Abstract: A control system including both a method and apparatus for use on an aircraft during flight utilizes real-time data provided by sensing equipment on the aircraft to iteratively generate values for an efficiency parameter. The aircraft controls are adjusted after each iteration, and successive values of the efficiency parameter are compared until such comparison shows that the parameter has been substantially optimized. Iterations may then continue without corresponding control adjustments until comparison indicates that a current parameter value differs by a predetermined magnitude from the previously determined optimum value, at which time control adjustments resume in order to bring the efficiency parameter to a new substantially optimum parameter value.