An Approach to Predict Flight Dynamics and Stability Derivatives of Distressed Aircraft

This paper presents an approach to predict the flight dynamics and stability derivatives of a structurally damaged transport category subsonic aircraft based on a spanwise full loss damage model. Stability derivatives are derived using basic principles and theoretical aerodynamics, resulting equations are tabulated for a distressed aircraft due to wing damage. We determined two new stability derivatives based on our theoretical derivations using a wing damaged aircraft model. Our new approach and the stability derivatives derived should prove useful in the evaluation of damaged aircraft systems as well as in development of flight simulations. A case study conducted includes prediction of changes in stability derivatives and coefficients with damage parameter using a digital C-17 Globemaster aircraft model. The newly derived damaged aircraft stability derivatives are validated using C-5 Galaxy aircraft flight test data available. Results show excellent correlation.