We’ve Always Done It That Way
Magnetic north, modern navigation, and the inertia of legacy systems
Have you ever looked at something in your work and thought:
“Why do we do it that way?”
You ask around.
Nobody really knows.
“We’ve just always done it that way.”
Navigation might be one of those things.
In aviation, marine travel, and even backcountry hiking, we still talk about direction using magnetic north.
But here’s the thing: almost all modern navigation systems don’t actually navigate using magnetic north.
So… why are we still speaking that language?
A Quick Step Back
Any point on Earth can be described using latitude and longitude. If you know where you are and where you want to go, you can theoretically travel in a straight line between those two points.
The direction of that straight line is based on true north — geographic north — the fixed North Pole where all lines of longitude meet.
But your compass?
It doesn’t point there.
It points to magnetic north, which is somewhere else entirely… and moving.
For decades, magnetic north sat in the Canadian Arctic. Today it’s drifting across the Arctic Ocean toward Siberia.
Which means this:
The reference point we use for direction is literally sliding across the planet.
That’s Where “Variation” Comes In
Maps are drawn relative to geographic north. Somewhere on the chart you’ll see a little note that says something like:
“Variation 15°W (2025), decreasing 0.2° annually.”
That difference between true north and magnetic north is called variation (or declination).
And because magnetic north moves, variation changes.
Slowly.
Constantly.
Forever.
Over short distances, it’s manageable. But over long distances — or where precision matters — those few degrees start to matter.
Here’s the Irony
In modern aircraft, direction is actually computed using true north.
GPS? True.
Inertial systems? True.
Radio-based position fixes? True.
The aircraft calculates position and track using geographic references.
Then the system converts everything to magnetic.
Aircraft present direction in magnetic.
Airways are published in magnetic.
ATC headings are magnetic.
Runway numbers are magnetic.
Wind direction reports are magnetic.
We built a system that thinks in true… but talks in magnetic.
Canada Already Does It Differently (Sometimes)
In northern Canadian airspace, headings are issued in true north.
Why?
Because near the magnetic north pole:
Magnetic variation becomes huge.
It changes rapidly over short distances.
Magnetic compasses get unreliable.
So they stopped using magnetic.
And it works.
Which brings us back to the question:
If true works… and modern navigation already uses true internally… why not just used true north?
Because Switching Would Be Massive
Imagine flipping the entire aviation system at once.
Every runway number would change.
Every chart would need updating.
ATC phraseology would shift.
Weather reports would need alignment.
Pilots would have to retrain muscle memory built over decades.
International coordination would be required.
From a safety perspective, the transition itself would be the biggest risk.
If you’re in an area with 20° of variation and someone misapplies it during the switchover? That’s not a small mistake.
But Once You Switch…
Something interesting happens.
The actual direction from Point A to Point B never changes.
What changes is the magnetic correction layered on top.
If everything were true-based:
Databases wouldn’t need magnetic updates.
Charts wouldn’t need variation adjustments.
Runways would never need renumbering.
The system would stabilize permanently.
It would align with how modern navigation actually works.
So Why Haven’t We Done It?
Probably because magnetic north still works well enough.
And because changing global aviation infrastructure is not like updating an app.
There have been white papers. There have been industry discussions. Even NAV CANADA, Canada’s air travel control organization, has written publicly about the cost and complexity of managing magnetic variation year after year.
But for now?
We keep converting true to magnetic.
Because we’ve always done it that way.
Or maybe, one day, a new generation of pilots will ask:
“Why are we still using a moving pole as our reference?”
And someone else will answer:
“We’ve just always done it that way.”