Optimal and near-optimal take-off manoeuvres in the presence of windshear

This paper is concerned with the development of short-range forward-look guidance strategies for take-off manoeuvres in the presence of windshear, with reference to flight in the vertical and horizontal planes. In addition to the horizontal shear, the presence of a downdraught is assumed. First, two open-loop optimal escape strategies are considered, i.e. a performance maintaining strategy and a survival strategy, where it is assumed that the windshear is detected in an early stage of the encounter. Next, two closed-loop guidance strategies featuring short-range forward-look detection, which closely approximate the open-loop optimal solutions, are developed. Numerical results show that lateral manoeuvring, in which an aircraft is turned away from the microburst, improves the flight performance significantly in both optimal escape strategies. The simulation results demonstrate that the employed closed-loop guidance strategies are able to approximate closely the open-loop optimal trajectories, in both longitudinal and lateral escape manoeuvres.