Abstract: Statistics of large civil airplanes reveal that the accident rate is the highest in the approach and landing phases and that most of these accidents exhibit initial abnormal energy status which evolves into one of the end accident types such as loss of control, hard landing, tail strike, runway overrun, or go-around failure. This paper summarizes and focuses on the above five types of end accident types, establishing a generic flight simulation tool for large civil airplanes. Stochastic simulation and correlation analysis show the deviation tendency of energy state parameters leading to different types of approach and landing risks. Stochastic simulation results further provide safety boundaries determined by the key energy parameters to avoid the above five end accidents. Warning criteria of the abnormal energy status are then established, described by air-speed vs. glide angle envelops under possible wind conditions and go-around throttle settings, which are shown to be accurate and non-conservative for approach and landing risk warnings caused by abnormal energy. The proposed methods can be applied to on-board risk warning and the related flight control function design for approaching and landing safety of large civil airplanes.

Key words: large civil airplanes, approach and landing, go-around, energy state, flight safety, abnormal energy warning