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Rockwell-MBB X-31 (EFM)

Thrust-Vectoring Experimental Aircraft

Two Rockwell-MBB X-31 aircraft were completed to test the nuances of vectored thrust - the series flew into 2003.
Authored By: Staff Writer | Edited: 1/20/2017
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Year: 1990
Manufacturer(s): Rockwell - USA / Messerschmitt-Bolkow-Blohm (MBB) - Germany
Production: 2
Capabilities: X-Plane;
Crew: 1
Length: 43.34 ft (13.21 m)
Width: 23.79 ft (7.25 m)
Height: 14.60 ft (4.45 m)
Weight (Empty): 11,409 lb (5,175 kg)
Weight (MTOW): 15,939 lb (7,230 kg)
Power: 1 x General Electric F404-GE-400 afterburning turbofan engine developing 16,000lb of thrust.
Speed: 901 mph (1,450 kph; 783 kts)
Ceiling: 40,026 feet (12,200 m; 7.58 miles)
Rate-of-Climb: 43,000 ft/min (13,106 m/min)
Operators: Germany; United States
The X-31 experimental aircraft was a joint development venture between Rockwell and Messerschmitt-Bolkow-Blohm (MBB) of Germany to test the viability of thrust-vectoring hardware and software. Two prototypes were used throughout the program's run with a first-flight recorded on October 11th, 1990. Of the pair, one crashed during a test flight (the pilot ejecting safely) while the surviving member ended its days as a showpiece at the Deutsches Museum Flugwerft Schleissheim in Germany.

Many off-the-shelf components, borrowed from designs like the F-16, F-16XL, F/A-18 Hornet and B-1 bomber, made up the actual aircraft to keep development costs down and construction times short. The result was a sleek, though largely conventional, fighter design sporting well-swept, low-mounted monoplane wings (in a canard delta configuration), a single rudder and no horizontal planes at the tail (instead nose-mounted canards took over their role). A retractable undercarriage assisted ground running. The pilot was given a commanding view over the nose thanks to an elevated seating position and tear-drop-style canopy. The fuselage appeared with rounded slab sides and a deep profile.

Power was derived from a single General Electric F404-GE-400 series turbofan engine of 16,000lb thrust output, giving the airframe a maximum speed of 900 miles per hour, a service ceiling up to 40,000 feet and a rate-of-climb nearing 43,000 feet per minute. The engine was aspirated through a rectangular intake identified under the cockpit floor aft of the nose cone. The key design element of the X-31 was its jet pipe exhaust structure which incorporated three moveable panels to direct the flow of outgoing thrust. The idea was to test high Angle-of-Attack (AoA) performance during maneuvers - in this respect, the program succeeded.

Between the two prototypes, 580 flights were completed. Prototype 1 was lost on January 19th, 1995 due to ice build-up at the pitot tube resulting in incorrect data being fed to the onboard computers. Prototype 2 flew on into 2003 before being put out to pasture.



Variants / Models

• X-31 - Base Series Designation; two flyable aircraft completed.
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