrier” and faster than the speed of sound).
And it was fast. Powered by two afterburning XJ-40 turbojet engines that delivered 20,000 pounds of thrust apiece, it maxed out at 1,350 miles per hour at an altitude of 45,000 feet. In flight, it topped out at Mach 2.05. It also had stamina. While so many supersonic test flights of the day lasted just minutes, the X-10 had enough power and carrier enough fuel to stay airborne for over an hour.
The business end of the X-10: it's twin XJ-40 turbojet engines. via
Staying level and on course while traveling more than twice the speed of sound meant the X-10 needed constant input from a driver. While it had the control systems of the Navaho, the drone also required a ground operator for all flight phases – takeoff, landing, and in-flight procedures. It was, after all, a technological demonstration vehicle. It was never designed to fly autonomously from runway to target.
Ten X-10s were built but only three ever flew. In total, the drone made just 27 flights, the last of which was on January 26, 1959. The Air Force briefly considered giving it a second life as a standalone missile, but nothing came from the idea. By the time the program ended, the Navaho program had been cancelled; the more capable Atlas and Titan ICBMs were nearer to being flight ready than this boosted missile. In 1998, the last remaining X-10 was put on display at the National Museum of the United States Air Force in Dayton, Ohio. The gallery was closed due to budget cuts in May—quietly removing the fastest drone in history from public view.