When a valid nav aid ICAO identifier is entered into a direction, the Magnetic Variation Area buttons are enabled which represent what magnetic variation type to use with the nav aid and the Direction.

The buttons from left to right stand for True (T), Slaved (S), Chart (C), User Defined (U) and Flight Sim (FS).

A default magnetic variation type is automatically selected based on the nav aid type. E.g. a VOR will default to Slaved.

Clicking on any of the buttons changes the magnetic variation type to be used.

When using User Defined, ensure you enter a magnetic variation in the User Defined field.


The Flight Sim button (FS) over-rides which data is used for Slaved and Chart magnetic variations.

When enabled for Slaved, the slaved magnetic variation from the flight sim data is used, instead of the Our Airports data. If the nav aid is a Custom Nav Aid the FS button makes no difference as Custom Nav Aids take priority in all circumstances.

When enabled for Chart, the magnetic variation of the FS Area is used instead of the Actual Chart value entered.

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