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by jonburs 4867 days ago
The magnetic north pole isn't in the same spot as the geographic north pole -- see http://en.wikipedia.org/wiki/Magnetic_declination.
1 comments

Does ATC use magnetic bearings?
Yes. This is why runway numbers (which are the heading with the last digit removed) are known to change from time to time. Aviation charts also display the variation between magnetic and true north. (See the purple dashed lines with 14/15° W http://skyvector.com/?ll=40.55464932694554,-70.9421666906757... )