5 December 1963: On Flight 97 of the X-15 Program, Major Robert A. Rushworth flew the number one aircraft, Air Force serial number 56-6670, to an altitude of 101,000 feet 30,785 meters) and reached Mach 6.06 (4,018 miles per hour/6,466 kilometers per hour).
The rocketplane was dropped from the Boeing NB-52B Stratofortress “mother ship” 52-008, Balls 8, flying at 450 knots (833.4 kilometers per hour) at 45,000 feet (13,716 meters) over Delamar Dry Lake, Nevada. Rushworth ignited the Reaction Motors XLR-99-RM-1 rocket engine, which burned for 81.2 seconds before shutting down.
The flight plan had called for an altitude of 104,000 feet (31,699 meters), a 78 second burn and a maximum speed of Mach 5.70. With the difficulties of flying such a powerful rocketplane, Rushworth’s flight was actually fairly close to plan. During the flight the right inner windshield cracked.
Bob Rushworth landed the X-15 on Rogers Dry Lake at Edwards Air Force Base, California, after a flight of 9 minutes, 34.0 seconds.
Mach 6.06 was the highest Mach number reached for an unmodified X-15.
56-6670 flew 81 of the 199 flights of the X-15 Program. It is in the collection of the Smithsonian Institution National Air and Space Museum.
From 1960 and 1966, Bob Rushworth made 34 flights in the three X-15s, more than any other pilot.
Albert Scott Crossfield, Jr., was born at Berkeley, California, 2 October 1921, the second of three children of Albert Scott Crossfield and Lucia Dwyer Scott Crossfield. (“Scott Crossfield” is the family name, going back for many generations.) His father was a chemist who was the superintendent of the Union Oil Refinery in Wilmington, California. At the age of 5 years, the younger Scott Crossfield contracted pneumonia. He was comatose for a time and not expected to survive. When he finally began to recover, he was confined to bed for many months. The effects of this illness lasted throughout his childhood.
It was during this time that he developed his interest in aviation. He learned to draw, studied airplanes, and built scale models. Charles Lienesch, who was a pilot for the Union Oil Company, gave Scotty his first ride aboard an airplane at age 6. As a teenager, he took flight lessons in an Inland Sportster at the Wilmington Airport.
After his family bought a farm in Oregon, Scott Crossfield continued flight lessons and soloed a Curtis Robin at the age of 15. He earned his private pilot certificate at 18. After graduating from high school, he helped his father with the family farm before attending the University of Washington as a student of aeronautical engineering. He took a job at Boeing to pay his tuition and support.
After America’s entry into World War II, Scott Crossfield enlisted in the U.S. Army Air Corps as an aviation cadet, but quickly transferred to the U.S. Navy. He completed military flight training and was commissioned an Ensign, United States Navy, in December 1942.
During World War II, Scott Crossfield served as a fighter pilot, flight and gunnery instructor, flying the Chance Vought F4U Corsair and Grumman F6F Hellcat. Though he was assigned overseas, he did not serve in combat. After the war he joined the Naval Reserve and flew the Goodyear Aircraft Co. FG-1D Corsair at NAS Sand Point, Washington. During this time he resumed his education at the University of Washington and graduated with a bachelor’s degree in aeronautical engineering in 1949 and a master’s degree in 1950. As a graduate student he was the operator of the university’s wind tunnel.
In 1950 Scott Crossfield joined the National Advisory Committee for Aeronautics (NACA, the predecessor of NASA) as an Aeronautical Research Pilot at the NACA High Speed Flight Station, Edwards Air Force Base, California. He flew many high-performance jet aircraft like the North American Aviation F-100 Super Sabre, and experimental airplanes such as the Convair XF-92, Douglas X-3, Bell X-4 and X-5. He also flew the research rocketplanes, making 99 rocket flights in the Bell X-1, Douglas D-558-I Skystreak and D-558-II Skyrocket, more than any other pilot.
On 20 November 1953, Scott Crossfield became the first pilot to fly faster than twice the speed of sound (Mach 2). The D-558-II was carried aloft by a Boeing P2B-1S Superfortress drop ship (a four-engine B-29 heavy bomber which had been transferred from the U.S. Air Force to the Navy, then heavily modified by Douglas) to 32,000 feet (9,754 meters) and then released. Scotty fired the LR8 rocket engine and climbed to 72,000 feet (21,945 meters). He put the Skyrocket into a shallow dive and, still accelerating, passed Mach 2 at 62,000 feet (18,898 meters). After the rocket engine’s fuel was expended, he flew the rocketplane to a glide landing on Rogers Dry Lake.
In 1955 Crossfield left NACA and joined North American Aviation, Inc., as Chief Engineering Test Pilot. He planned and participated in the design and operation of the X-15 hypersonic research rocketplane for the Air Force and NASA. He also worked closely with the David Clark Co., in the development of the projects’ full-pressure suits.
Milton O. Thompson, another X-15 test pilot, wrote in At the Edge of Space, “. . . he was intimately involved in the design of the aircraft and contributed immensely to the success of the design, as a result of his extensive rocket airplane experience. . . Scott was responsible for a number of other excellent operational and safety features built into the aircraft. Thus, one might give Scott credit for much of the success of the flight program.”
In 1959–1960, Scott Crossfield flew all of the contractor’s demonstration phase flights in the X-15, including 16 captive carry flights under the wing of the NB-52A Stratofortress while systems were tested and evaluated, one glide flight, and thirteen powered flights. He reached a maximum speed of Mach 2.97 (1,960 miles per hour/3,154 kilometers per hour) on Flight 26 and a maximum altitude of 88,116 feet (26,858 meters) on Flight 6. The X-15 was then turned over to NASA and the Air Force. The X-15 Program involved a total of 199 flights from 1959 until 1968.
After leaving the X-15 Program, Scott Crossfield continued as a Systems Director with North American Aviation, Inc., working on the Apollo Command and Service Module and the S-IVB second stage of the Saturn V rocket. He left North American in the late ’60s and served as an executive with Eastern Air Lines and Hawker Siddeley. He also continued as a aeronautical engineering consultant to private industry and government.
Among many other awards, Scott Crossfield was received the Harmon International Trophy and the Collier Trophy.
In 1980 Crossfield resumed flying when he purchased a 1960 Cessna 210A Centurion, N6579X, serial number 21057579, a single-engine, four-place light airplane, powered by an air-cooled Continental six-cylinder engine. He had flown more than 2,000 hours in this airplane when it crashed during a severe thunderstorm, 19 April 2006, while on a flight from Prattville, Alabama to Manassas, Virginia.
Albert Scott Crossfield, jr., was killed. He is buried at Arlington National Cemetery.
Highly recommended: Always Another Dawn: The Story Of A Rocket Test Pilot, by Albert Scott Crossfield and Clay Blair, Jr., The World Publishing Company, Cleveland and New York, 1960.
17 September 1959: After previously making one glide flight, North American Aviation Chief Engineering Test Pilot Albert Scott Crossfield made the first powered flight of an X-15 hypersonic research rocket plane.
Carried aloft under the right wing of an eight-engine Boeing NB-52A Stratofortress bomber, USAF serial number 52-003, the first of three North American Aviation X-15s, 56-6670, was airdropped from 35,000 feet (10,668 meters) over Rosamond Dry Lake, 40 miles (64 kilometers) north of Edwards Air Force Base. Launch time was 08:08:48.0 a.m., Pacific Daylight Savings Time (15:08.48.0 UTC).
The X-15 was designed to use the Reaction Motors XLR-99 rocket engine, but early in the test program that engine was not yet available so two smaller XLR-11 engines were used. This was engine the same type used in the earlier Bell X-1 rocket plane that first broke the sound barrier in 1948. Though producing just one-fourth the thrust of the XLR-99, it allowed the functional testing of the X-15 to proceed.
Scott Crossfield wrote:
Two minutes after launch I reached 50,000 feet and pushed over in level flight. Then I dropped the nose slightly for a speed run, meanwhile maneuvering the ship through a series of turns and rolls, conscious of a deep rumbling noise of the rocket and a great rush of wind on the fuselage. It was obvious the black bird was in her element at supersonic speeds. She responded beautifully. I stared in fascination at the Mach meter which climbed from 1.5 Mach to 1.8 Mach and then effortlessly to my top speed for this flight of 2.3 Mach or about 1,500 miles and hour. Then, because I was under orders not to take the X-15 wide open, I shut off three of the rocket barrels. As I slowed down, I recalled the agony at Edwards many years before when we had worked for months pushing, calculating, polishing and who knows what else to achieve Mach 2 in the Skyrocket. Now with the X-15 we had reached that speed in three minutes on our first powered flight and I had to throttle back.
—Always Another Dawn, The Story Of A Rocket Test Pilot, by A. Scott Crossfield with Clay Blair, Jr., The World Publishing Company, Cleveland and New York, 1960. Chapter 39 at Pages 362.
The X-15 dropped 2,000 feet (610 meters) while Scott Crossfield ignited the two XLR-11 engines and then started “going uphill.” During the 224.3 seconds burn duration, the X-15 reached Mach 2.11 (1,393 miles per hour, 2,242 kilometers per hour) and climbed to 52,300 feet (15,941 meters), both slightly higher than planned.
Problems developed when the rocket engine’s turbo pump case failed, and fire broke out in the hydrogen peroxide compartment, engine compartment and in the ventral fin. Crossfield safely landed on Rogers Dry Lake at Edwards Air Force Base. The duration of the flight was 9 minutes, 11.1 seconds. Damage to the rocket plane was extensive but was quickly repaired. 56-6670 flew again 17 October 1959.
Over the next nine years the three X-15s would make 199 flights, setting speed and altitude records nearly every time they flew, and expanding NASA’s understanding of flight in the hypersonic range. The first two X-15s, 56-6670 and 56-6671, survived the program. 670 is at the Smithsonian Institution National Air and Space museum and 671 is at the National Museum of the United States Air Force.
12 August 1960: At Edwards Air Force Base, California, Major Robert M. White flew the North American Aviation X-15 rocketplane to an altitude of 136,500 feet (41,605 meters), exceeding the previous unofficial record of 126,200 feet (38,466 meters) set by the late Captain Iven C. Kincheloe, Jr., with the Bell X-2, 7 September 1956.
Iven Kincheloe had been assigned as the Air Force’s project pilot for the X-15. When he was killed on a routine flight, Bob White was designated to replace him.
This was White’s fourth flight in an X-15, and the 19th flight of the X-15 Program. The Number 1 rocketplane, serial number 56-6670, was carried aloft under the right wing of the “mothership,” Boeing NB-52A Stratofortress 52-003. At 08:48:43.0 a.m., PDT, 56-6670 was dropped over Silver Lake, near the Nevada-California border. White fired the two Reaction Motors XLR11-RM-13 rocket engines and they burned for 256.2 seconds.
This flight took place in Phase II of the Program and was intended to gradually increase the envelope of X-15 performance with the XLR11 engines while waiting for the much more powerful XLR99. The purpose of Flight 19 was to reach maximum altitude in order to test the rocketplane’s stability and controllability above the atmosphere.
The X-15 accelerated to Mach 2.52, 1,773 miles per hour (2,853 kilometers per hour) while climbing at nearly a 70° angle and reached a peak altitude of 136,500 feet (41,605 meters). After engine shutdown, White glided to a landing on Rogers Dry Lake and touched down. The duration of the flight was 11 minutes, 39.1 seconds.
Neither Kincheloe’s or White’s altitudes are recognized as records by the Fédération Aéronautique Internationale(FAI). Over the next few years, the X-15 would reach to nearly three times higher.