What effect does a change in magnetic variation have on flight plans?

A change in magnetic variation directly affects the relationship between true north and magnetic north. In aviation, navigation relies on magnetic headings, which are based on magnetic north. When there is a change in magnetic variation, it can lead to discrepancies between the pilot’s intended course and the actual heading needed to maintain that course.

If the magnetic variation has changed, pilots must recalibrate the headings they use for navigation to ensure they are still accurate. This recalibration might involve adjusting for a greater or lesser angle depending on whether the variation has increased or decreased. Thus, as the magnetic variation shifts, it can necessitate recalculating the headings to ensure that the aircraft remains on the correct flight path.

Understanding this adjustment is crucial for providing safe and precise navigation during flight, particularly because failing to account for these changes could lead to navigation errors. Such errors could result in deviating from the intended route, which could impact overall flight safety and efficiency.