Beschreibung

X-31 in Flight with F-18 Chase

Photo Number: EC94-42478-17
Photo Date: 1994

Formats: 558x480 JPEG Image (75 KBytes)
1191x1024 JPEG Image (615 KBytes)
2000x1720 JPEG Image (791 KBytes)

Photo
Description: A head-on view of the X-31 Enhanced Fighter Maneuverability Demonstrator aircraft (right), accompanied by a NASA F-18 chase aircraft during a research flight over the desert floor. The X-31 had a three-axis thrust-vectoring system, coupled with advanced flight controls, to allow it to maneuver tightly at very high angles of attack.

Project
Description: The X-31 Enhanced Fighter Maneuverability (EFM) demonstrator flew at the Ames- Dryden Flight Research Facility, Edwards, California (redesignated the Dryden Flight Research Center in 1994) from February 1992 until 1995 and before that at the Air Force’s Plant 42 in Palmdale, California. The goal of the project was to provide design information for the next generation of highly maneuverable fighter aircraft.

This program demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with an advanced flight control system to provide controlled flight to very high angles of attack. The result was a significant advantage over most conventional fighters in close-in combat situations. The X-31 flight program focused on agile flight within the post-stall regime, producing technical data to give aircraft designers a better understanding of aerodynamics, effectiveness of flight controls and thrust vectoring, and airflow phenomena at high angles of attack.

Stall is a condition of an airplane or an airfoil in which lift decreases and drag increases due to the separation of airflow. Thrust vectoring compensates for the loss of control through normal aerodynamic surfaces that occurs during a stall. Post-stall refers to flying beyond the normal stall angle of attack, which in the X-31 was at a 30-degree angle of attack.

During Dryden flight testing, the X-31 aircraft established several milestones. On November 6, 1992, the X-31 achieved controlled flight at a 70-degree angle of attack. On April 29, 1993, the second X-31 successfully executed a rapid minimum-radius, 180-degree turn using a post-stall maneuver, flying well beyond the aerodynamic limits of any conventional aircraft. This revolutionary maneuver has been called the "Herbst Maneuver" after Wolfgang Herbst, a German proponent of using post-stall flight in air-to-air combat. It is also called a "J Turn" when flown to an arbitrary heading change.

The aircraft was flown in tactical maneuvers against an F/A-18 and other tactical aircraft as part of the test flight program. During November and December 1993, the X-31 reached a supersonic speed of Mach 1.28. In 1994, the X-31 program installed software to demonstrate quasi-tailless operation.

The X-31 flight test program was conducted by an international test organization (ITO) managed by the Advanced Research Projects Office (ARPA), known as the Defense Advanced Research Projects Office (DARPA) before March 1993. The ITO included the U.S. Navy and U.S. Air Force, Rockwell Aerospace, the Federal Republic of Germany, Daimler-Benz (formerly Messerschmitt-Bolkow-Blohm and Deutsche Aerospace), and NASA. Gary Trippensee was the ITO director and NASA Project Manager. Pilots came from participating organizations.

The X-31 was 43.33 feet long with a wingspan of 23.83 feet. It was powered by a single General Electric P404-GE-400 turbofan engine that produced 16,000 pounds of thrust in afterburner.

Keywords: Ames-Dryden Flight Research Facility ; Dryden Flight Research Center; Herbst Maneuver; Wolfgang Herbst; J Turn; Advanced Research Projects Agency; Defense Advanced Research Projects Agency; U.S. Navy; U.S. Air Force; Rockwell Aerospace; the Federal Republic of Germany; Daimler-Benz; Deutsche Aerospace; Messerschmitt-Bolkow-Blohm; Gary Trippensee; General Electric; X-31 Enhanced Fighter Maneuverability Demonstrator; F-18; F/A-18; Hornet

source:http://www1.dfrc.nasa.gov/Gallery/Photo/X-31/HTML/EC94-42478-17.html

Lizenz

	Diese Datei ist gemeinfrei (public domain), da sie von der NASA erstellt worden ist. Die NASA-Urheberrechtsrichtlinie besagt, dass „NASA-Material nicht durch Urheberrecht geschützt ist, wenn es nicht anders angegeben ist“. (NASA-Urheberrechtsrichtlinie-Seite oder JPL Image Use Policy).
	Warnung: Die Verwendung von NASA-Logos, Wappen und Symbolen ist durch das US-Gesetz 14 CFR 1221 eingeschränkt. Die NASA-Homepage hostet viele Bilder der Sowjetischen bzw. Russischen Raumfahrtagentur sowie anderer nicht-amerikanischer Raumfahrtagenturen. Diese sind nicht gemeinfrei. Material des Hubble-Weltraumteleskops kann urheberrechtlich geschützt sein, wenn es nicht ausdrücklich vom STScI ist. [1] Jegliches Material des Solar and Heliospheric Observatory (SOHO) ist urheberrechtlich geschützt und benötigt eine gesonderte Genehmigung für kommerzielle, nicht-pädagogische Zwecke. [2] Bilder, die als Astronomie-Bild des Tages (APOD) veröffentlicht werden, sind unter Umständen urheberrechtlich geschützt. [3]