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Old 25th Jun 2013, 16:55
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MarkerInbound
 
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Here you go.

What the writer is seeing is normal, and is not generally a problem.

There is magvar and then there is magvar. Magnetic variation at its most basic is simply the difference between true north and magnetic north. With facilities, it gets more complicated, because actual magnetic variation moves constantly as the magnetic poles move. Procedures cannot be updated constantly to reflect exact magnetic variation at any given time, so facilities are assigned a magnetic variation value, or reference north angle, based on a five year epoch magvar value for the area (Determined by NOAA, NGS and NOS.), and is not changed until it differs from the epoch year value by by several degrees (Used to be 3 degrees; might still be but I don't know what's current.). In some cases, facility reference north can vary from chart calculated magvar by several degrees because it's a big job to update magvar on facilites, especially some facilities that support dozens of procedures. It's a compromise between use of available resources and keeping facility magvars reasonably close to actual values. This does not present a problem in practice, since airplanes are protected when using VORs by selecting the published radial, and accurately navigating the presented course.

Here is a relevant excerpt from the 8260.19E:
http://www.faa.gov/documentLibrary/m...r/8260.19E.pdf

Start at Page 67 (Chapter 5, Section 2)
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