Weight Functions Method application on a delta-wing X-31 configuration

The stability analysis of an aircraft configuration is studied using a new system stability method called the weight function method. This new method finds a number of weight functions that are equal to the number of first-order differential equations. This method is applied for longitudinal and lateral motions on a delta-wing aircraft, the X-31, designed to break the “stall barrier”. Aerodynamic coefficients and stability derivatives obtained using the Digital DATCOM code have been validated with the experimental Low-Speed Wind tunnel data obtained using the German-Dutch Wind Tunnel (DNW-NWB). Handling Qualities Methods are used to validate the method proposed in this paper.