5 November 1959: During his fourth X-15 flight—the third in the Number Two ship, 56-6671—North American Aviation chief test pilot Albert Scott Crossfield made an emergency landing at Rosamond Dry Lake after one of the two Reaction Motors XLR11-RM-13 rocket engines exploded, causing an engine compartment fire.
The X-15 had been launched by the Boeing NB-52A Stratofortress, 52-003, at 0.82 Mach and approximately 45,000 feet (13,716 meters) over Bouquet Canyon Reservoir, about 35 miles (56 kilometers) southwest of Edwards Air Force Base. Scott Crossfield ignited both XLR11 rocket engines and began to accelerate and climb, but one of four combustion chambers of the lower engine exploded almost immediately. He shut both engines down after 11.7 seconds. Crossfield kept the rocketplane in a level attitude for the 114 seconds it took to jettison the liquid oxygen and water-alcohol propellants to lighten the X-15 for the landing. The tanks could not fully drain and the aircraft remained approximately 1,000 pounds (455 kilograms) overweight.
The X-15 approached the emergency landing site at Rosamond Dry Lake, about ten miles (16 kilometers) southwest of Edwards, while Major Robert M. White, flying a Lockheed F-104 chase plane, called out Crossfield’s distance from the dry lake and his altitude. As he neared the touch down point, Crossfield raised the X-15’s nose to decelerate.
“I lowered the skids and nose wheel, pulled the flaps, and felt for the lake bed.
“The skids dug in gently. The nose wheel slammed down hard and the ship plowed across the desert floor, slowing much faster than usual. Then she came to a complete stop within 1500 feet instead of the usual 5000 feet. Something was wrong; the skids failed, I was sure. . . Quickly I scrambled out of the cockpit. What I saw almost broke my heart. The fuselage had buckled immediately aft of the cockpit, two hundred and thirty inches back from the nose. Her belly had dragged in the sand, causing the abrupt deceleration on the lake. The rocket chambers which had exploded at launch were a shambles.”
—Always Another Dawn: The Story of a Rocket Test Pilot, by A. Scott Crossfield and Clay Blair, Jr., The World Publishing Company, Cleveland and New York, 1960, Chapter 41 at Pages 383–384.
It was determined that the engine had exploded due to an ignition failure, a relatively simple problem not connected to the design of the X-15. But there remained the question as to why the rocketplane had broken in half. The investigation found that the rapid extension of the nose wheel strut when lowered caused the oil inside the strut to foam and vaporize, providing almost no shock absorption. This was corrected and the check list changed to lower the gear sooner.
The total duration of this flight was 5 minutes, 28.0 seconds. The peak altitude was 45,462 feet (13,857 meters) and the maximum speed was 660 miles per hour (1,062 kilometers per hour).
56-6671 was taken back to the North American Aviation plant for repair. It returned to flight operations three months later.
12 October 1954: North American Aviation Chief Engineering Test Pilot George S. Welch, testing the ninth production F-100A-1-NA Super Sabre, serial number 52-5764, made a planned 7.3 G pullout from a Mach 1.55 dive to verify the aircraft’s design limits.
A Boeing B-47 Stratojet crew flying at 25,000 feet (7,620 meters) reported that Welch’s F-100 winged over and began a rapid descent, passing within four miles (6.4 kilometers) of their position and diving at a very high speed. The aircraft appeared to be under control but then suddenly disintegrated.
The Super Sabre had encountered Inertial Roll Coupling. It went out of control and then disintegrated. Its nose folded over the windshield, crushing Welch in his seat. The vertical fin broke away. The ejection seat fired but because of the supersonic speeds the parachute was shredded.
Welch was still alive when rescue teams arrived. He died while being flown to a hospital by helicopter.
Inertial roll coupling led to the death of test pilot Mel Apt when his rocket-powered airplane, the Bell X-2, went out of control at Mach 3.2 It nearly killed Chuck Yeager when he lost control of the Bell X-1B at Mach 2.4. It is a complex phenomenon which I will briefly attempt to explain:
To increase maximum speed of transonic and supersonic airplanes during the late 1940s and early 1950s, their wings and tail surfaces were made smaller in order to decrease aerodynamic drag. At the same time, the fuselage became longer and the placement of engines, armament, landing gear, fuel, etc., within the fuselage concentrated the airplane’s mass near its center. While the gyroscopic effects of the turbojet engine contributed some degree of longitudinal stability, the torque effect made rolls to the left occur more easily, but with a higher rate than a roll to the right. The resistance to a change in attitude—inertia—decreased at the same time that the control surfaces’ ability to control the airplanes’ attitude also decreased. The airplanes became unstable.
When George Welch tried to pull the F-100 out of its supersonic dive, the airplane’s speed began to decrease as the angle of attack increased. The wings’ ability to stabilize the natural roll instability of the fuselage’s concentrated mass was lessened, and the ailerons could not provide sufficient control to counteract this rolling tendency. The low vertical fin of the original F-100A did not provide adequate directional stability. The Super Sabre rolled and then yawed, entering a side slip. This caused the Super Sabre to pitch down and it was suddenly out of control in all three axes. The physical forces exceeded the strength of the aircraft structure and it came apart.¹
[Aerodynamicists and Aeronautical Engineers: Your corrective comments are welcome.]
Following the death of George Welch, NACA High Speed Flight Station research test pilot Albert Scott Crossfield spent three months conducting flight tests of the F-100A, demonstrating its inertial roll coupling characteristics using three different vertical fins. F-100A-5-NA 52-5778 was Crossfield’s test aircraft.
The North American Aviation F-100 Super Sabre was designed as a supersonic day fighter. Initially intended as an improved F-86D and F-86E, it soon developed into an almost completely new airplane. The fuselage incorporated the “area rule,” a narrowing in the fuselage width at the wings to increase transonic performance, similar to the Convair F-102A. The Super Sabre had a 49° 2′ sweep to the leading edges of the wings and horizontal stabilizer. The ailerons were placed inboard on the wings and there were no flaps, resulting in a high stall speed in landing configuration. The horizontal stabilizer was moved to the bottom of the fuselage to keep it out of the turbulence created by the wings at high angles of attack. The F-100A had a distinctively shorter vertical fin than the YF-100A. The upper segment of the vertical fin was swept 49° 43′.
There were two service test prototypes, designated YF-100A, followed by the production F-100A series. The first ten production aircraft (all of the Block 1 variants) were used in the flight testing program.
The F-100A Super Sabre was 47 feet, 1¼ inches (14.357 meters) long with a wingspan of 36 feet, 6 inches (11.125 meters). With the shorter vertical fin, the initial F-100As had an overall height of 13 feet, 4 inches (4.064 meters), 11 inches (27.9 centimeters) less than the YF-100A.
The F-100A had an empty weight of 18,135 pounds (8,226 kilograms), and gross weight of 28,899 pounds (13,108 kilograms). Maximum takeoff weight was 35,600 pounds (16,148 kilograms). It had an internal fuel capacity of 755 gallons (2,858 liters) and could carry two 275 gallon (1,041 liter) external fuel tanks.
The early F-100As were powered by a Pratt & Whitney Turbo Wasp J57-P-7 afterburning turbojet engine. It was rated at 9,700 pounds of thrust (43.148 kilonewtons) for takeoff, and 14,800 pounds (65.834 kilonewtons) with afterburner. Later production aircraft used a J57-P-39 engine. The J57 was a two-spool axial flow turbojet which had a 16-stage compressor, and a 3-stage turbine. (Both had high- and low-pressure stages.) The engine was 15 feet, 3.5 inches (4.661 meters) long, 3 feet, 5.0 inches (1.041 meters) in diameter, and weighed 4,390 pounds (1,991 kilograms).
The Super Sabre was the first U.S. Air Force fighter capable of supersonic speed in level flight. It could reach 760 miles per hour (1,223 kilometers) at Sea Level. (Mach 1 is 761.1 miles per hour, 1,224.9 kilometers per hour, under standard atmospheric conditions.) Its maximum speed was 852 miles per hour (1,371 kilometers per hour) at 35,000 feet (10,668 meters). The service ceiling was 44,900 feet (13,686 meters). Maximum range with external fuel was 1,489 miles (2,396 kilometers).
The F-100 was armed with four M-39 20 mm autocannons, capable of firing at a rate of 1,500 rounds per minute. The ammunition capacity of the F-100 was 200 rounds per gun.
North American Aviation built 199 F-100A Super Sabres at its Inglewood, California, plant before production shifted to the F-100C fighter bomber variant. Approximately 25% of all F-100As were lost in accidents.
George Welch was born George Lewis Schwartz, Jr., in Wilmington, Delaware, 10 May 1918. He was the first of two sons of George Lewis Schwartz, a chemist at the Dupont Experimental Station in Wilmington, and Julia Welch Schwartz. His parents changed his surname to Welch, his mother’s maiden name, so that he would not be effected by the anti-German prejudice that was widespread in America following World War I.
He studied mechanical engineering at Purdue University, Indiana, and enlisted in the Army Air Corps in 1939. Welch graduated from pilot training at Kelly Field, Texas, and on 4 October 1940, was commissioned as a second lieutenant, U.S. Army Air Corps.
George S. Welch is best remembered as one of the heroes of Pearl Harbor. He, along with Second Lieutenant Kenneth M. Taylor, were the only two fighter pilots to get airborne from Haleiwa Auxiliary Airfield during the Japanese surprise attack on Hawaii, 7 December 1941. Flying a Curtiss P-40B Warhawk, he shot down three Aichi D3A “Val” dive bombers and one Mitsubishi A6M2 Zero fighter. Taylor also shot down four Japanese airplanes. For this action, Lieutenant General Henry H. “Hap” Arnold recommended the Medal of Honor, but because Lieutenants Welch and Taylor had taken off without orders, an officer in their chain of command refused to endorse the nomination. Both fighter pilots were awarded the Distinguished Service Cross.
During the War, Welch flew the Bell P-39 Airacobra and Lockheed P-38 Lightning on 348 combat missions. He had 16 confirmed aerial victories over Japanese airplanes and rose to the rank of Major. In addition to the Distinguished Service Cross, George Welch was awarded the Silver Star, the Distinguished Flying Cross with two oak leaf clusters (three awards), the Air Medal with one oak leaf cluster (two awards), the Presidential Unit Citation with two oak leaf clusters (three awards), American Defense Service medal with one service star, American Campaign Medal, Asiatic-Pacific Campaign Medal with one silver and one bronze star (six campaigns), and the World War II Victory Medal.
Welch received the nickname, “Wheaties,” because he was the first military officer to be featured on a box of Wheaties cereal. (Wheaties, “The Breakfast of Champions,” was a toasted wheat bran cereal produced by General Mills. It normally featured champion athletes on its distinctive orange-colored boxes.)
Suffering from malaria, George Welch was out of combat and recuperating in Australia. There he met Miss Janette Alice Williams and they were soon married. Welch returned to the United States with his new wife. They had a son, Giles, born in October 1947. Their home was in Brentwood, California.
North American Aviation approached General Arnold to recommend a fighter pilot who could bring his combat experience to testing new fighters. Welch was one of two that General Arnold suggested. The general authorized Welch’s release from active duty so that he could join North American. Welch held the rank of major, Air Reserve, from 13 November 1944 to 1 April 1953.
Welch went on to test fly the North American P-51H Mustang, FJ-1 Fury, F-86 Sabre and F-100 Super Sabre.
George Welch made the first flight of the XP-86 prototype, 1 October 1947. There is some evidence that on that flight, and during a subsequent flight on 14 October, Welch exceeded the speed of sound while in a dive. It has been said that during the Korean War, while teaching U.S. Air Force pilots how to best use the F-86 Sabre, he shot down several enemy MiG-15 jet fighters.
George S. Welch is buried at the Arlington National Cemetery, Section 6, Site 8578-D.
¹ Recommended: Coupling Dynamics in Aircraft: A Historical Perspective, by Richard E. Day, Dryden Flight Research Center, Edwards AFB, California. NASA Special Publications 532, 1997.
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.
8 September 1954: Scott Crossfield, a NACA Aeronautical Research Pilot at the High Speed Flight Station, Edwards Air Force Base, California, took the North American Aviation F-100A-5-NA Super Sabre, 52-5778, on its first NACA test flight—and his first flight in an F-100.
Tests of the prototype and early production Super Sabres revealed directional stability problems, a very dangerous inertia coupling characteristic that could cause the aircraft to go violently out of control (and which would result in the death of North American’s chief test pilot, George Welch, in just another three weeks). The highly swept wings could stall at high angles of attack, causing the airplane to pitch up in the deadly “Sabre dance”. NACA wanted to explore the causes of these aerodynamic problems and design solutions.
During the flight there was an engine fire warning and Crossfield shut down the Pratt & Whitney J57-P-7 turbojet engine. The F-100A had no flaps and North American’s own test pilots did not think a “dead stick” landing was possible due the very high landing speed required.
Scott Crossfield tells the story in his autobiography:
. . . As a matter of fact, North American tests pilots were then flipping coins to see who would bring an F-100 in dead-stick to fulfill a requirement of the Air Force acceptance tests. I was not concerned. Dead-stick landings in low L-over-D[Lift-over-Drag]airplanes were my specialty. Every test pilot develops a strong point. I was certain that my talent lay in dead-stick landings.
With the engine idling and generating no energy to the plane’s systems, I was running out of hydraulic pressure to operate the controls. Following the handbook instructions, I pulled a lever which extended a miniature “windmill” into the slipstream. This “windmill” churned, building up pressure in the hydraulic lines. Unknown to me, there was a major leak in the line. The windmill was not helping, but hurting me. It was pumping hydraulic fluid overboard as fast as it could turn.
I called Edwards tower and declared an emergency. All airborne planes in the vicinity of the base were warned away from the lake area. I held the ailing F-100 on course, dropping swiftly, following the glide path that I used for the dead-stick Skyrocket.[Douglas D-558-II Skyrocket] I flared out and touched down smoothly. It was one of the best landings I have ever made, in fact. Seconds later, while the F-100 was rolling out, the remaining bit of hydraulic pressure in the control lines drained out and the controls froze.
I then proceeded to violate a cardinal rule of aviation: never try tricks with a compromised airplane. The F-100 was still rolling at a fast clip, coming up fast on the NACA ramp, when I made my poor decision. I had already achieved the exceptional, now I would end it with a flourish, a spectacular wind-up. I would snake the stricken F-100 right up the ramp and bring it to a stop immediately in front of the NACA hangar. This trick, which I had performed so often in the Skyrocket, was a fine touch. After the first successful dead-stick landing in an F-100, it would be fitting.
According to the F-100 handbook, the hydraulic brake system—a separate hydraulic system from the controls—was good for three “cycles,” engine out. This means three pumps on the brake, and that proved exactly right. The F-100 was moving at about fifteen miles an hour when I turned up the ramp. I hit the brakes once, twice, three times. The plane slowed, but not quite enough. I was still inching ahead ponderously, like a diesel locomotive. I hit the brakes a fourth time—and my foot went clear to the floorboards. The hydraulic fluid was exhausted. The F-100 rolled on, straight between the yawning hangar doors!
The good Lord was watching over me—partially anyhow. The NACA hangar was then crowded with expensive research tools—the Skyrocket, all the X-1 series, the X-3, X-4 and X-5. Yet somehow, my plane, refusing to halt, squeezed by them all and bored steadily on toward the side wall of the hangar.
The nose of the F-100 crunched through the corrugated aluminum, punching out an eight-inch steel I-beam. I was lucky. Had the nose bopped three feet to the left or right, the results could have been catastrophic. Hitting to the right, I would have set off the hangar fire-deluge system, flooding the hangar with 50,000 barrels of water and ruining all the expensive airplanes. Hitting to the left, I would have dislodged a 25-ton hangar-door counterweight, bringing it down on the F-100 cockpit, and doubtless ruining Crossfield.
Chuck Yeager never let me forget the incident. He drew many laughs at congregations of pilots by opening his talk: “Well, the sonic wall was mine. The hangar wall was Crossfield’s.” That’s the way it was at Edwards. Hero one minute, bum the next. That I was the first pilot to land an F-100 dead-stick successfully, and memorized elaborate and complete instrument data on the engine failure besides, was soon forgotten.
The F-100 is a tough bird. Within a month NACA’s plane was flying again, with Crossfield back at the helm. In the next few weeks I flew forty-five grueling flights in the airplane, pushing it to the limits, precisely defining the roll coupling. (On one flight the coupling was so severe that it cracked a vertebra in my neck.) These data confirmed, in actual flight, the need for a new F-100 tail, which North American was planning to install on later models of the airplane.
Every night after landing, I taxied the F-100 slowly to the NACA ramp. At the bottom, placed there on orders of Walt Williams, there was a large new sign, symbolic of the new atmosphere at Edwards. It said:
PLEASE COME TO A COMPLETE STOP BEFORE TAXIING UP RAMP
—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 20 at Pages 196–199.