I found out that "All charts are drawn in reference to true north". But if my heading indicator shows a magnetic heading on my flight display, how do I apply the true heading value on the charts using my magnetic heading in pdf when flying in IFR conditions? Also, I wonder about the MSA alignment on the chart which I posted. Usually, in MSA parts, the MSA is not aligned with the chart's longitudes and parallels. It's rotated slightly clockwise or counterclockwise. And finally, are the coordinate lines on the charts relative to true north or to magnetic north? They're all mixed up in my head, I'd appreciate it if you could help.

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1 Answer 1


Magnetic North is generally used for a both aircraft navigation displays and chart representations.

Yes, it is correct that "All charts are drawn in reference to true north", but all headings and tracks are given as Magnetic.

The exception is aircraft and charts used in the high Arctic latitudes. (generally north of 82N or south of 82S)

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Most aircraft navigation displays are designed to display magnetic north. (some aircraft can select between Magnetic North and True North).

MSA charts are rotated to orient to Magnetic North, but so is the rest of the chart.

The Lat/Long coordinate lines are oriented to True North because they don’t represent headings or tracks.

Some charts used in the far north will use True North headings and tracks, but they will include “T” as in “359T”.

So, when using your chart, just follow the magnetic headings or tracks and as written, and disregard the orientation of the chart.

  • $\begingroup$ Are the MSA sections based off a VOR referenced to current magnetic North or to the VOR radials, which used magnetic North when the VOR was built (or last adjusted)? $\endgroup$
    – Bianfable
    Oct 2, 2022 at 13:14
  • $\begingroup$ @Mike Sowsun thank you so much sir, much obliged. $\endgroup$
    – pilot162
    Oct 2, 2022 at 13:20
  • $\begingroup$ @Bianfable I don’t know, but I would think that any differences would be negligible. $\endgroup$ Oct 2, 2022 at 13:39
  • 1
    $\begingroup$ @MikeSowsun Well that would depend on the VOR. For most it's probably insignificant, but for some VORs the difference can be quite large. Anyway, I looked at the Jeppesen chart legend and it says "Sector defining radial/bearing", which to me sounds like they are using VOR radials (if it is based off a VOR, else bearing to fix). $\endgroup$
    – Bianfable
    Oct 2, 2022 at 13:48
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    $\begingroup$ @Bianfable If they’re shown as radials off a VOR, they’ll be from whenever that VOR was last calibrated, so use the CDI. If they’re just headings, use the compass. $\endgroup$
    – StephenS
    Oct 2, 2022 at 18:52

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