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Why Airports Rename Runways When the Magnetic Poles Move (wired.com)
An anonymous reader shares a report: For decades, pilots heading into or out of Wichita Eisenhower National Airport in southeast Kansas have had three runways to choose from: 1L/19R, 1R/19L, and 14/32. Now, at the orders of the FAA, the airport will spend hundreds of thousands of dollars to give itself a makeover. Workers will repaint those huge numbers at the ends of each runway and replace copious signage. Pilots and air traffic controllers will study new reference manuals and approach plates, all updated to reflect an airport whose three runways have been renamed. World, meet 2L/20R, 2R/20L, and 15/33 -- which happen to be the same runways that have been welcoming planes since 1954.
This is not a "What's in a name?" situation. The runways may be the same sweet-smelling stretches of tarmac they've always been, but the world around them has changed. Well, the magnetic fields around the world have changed. The planet's magnetic poles -- the points that compasses recognize as north and south -- are always wandering about. That's a problem, because most runways are named for their magnetic headings. Take Wichita's 14/32. First off, because planes can land or take off from either direction, you can think of it as two runways: 14 and 32. (Pro tip: Pilots say "one-four" and "three-two," not 14 and 32.) If you're looking at a compass, one end is about 140 degrees off of north, counting clockwise. For simplicity's sake, the headings are rounded to the nearest five, and dropped to two digits. So if you're looking down at Wichita Eisenhower, runway 14/32 is the one running from the northwest to the southeast.
This is not a "What's in a name?" situation. The runways may be the same sweet-smelling stretches of tarmac they've always been, but the world around them has changed. Well, the magnetic fields around the world have changed. The planet's magnetic poles -- the points that compasses recognize as north and south -- are always wandering about. That's a problem, because most runways are named for their magnetic headings. Take Wichita's 14/32. First off, because planes can land or take off from either direction, you can think of it as two runways: 14 and 32. (Pro tip: Pilots say "one-four" and "three-two," not 14 and 32.) If you're looking at a compass, one end is about 140 degrees off of north, counting clockwise. For simplicity's sake, the headings are rounded to the nearest five, and dropped to two digits. So if you're looking down at Wichita Eisenhower, runway 14/32 is the one running from the northwest to the southeast.
Runways are numbered in 10s of degrees. 19R is the right hand runway where the approach is at 190 degrees.
The magnetic poles haven't shifted by 10 degrees, so the better question is why it was labelled 19R in the first place.
Moderating "-1, Disagree" is simple censorship. Have the guts to post your opinion.
The old general aviation runway at San Jose International Airport was runway 29. It was exactly parallel to runways 30R and 30L, they were just built at different times and the pole wandered. The pilots all knew the deal; it seems more confusing to change everything than for pilots to just deal with it.
E pluribus unum
its says they round to nearest 5 then truncate to two digits. Perhaps it was 197-->198.
Forget moving the runways. Move the whole airport to the appropriate place.
Yes.
There is no XUL, only WebExtensions...
For simplicity's sake, the headings are rounded to the nearest five, and dropped to two digits.
This is not consistent with the names given i.e. '1' or '2' since these have only one digit remaining. Either these names should be '01' or '02' or the method is something even simpler: round to the nearest ten and drop the final zero.
... And?
From TFA: "Things only change when the compass reading shifts a certain amount. Say the pole shifts such that the heading of 258 degrees is actually 259 degrees. That still rounds to 260, and the runway would still be called 26. But if the compass reading goes from 258 to 254, you’re now looking at runway 25."
The deviation between magnetic and geographic north depends not just on the poleâ(TM)s degree of movement, but also the angle you are away from the pole. In some areas of the US, yes, the movement has been about 10 degrees since the mid 20th century.
E pluribus unum
That is the problem.
Grandparents point was that if they had built the runway a little more to the right, at 200 degrees rather than 197, it would have been a change from 200 to 201 and no change would be necessary.
Don't index your objects using Natural Keys that are a function of slowly changing values. Yes, the naming convention has a value in identifying location as a function of geographic location, but it's a function of a projected geolocation (magnetic field strength) that turns out to move.
Instead of spending all the money renaming/renumbering the runways, and renumbering them again a couple of decades from now, an engineer would say create a surrogate key that will be constant for all time. Heck, Alpha Beta Gamma, etc would be just as useful in this world of GPS.
Yes. Global Warming on the crust is causing the magnetic dynamo of the earth's core to rotate. That makes total sense.
It takes hundreds of thousands of dollars to paint new numbers? why not wait until they just need repainting?
Magnets, always with the magnets.
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
With the advent of GPS and advancements in ground-based technology able to offer redundancy and higher accuracy, is there a reason we're still this concerned about maintaining a naming schema based on compass readings? Are there that many aircraft still in use today that use nothing but a compass for navigation?
This is kind of like making sure every new car sold comes with a paper map, and every new house comes with a printed copy of the Yellow Pages.
I guess that's what they are doing at the BER construction site....
http://www.der-postillon.com/2018/01/sturm-ber.html
bickerdyke
"You are approved to land on runway Kardashian, lookout for cross traffic from runway Jenner"
If you don't use numbers, that will be the end result.
So if you're looking down at Wichita Eisenhower, runway 14/32 is the one running from the northwest to the southeast.
Incorrect.
Runway 14 would be from the northwest to the southeast, and 32 is southeast to northwest.
So, one, two, or three plane crashes before someone blames another miscommunication on fog? Just another airport for me to avoid. Love it.
I don't get it. One can easily save them the work of renaming the runways (painting and what-not) by inserting a ball bearing in the middle and magnets along the runway! It will automatically align to the magnetic field. Sshhh... some people.
The Runway Naming System allows pilots to send RNS requests to the local Runway Naming Service which of course run on the local Runway Naming Server (Be aware the same acronym holds several correct definitions). Also I t is appropriate to use the designation "RNS Server", "RNS Service", or "RNS System" even though it may be redundant.
These local RNS databases are owned by the airports and are synchronized with the root RNS server several layers up in the RNS hierarchy.
While planes may choose to make RNS requests directly from the root server, for traffic management (bandwidth, not air traffic) they are strongly encouraged to maintain their own local RNS server that caches RNS data from RNS servers at levels lower from the root and geographically local to them. This may be accomplished via RNS Zone Transfers.
It must also be remember that RNS name updates may take several hours to propagate through the RNS hierarchy and for all RNS servers to update with accurate information. So while pilots may have a local cached copy while in flight from their local RNS server, care must be made to verify the RNS data with the authoritative RNS server while approaching the destination airport.
As an example the Wichita "Gandalf" runway upon local RNS resolution currently returns 14/32.
There have been recent reports of RNS spoofing and RNS cache corruption attacks being used, as well as malicious RNS database updates pushed to the RNS root servers and propagated across the RNS network. We are currently working on the next generation of secure RNS Services known as RNSSEC.
Cwm, fjord-bank glyphs vext quiz
The molten iron core of Earth is to blame. All we need to do is wait for the magnetic north to be where we want it, then quickly cool the core so it solidifies in place.
Trolling is a art,
You seriously think that surface conditions have an effect on "the global geodynamo" (the Earth's core)? The wandering of the magnetic poles isn't the result of mysterious changes thousands of miles below the surface; in general it's caused by variations in the Earth's wobbling as it spins on its axis. According to this, the relatively recent acceleration of pole movement is the result of a water deficit in India and the Caspian Sea region.
The magnetic poles have reversed many times in Earth's history. According to this, over the last 20 million years a pole reversal happens every 300,000 years or so. It's been 780,000 years since the last one, so maybe we're overdue.
I suppose it would be too much to ask that runways be named by _compass_ directions rather than magnetic directions, and have the plane's compass + GPS internally compensate for the wandering poles via software updates? Well, I guess that would require every compass to be replaced. Never mind.
captcha: "rambling"
Have you tried talking to a scientist?
So basically you are saying is "why not just round to the nearest 10"? If so, I'm afraid I don't see how that would change anything. You'd still have the same problem, it would just be centered around fluctuations between XX4 and XX5 degrees instead of XX7 and XX8 degrees.
No, it's saying if you are building a runway, it would be wise to try to be angled at the center of an interval, rather than right at the edge of an interval. If it is going to round to 190, then try to exactly be 190, and then it's very tolerant to fluctuations and still be accurate enough.
XML is like violence. If it doesn't solve the problem, use more.
Even with numbered runways, the occasinal pilot still goofs things up. They're supposed to check their compass against the runway numbers when they're at the takeoff point. Even so, one pilot long ago had his compass set not SIX degrees of magnetic variation, but SIXTY. Instead of landing in London they ended up running out of gas over the Sahara. Another time, a cargo plane took off in the 180 direction from Marseilles, and they crashed into a tall hill miles away.
Anthropomorphic magnetic pole shifting is a hoax! The poles have always been where they are, and the Fake Liberal Media just wants you to believe that they're moving to advance their left-wing agenda!
Have you read my blog lately?
To be fair until the mid-90s the poles had wandered but stayed in roughly the same area, since then they've moved dramatically far away from that spot. They might not have thought the heading at Wichita was going to fluctuate that much.
Do they still use magnetic cpmpasses in commecial aviation?
Y thought it would be based a mountain
on GPS thwaw days
They were ysing inertial navigation systems in airliners back in the later 70's
when Air New Zealand were flying scenic trops to Antarctica
of course if someone transposed numbers when typing in the waypoints you could still run into
can it be possible that they are ...
https://imgflip.com/i/22zals">img src="https://i.imgflip.com/22zals.jpg
Higuita
Circular runways are a great idea in theory. The problems are:
1. Repaving / maintenance takes much longer
2. Making a relatively level paved surface 6000' in diameter is tricky to say the least, and might be impossible in marshy areas
3. Keeping a runway of that size snow and ice-free is difficult
4. In rainy areas you need to carve metal-reinforced grooves into the asphalt for traction, which would be ungodly expensive to do in giant concentric circles
It's not like we don't know how to use true north. TVMDC, and all that. What with modern avionics, GPS, etc. you'd think they could deal with true north and not have this problem.
"National Security is the chief cause of national insecurity." - Celine's First Law
magnetic shifts aren't universal. Well, they are, but the measurement of how much they shifted isn't universal. If one is inline with the direction it moved, there is virtually zero change in magnetic compass heading, but if one is perpendicular to its movement, then there is a very large change. This rate of change gets larger the closer one is to the magnetic pole.
Z
Looks like our planet earth is pregnant.
Go ahead and find an example, because your'e just dead wrong.
Hey, I heard that Blockchain is going to solve this problem! Where can I invest?
Geologists are concerned that the magnetic poles might soon go through one of their cyclic reversals, flipping north and south. This would result in a number of years where the earth has no net magnetic field.
If that happens, the FAA will have to direct airports to rename every single runway in this country to "NULL".
The same thing happened at Burbank airport in California decades ago. Runway 7/25 shifted to runway 8/26 when the actual magnetic bearing passed through the midpoint between the two. I fly out of there and it took me ages not to get it wrong...
A more interesting - and physically, more possible - relationship would be the magnetic field wandering and causing climate change. The ratio of masses between our molten core (about 2 * 10^24 kg) and the atmosphere (5 * 10^18) is close to 6 orders of magnitude. Given the temperature of the core (over 4000K), I think taking the atmosphere from ~288K to 290K (like is the concern over the rest of this century, a 2 deg K rise) would have effectively zero impact on that much more massive, much hotter core. However, we do know that the magnetic field has quite a bit of impact on shielding for the Earth, which affects not just solar inputs to the system but cloud formation.
Browsing at +1 - no ACs, I ignore their posts. So refreshing!
The magnetic poles haven't shifted by 10 degrees
They don't need to move 10degrees, they just need to move 1degree when your policy is to round to nearest. That's the problem with rounding. The difference may be represented as 13 and 14, but the actual difference could be 13.4999 and 13.5000. As soon as you round something you lose the information underneath.
Thank God for Slashdot where this can be discussed, because the aviation boneheads who came up with the runway naming conventions obviously never thought any of this stuff through! Moreover, none of the reasoning has ever been documented by those (Government, naturally) selfsame boneheads.
Actually it's moved an awful lot since 1994. For a couple of hundred years it wandered around in a circle in a relatively small area. Since then it's moved very quickly north. If you are standing in the correct place (read: a few hundred miles away from it) you could easily find a spot where it has shifted by 45 degrees since 1990. On top of that magnetic deviation varies depending on where on earth you're standing and varies year by year.
I looked it up and 'magnetic north' at Wichita has shifted by six degrees, hence the change.
Available land and obstacles in the approach have a lot more to do with runway alignment than avoidance of a designation change, which is inevitable.
Reading this aviation stuf and the details in the comments reminds me of messing with AICC e-learning data back in 2002 and trying to convert it into XML or something other more useful. This was an amazing head-trip. You could smell the punchcards and hear the noise of the 60ies batch processors simply by looking at the raw data files. n-dimensional relations were (are) covered across files, data access based on column count, 126 character ASCII (and not a single one more!) more and some other awesome old-school sh*t. It's basically a data format from the steam age of computing. Very interesting, amazing and hilarious in a way but gawdawful annoying to work with in the microcomputer age.
Since Aviation was one of the first industries to have widespread adoption of mission critical electronic data processing this isn't all that surprising, but to be honest, they could really do with a complete redo of all their standards including this arcane runway naming scheme they apparently still have going.
That's just my impression anyway. ... ... Errrm ... maybe they *should* keep things as they are. ...
The offcial replacement for AICC data format btw. is SCROM, an XML based format from hell designed by the US DoD - so it's actually worse.
We suffer more in our imagination than in reality. - Seneca
When an airport has two parallel runways, they are often numbered differently in order to "avoid confusion". When landing at CDG, runways 26R and 27L are parallel.
Online sources of information are probably updated immediately when the runway numbers are repainted. However, many pilots fly with paper charts and airport directories. Either they fly old planes without modern avionics, or they simply want information that will survive a computer hardware failure. These paper documents expire in a few months and _should_ be replaced after expiration. For at least a few months (possibly longer), pilots rely on old information from paper charts and directories to get runway numbers for the airport they are using. If you are approaching XYZ airport and you see runway 19, but your airport directory says XYZ has runway 18 and 00 instead of 19 and 01, that's a problem..
It's not so bad at controlled airports, where pilots have to request landing clearance from air traffic control. The current runway number is given by ATC as part of that clearance. For example: "Cessna 236, cleared to land, runway 19". But at non-controlled airports, it's up to the pilot to broadcast his/her intention to land. There is room for confusion when the number painted on the ground does not match the paper chart. Some pilots would reasonably believe they have arrived at the wrong airport.
Better solution: Only land helicopters.
Actually, the poster seems to be absolutely correct. Here is the Google Maps image for the end of one of Edmonton Airport's runways in Canada clearly showing the leading '0' so Canada, like Europe, appears to require it. However, if you go south of the border to Helena in Montana then their runway does not contain a leading zero.
Consider JFK's longest runway. It's around 14,511 ft long. Even a 1 change will mean more than "a little bit to one side".
Also, runways are typically oriented with regard to prevailing wind direction, so moving the runway may not be optimal for landings and takeoffs.
That's 1 degree. Who knew /. cannot accept degree symbols?
All landings end with a pilot looking out the window and deciding "yeah, that looks about right". The magnetic compass and the data it generates are one piece of a much larger puzzle.
Yes, I'm aware of things like Category 2 ILS, but they don't do stuff like that unless they absolutely have to.
...laura
Isn't everything from 127.51 to 137.4 represented as 13?
The nearest 5 would be either 130 or 135, then the truncation 13
Wow, sent an e-mail as suggested when clicking on "use classic" banner, and got a fast response that addressed my msg
If it is going to round to 190, then try to exactly be 190, and then it's very tolerant to fluctuations and still be accurate enough.
That's not how this works. Runways are built to ensure aircraft have their nose pointed into the wind as much as possible. So if the wind comes from the west during most time of the year, they will build runway 270/90 (27/9). Another matter is, as said here, obstacles. But most of the times airports are built when there are few surrounding buildings.
I'm not a complete idiot... Some parts are missing.
No, it's saying if you are building a runway, it would be wise to try to be angled at the center of an interval, rather than right at the edge of an interval. If it is going to round to 190, then try to exactly be 190, and then it's very tolerant to fluctuations and still be accurate enough.
The primary concern for planning a runway direction is the prevailing wind. It's very difficult for a pilot to land a plane in a crosswind. (There are many YouTube videos on this subject.) Therefore, runways are planned so the plane is flying into the wind as often as possible. If the wind typically has a heading of 185, then that's where the runway goes. Making the heading 190 will only make it more difficult to land the plane.
One of our competitors trademarked the term "hypothesis". From now on, we will call them "boneheaded ideas".
Have you tried talking to a scientist?
Yes, actually. ;-)
https://www.youtube.com/watch?...
Isn't everything from 127.51 to 137.4 represented as 13?
What? No. I have no clue how you got those numbers.
Anything between 125 and 135 is 13.
The runways must move to accommodate the poles shifting. Do I have to explain everything??
The summary says they round to the nearest 5 and then truncate, you seem to be rounding to the nearest 10 (which definitely makes more sense, so maybe the summary is wrong).
Wow, sent an e-mail as suggested when clicking on "use classic" banner, and got a fast response that addressed my msg
Oh I see.
Yeah, the article is confused. There's not much point in "rounding to the nearest 5" if you're then just going to drop the five.
The easiest way to think about it is that you divide the heading by 10, them round to the nearest whole number. Eg. 173 degrees becomes 17.3, round down to 17.
Scientists already know about the climate change in the past and also already know about the previous magnetic reversals. You really think every one of those scientists is dumber than you, and you are the first to think about it? How about the simple fact that the times don't match, so it was tossed as junk right at the start.
It's very difficult for a pilot to land a plane in a crosswind.
It's very difficult for a non-pilot to land a plane in a crosswind. Once your instructor pounds the procedures into your head and you've practiced a bit, landing a plane in a crosswind isn't a big deal. Sometimes it's fun, especially when you can land straight ahead on one main and gradually bleed off airspeed until the other main touches down. That'll put a big smile on your face!
Circle the wagons and fire inward. Entropy increases without bounds.
Yes. Winds, land & obstructions. The pole will move no matter which way you point the runway.
That said, the bigger the plane, the more crosswind component it will tolerate. Crosswind component is the vector perpendicular to the runway. Large aircraft will see increased consideration to land and obstructions, particularly is there is an instrument approach. Lots of airports will have the longest, widest, heaviest rated runway pointed at less than optimal wind direction and have a second (shorter, narrower, lighter duty) runway pointed to match (generally seasonal) high wind from another direction.
Difficulty depends on the crosswind component. Small planes handle 10 knots. Bigger handle a larger component.
FAA would like all airports to have runways appropriate to the prevaling winds at least 95% of the time. If one runway handles it, then you donâ(TM)t get funds for a crosswind. If not, a crosswind is eligible for federal funding. Busier airports like Wichita also get funding for additional parallel runways to increase capacity.
...except when that crosswind exceeds the maximum demonstrated cross-wind for your airplane.
Yes there is, because you get a different result for 156 -> 15 and 158 -> 16.
Take off every 'sig' !!
Yes, I know you get a different result, but that just makes things even worse for that scenario. The whole point of numbering runways the way we do is to get them as close as possible to the actual bearing while using only two digits. So why the hell would you round 177.4 down to 175, and then turn it into 17, when 177.4 is much closer to 18?
"You seriously think that surface conditions have an effect on "the global geodynamo""
And then you continue to explain that that's exactly the case? And link to an article that states that it was generally believed among scientists that the mass redistribution from melting ice caps are the main cause, until someone proposed that smaller climate/human related mass changes at 45 deg latitude have more impact.
Avantslash: low-bandwidth mobile slashdot.
Small planes handle 10 knots [crosswind].
The 1974-75 Cessna 172 has a maximum demonstrated crosswind of 17 MPH (15 knots). This is the maximum crosswind component during which the aircraft has been landed by the manufacturer test pilot. Info from http://www.beverlyflightcenter.com/wp-content/uploads/2017/05/172SPEEDmph.pdf. I'd be interested in seeing the equivalent for a similar sized Piper.
Circle the wagons and fire inward. Entropy increases without bounds.
WTF is the point of this article?
So they change runway designations every half-century due to changing magnetic declination. What is the big deal? How is this even newsworthy?
Anything that uses the earth's magnetic field needs to keep up to date with changing declination. Ever been a scout? Ever done any orienteering? Remember having to correct for it?
Holy crap, are their ANY nerds left in the tech industry? Or, have the hipsters totally taken over? "Like, OMG, you'll never guess what I just heard. Like, the earth's magnetic poles move. Fer real. Like, north ain't really north. Hella cray cray, yo. Now, let's go disrupt some industries with our stable geniusness. "
Pilots know about this and so do airports, it's a part of any navigation system.
Magnetic poles wander a little each year. Around most of the world that translates to a degree or so of drift per year (in some places it can be 2-3, if you're closer to the pole)
A 60-year old runway like at Wichita will have been renamed several times. Yes the signage needs changing but it needs periodic replacement due to weathering anyway.
Depends on where you are. My airport went from 10 and 28 to 11 and 29 about 15 years ago. It's when the needle crosses over and it's less than 5 degrees to the next 10. That is done yearly. Some places are worse than others because of where the mag north is, which is about in the middle of the Hudson Bay right now. It moves around a football field a year. So if you're closer and south, it'll tend to change more. If you're in Florida or Texas, not so much.
Supposedly scientists are concerned that it may switch soon. Perhaps in our lifetime.
Magnetic North vs True North is actually a thing. Since compasses are all magnetic (except for GPS-based compasses), you have to keep track of the angle of declination or you will be truly lost. And this number changes a lot, especially if you are looking at how much it changes "over decades." It's a thing, ask you backpacking friend who actually knows a thing or two about orienteering.
TV-MA - the Beginning: "Ward, don't you think you were a little hard on the Beaver last night?"