A method for flight plan modification in an aircraft, comprising: determining, by a processing system comprising a processor and a memory device, that the aircraft is operating on a flight plan; identifying a segment of interest within the flight plan, wherein the segment of interest is defined by a starting location and an ending location that is a distance from the starting location; by a starting waypoint and an ending waypoint; or by a current position and an amount of time; determining a geographical environment associated with the segment of interest; determining, by the processing system, a relevant air traffic control for the geographical environment; requesting, from the relevant ATC, an amount of deviation from the flight plan for the segment of interest; obtaining, from the relevant ATC, permission for the amount of deviation from the flight plan for the segment of interest; using at least the amount of deviation to calculate a shortest path for the segment of interest, wherein the shortest path is an air distance; modifying the flight plan for the segment of interest such that the aircraft flies the shortest path for the segment of interest; and, prior to reaching the ending location, the ending waypoint or an expiration of the amount of time, the method further comprises the steps of identifying, by the processing system, a second geographical environment associated with a second segment of interest; determining, by the processing system, a second relevant air traffic control for the second geographical environment, the second relevant ATC being different from the relevant ATC; requesting, from the second relevant ATC, a second amount of deviation from the flight plan for the second segment of interest; obtaining, from the second relevant ATC, permission for the second amount of deviation from the flight plan for the second segment of interest; using at least the second amount of deviation to calculate a second shortest path for the second segment of interest; and modifying the flight plan for the second segment of interest such that the aircraft flies the second shortest path for the second segment of interest. determining, by a processing system comprising a processor and a memory device, that the aircraft is operating on a flight plan; identifying a segment of interest within the flight plan, wherein the segment of interest is defined by a starting location and an ending location that is a distance from the starting location; by a starting waypoint and an ending waypoint; or by a current position and an amount of time; determining a geographical environment associated with the segment of interest; determining, by the processing system, a relevant air traffic control for the geographical environment; requesting, from the relevant ATC, an amount of deviation from the flight plan for the segment of interest; obtaining, from the relevant ATC, permission for the amount of deviation from the flight plan for the segment of interest; using at least the amount of deviation to calculate a shortest path for the segment of interest, wherein the shortest path is an air distance; modifying the flight plan for the segment of interest such that the aircraft flies the shortest path for the segment of interest; and, prior to reaching the ending location, the ending waypoint or an expiration of the amount of time, the method further comprises the steps of identifying, by the processing system, a second geographical environment associated with a second segment of interest; determining, by the processing system, a second relevant air traffic control for the second geographical environment, the second relevant ATC being different from the relevant ATC; requesting, from the second relevant ATC, a second amount of deviation from the flight plan for the second segment of interest; obtaining, from the second relevant ATC, permission for the second amount of deviation from the flight plan for the second segment of interest; using at least the second amount of deviation to calculate a second shortest path for the second segment of interest; and modifying the flight plan for the second segment of interest such that the aircraft flies the second shortest path for the second segment of interest.