A methodology for estimating the flight envelope of impaired aircraft using an innovative differential vortex lattice algorithm tightly coupled with an extended Kalman filter is presented. The approach exploits prior knowledge about the undamaged aircraft parameters to reduce the order of the estimation problem. Point-mass flight dynamic model and a set of approximate analytical methods for structural analysis are used in the development. Estimated damage parameters are used to determine the aircraft aerodynamic, structural, structural dynamic, and aeroelastic parameters. These parameters are then used to estimate the aircraft performance envelope and maneuver limits. As conceptualized in the present work, this data is displayed to the pilot to aid in effectively managing the aircraft flight after impairment. The data can also be used for implementing safe maneuvering and landing guidance laws in the future.