1. A stability augmentation method for an adaptive guidance system for a parasail, for use in regulating the altitude and heading of the parasail, said method comprising the acts of: generating a reference model output signal based on a reference model; receiving from an attitude and heading reference system, an actual heading rate signal; generating an error signal by a summer, said error signal proportionate to the difference between said reference model output signal and said actual heading rate signal; and responsive to said error signal, generating by a neural network an adaptive signal, wherein said neural network is responsive to both weights and to a vector comprising a plurality of known variables, wherein said weights of the neural network are adapted based on said error signal for use in regulating the altitude and heading of the parasail.