An Emergency Engine Response Requirement Analysis Tool for Lateral-Directional Dynamic Aircraft Stability

In an effort to use the propulsion system to augment or replace a damaged flight control system in emergency situations, engine response requirements must be developed to set goals for engine transient operation. The propulsion system dynamics are much slower than the response obtained from conventional flight controls, and depending on placement may be much less effective. In this paper, an analysis method to determine engine response requirements for lateral-directional stability is developed for the case where the vertical stabilizer has sustained damage. The output of the tool is then validated against the nonlinear Generic Transport Model (GTM) with second order engine models. Results from the application of the analysis tool to various types of aircraft, including the GTM, are presented for various flight conditions and levels of vertical stabilizer damage.