Video Description: This video taken from the chase aircraft is of the F-15's responses during tests of an Intelligent Flight Control System. The voice heard is that of the pilot in the F-15 test aircraft. Credit: NASA

NASA conducted a series of flight tests of the Intelligent Flight Control System (IFCS) this month under the direction of the Aviation Safety program. The tests were conducted for a project that addresses the needs of NASA and the U.S. aerospace industry for control systems that can efficiently optimize aircraft performance in both normal and failure conditions, including changes in aircraft stability and control characteristics that result from failures or accidents.

The IFCS team has integrated state-of-the-art direct adaptive neural network technologies with flight control algorithms to correctly respond to changes in aircraft stability and control characteristics, and to adjust to maintain the best possible flight performance during an unexpected failure.

During the tests, the angle-of-attack feedback to the canards was modified to create a destabilizing condition. IFCS behaved as predicted in the presence of real world turbulence and noise to correctly compensate for the failure. Tests were also performed by locking one of the horizontal stabilators in a biased (frozen) position.

The goal of the test was to evaluate how well the direct adaptive neural networks helped ensure a safe, in-flight failure recovery. With the direct adaptive neural networks turned on, the pitch rate of the aircraft more closely followed the pilot pitch commands than when the neural networks were turned off. Plans are currently in place to examine the ability of IFCS to compensate for even larger destabilizing effects.

Intelligent Flight Control System Team
NASA Ames Research Center; NASA Dryden Flight Research Center; Boeing Phantom Works, St. Louis, Missouri; the Institute for Scientific Research, Inc.; West Virginia University, Fairmont, West Virginia; and the Georgia Institute of Technology