April 21, 1998 (by Lieven Dewitte) - Lockheed Martin has begun testing the flight control software for its X-35 Joint Strike Fighter (JSF) concept demonstrator aircraft in flights conducted with the Variable Stability In-Flight Simulator Test Aircraft (NF-16D), or VISTA/F-16.
The VISTA/F-16 crew of John Ball and Jeff Peer of Calspan completed all the planned test points in the first VISTA
flight for the X-35 development program in Buffalo, N. Y., on March 29. The test points included commands in all flight axes -- pitch, yaw and roll. These maneuvers were completed in up-and-away flight and during one landing in a power approach mode. The first flight began the calibration process of tuning the VISTA/F-16to match the dynamic response characteristics of the Lockheed Martin JSF
demonstrator aircraft, which are being assembled at the Lockheed Martin Skunk Works in Palmdale, Calif. The expected responses are derived from wind tunnel data and computer modeling.
The VISTA/F-16's response characteristics will be refined in several calibration flights, before evaluation of handling qualities begins in subsequent test flights. In the upcoming evaluation phase, four pilots (two Lockheed Martin, one U.S. Navy, and one U.S. Air Force) will evaluate the guidelines for handling qualities that are being used to design the X-35 flight control system. Evaluation maneuvers will consist of realistic tasks, including simulated carrier landing approaches, aerial refueling, air-to-air tracking and formation flight. The VISTA/F-16 test flights for the X-35 are scheduled to run through May 1998. Once established, he control system design guidelines will be used by engineers and test pilots to refine the actual flight control software for the X-35 aircraft. The two X-35 demonstrator aircraft are scheduled to be evaluated in the year 2000.