A novel emergency flight path planning strategy for civil airplanes in total loss of thrust

Emergency flight path planning process was established for the failure of total loss of thrust of both the commercial transport aircraft and the general aviation to improve the flight safety. The process of the path planning combined the landing site search and the post failure trajectory generation together. The dynamic pressure schedule was substitute for the rigid geometric preset as the restriction to ensure the smooth speed variation. Based on the variation time scales separation, the propagation logic without iteration was established for longitudinal states and commands. The top ranked landing site was selected from the approximate footprint with the radius determined by current flight states, according to the safe condition. Furthermore, a three step lateral trajectory generation algorithm can generate final trajectory and commands by linear interpolation. The trajectory can be rapidly generated for the selected landing site with satisfactory accuracy due to the incorporation of the coupling effects in flight dynamics, and the guidance commands can be tracked by basic guidance control law.