Aircraft Longitudinal Guidance Based on a Spatial Reference

In this study, instead of using time as the independent variable to describe the guidance dynamics of an aircraft, distance to land, which can be considered today to be available online with acceptable accuracy and availability, is adopted. A new representation of aircraft longitudinal guidance dynamics is developed according to this spatial variable. Then a nonlinear inverse control law based-on this new representation of guidance dynamics is established to make the aircraft follow accurately a vertical profile and a desired airspeed. The desired airspeed can be regulated to make the aircraft overfly different waypoints according to a planned time-table. Simulations results with different wind conditions for a transportation aircraft performing a descent approach for landing under this new guidance scheme are displayed.