Rockwell-MBB X-31

infobox Aircraft
name = X-31
type = Experimental
manufacturer = Rockwell
Messerschmitt-Bölkow-Blohm



caption =The X-31 aircraft returns from a test flight for VECTOR.
designer =
first flight = 1990
introduced =
number built = 2
status =
unit cost =
primary user = DARPA
more users = NASA
variants with their own articles =

The collaborative U.S.-German Rockwell-MBB X-31 "Enhanced Fighter Maneuverability" program was designed to test fighter thrust vectoring technology. Thrust vectoring allows the X-31 to fly in a direction other than where the nose is pointing, resulting in significantly more maneuverability than most conventional fighters. An advanced flight control system provides controlled flight at high angles of attack where conventional aircraft would stall.

History

Two X-31s were built, and over 500 test flights were carried out between 1990 and 1995. The X-31 featured fixed strakes along the aft fuselage, as well as a pair of movable computer-controlled canards to increase stability and maneuverability. There are no horizontal tail surfaces, only the vertical fin with rudder. Pitch and yaw are controlled by the three paddles directing the exhaust (thrust vectoring). Eventually, simulation tests on one of the X-31s showed that flight would have been stable had the plane been designed without the vertical fin, because the thrust-vectoring nozzle provided sufficient yaw and pitch control.

During 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 Dr. Wolfgang Herbst, an MBB employee and proponent of using post-stall flight in air-to-air combat.cite paper | author = Smith, R. E.; Dike, B. A.; Ravichandran, B.; El-Fallah, A.; Mehra, R. K. | title = Discovering Novel Fighter Combat Maneuvers in Simulation: Simulating Test Pilot Creativity | version = | publisher = United States Air Force | date = 2001 | url = http://www.cs.ucl.ac.uk/staff/Rob.Smith/PCES.pdf | format = PDF | accessdate = 2007-01-16 ] Herbst was the designer of the Rockwell SNAKE, which formed the basis for the X-31." [http://oea.larc.nasa.gov/PAIS/Partners/X_31.html Partners in Freedom: Rockwell-MBB X-31] ." Langevin, G. S.; Overbey, P. NASA Langley Research Center. October 17, 2003.]

In the mid-1990s, the program began to revitalize and a $53 million VECTOR program was initiated capitalizing on this previous investment. VECTOR is a joint venture that includes the US Navy, Germany’s defense procurement agency BWB, Boeing's Phantom Works, and the European Aeronautic, Defense and Space Company in Ottobrunn, Germany. As the site for the flight testing, Naval Air Station Patuxent River in Maryland was chosen. From 2002 to 2003, the X-31 flew extremely short takeoff and landing approaches first on a virtual runway at 5,000 feet in the sky, to ensure that the Inertial Navigation System/Global Positioning System accurately guides the aircraft with the centimeter accuracy required for on the ground landings. The program then culminated in the first ever autonomous landing of a manned aircraft with high angle of attack (24 degree) and short landing. The technologies involved a differential GPS System based on pseudolite technology from Integrinautics, California, and a miniaturized flush air data system from Nordmicro, Germany.

erial numbers

* BuNo 164584, 67 flights [http://www.check-six.com/Crash_Sites/X-31_crash_site.htm Crashed January 19, 1995 north of Edwards AFB, CA] .
* BuNo 164585, 292 flights. Now on display at Oberschleißheim museum (part of Deutsches Museum).

pecifications (X-31)

aircraft specifications
plane or copter?=plane
jet or prop?=jet
ref=
crew=one, pilot
capacity=
payload main=
payload alt=
length main= 44 ft 4 in
length alt= 13.2 m
span main= 23 ft 10 in
span alt= 7.3 m
height main= 14 ft 5 in
height alt= 4.4 m
area main= 226 ft²
area alt= 21 m²
airfoil=
empty weight main= 10,214 lb
empty weight alt= 4,633 kg
loaded weight main= 13,969 lb
loaded weight alt= 6,336 kg
useful load main=
useful load alt=
max takeoff weight main= 13,969 lb
max takeoff weight alt= 6,336 kg
more general=
engine (jet)=General Electric F404-GE-400
type of jet= turbofan
number of jets=1
thrust main= 16,000 lb_f
thrust alt= 71 kN
thrust original=
afterburning thrust main=
afterburning thrust alt=
max speed main= Mach 1.28 @ 35,000 ft
max speed alt= 975 mph / 1,550 km/h
cruise speed main=
cruise speed alt=
stall speed main=
stall speed alt=
never exceed speed main=
never exceed speed alt=
range main=
range alt=
ceiling main= 40,000 ft
ceiling alt= 12,200 m
climb rate main= 715 ft/s
climb rate alt= 218 m/s
loading main= 62 lb/ft²
loading alt=300 kg/m²
thrust/weight=
power/mass main=
power/mass alt=
more performance=
armament=
avionics=

References

Gallery

ee also

aircontent
related=
similar aircraft=
* Grumman X-29
* Boeing X-32
* Lockheed Martin X-33

lists=
* List of experimental aircraft
* List of military aircraft of the United States

see also=
* Comparison of 21st century fighter aircraft
* Future Offensive Air System

External links

* [http://www.dfrc.nasa.gov/Newsroom/FactSheets/FS-009-DFRC.html NASA Dryden: X-31]
* [http://abyss.uoregon.edu/~js/space/lectures/x-planes.html James Schombert's X-Plane history]
* [http://nix.larc.nasa.gov/search;jsessionid=7n7121u171i8j?b=SC000158 NASA X-31 image gallery]
* [http://www.esteco.it/case_studies/aerospace1.jsp Flap Splitting and Setting of the X-31 Wing]