I. Introduction n Ref.[1] nonlinear guidance logic is proposed that showed superior performance in guiding UAV’s on circular trajectories. The logic approximates a proportional derivative PD linear controller for small departures from a straight path. It includes adaptive gains depending on inertial velocity of the UAV, making it more suitable for external interferences. That research did not cover longitudinal controls. As the UAV tracks a straight line for small deviations the guidance law tends to be a PD controller of the cross track error. For a type 0 system subject to external disturbances this controller could create constant errors. In Ref.[2] a nonlinear guidance law using the across and along track error is implemented for a straight path. It is designed to handle both low-wind and high-wind cases in a simple manner. That design does not require complex switching decision logic as did their previous design, and it stably tracked flight plan segments starting from any initial condition. That design was verified in nonlinear flight simulations. That research did not deal with the longitudinal dynamics and was conceived for a single straight segment path.