A SYSTEM AND METHOD FOR NAVIGATING AN AIRCRAFT

System 10 for navigating an aircraft 12, comprising a flight planning system 14 configured to prepare a set of at least three different trajectories for a flight from a departure point to a destination point, a flight verification system 16 configured to verify each trajectory of the set of trajectories, an onboard flight management system 26 to be installed at an aircraft 12 and having a storage unit 28 for storing the set of trajectories, wherein the flight management system is configured to select one of the trajectories from the set of trajectories as an active trajectory for a current flight of the aircraft, wherein the flight management system 26 includes a replanning unit 30 configured to change, during the current flight, the active trajectory by selecting a second trajectory from the set of trajectories as the active trajectory for the current flight, such as to continue the current flight based on the second trajectory t.