Aviation Naval Warfare Land Systems Small Arms By Flag By Year By Tag

North American X-15

1959 COLD WAR X-PLANE

History

The North American X-15 was the pinnacle of rocket-powered research aircraft that defined the 1940s and 1950s, starting with the famous Bell X-1. Each of these important "X-Plane" aircraft received specific program objectives and were further developed with time permitting technology.

Early flights processed data from over Mach 1.0 to Mach 3.0, evolving from the straight-wing X-1 to the swept Bell X-2. To advance the envelope, ideas turned to the use of advanced, highly specialized rocket planes to collect data to penetrate the hypersonic flight envelope (speeds in excess of Mach 5.0) to transcend Earth's atmosphere for future space efforts.

The X-15 was built by North American Aerospace (best known for its World War II-winning P-51 Mustang fighter jet) as a research platform in support of NASA, the United States Air Force (USAF) and the United States serving the National Navy (United States). Specifications for the rocket plane were developed by NASA (then known as NACA - National Advisory Committee for Aeronautics) as early as 1952, and the information was passed on to USAF/USN in July 1954.

In September 1955, the North American company was selected to build three prototypes of the "X-15".

The final design became an elongated aircraft with a pointed cone, a forward-set single-seat cockpit and a tubular fuselage. A short swept (25 degree) center wing main wing was added on either side amidships, the empennage included vertical dorsal and pelvic fins, and a pair of side-mounted swept horizontals. The rocket engine of choice was a Reaction Motors XLR-99 with a thrust of 28,000 lbs - 57,000 lbs (throttled). However, delays on this rocket resulted in the 2 x XLR-11 rocket engines taking their place during the transition and dominating the early flight. Due to the high temperatures generated during high-speed, high-altitude flight, the X-15's fuselage structure consists of a nickel-chromium alloy shell called "Inconel X." Despite its advanced flight scheme, the X-15 still relies on traditional control systems to handle denser air environments.

Upon reaching the thinner air atmosphere, the "reaction control system" came into play, using hydrogen peroxide rocket motors located on the nose and wings. The structural dimensions of the aircraft include a length of 50 feet and a wingspan of 22 feet.

The X-15's rocket motor only served the aircraft during its active flight test phase - so it was air-launched from a mothership like the X-1 before it. While it doesn't take off on its own power like a conventional plane, it is able to glide during the descent and land as usual using special landing gear.

The landing gear consisted of a non-steerable front leg with wheels and a main body of steel skid plates. For this reason, a dry lake bed was chosen as the landing/recovery area (Rogers Dry Lake near Edwards AFB). The mothership selected for the program became an improved Boeing B-52 Stratofortress jet bombera continuation of the Boeing mothership tradition that began with the WWII-era Boeing B-29 Superfortress propeller bomber and continues through Continued to the Boeing B-50.

There are two typical flight plans for the X-15 programthe first is a flat-air speed test after takeoff, and the second is a high-altitude, steep rate-of-climb maneuver before level flight and descent. Due to the high fuel consumption of the rocket, the rocket plane has a little over two minutes of powered flight available. The B-52 will release its X-15 payload at about 45,000 feet, and the X-15's missiles will then target it.

After all fuel supplies were burned, the unpowered flight lasted between 8 and 12 minutes before it needed to descend.

The first X-15 aircraft was delivered to NASA in early 1959 and made its first unpowered glide flight on June 8, 1959, with pilot Scott Crossfield in control. Aircraft No.

2, the X-15A-2, arrived in February 1964 with some changes from the first model. ) fuselage, improved cockpit canopy, extended nose landing gear and onboard photo storage. It was this aircraft that achieved Mach 6.7 during a test flight on October 3, 1967.

While the X-15 family proved to be very successful during its testing career, it was a product and program that was always fraught with danger - accidents and forced landings were not uncommon during its flight. Test pilot Jack McKay and his plane were turned over when the nasal bone collapsed on landing.

His injury was enough to end his flying career on the X-15. Test pilot Michael Adams was killed during a flight on November 15, 1967, when his X-15A-4 (No. 3) crashed - the plane fell into a recoverable spin, but Adams was unable to pull it out of the steep dive happened.

The X-15 ended its career in December 1968 when it was about to be officially retired, ending nearly a decade of critical work in the U.S. aerospace and military industries. The data collected by the X-15 has proven invaluable in advancing the U.S. space race (rocket programs like Mercury, Gemini, and Apollo). Its effective flight time includes 199 flights under the guidance of a total of 12 test pilots.

During the flight, the X-15 is credited with setting a new altitude (354,200 feet in 1963) and speed (4,520 mph/Mach 6.7 in 1967), thus cementing its name in aviation history books with its The iconic shape has been imprinted in the minds of observers and aviation enthusiasts alike.