An example method for modifying a flight path of an aircraft includes receiving real time positioning estimates for an aircraft, receiving an actual navigation performance (ANP) of the aircraft informative of uncertainty in the position estimate, receiving a required navigation performance (RNP) instrument flight procedure for the aircraft, receiving spacing input from an air traffic controller that indicates spacing requirements between the aircraft and one or more other aircraft, receiving information relating to communities underneath the flight path, calculating, by a system onboard the aircraft, a modification to the flight path to be flown by the aircraft that causes the aircraft to remain within the containment boundaries of the RNP instrument flight procedure while reducing noise impact to the communities underneath the flight path and meeting the spacing requirements of the air traffic controller, and displaying a visual representation of a modified flight path for the aircraft.