Supporting Numerical Investigation During the Recovery of a Steady Longitudinal Flight with Constant Forward Velocity

In the case of unmanned aerial vehicles, for the variation of the elevator deflection there exists a safe interval, the interval for which steady longitudinal flight with constant forward velocity is present. As the elevator deflection is one of the control parameters, when the automated flight control system (AFCS) is decoupled and the value of δ_e is situated outside the safe interval then steady longitudinal flight with constant forward velocity doesn´t exist any more and the flight becomes oscillatory. This phenomenon, and the recovery of the steady longitudinal flight, raise a number of interesting research problems. This paper offers an overview of an instrument able to support numerical investigation for studying the variations of the components of the aerodynamic forces and moments during the recovery of a steady longitudinal flight with constant forward velocity, in the case of an unmanned aircraft.