22 October 1938: Lieutenant Colonel Mario Pezzi, Regia Aeronautica, set a Fédération Aéronautique Internationale (FAI) World Record for altitude when he flew an experimental Società Italiana Caproni Ca.161bis to an altitude of 17,083 meters (56,047 feet).¹
Pezzi was awarded the Medaglia d’oro al Valore Aeronautico and promoted to the rank of colonel.
The Caproni Ca.161bis was an experimental single-seat, single engine, two-bay biplane developed from the earlier Ca.113. It was 27 feet, ¾ inch (8.249 meters) long with a wingspan of 46 feet, 9 inches (14.249 meters) and height of 11 feet, 5¾ inches (3.500 meters). The airplane’s empty weight was 1,205 kilograms (2,657 pounds) and gross weight was 1,650 kilograms (3,638 pounds).
The Ca.161bis was powered by an air-cooled, supercharged, 38.673 liter (2,359.97 cubic inch) Piaggio P.XI R.C.100/2v two-row 14-cylinder radial engine which produced 700 horsepower and drove a four-bladed propeller through a 0.62:1 reduction gear. This engine was a license-built version of the French Gnome-Rhône 14K Mistral Major.
21 August 1953: Major Marion E. Carl, United States Marine Corps, flew the number three Douglas D-558-II Skyrocket, Bu. No. 37974, to an unofficial world altitude record of 83,235 feet (25,370 meters).
The supersonic research rocketplane had been dropped from a Boeing P2B-1S Superfortress at 30,000 feet (9,144 meters) over Edwards Air Force Base. During this flight the Skyrocket reached Mach 1.728.
The Associated Press wire service reported the event:
Altitude Record Set By Hubbard Pilot
WASHINGTON (AP) —The Navy said Monday Lt. Col. Marion E. Carl, a Marine Corps pilot set a new altitude record of 83,235 feet in the Douglas Skyrocket research plane on Aug. 21.
The Navy said the unofficial world mark was established during a test of a newly developed high-altitude flying suit. ¹
The previous altitude record was 79,494 feet, set in the same airplane by Douglas test pilot Bill Bridgeman on Aug. 7, 1951.
A Navy spokesman said Carl is at Edwards Air Force Base, Calif. for an attempt Monday or Tuesday on the speed mark of 1,238 miles an hour set by Bridgeman in the Navy D-558-2 Skyrocket Aug. 1, 1951.
As in Bridgeman’s altitude and speed record flight, Carl’s runs are being made through aerial launching. The Skyrocket is carried to an altitude of 30,000 feet or better by a B29 “mother plane,” and then released.
National Aeronautic Assn. rules require that altitude record attempts be launched from the ground and that speed runs be made at specified altitudes.
For these reasons, none of the Skyrocket records is, or likely to become, official. Some flying authorities have urged that official rules be rewritten to conform to modern developments in flying technique.
Carl is from Hubbard, Ore. and is stationed at the Quantico, Va., Marine Corps Air Station. He has been assigned as assistant Marine Corps project officer for the national aircraft show at Dayton next week.
Five Years ago Carl set a world speed mark of 650.8 miles an hour in the Skyrocket’s Navy predecessor, the D-558-1 Skystreak.
—Eugene Register-Guard, Vol. XXCVII, No. 243, 31 August 1951, at Page 1A, Columns 6 and 7
20 November 1953: At Edwards Air Force Base, California, NACA’s High Speed Flight Station test pilot Albert Scott Walker rode behind the flight crew of the Boeing P2B-1S Superfortress as it carried the Douglas Aircraft Company D-558-II Skyrocket supersonic research rocketplane to its launch altitude. As the four-engine bomber climbed through 18,000 feet (5,486 meters), Crossfield headed back to the bomb bay to enter the Skyrocket’s cockpit and prepare for his flight.
The Douglas D-558-II was Phase II of a U.S. Navy/Douglas Aircraft Company/National Advisory Committee on Aeronautics joint research project exploring supersonic flight. It was a swept-wing airplane powered by a single Reaction Motors LR8-RM-6 four-chamber rocket engine. The Skyrocket was fueled with alcohol and liquid oxygen. The engine was rated at 6,000 pounds of thrust (26.69 kilonewtons) at Sea Level.
There were three Phase II aircraft. Originally, they were also equipped with a Westinghouse J34-W-40 turbojet engine which produced 3,000 pounds of thrust (13.35 kilonewtons) and the Skyrockets took off from the surface of Rogers Dry Lake. Once the D-558-II reached altitude, the rocket engine was fired for the speed runs. As higher speeds were required, the program shifted to an air launch from a B-29 (P2B-1S) “mothership”. Without the need to climb to the test altitude, the Skyrocket’s fuel load was available for the high speed runs.
The D-558-II was 42.0 feet (12.80 meters) long, with a wingspan of 25.0 feet (7.62 meters). The leading edge of the wing was swept at a 35° angle and the tail surfaces were swept to 40°. The aircraft weighed 9,421 pounds (4,273 kilograms) empty and had a maximum takeoff weight of 15,787 pounds (7,161 kilograms). It carried 378 gallons (1,431 liters) of water/ethyl alcohol and 345 gallons (1,306 liters) of liquid oxygen.
The mothership, NACA 137, was a Boeing Wichita B-29-95-BW Superfortress, U.S. Air Force serial number 45-21787. It was transferred to the U.S. Navy, redesignated P2B-1S and assigned Bureau of Aeronautics number 84029. Douglas Aircraft modified the bomber for its drop ship role at the El Segundo plant.
Between 4 February 1948 and 28 August 1956, the three rocketplanes made a total of 313 flights.
Marion Eugene Carlwas born at Hubbard, Oregon, 1 November 1915. He was the second of four children of Herman Lee Carl, a dairy farmer, and Ellen Lavine Ellingsen Carl.
Carl graduated from Oregon State College at Corvallis, Oregon, and was commissioned as a second lieutenant in the United States Army Reserve, 31 May 1938. Lieutenant Carl soon resigned this commission to accept an appointment as an Aviation Cadet, United States Navy. He enlisted as a private, first class, Volunteer Marine Corps Reserve, 17 July 1938, and was designated a student Enlisted Naval Aviation Pilot assigned to the Naval Reserve Aviation Base, Squantum, Massachusetts. He entered flight school as an Aviation Cadet at Naval Air Station Pensacola near Pensacola, Florida, 26 July 1938.
After completing flight training, Carl was commissioned as a Second Lieutenant, United States Marine Corps Reserve, 20 October 1939. He was then assigned to Marine Fighting Squadron One (VMF-1) at Brown Field, Quantico, Virginia.
In 1940, Lieutenant Carl returned to NAS Pensacola as a flight instructor. On 25 February 1941, Second Lieutenant Carl, U.S.M.C.R., was appointed a Second Lieutenant, United States Marine Corps.
Lieutenant Carl was transferred to VMF-221 at San Diego, California, as a fighter pilot. The unit was assigned to the aircraft carrier USS Saratoga (CV-3) for transportation to MCAS Ewa, Oahu, Territory of Hawaii. On 25 December 1941, VMF-221 was deployed to Midway Atoll.
Marion Carl and his squadron fought during the Battle of Midway. Flying a Grumman F4F-3 Wildcat, Bu. No. 1864,² on 4 June 1942, he shot down his first enemy airplane, a Mitsubishi A6M Zero fighter, and damaged two others. Lieutenant Carl was awarded the Navy Cross for his actions in that decisive battle.
Marion Carl was next assigned to VMF-223 under the command of Captain John L. Smith. The Marine fighter squadron was the first air unit to arrive at Henderson Field on the island of Guadalcanal in the Solomons, 20 August 1942. This was a critical airfield, originally built by the Japanese military but occupied by Allied forces. On 26 August, Lieutenant Carl became the Marine Corps’ first “ace.”
Carl was shot down in 9 September 1942 and was missing for five days. He was helped by islanders who eventually returned him to his base.
The squadron departed Guadalcanal 16 October 1942, and sailed to San Francisco, California. VMF-223 was credited with destroying 110½ enemy aircraft. Carl was credited with 16.
Lieutenant Carl married Miss Edna T. Kirvin at New York City, New York, 7 January 1943.
On 26 January, he took command of VMF-223. On 8 May 1943, Lieutenant Carl was promoted to the temporary rank of captain. The squadron was re-equipped with the new Vought-Sikorsky F4U-1 Corsair. Training in the new fighter took place at MCAS El Toro, in southern California.
In August, the squadron returned to combat in the Solomons. By the end of 1943, Major Carl’s total of enemy aircraft destroyed was 18½ with 3 damaged, making him the seventh highest-scoring Marine fighter pilot of World War II.
After the War Marion Carl trained as a test pilot at NAS Patuxent River, Maryland, testing jet aircraft on aircraft carriers and he was also the first Marine Corps pilot to fly a helicopter. He commanded the Marine’s first jet squadron, VMF-122, which flew the McDonnell FH-1 Phantom. He was promoted to lieutenant colonel 7 August 1947.
In May 1955, Colonel Carl commanded Marine Photo Reconnaisance Squadron One (VMJ-1). The squadron flew the McDonnell FH-2 Banshee from air bases on Taiwan on secret missions over the People’s Republic of China.
At Muroc Army Air Field (now Edwards Air Force Base) he tested the Douglas D-558-I Skystreak and D-558-II Skyrocket, setting world records for speed and altitude. He was promoted to colonel, 1 October 1956.
By 1962 Colonel Carl was Director of Marine Corps Aviation. He was promoted to brigadier general, 1 June 1964.
Brigadier General Carl commanded the First Marine Brigade during the Vietnam War and flew combat missions in jet fighters and helicopter gun ships.
Promoted to major general in August 1967, with his date of rank retroactive to 1 June 1964. Carl commanded the 2nd Marine Aircraft Wing, then served as Inspector General of the Marine Corps from 1970 until 1973. When he retired in 1973, General Carl had accumulated more that 13,000 flight hours.
During his military career, Major General Carl was awarded the Navy Cross with two gold stars (three awards); The Legion of Merit with valor device and three gold stars (four awards); The Distinguished Flying Cross with four gold stars (five awards); and the Air Medal with two gold and two silver stars (twelve awards).
Tragically, General Carl was murdered in Roseburg, Oregon, 28 June 1998, as he defended his wife, Edna, during a home-invasion robbery. Mrs. Carl was wounded, but survived.
Major General Marion E. Carl, United States Marine Corps, is buried at Arlington National Cemetery.
¹ The pressure suit Lieutenant Colonel Carl was testing was a David Clark Co. Model 7 full-pressure suit.
² Often cited as Grumman F4F-3 Bu. No. 4000 (second bureau number series, 1935–1940) the entry in Carl’s certified pilot logbook for 4 June 1942 states the airplane he flew to shoot down the enemy fighter was F4F-3 Bu. No. 1864.
20 December 1968: After 199 flights, the National Aeronautics and Space Administration cancelled the X-15 Hypersonic Research Program. A 200th X-15 flight had been scheduled, but after several delays, the decision was made to end the program. (The last actual flight attempt was 12 December 1968, but snow at several of the dry lakes used as emergency landing areas resulted in the flight being cancelled.)
The X-15A rocketplane was designed and built for the U.S. Air Force and the National Advisory Committee for Aeronautics (NACA, the predecessor of NASA) by North American Aviation, Inc., to investigate the effects of hypersonic flight (Mach 5+). Design work started in 1955 and a mock-up had been completed after just 12 months. The three X-15s were built at North American’s Los Angeles Division, at the southeast corner of Los Angeles International Airport (LAX), on the shoreline of southern California.
The first flight took place 8 June 1959 with former NACA test pilot Albert Scott Crossfield in the cockpit of the Number 1 ship, 56-6670.
While earlier rocketplanes, the Bell X-1 series, the the Douglas D-558-II, and the Bell X-2, were airplanes powered by rocket engines, the X-15 was a quantum leap in technology. It was a spacecraft.
Like the other rocketplanes, the X-15 was designed to be carried aloft by a “mothership,” rather than to takeoff and climb to the test altitude under its own power. The carrier aircraft was originally to be a Convair B-36 intercontinental bomber but this was soon changed to a Boeing B-52 Stratofortress. Two B-52s were modified to carry the X-15: NB-52A 52-003, The High and Mighty One, and NB-52B 52-008, Balls 8.
From 8 June 1959 to 24 October 1968, the three X-15s were flown by twelve test pilots, three of whom would qualify as astronauts in the X-15. Two would go on to the Apollo Program, and one, Neil Alden Armstrong, would be the first human to set foot on the surface of the Moon, 20 July 1969. Joe Engle would fly the space shuttle. Four of the test pilots, Petersen, White, Rushworth, and Knight, flew in combat during the Vietnam War, with Bob White being awarded the Air Force Cross. Petersen, Rushworth and White reached flag rank.
One pilot, John B. (“Jack”) McKay, was seriously injured during an emergency landing at Mud Lake, Nevada, 9 November 1962. Michael James Adams, was killed when the Number 3 ship, 56-6672, went into a hypersonic spin and broke up on the program’s 191st flight, 15 November 1967.
Flown by a single pilot/astronaut, the X-15 is a mid-wing monoplane with dorsal and ventral fin/rudders and stabilators. The wing had no dihdral, while the stabilators had a pronounced -15° anhedral. The short wings have an area of 200 square feet (18.58 square meters) and a maximum thickness of just 5%. The leading edges are swept to 25.64°. There are two small flaps but no ailerons. The entire vertical fin/rudder pivots for yaw control.
Above 100,000 feet (30,840 meters) altitude, conventional aircraft flight control surfaces are ineffective. The X-15 is equipped with a system of reaction control jets for pitch, roll and yaw control. Hydrogen peroxide was passed through a catalyst to produce steam, which supplied the control thrusters.
The forward landing gear consists of a retractable oleo strut with steerable dual wheels and there are two strut/skids at the rear of the fuselage. The gear is retracted after the X-15 is mounted on the NB-52 and is extended for landing by its own weight.
The rocketplane’s cockpit featured both a conventional control stick as well as side-controllers. It was pressurized with nitrogen gas to prevent fires. The pilot wore an MC-2 full-pressure suit manufactured by the David Clark Company of Worcester, Massachusetts, with an MA-3 helmet. The suit was pressurized below the neck seal with nitrogen, while the helmet was supplied with 100% oxygen. This pressure suit was later changed to the Air Force-standardized A/P22S.
The X-15 is 50.75 feet (15.469 meters) long with a wing span of 22.36 feet (6.815 meters). The height—the distance between the tips of the dorsal and ventral fins—is 13.5 feet (4.115 meters). The stabilator span is 18.08 feet (5.511 meters). The fuselage is 4.67 feet (1.423 meters) deep and has a maximum width of 7.33 feet (2.234 meters).
Since the X-15 was built of steel rather than light-weight aluminum, as are most aircraft, it is a heavy machine, weighing approximately 14,600 pounds (6,623 kilograms) empty and 34,000 pounds (15,422 kilograms) when loaded with a pilot and propellants. The X-15s carried as much as 1,300 pounds (590 kilograms) of research instrumentation, and the equipment varied from flight to flight. The minimum flight weight (for high-speed missions): 31,292 pounds (14,194 kilograms) The maximum weight was 52,117 pounds (23,640 kilograms) at drop (modified X-15A-2 with external propellant tanks).
Initial flights were flown with a 5 foot, 11 inch (1.803 meters)-long air data boom at the nose, but this would later be replaced by the “ball nose” air sensor system. The data boom contained a standard pitot-static system along with angle-of-attack and sideslip vanes. The boom and ball nose were interchangeable.
The X-15s were built primarily of a nickel/chromium/iron alloy named Inconel X, along with corrosion-resistant steel, titanium and aluminum. Inconel X is both very hard and also able to maintain its strength at the very high temperatures the X-15s were subjected to by aerodynamic heating. It was extremely difficult to machine and special fabrication techniques had to be developed.
Delays in the production of the planned Reaction Motors XLR99 rocket engine forced engineers to adapt two vertically-stacked Reaction Motors XLR11-RM-5 four-chamber rocket engines to the X-15 for early flights. This was a well-known engine which was used on the previous rocketplanes. The XLR-11 burned a mixture of ethyl alcohol and water with liquid oxygen. Each of the engines’ chambers could be ignited individually. Each engine was rated at 11,800 pounds of thrust (58.49 kilonewtons) at Sea Level.
The Reaction Motors XLR99-RM-1 rocket engine was throttleable by the pilot from 28,500 to 60,000 pounds of thrust. The engine was rated at 50,000 pounds of thrust (222.41 kilonewtons) at Sea Level; 57,000 pounds (253.55 kilonewtons) at 45,000 feet (13,716 meters), the typical drop altitude; and 57,850 pounds (257.33 kilonewtons) of thrust at 100,000 feet (30,480 meters). Individual engines varied slightly. A few produced as much as 61,000 pounds of thrust (271.34 kilonewtons).
The XLR99 burned anhydrous ammonia and liquid oxygen. The flame temperature was approximately 5,000 °F. (2,760 °C.) The engine was cooled with circulating liquid oxygen. To protect the exhaust nozzle, it was flame-sprayed with ceramic coating of zirconium dioxide. The engine is 6 feet, 10 inches (2.083 meters) long and 3 feet, 3.3 inches (0.998 meters) in diameter. It weighs 910 pounds (413 kilograms). The Time Between Overhauls (TBO) is 1 hour of operation, or 100 starts.
The XLR99 proved to be very reliable. 169 X-15 flights were made using the XLR99. 165 of these had successful engine operation. It started on the first attempt 159 times.
The highest speed achieved during the program was with the modified number two ship, X-15A-2 56-6671, flown by Pete Knight to Mach 6.70 (6,620 feet per second/4,520 miles per hour/ kilometers per hour) at 102,700 feet (31,303 meters). On this flight, the rocketplane exceeded its maximum design speed of 6,600 feet per second (2,012 meters per second).
The maximum altitude was reached by Joe Walker, 22 August 1963, when he flew 56-6672 to 354,200 feet (107,960 meters).
The longest flight was flown by Neil Armstrong, 20 April 1962, with a duration of 12 minutes, 28.7 seconds.
North American Aviation X-15A-1 56-6670 is on display at the Smithsonian Institution National Air and Space Museum. X-15A-2 56-6671 is at the National Museum of the United States Air Force.
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
At The Edge Of Space, by Milton O. Thompson, Smithsonian Institution Press, 1992
X-15 Diary: The Story of America’s First Spaceship, by Richard Tregaskis, E.F. Dutton & Company, New York, 1961; University of Nebraska Press, 2004
X-15: Exploring the Frontiers of Flight, by David R. Jenkins, National Aeronautics and Space Administration http://www.nasa.gov/pdf/470842main_X_15_Frontier_of_Flight.pdf
The X-15 Rocket Plane: Flying the First Wings into Space, by Michelle Evans, University of Nebraska Press, Lincoln and London, 2013