Similarity-based modeling of aircraft flight paths

Modeling methods based on historical data can be used to model the values of parameters describing the flight paths of both military and commercial jet aircraft. Flight path parameters that are modeled typically include: pilot inputs such as the positions of the stick or control column and control wheel, power levers, rudder pedal, and controls for the slats, spoilers, stabilizer, and landing gear; control surface and controller responses such as the positions of the ailerons, elevators, flaps, rudder, slats, spoilers, stabilizer, and fuel flows; and aircraft responses such as airspeed, altitude, angle of attack, acceleration components, pitch, roll, yaw, the speeds of the low-pressure and high-pressure turbines, and exhaust gas temperatures. The utility of the models lies in their ability to confirm normal behavior and to detect abnormal behavior of control surfaces and engine systems during takeoff, cruise, and landing. Examples of several methods applied to a newly manufactured military jet to confirm acceptance test results during an entire flight are illustrated. Also illustrated are examples of several methods applied to the analysis of a commercial jet aircraft incident involving a control surface failure during a landing approach, an analysis that illustrates the capability of the method to support fault isolation. One of the versions, a similarity-based modeling method, exhibits a superior ability to achieve the intended purposes.