Douglas D-558-II
| Douglas D-558-II | |
|---|---|
 Douglas Skyrocket D-558-II |
|
| Type: | Experimental airplane |
| Design country: | |
| Manufacturer: | |
| First flight: |
February 4, 1948 |
| Commissioning: |
Flight tests ended on December 12, 1956 |
| Number of pieces: |
3 |
The Douglas D-558-II Skyrocket (also Douglas D-558-2 ) was a test aircraft of the United States Navy . It was built by the Douglas Aircraft Company and was the first manned aircraft to reach twice the speed of sound .
The machine was a pressurized mid - decker with a retractable landing gear. The aim was to research aerodynamic effects in the transonic range as well as in supersonic flight. The wings therefore had a sweep of 35 °, the horizontal stabilizer of 40 ° and the vertical stabilizer of 49 °.
history
The first flight took place at Muroc Army Airfield on February 4, 1948.
Three machines were made, which differed in details. A total of 313 flights could be undertaken: 123 from the first with the Bureau Number (BuNo) 37973 (NACA-143), 103 from the second, BuNo 37974 (NACA-144) and 87 from the third aircraft, BuNo 37975 (NACA-145 ).
The first machine was initially equipped with a Westinghouse J34-40 jet engine with a thrust of 13 kN and capable of self-launching with a takeoff weight of 4,795 kg. The amount of fuel was 980 liters of kerosene . The machine received a Reaction Motors XLR-8 rocket engine with four combustion chambers in 1954-55 and thus corresponded to the NACA-144 on the drive side. However, only one flight (on September 17, 1956) was performed in this configuration.
The second machine, NACA-144, also initially had a jet engine. During flight tests in 1949, aerodynamic effects, the so-called pitch-up , were found in the transonic range. Despite everything, the machine was converted to the Reaction Motors XLR-11 engine with a thrust of 27 kN in 1950 and flown to Mach 1.88 at an altitude of 25,370 m, which again showed aerodynamic instabilities. For this purpose, the machine (like the Bell X-1 in 1946 ) was carried to the air by a B-29 version of the US Navy and then dropped. With a takeoff weight of 7,161 kg, 1,306 liters of liquid oxygen and 1,431 liters of alcohol could be carried.
It was decided to fly the machine up to Mach 2. For this purpose, the thrust nozzle was modified, the fuel was deep-frozen and the surface was polished again. On November 20, 1953, Scott Crossfield reached Mach 2.005 at an altitude of 21,900 m (corresponds to a speed of 2078 km / h at this altitude). This speed was not exceeded in any other flight with the D-558-II.
The last flight of all three machines was carried out on December 20, 1956.
The third machine, NACA-145, had both the jet engine with 13 kN thrust and the rocket engine with 27 kN thrust. It was used with a number of modifications to the wing to study the effects of the transonic range and improve handling. The data obtained in this way were required for the development of the combat aircraft. The last flight of the NACA-145 took place on August 28, 1956. The takeoff weight of this variant was 6,925 kg. 984 liters of kerosene, 644 liters of liquid oxygen and 727 liters of alcohol could be carried as fuel.
All three machines have been preserved. NACA-143 is in the Planes of Fame Museum in Chino, California , NACA-144 is on display at the National Air and Space Museum in Washington DC , and NACA-145 is in front of Antelope Valley College , Lancaster, California .
Technical data (NACA 144)
- Length: 12.8 m
- Span: 7.6 m
- Height: 3.8 m
- Wing area: 16.2 m²
- Empty weight: 4273 kg
- Takeoff weight: 7161 kg
- Powerplant: 1 × Reaction Motors XLR-8-RM-5 with 27 kN thrust
- Top speed: 2078 km / h
Web links
- Towards Mach 2: The Douglas D-558 Program . NASA History Series 1999. (PDF; 7.3 MB)
- List of Skyrocket # 2 37-974 flights
Individual evidence
- ↑ Description on history.nasa.gov p. 62 (D-558). (PDF; 1.2 MB) Retrieved April 19, 2013 .