NASA AD-1
| NASA AD-1 | |
|---|---|
 Oblique Wing Airplane AD-1 (1980) |
|
| Type: | Experimental airplane |
| Design country: | |
| Manufacturer: |
Ames Industrial Corporation |
| First flight: |
December 21, 1979 |
| Number of pieces: |
1 |
As NASA-AD-1 both an aircraft and an associated flight test program was designated, which was carried out between 1979 and 1982 at NASA Dryden Flight Research Center in Edwards , California . It successfully demonstrated that a single, continuous aircraft wing can be rotated from zero to 60 degrees at an angle to the direction of flight during flight.
The unique oblique wing (also Oblique Wing ) was established at the small turbine driven subsonic experimental aircraft AD-1 ( Ames Dryden-1 tested).
It flew 79 times during the research program to determine the basic properties of the pitched wing concept and to collect information about the flight properties and aerodynamics at different speeds and angles of the wing.
Background of the project
The slanted wing concept originally came from Robert T. Jones , an aerospace engineer at NASA Ames Research Center, in Moffett Field , California. The German designer Richard Vogt from Blohm & Voss had already dealt with such a concept in 1943 (Project P.202, see also BV 141 ), but only Jones was able to put this idea into practice and test it.
Analytical and wind tunnel studies carried out by Jones in Ames indicated that such an aircraft could have significantly better aerodynamic properties than aircraft with conventional (unswept wings) at speeds of up to Mach 1.4.
At high speeds, both subsonic and supersonic, the wings were rotated up to 60 degrees relative to the fuselage of the aircraft for better performance.
The studies showed that this would reduce drag , enabling higher speeds and longer range with the same fuel consumption.
At lower speeds (during take-offs and landings) the wing stood perpendicular to the fuselage like a conventional wing and thus offered the highest level of lift and flight control. When the aircraft accelerated to higher speeds, the wing was rotated as a whole (in contrast to the swivel-wing aircraft ), whereby the air resistance and thus also the consumption decreased. The mechanism was designed so that the wing could only be turned in one direction, with the right wing tip first.
plane
The AD-1 aircraft was delivered to Dryden in February 1979. The Ames Industrial Corporation of Bohemia , New York , built it under a $ 240,000 fixed price contract.
NASA specified the overall design using a geometric configuration that had been studied by Boeing Commercial Airplanes Seattle , Washington .
The Rutan Aircraft Factory in Mojave , California, provided the detailed design and stress analysis for the low speed and low-cost airplane (it was internally referred to as the Model 35). The low speed and low costs naturally limited the complexity of the vehicle and the test framework to the technical feasibility.
The first flight took place on December 21, 1979 with NASA research pilot Thomas C. McMurtry at the wheel. He also controlled the aircraft on its last flight on August 7, 1982.
Another well-known test pilot who was involved in the project was Pete Knight .
Driven by two small TRS18-046 turbojet engines, which for safety reasons were limited to 1 kN static thrust at sea level, the aircraft reached a speed of only 280 km / h.
The AD-1 was 11.8 m long and had a wingspan of 9.8 m with the wing in an upright position. It consisted of glass fiber reinforced plastic (GRP), with the surface being separated from the structure by rigid foam. She had a total weight of 2,145 pounds and a curb weight of 1,450 pounds. A fixed tricycle landing gear , which was mounted close to the fuselage to reduce air resistance, gave the aircraft a very unusual appearance on the ground with a height of 2.06 m.
The wing was rotated by means of an electric gearbox, which was located in the fuselage in front of the engines.
Flight research
The research program to validate the pitched wing concept was typical of all NASA high risk projects. The operating range was expanded with the help of each individual test element. The basic aim of the AD-1 project was to study the characteristics of an inclined wing configuration at low speeds.
The AD-1 had its maiden flight in late 1979. The wing rotation was increased gradually over the next 18 months until the full 60-degree angle was reached in mid-1981, although problems with the flight control emerged due to the uneven distribution of lift on the wing.
The aircraft was then further tested until its last flight in August 1982 to obtain data for various speeds and wing angles.
The AD-1's final flight was not in Dryden, but instead at the Experimental Aircraft Association (EAA) annual airshow in Oshkosh , Wisconsin , where it was flown eight times to show off its unique configuration.
After completing the test program, the AD-1 was taken out of service and can now be seen in the Hiller Aviation Museum in San Carlos , California.
After the end of the flight test program, Jones investigated inclined wing concepts for long-haul transport aircraft, although here too there were control problems at angles above 45 degrees. The GRP structure of the wings limited their rigidity, which could otherwise only be compensated for by a better (and therefore more expensive) control system.
Even if the AD-1 allowed the planned technical objectives to be completed, there was still a need for more extensive research in the high subsonic and supersonic range with inclined-wing aircraft. So there are currently (until March 2008)
a 25 month study by Northrop Grumman on this concept, which includes extensive wind tunnel tests up to Mach 1.3 and then the construction of a demonstrator with a span of 17 m.
Individual evidence
- ^ Hiller Aviation Museum Briefing. (PDF; 1.3 MB) (No longer available online.) Hiller Aviation Museum, November 2005, p. 4 , archived from the original on October 25, 2006 ; accessed on October 27, 2006 (English).
Web links and receipts
- NASA Dryden AD-1 data sheet (English)
- FliegerRevue 2/2008, pp. 58–60, series: X-planes, chapter: rotary wings and tilt rotors, ISSN 0941-889X