| Version | 1 |
| Created | 01/01/2016 00:00 |
| Last Updated | 11/24/2020 22:31 by Finn Hutter |
Winds reported in the METAR are in TRUE heading while all flying is done using MAGNETIC heading. FS9, X-Plane, MSFS, P3D, and all other modern sims do this conversion on the fly. In the Seattle ARTCC, the difference between TRUE and MAGNETIC heading varies between 15 and 19 degrees East. This could significantly affect the handling of a small aircraft when attempting a cross-wind landing.
MAGNETIC heading should be used for determining the active runway. Also, winds, when given to the pilot, should be given using MAGNETIC HEADING. The conversion for the entire ARTCC is achieved by SUBTRACTING 20 from the TRUE heading. The magnetic variance changes annually, but to make it a little bit easier, just subtract 20.
So, given the following METAR for Seattle:
KSEA 020653Z 31005KT 10SM FEW045 FEW250 22/16 A3004 RMK AO2 SLP176 T02170156
Winds should be reported to the pilot as: Wind 290 at 05