Abstract: The invention relates to a method for controlling aircraft. A specified flight position of the aircraft is compared with a piece of geographical height information corresponding to the provided flight position. The piece of geographical height information is obtained from a set of pieces of height information, said set corresponding to a geographical area, wherein for a first part of the geographical area, the set of pieces of height information indicates a piece of relevant geographical height information and for a second part of the geographical area, the set indicates a piece of height information deviating from the actual geographical height. The second part of the geographical area comprises a first special area, in which the aircraft is only permitted to operate to a limited degree.