Abstract: A flight management system of an aircraft is provided allowing notably the calculation of a trajectory over the terrestrial globe. The calculation of a trajectory is carried out with respect to a true North, true North being a navigation term referring to the direction of the geographical North pole with respect to a given position. When the current or estimated position of the aircraft is level with the pole, it then becomes impossible to define true North, true North being defined in all the directions or in no direction, depending on the calculation facilities used. The flight management system makes it possible to use a single calculation procedure whatever the current position or the position to be reached of the aircraft on the terrestrial globe.

Abstract: A flight management system of an aircraft is provided allowing notably the calculation of a trajectory over the terrestrial globe. The calculation of a trajectory is carried out with respect to a true North, true North being a navigation term referring to the direction of the geographical North pole with respect to a given position. When the current or estimated position of the aircraft is level with the pole, it then becomes impossible to define true North, true North being defined in all the directions or in no direction, depending on the calculation facilities used. The flight management system makes it possible to use a single calculation procedure whatever the current position or the position to be reached of the aircraft on the terrestrial globe.