The Douglas D-558-2 Skyrocket (or D-558-II) is a
rocket
A rocket (from it, rocchetto, , bobbin/spool) is a vehicle that uses jet propulsion to accelerate without using the surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely fr ...
and
jet-powered research
supersonic aircraft
A supersonic aircraft is an aircraft capable of supersonic flight, that is, flying faster than the speed of sound (Mach number 1). Supersonic speed, Supersonic aircraft were developed in the second half of the twentieth century. Supersonic airc ...
built by the
Douglas Aircraft Company
The Douglas Aircraft Company was an American aerospace manufacturer based in Southern California. It was founded in 1921 by Donald Wills Douglas Sr. and later merged with McDonnell Aircraft in 1967 to form McDonnell Douglas; it then operated as ...
for the
United States Navy
The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...
. On 20 November 1953, shortly before the (
17 December
Events Pre-1600
*497 BC – The first Saturnalia festival was celebrated in ancient Rome.
* 546 – Siege of Rome: The Ostrogoths under king Totila plunder the city, by bribing the Byzantine garrison.
* 920 – Romanos I Lekapen ...
) 50th anniversary of powered flight,
Scott Crossfield
Albert Scott Crossfield (October 2, 1921 – April 19, 2006) was an American naval officer and test pilot. In 1953, he became the first pilot to fly at twice the speed of sound. Crossfield was the first of twelve pilots who flew the North America ...
piloted the Skyrocket to Mach 2, or more than 1,290 mph (2076 km/h), the first time an aircraft had exceeded twice the
speed of sound
The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elastic medium. At , the speed of sound in air is about , or one kilometre in or one mile in . It depends strongly on temperature as w ...
.
Design and development
![Douglas D-558-II Skyrocket front upper view](https://upload.wikimedia.org/wikipedia/commons/9/92/Douglas_D-558-II_Skyrocket_front_upper_view.jpg)
The "-2" in the aircraft's designation referred to the fact that the Skyrocket was the phase-two version of what had originally been conceived as a three-phase program. The phase-one aircraft, the
D-558-1, was jet powered and had straight wings. The third phase, which never came to fruition, would have involved constructing a
mock-up
In manufacturing and design, a mockup, or mock-up, is a scale model, scale or physical model, full-size model of a design or device, used for teaching, demonstration, design evaluation, promotion, and other purposes. A mockup may be a ''protot ...
of a combat type aircraft embodying the results from the testing of the phase one and two aircraft. The eventual
D-558-3 design, which was never built, was for a hypersonic aircraft similar to the
North American X-15
The North American X-15 is a hypersonic rocket-powered aircraft. It was operated by the United States Air Force and the National Aeronautics and Space Administration as part of the X-plane series of experimental aircraft. The X-15 set speed an ...
.
[Hunley, J.D., ed]
"Toward Mach 2: The Douglas D558 Program (NASA SP-4222)."
Washington, DC: National Aeronautics and Space Administration, 1999.
When it became obvious that the D558-1 fuselage could not be modified to accommodate both rocket and jet power, the D558-2 was conceived as an entirely different aircraft. A contract change order was issued on 27 January 1947 to formally drop the final three D558-1 aircraft and substitute three new D558-2 aircraft instead.
[Francillon, René J. ''McDonnell Douglas Aircraft Since 1920: Volume I''. Annapolis, Maryland: Naval Institute Press, 1988. .]
The Skyrocket featured wings with a 35-degree sweep and horizontal stabilizers with 40-degree sweep. The wings and empennage were fabricated from aluminum and the large fuselage was of primarily magnesium construction. The Skyrocket was powered by a
Westinghouse J34-40 turbojet engine fed through side intakes in the forward fuselage. This engine was intended for takeoff, climb and landing. For high speed flight, a four-chamber
Reaction Motors
Reaction Motors, Inc. (RMI) was an early American maker of liquid-fueled rocket engines, located in New Jersey. RMI engines with thrust powered the Bell X-1 rocket aircraft that first broke the sound barrier in 1947, and later aircraft such th ...
LR8-RM-6 engine (the Navy designation for the Air Force's
XLR11 used in the
Bell X-1
The Bell X-1 (Bell Model 44) is a rocket engine–powered aircraft, designated originally as the XS-1, and was a joint National Advisory Committee for Aeronautics– U.S. Army Air Forces–U.S. Air Force supersonic research project built by Be ...
), was fitted. This engine was rated at 6,000 lbf (27 kN) static thrust at sea level. A total of of aviation fuel, of alcohol, and of liquid oxygen were carried in fuselage tanks.
The Skyrocket was configured with a flush cockpit canopy, but visibility from the cockpit was poor, so it was re-configured with a raised cockpit with conventional angled windows. This resulted in a greater profile area at the front of the aircraft, which was balanced by an additional 14 inches (36 cm) of height added to the vertical stabilizer. Like its predecessor, the D558-1, the D558-2 was designed so that the forward fuselage, including cockpit, could be separated from the rest of the aircraft in an emergency. Once the forward fuselage had decelerated sufficiently, the pilot would then be able to escape from the cockpit by parachute.
Operational history
Douglas pilot
John F. Martin made the first flight at Muroc Army Airfield (later renamed
Edwards Air Force Base
Edwards Air Force Base (AFB) is a United States Air Force installation in California. Most of the base sits in Kern County, but its eastern end is in San Bernardino County and a southern arm is in Los Angeles County. The hub of the base is E ...
) in California on 4 February 1948 in an aircraft equipped only with the jet engine. The goals of the program were to investigate the characteristics of swept-wing aircraft at transonic and supersonic speeds with particular attention to
pitch-up
In aerodynamics, pitch-up is an uncommanded nose-upwards rotation of an aircraft. It is an undesirable characteristic that has been observed mostly in experimental swept-wing aircraft at high subsonic Mach numbers or high angle of attack.
History
...
(un-commanded rotation of the nose of the aircraft upwards), a problem prevalent in high-speed service aircraft of that era, particularly at low speeds during takeoff and landing, and in tight turns.
The three aircraft gathered a great deal of data about pitch-up and the coupling of lateral (yaw) and longitudinal (pitch) motions; wing and tail loads, lift, drag and
buffeting
Aeroelasticity is the branch of physics and engineering studying the interactions between the inertial, elastic, and aerodynamic forces occurring while an elastic body is exposed to a fluid flow. The study of aeroelasticity may be broadly classi ...
characteristics of swept-wing aircraft at transonic and supersonic speeds; and the effects of the rocket exhaust plume on lateral dynamic stability throughout the speed range. (Plume effects were a new experience for aircraft.) The number three aircraft also gathered information about the effects of external stores (bomb shapes, drop tanks) upon the aircraft's behavior in the transonic region (roughly 0.7 to 1.3 times the speed of sound). In correlation with data from other early transonic research aircraft such as the
XF-92A
The Convair XF-92 (re-designated from XP-92 in 1948) was an American, delta wing, first-generation jet prototype. Originally conceived as a point-defence interceptor, the design was later used purely for experimental purposes and only one was ...
, this information contributed to solutions to the pitch-up problem in swept-wing aircraft.
Its flight research was done at the NACA's Muroc Flight Test Unit in
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
, redesignated in 1949 the High-Speed Flight Research Station (HSFRS). The HSFRS became the High-Speed Flight Station in 1954 and was then known as the
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeeding t ...
Dryden Flight Research Center. In 2014 it was renamed
Armstrong Flight Research Center
The NASA Neil A. Armstrong Flight Research Center (AFRC) is an aeronautical research center operated by NASA. Its primary campus is located inside Edwards Air Force Base in California and is considered NASA's premier site for aeronautical res ...
in honor of
Neil Armstrong
Neil Alden Armstrong (August 5, 1930 – August 25, 2012) was an American astronaut and aeronautical engineer who became the first person to walk on the Moon in 1969. He was also a naval aviator, test pilot, and university professor.
...
.
![D-558-2 Dropped from B-29 Mothership - GPN-2000-000251](https://upload.wikimedia.org/wikipedia/commons/9/9d/D-558-2_Dropped_from_B-29_Mothership_-_GPN-2000-000251.jpg)
The three aircraft flew a total of 313 times – 123 by the number one aircraft (Bureau No. 37973—NACA 143), 103 by the second Skyrocket (Bureau No. 37974 – NACA 144), and 87 by aircraft number three (Bureau No. 37975 – NACA 145). Skyrocket 143 flew all but one of its missions as part of the Douglas contractor program to test the aircraft's performance.
NACA aircraft 143 was initially powered by the jet engine only, but was later fitted with the rocket engine. In this configuration, it was tested by Douglas from 1949 to 1951. After Douglas' test program, it was delivered to NACA, who stored it until 1954. In 1954–55 the contractor modified it to an all-rocket air-launch capability with the jet engine removed. In this configuration, NACA research pilot
John McKay flew the aircraft only once for familiarization on 17 September 1956. The 123 flights of NACA 143 served to validate wind-tunnel predictions of the aircraft's performance, except for the fact that the aircraft experienced less drag above Mach 0.85 than the wind tunnels had indicated.
NACA 144 also began its flight program with a turbojet powerplant. NACA pilots
Robert A. Champine
The name Robert is an ancient Germanic given name, from Proto-Germanic "fame" and "bright" (''Hrōþiberhtaz''). Compare Old Dutch ''Robrecht'' and Old High German ''Hrodebert'' (a compound of '' Hruod'' ( non, Hróðr) "fame, glory, honou ...
and
John H. Griffith flew 21 times in this configuration to test airspeed calibrations and to research longitudinal and lateral stability and control. In the process, during August 1949 they encountered pitch-up problems, which NACA engineers recognized as serious because they could produce a limiting and dangerous restriction on flight performance. Hence, they determined to make a complete investigation of the problem.
In 1950, Douglas replaced the turbojet with an LR-8 rocket engine, and its pilot,
Bill Bridgeman
William Barton Bridgeman (June 25, 1916 – September 29, 1968) was an American test pilot who broke aviation records while working for the Douglas Aircraft Company, testing experimental aircraft. In July 1951, the United States Navy announced t ...
, flew the aircraft seven times up to a speed of Mach 1.88 (1.88 times the speed of sound) and an altitude of 79,494 ft (24,230 m), the latter an unofficial world's altitude record at the time, achieved on 15 August 1951. In the rocket configuration, the aircraft was attached beneath the bomb bay of a Navy
P2B, a variant of the
B-29 bomber
The Boeing B-29 Superfortress is an American four-engined propeller-driven heavy bomber, designed by Boeing and flown primarily by the United States during World War II and the Korean War. Named in allusion to its predecessor, the B-17 Fly ...
. The P2B would fly to about , then release the rocket plane. During Bridgeman's supersonic flights, he encountered a violent rolling motion known as lateral instability. The motion was less pronounced during the Mach 1.88 flight on 7 August 1951 than during a Mach 1.85 flight in June when he pushed over to a low
angle of attack
In fluid dynamics, angle of attack (AOA, α, or \alpha) is the angle between a reference line on a body (often the chord line of an airfoil) and the vector representing the relative motion between the body and the fluid through which it is m ...
.
The NACA engineers studied the behavior of the aircraft before beginning their own flight research in the aircraft in September 1951. Over the next couple of years, NACA pilot
Scott Crossfield
Albert Scott Crossfield (October 2, 1921 – April 19, 2006) was an American naval officer and test pilot. In 1953, he became the first pilot to fly at twice the speed of sound. Crossfield was the first of twelve pilots who flew the North America ...
flew the aircraft 20 times to gather data on longitudinal and lateral stability and control, wing and tail loads, and lift, drag, and buffeting characteristics at speeds up to Mach 1.878.
At that point, Marine Lt. Col.
Marion Carl
Major General Marion Eugene Carl (November 1, 1915 – June 28, 1998) was an American military officer, World War II fighter ace, record-setting test pilot, and naval aviator. He was the United States Marine Corps' first ace in World War II.
Ear ...
flew the aircraft to a new (unofficial) altitude record of 83,235 feet (25,370 m) on 21 August 1953, and to a maximum speed of Mach 1.728. The altitude record was not recognized by the Federation of Aeronautique Internationale, because at that time aircraft making record attempts had to take off on their own power.
"Marine Flies Rocket Plane to Altitude of Nearly 16 miles."
''Popular Mechanics'', December 1953, p. 127.
Following Carl's completion of these flights for the Navy, NACA technicians at the High-Speed Flight Research Station (HSFRS) near Mojave, California, outfitted the LR-8 engine's combustion chambers with nozzle extensions to prevent the exhaust gas from affecting the rudders at supersonic speeds. This addition also increased the engine's thrust by 6.5 percent at Mach 1.7 and 70,000 feet (21,300 m).
Even before Marion Carl had flown the Skyrocket, HSFRS Chief Walter C. Williams had petitioned NACA headquarters unsuccessfully to fly the aircraft to Mach 2 to garner the research data at that speed. Finally, after Crossfield had secured the agreement of the Navy's Bureau of Aeronautics, NACA director Hugh L. Dryden
Hugh Latimer Dryden (July 2, 1898 – December 2, 1965) was an American aeronautical scientist and civil servant. He served as NASA Deputy Administrator from August 19, 1958, until his death.
Biography Early life and education
Dryden was born in ...
relaxed the organization's usual practice of leaving record setting to others and consented to attempting a flight to Mach 2.
In addition to adding the nozzle extensions, the NACA flight team at the HSFRS chilled the fuel (alcohol) so more could be poured into the tank and waxed the fuselage to reduce drag. Project engineer Herman O. Ankenbruck drew up a plan to fly to about 72,000 feet (21,900 m) and push over into a slight dive. Crossfield made aviation history on 20 November 1953, when he flew to Mach 2.005, 1,291 miles per hour (2,078 km/h). It was the only Mach 2 flight the Skyrocket ever made.
Following this flight, Crossfield and NACA pilots Joseph A. Walker
Joseph Albert Walker (February 20, 1921 – June 8, 1966) (Capt, USAF) was an American World War II pilot, experimental physicist, NASA test pilot, and astronaut who was the first person to fly an airplane to space. He was one of twelve pilots ...
and John B. McKay flew the aircraft for such purposes as to gather data on pressure distribution, structural loads, and structural heating, with the last flight in the program occurring on 20 December 1956, when McKay obtained dynamic stability data and sound-pressure levels at transonic speeds and above.
Meanwhile, NACA 145 had completed 21 contractor flights by Douglas pilots Eugene F. May
Eugene may refer to:
People and fictional characters
* Eugene (given name), including a list of people and fictional characters with the given name
* Eugene (actress) (born 1981), Kim Yoo-jin, South Korean actress and former member of the sin ...
and William Bridgeman in November 1950. In this jet-and-rocket-propelled craft, Scott Crossfield and Walter Jones began the NACA's investigation of pitch-up lasting from September 1951 well into summer 1953. They flew the Skyrocket with a variety of wing-fence, wing-slat and leading edge chord extension configurations, performing various maneuvers as well as straight-and-level flying at transonic speeds. While fences significantly aided recovery from pitch-up conditions, leading edge chord extensions did not, disproving wind-tunnel tests to the contrary. Slats (long, narrow auxiliary airfoils) in the fully open position eliminated pitch-up except in the speed range around Mach 0.8 to 0.85.
In June 1954, Crossfield began an investigation of the effects of external stores (bomb shapes and fuel tanks) upon the aircraft's transonic behavior. McKay and Stanley Butchart completed the NACA's investigation of this issue, with McKay flying the final mission on 28 August 1956.
Besides setting several records, the Skyrocket pilots had gathered important data and understanding about what would and would not work to provide stable, controlled flight of a swept-wing aircraft in the transonic and supersonic flight regimes. The data they gathered also helped to enable a better correlation of wind-tunnel test results with actual flight values, enhancing the abilities of designers to produce more capable aircraft for the armed services, especially those with swept wings. Moreover, data on such matters as stability and control from this and other early research aircraft aided in the design of the Century Series
The Century Series is a popular name for a group of US fighter aircraft representing models designated between F-100 and F-106 which went into full production. They included the first successful supersonic aircraft designs in the United State ...
of fighter aircraft, all of which featured the movable horizontal stabilizers first employed on the X-1 and D-558 series.
Variants
All three of the Skyrockets had 35-degree swept wings.
Until configured for air launch, NACA 143 featured a Westinghouse J-34-40 turbojet engine rated at static thrust. It carried of aviation gasoline and weighed 10,572 lb (4,795 kg) at takeoff.
NACA 144 (and NACA 143 after modification in 1955) was powered by an LR-8-RM-6 rocket engine rated at static thrust. Its propellants were of liquid oxygen and of diluted ethyl alcohol. In its launch configuration, it weighed 15,787 lb (7,161 kg).
NACA 145 had both an LR-8-RM-5 rocket engine rated at static thrust and featured a Westinghouse J-34-40 turbojet engine rated at static thrust. It carried of liquid oxygen, of diluted ethyl alcohol, and of aviation gasoline for a launch weight of 15,266 lb (6,925 kg).
Aircraft serial numbers
*D-558-2 Skyrocket
**D-558-2 #1 – #37973 NACA-143, 123 flights
**D-558-2 #2 – #37974 NACA-144, 103 flights
**D-558-2 #3 – #37975 NACA-145, 87 flights
Surviving aircraft
D-558-2 #1 Skyrocket is on display at the , Chino, California
Chino ( ; Spanish for "Curly") is a city in the western end of San Bernardino County, California, United States, with Los Angeles County to its west and Orange County to its south in the Southern California region. Chino is adjacent to Chino ...
. The number two Skyrocket, the first aircraft to fly Mach 2, is on display at the National Air and Space Museum
The National Air and Space Museum of the Smithsonian Institution, also called the Air and Space Museum, is a museum in Washington, D.C., in the United States.
Established in 1946 as the National Air Museum, it opened its main building on the Nat ...
in Washington D.C.
)
, image_skyline =
, image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan, Na ...
The third aircraft is displayed on a pylon in the grounds of Antelope Valley College
Antelope Valley College (AVC) is a public community college in Lancaster, California. It is part of the California Community College system. It is operated by the Antelope Valley Community College District, with a primary service area of cove ...
, Lancaster, California
Lancaster is a charter city in northern Los Angeles County, California, Los Angeles County, in the Antelope Valley of the western Mojave Desert in Southern California. As of the 2020 United States Census, 2020 census, the population was 173,51 ...
.
Specifications (D-558-2 Skyrocket)
(Configured with mixed propulsion)
See also
References
;Notes
;Bibliography
* Bridgeman, William and Jacqueline Hazard. ''The Lonely Sky''. New York: Henry Holt & Co., 1955. .
* Hallion, Dr. Richard P. "Saga of the Rocket Ships" ''AirEnthusiast Five'' November 1977 – February 1978. Bromley, Kent, UK: Pilot Press Ltd., 1977.
* Libis, Scott. ''Douglas D-558-2 Skyrocket'' (Naval Fighters Number Fifty-Seven). Simi Valley, California: Ginter Books, 2002. .
* Libis, Scott. ''Skystreak, Skyrocket, & Stiletto: Douglas High-Speed X-Planes''. North Branch, Minnesota: Specialty Press, 2005. .
External links
The NASA Dryden webpage
"Needle Nose Rocket Probes Sonic Speeds," ''Popular Mechanics,'' January 1948
a 1948 ''Flight'' article on the Skyrocket
*
{{US Navy experimental aircraft
D-558-2
1940s United States experimental aircraft
Mixed-power aircraft
Single-engined jet aircraft
Rocket-powered aircraft
Mid-wing aircraft
Cruciform tail aircraft
Aircraft first flown in 1948