This thesis refers to windshear recovery systems, designed to increase the survival capability of an aircraft. It is known that optimal trajectories in take-off are difficult to implement because of the lack of global information on the wind flow field and the lack of enough time and computing capability onboard. Consequently, one is forced to employ local/prior information on the windshear and the downdraft. An investigation of the gamma guidance scheme is presented with reference to the take-off problem. Attention is focused on the feedback control form of the gamma guidance law. This law is modified so that not only the aircraft can react to unfavorable shears, but can take advantage of favorable shears. Indeed, every unfavorable shear (central core of the downburst) is both preceded and followed by favorable shears. Therefore, a systematic investigation of the effect of parameters on survival capability is presented for two windshear models. The results indicate that, through a proper choice of the parameters, the windshear efficiency of the gamma guidance law is within 5% of that of an optimal trajectory. (Abstract shortened with permission of author.)