The United States Air Force flew its first evaluation of the Lockheed Martin Joint Strike Fighter (JSF) X-35A Friday as the supersonic stealth aircraft logged its fifth flight.

USAF Lt. Col. Paul Smith took off from Edwards Air Force Base and flew a series of maneuvers, including afterburner operation, designed to evaluate the airplane's basic handling characteristics. During the 36-minute flight, Smith reached an altitude of 10,000 feet and a maximum speed of 360 knots.

Smith said the X-35A is an "excellent handling aircraft, very thrust- responsive -- it flies like a world-class fighter."

On Thursday, Lockheed Martin test pilot Tom Morgenfeld continued expansion of the X-35A's flight envelope to 390 knots at 10,000 feet with a series of increasingly aggressive maneuvers, including rolls, sideslips and afterburner transients. The successful flight lasted 45 minutes. The next series of flights will expand the envelope to higher airspeeds and altitudes as the X-35 program builds up to supersonic flight.

"The airplane has been very predictable and is a pleasure to fly," Morgenfeld said. "We're eager to continue expanding the flight envelope and validating our performance predictions."

Smith and Morgenfeld successfully completed flights six through eight over the weekend.

Flight testing of the conventional takeoff and landing (CTOL) X-35A will continue for about a month. The aircraft will then be fitted with a shaft- driven lift-fan propulsion system to test short-takeoff/vertical-landing (STOVL) JSF performance required by the U.S. Marine Corps and the British Royal Air Force and Royal Navy. Both planes share the same external configuration and dimensions, so flight-testing of the X-35A will satisfy many of the government's requirements for the X-35B. Many elements of the STOVL aircraft are already present on the X-35A, which provides early test-point evaluations of the STOVL configuration.

"By proving out this design, we're also validating the aircraft we're proposing to produce," said Frank J. Cappuccio, vice president and program manager of the Lockheed Martin team. "And, by having a highly representative aircraft, we can tackle risk in this phase, rather than waiting for the Engineering and Manufacturing Development phase when it will be more expensive."

Lockheed Martin, in partnership with Northrop Grumman and BAE SYSTEMS, is in competition to build the JSF for the United States and United Kingdom. Government selection of a single contractor for the Engineering and Manufacturing Development phase is set for 2001.

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For information on Lockheed Martin Aeronautics Company, visit: http://www.lmaeronautics.com/

For government information on the Joint Strike Fighter program, visit http://www.jast.mil/

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SOURCE: Lockheed Martin Aeronautics Company