H∞ longitudinal control of crippled trijet aircraft with throttles only

Abstract

A novel propulsion controlled aircraft (PCA) design technique for airplanes with control surface failures is presented. The H ∞ model-matching methodology is applied to the problem of controlling the crippled aircraft from conventional stick input commands using the engines as the only available actuators. This paper focuses on pitch control of trijet configuration aircraft, and more specifically on the effect of the height of the tail engine above the center of gravity of the airplane. Simulations on “modified” L-1011 models demonstrate the concept.