X-15 Walkaround
A short guide to the fastest airplane ever.
- By Linda Shiner
- Air & Space magazine, November 2007
The X-15 that hangs in the Smithsonian Institution's National Air Space Museum is the first of three built by North American Aviation. It was rolled out on October 15, 1958, 15 days after its original sponsor, the National Advisory Committee for Aeronautics, became NASA. Half of its 51-foot fuselage is devoted to propellant tanks for its rocket motor. X-15 number 56-6670 flew 81 missions, including the last eight of the program. It reached a speed of 4,104 mph (Mach 6.06), and an altitude of 266,500 feet. Eric Long/NASM
Still the fastest airplane ever flown, the North American X-15 earned its title 40 years ago, when on October 3, 1967 Air Force Major William “Pete” Knight flew the rocket-powered aircraft to 4,520 mph, Mach 6.72. It was built to find out how aircraft structures, materials, and control surfaces would perform at hypersonic speeds and very high altitudes. In 199 research flights, the X-15 provided that information and more. The program has been acknowledged as the most successful flight research program in history, and it helped make human spaceflight possible.
X-15 flights were short; each lasted about ten minutes. So that the rocketplane could use all its fuel for acceleration, it was carried beneath the wing of a NASA B-52 to 45,000 feet, where it was dropped. NASA test pilot Milt Thompson remembered the experience in his book At the Edge of Space: “[The launch] was a surprise no matter how many times I went through it. It felt as if the X-15 exploded off the hooks.…
“The pilot did not have much time to waste after launch. He either had to get the engine lit or abort the flight and make a landing at the launch lake. The problem was that he was losing altitude rapidly (about 12,000 feet per minute) while waiting for the engine to light.”
Joe Walker reached 354,200 feet, an altitude not exceeded until 2004, when Brian Binnie reached 367,442 feet in SpaceShipOne. The pilots would aim for an altitude but were rarely able to predict exactly how high they would end up. The X-15 climbed at 4,000 feet per second, so if the pilot was even one second late (or early) in shutting down the engine, he would miss the mark by 4,000 feet.
The powered portion of an X-15 flight lasted approximately 85 seconds. Each mission ended in an unpowered landing after a steep descent. The pilots flew a low-lift glide that helped develop the energy management techniques space shuttle pilots would use many years later. Only one X-15 pilot did not make it back for a landing. Air Force Major Michael Adams was killed in 1967 when the aircraft broke apart in a hypersonic spin shortly after reentry. The program ended the following year.
Click on the images to explore some of the X-15’s finer points.
Related topics: X-15 Cold War Era
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Comments (5)
does anyone know what thrusters are on the x-15???????
Posted by ssss on August 12,2008 | 12:19 AM
Thrusters were used to control the X-15's attitude (e.g., roll, pitch, yaw) at altitudes where conventional flight surfaces (e.g., elevators, ailerons, rudder, etc.) were ineffective due to low air density.
Wikipedia offers a nice overview of Reaction Control Systems, of which the thrusters are a critical part, and thrusters themselves:
http://en.wikipedia.org/wiki/Reaction_control_system
http://en.wikipedia.org/wiki/Thrusters
Posted by Scott Brierley on February 12,2009 | 12:10 AM
Great web site! My father worked for Reaction Motors in Denville New Jersey. We went to Edwards AFB in 1959-1963 on the project. He serviced and maintained the Xlr-11 and Xlr-99 engine. When we look back those were important days in space exploration.
Posted by David Faust on February 26,2009 | 12:23 AM
Hi Folks...being a nostalgic time for me, with the 40th anniversary of the Apollo 11 moonlanding, I find myself online looking at history that I was priveleged to be a small part of. As an enlisted man, in Dec 1961, I was assigned to Edwards AFB to the Physiological Training unit (high altitude pressure chamber technician). One of our main focuses was on maintaining, updating & modifying the X-15 high altitude pressure suits that all pilots had to wear. I had the privelege of suiting up all the x-15 pilots from Dec 1961 through August 1965. We also maintained the SR-71 program & ARPS suits. As an enlisted man, I got to fly almost 300 hours in mostly F-104,s f-106 & T-38,s as a passenger.( I was considered to be what was thought as the average size of what a future Astronaut would be), so I had a fabulous 4 years at Edwards.
I went on to be a part of the engineering team that designed & built all the Apollo Spacesuits at ILC Industries, Dover, Del ( from 1965 through 1973 )
Anyway, I don't talk much about my early years,( I was 19 when I flew with Armstrong, when he was chasing an X-15 flight, as the back seat was open & I was fortunate enough to be available for my 1st Jet flight )but this is the 40th anniversary & I'm feeling quite nostalgic...
Thank you for this website
Posted by Ray Winward on July 19,2009 | 09:31 PM
Hi all,
I have been wondering how the X-15 managed to maintain longitudinal stability during both hypersonic and subsonic flight? The X-15's center of lift must have moved back significantly at those high Mach numbers, not to mention back forward again during approach and landing. I would really appreciate some information on this.
Thanks,
mike
Posted by Michael Ammon on March 10,2010 | 07:26 AM