3 ms·

If it's a compass, then why is it 20 degrees off?

• jonburs 14y ago
  The magnetic north pole isn't in the same spot as the geographic north pole -- see http://en.wikipedia.org/wiki/Magnetic_declination http://en.wikipedia.org/wiki/Magnetic_declination.
  • taejo 14y ago
    Does ATC use magnetic bearings?
    • rory096 14y ago
      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,-70.94216669067579&chart=15&zoom=4 http://skyvector.com/?ll=40.55464932694554,-70.9421666906757... )