Boeing Field renumbers runways

This was pretty interesting. Boeing Field in Seattle released a Notice To Airmen recently that the runway numbers have changed at the airport. Runway numbers align with their heading, and the magnetic pole has moved far enough that the runway heading changed.

The previous runway numbers were 13R/31L (landing one way, the runway heading was 130 degrees,going the other, it was 310 degrees). The pole has moved more than 5 degrees, which makes the new runway heading 140 and 320 (14R/32L). The last time this happened was in the 1950s, when it was 12R/31L. The Seattle-Tacoma airport and others in the area are evaluating when they will change their runway numbers.

www.seattletimes.com...

a reply to: Zaphod58

That is fricken cool!

That is just significantly "wow"...

Gee, I wonder if the change of the poles axis has anything to do with that climate change thingy....

That's interesting . Maybe it changes every 70 years ish...(give or take )... Are other airports across the world changing their lanes ?

a reply to: Meldionne1

Not yet, but they're going to have to before long.

I was under the impression that with GPS and modern avionics this was no longer necessary. I did not realize pilots still rely on magnetic compasses.

It is interesting to look at old navigation charts to get an idea of how fast magnetic north is moving. (Nav charts give the variation of magnetic north plus the expected rate of change)

originally posted by: HorizonFall
Gee, I wonder if the change of the poles axis has anything to do with that climate change thingy....

Yes, sure it does!!
It is people's fault, because...because humans use electricity which creates magnetic fields, yes, that's it!

Now, please send your check to Al "rapist of masseuse in hotel" Gore, so that he can use the money to "save" the planet by...by.....by doing......real important stuff and sheeet.....

a reply to: jrod

Those are great tools, but you still need runway heading. It lets you plan ahead and be mostly lined up before you get there and you can be ready for any obstacles in your way, depending on airport.

originally posted by: Zaphod58
a reply to: jrod

Those are great tools, but you still need runway heading. It lets you plan ahead and be mostly lined up before you get there and you can be ready for any obstacles in your way, depending on airport.

you'll have to excuse my ignorance, but how does changing the numbers painted on a runway help in determining where to "line up"?....wouldn't flying over a 6,000+ foot-long, straight-as-an-arrow, runway(S) that has a #(number) and an "L" for left, and a "R" for right on it, be enough?...how about when it's foggy, or cloudy, don't you rely on instruments at that point to get your "line up"?

a reply to: jimmyx

You generally don't overfly the runway. You start your approach miles out from the runway, and line up on the runway heading. You do use instruments, but you have to be more or less pointed at them during the approach. Knowing the runway heading makes things a lot easier.

originally posted by: Zaphod58
a reply to: jimmyx

You generally don't overfly the runway. You start your approach miles out from the runway, and line up on the runway heading. You do use instruments, but you have to be more or less pointed at them during the approach. Knowing the runway heading makes things a lot easier.

sorry about the delete

a reply to: jimmyx

No. The runway number is the magnetic heading of the runway. They line up on that heading to line up with the runway. The number on the runway is a final confirmation on approach.

This isn't really anything new. I remember reading about runway heading realignments decades ago because of the wandering poles. I suppose what floats it to the top is it's Boeing Field. Realigning O'Hare would get attention, too.

so how many % have we observed it shifting since 1950s?

originally posted by: jrod
I was under the impression that with GPS and modern avionics this was no longer necessary. I did not realize pilots still rely on magnetic compasses.

It is interesting to look at old navigation charts to get an idea of how fast magnetic north is moving. (Nav charts give the variation of magnetic north plus the expected rate of change)

GPS is so that the avionics displays know the location automatically and display the position of the aircraft on aviation charts of airports accordingly. They still need to know that their heading and the flight corridor of each runway are aligned.