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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.
There are a *lot* of aircraft out there that don't have GPS systems built in, and even if they are, they are subject to failure. Airports are built to be properly usable to the lowest common denominator of available technology, and in an emergency, the lowest common denominator may well be the basic magnetic compass.
Emergencies aside, many aircraft (especially home built's, ultralights, and a lot of other non-commercial aircraft) don't bother with things like GPS.
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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 general idea is to REDUCE the number of things that a person flying with passengers in a can in the air has to think about in an emergency, under stress in low visibility conditions when the aircraft has lost GPS or other critical systems and the baby in the back seat is screaming because of ear pain from required rapid altitude changes and the tower's radio system is down ... but the magnetic compass is working as always, and the sectional chart has a nice big number that MATCHES THE COMPASS. Because you're going to land or die in the next 60 seconds. All of these things are designed around worst-case, high-stress possibilities (which almost never occur, but sometimes do).
Don't disappoint your bird dog. Go to the range.