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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.
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
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.
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.
The summary was wrong here (writer didn't understand how rounding works)
Dammit, Jim - I’m a Writer, not a Mathematician!
#DeleteChrome
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?
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
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
Hey, I heard that Blockchain is going to solve this problem! Where can I invest?
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!
Nah! Pilot's will just have to fly their planes between the falling skyscrapers on their way to finding the hidden arks that will save the vestiges of the human race. The runway will only need to be realigned after the continents have finished shifting.
Aah, change is good. -- Rafiki
Yeah, but it ain't easy. -- Simba
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.
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.
Actually, it is easy to see if you just use Google Maps - Chicago, O'Hare has single digits painted on the relevant runways as does Montana. Edmonton, Canada and Heathrow, UK have the leading zeroes. So clearly the US does not use the leading zero while everyone else appears to.
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".