Air travel can be a real headache. Before even taking off, there are so many steps to complete and account for. Gathering boarding passes, getting through security, finding the right terminal, and waiting at the gate all add up to a rather hectic and draining experience. On top of all this, Earth’s magnetic field is creating a new problem for runways around the world.

Believe it or not, every plane is guided by Earth’s magnetic field, or at least its influence on a compass. Every runway is assigned a two-digit number that corresponds with how many degrees away from magnetic north the runway is positioned. Another way of putting it is the compass direction. For example, a runway marked 14 would have a directional heading of 140 degrees. A runway with 26 would be 260 degrees.

These numbers give the pilot and air traffic control a precise direction in order to keep track of the plane’s trajectory. In other words, it’s not specific enough to simply designate between north, south, east, and west.

To complicate things a bit more, airports around the world will soon find themselves with runway numbers that don’t match up to true magnetic north. Estimates suggest some runway numbers could be off by as much as 10 degrees! But why the sudden change?

Poles on the Move

There’s a difference between “true” north and magnetic north. The former refers to the top of the world where the only direction you can go is south. On the other hand, magnetic north is a little more elusive. Over time, Earth’s magnetic poles “wander.” In fact, since 1831 (when we began tracking it), the magnetic north pole has meandered hundreds of miles across the arctic. While this is a gradual phenomenon, it eventually skews the direction of a compass needle.

So what does this mean for the world’s runways? Only that ground crews are going to be pretty busy repainting numbers to match each runway’s true direction. Have no fear, Earth’s magnetic field won’t be the reason your next flight is delayed.

For more magnetic news and facts, check out the rest of our blog!