Which sources can be used to obtain local magnetic variation?

• A. DoD FLIPs
• B. Tactical Plotting Chart
• C. National Geophysical Data Center
• D. All of the above

Answer: (D)

Local magnetic variation is the difference between true north and magnetic north at your location and time, and you use it to convert between true and magnetic headings for accurate navigation. You can pull this information from several official sources. DoD Flight Information Publications (FLIPs) include planning data that covers local variation for flight routes, making them a valid reference during preflight planning. The Tactical Plotting Chart shows magnetic variation in the plotted area, so you can directly read the values while plotting courses. The National Geophysical Data Center provides authoritative geomagnetic data and declination maps, which let you determine local variation for areas or times not explicitly shown on a chart or to cross-check chart data. Because each source can supply current local variation, all of the above are usable sources. Be mindful that variation changes over time, so verify the data date to ensure accuracy for the intended flight.