The invention relates to a procedure for guiding an aircraft in the approach phase comprising of receiving information on a predefined approach path, this information being contained in a message M4 originating from a ground beacon transmitting on the same transmission channel as that of a beacon of a GBAS type positioning accuracy augmentation system, receiving differential positioning radio satellite signals, and correction information from these satellite radio signals in the form of a message M1' originating from a ground central station of an SBAS type positioning accuracy augmentation system, via geostationary satellites of this augmentation system, calculating a corrected position based on the positioning signals and correction information, calculating an elevation and horizontal guidance deviation of the aircraft relative to the predefined approach path, based on the corrected position and information on the predefined approach path.