If you’ve just taken off ATC may say fly runway heading - again an easy one using your heading indicator which is synced to your magnetic compass.Īs a side note, modern avionics like G1000 auto sync your heading indicator to magnetic. Wind direction reports at the field? Magnetic, so that you know how many degrees off the wind is from your landing direction and can do a bit of mental math to get the crosswind component. So that’s the fundamental reason why most things flight related are magnetic except rare items like winds aloft reports. Took me a while to get the compass visualized in my head but now if I’m making a visual approach and they give me a runway I can look at my current magnetic heading on my heading indicator - which you periodically sync to your magnetic compass - and know exactly what direction relative to my current heading I’ll be landing. It’s super helpful and intuitive when you’re flying. When you take off / land, runway headings directly corresponding to your heading are a good sanity check - alarm bells go off if you're meant to be flying west but come across Runway 09 in front of you (the opposite!), not to mention we still rely on magnetic compasses - you don't want to be coming into land at a track for 281 degrees and see 27 painted on it chances are something went wrong somewhere. If you go long enough - the variance also changes so you have to take that into account when planning your route.

What's more interesting is that most navigation charts have all their directions and bearings in 'true' north, with the variance also charted, whereas when you actually fly you track the magnetic headings plus/minus the variance. My actual track will be 281 degrees magnetic, not 270. In order to head directly west, I can't just let my compass point north and go directly perpendicular port - I have to point north plus 11 degrees, and then go. Magnetic compasses always point to magnetic north, but with earth being molten metals - magnetic north likes to move around a bit, so we work out the difference between the two and apply it to the directions we track.įor example, where I am - the difference is around 11 degrees. The difference between them depends on where you are on the globe - it could even be 180 if you happen to stand in the middle of the two! This is only one half of what actually happens while navigating you have true north and magnetic north - see.

Tampa airport runway numbers