A nontrivial fraction of aviation accidents are caused by in-flight damage or failures that reduce performance. Researchers are working to ensure future avionics recognize the impact of damage/failures and guide the aircraft to a safe landing. This thesis presents an end-to-end Adaptive Flight Planner (AFP) for such emergencies and applies it to a damage situation in which a Generalized Transport Model (GTM) aircraft loses a significant fraction of its left wingtip. Trimmed (non-accelerating) flight conditions define the post-damage/failure aircraft flight envelope. A landing site search algorithm is augmented to define the reachable landing footprint and to prioritize the feasible landing runways within this region. End-to-end landing trajectories are constructed as a sequence of trim states and corresponding transitions. An LQR-based PID nonlinear controller enables the damaged GTM aircraft to correctly track trajectory commands over trimmed flight and transition segments. A suite of emergency scenarios are used to evaluate AFP performance.