I can actually answer this one. They are both computer generated and created by people. Depending on what they are trying to do they will sometimes create waypoints that makes a sentence like the one for the RNAV plate at Portsmouth, NH that spells out “I tawt I taw a puddy tat”. I know I’ve a number of plates that were made with funny points.
In the past 6 months or so there were a bunch of waypoints in the midwest that were named for Star Wars vehicles and characters. Some points are named so the pilot knows they are leaving or entering a new airspace.
Every so often the computer will throw out a name that wouldn’t normally get approved. I’ve seen NIPPL or NIPLE at least twice. They get rescinded within a day or two.
Thank you for that. It’s always mystified me. For example a current flight from Toronto to Vancouver has the following routing: URSAL3 KASED DLH MOT BEVEL YXC J500 LOCAN BOOTH CANUC5. Craziness! The only one that makes any sense is YXC, which presumably refers to Cranbrook airport and would be more or less directly on the flight path into Vancouver.
Out of curiosity I’ve done some in-depth looking into the origins of IATA airport codes and most of them make some kind of mnemonic sense, though sometimes you need to do some digging to discover their origin. Not sure about the 4-letter ICAO codes, but in North America, all (or almost all) are simply the IATA code prefixed by “K” for the US, and by “C” for Canada. In Europe and elsewhere there’s typically no relationship between the IATA and ICAO codes. The ICAO codes are used for navigation, the IATA codes for most other things.
Also of interest: those letters come from the universal ITU-assigned prefixes for each country in the world, which may consist of one or two letters. The US is assigned more prefixes than any other country, including K, N, and W and possibly a couple of others that I forget. They’re used for a variety of purposes but they all come from the same assignment authority. Thus the ICAO codes for all US airports begin with “K”, all US commercial broadcast station call signs begin with “W” or “K” (based on an east-west divide), and all aircraft tail numbers begin with “N”.
I don’t know much about Canada, and I am not a pilot, I just make the US charts. I looks like J500 is a Jet route so the plane would follow that and the fixes along the way. I’m guessing that URSAL3 is a departure plate and CANUC5 is an arrival plate.
Some of the airport codes are sometimes older airport names and the codes don’t change. They might have made more sense then. You can name your airport anything you want, I know there are a couple of Spaceports out there that are not meant for actual space flights and one was a dirt runway. I wish I could remember where it was at as we had a big discussion on how to chart the name as it was so long.
BTW, thanks for that actual chart. I forwarded it on to a friend who is interested in such things. The actual waypoint names are “ITAWT ITAWA PUDYE TTATT”. And if you miss the approach and need to go into a hold, you circle around IDEED – as in, IDEED, IDEED TAWA PUDYE TTATT!
Your last paragraph is spot on. The rest is decent (and good sleuthing), but as you imply, it’s a complicated and not 100% consistent mess. That you didn’t get as right as I suspect you think. It got started in the 1920s w ITU and the US railroads, and here we are 100 years later, stretched well past the clear and simple point.
IATA codes are only really used for airline ticketing. And are 3-letter codes. Because that’s what US railroads used for station identifiers.
ICAO airport codes are 4 characters using essentially Kxxx for USA, Cxxx for Canada, and most everybody else is based on a regional model. In the regional model the first letter is the region, the second is the country and the last 2 are more or less arbitrary and identify the specific airport:
EGLL decodes as Northeast Europe, Great Britain, airport connected somehow (perhaps weakly) to the letters LL. In fact it’s London Heathrow.
MDSD decodes as Gulf of Mexico/Central America, Dominican Republic, Santo Domingo.
MPTY is Gulf of Mexico/Central America, Panama, Tocumen/Panama City.
The regional & country part is very logical, but with only 2 letters, the connection to the human readable name of the actual airport is often tenuous at best.
That’s airports. We don’t much navigate to, from, or via airports as such. So how do we navigate? With beacons, fixes, and airways.
Traditional radio navigation beacons (1940s-1990s VOR or the even earlier NDBs) generally have 3-letter ICAO identifiers. Some have just 1 or 2 letter identifiers. So the same format as an IATA airport, but totally not the same thing. In the modern IRS/GPS world, the lat/long of these stations is stored in the database so one can navigate relative to the same identifier, but using GPS, etc., not the actual radio signals coming from the VOR or NDB at that spot
“Fixes” are pre-defined arbitrary spots on the ground. By ICAO their identifier is 5 letters and is reasonably pronounceable. In the radio-based days they’re defined as X miles distance on the Y radial from VOR ABC. Or as the crossing of radial X from VOR ABC with radial Y from VOR DEF. In the modern IRS/GPS world, that same spot is defined by its lat/long.
“Airways” are pre-defined routes that connect a string of points, be they fixes or radio beacons. Like the numbered interstate highways, you can define the route from, say, Los Angeles to New York as “get on Interstate 10 eastbound and continue to Interstate 95 then north to NYC”. That route is 3400 miles long and has innumerable intersections and turn offs and distractions. But in just a few characters you’ve described the route in enough detail to get a driver who can read basic road signs all the way from the Santa Monica Pier on the Pacific to the Bronx on the East River.
In the US & Canada airway identifiers are Jnnn, Vnnn, Qnnn, or Tnnn where N is a 1 to 3 digit number. Outside those countries it’s a different list of letters, but is still 1 letter plus 1 to 3 digits. And optionally prefixed by a “U” meaning “upper” as in “high altitude”.
Finally, major airports have predefined arrival and departure routes. Which can be thought of as the on and off ramps to the long-haul airways. They’re based on VORs and fixes.
A departure (“SID” in the argot) starts at the airport, goes via a handful of fixes to a “main” fix 20 or 40 miles from the airport, then the route splits into several different directions for another 20 to maybe 75 miles to facilitate on-ramping to various airways towards various destinations.
An arrival (a “STAR”) is the same idea in reverse. It has several different start points at the outer perimeter, which all converge on the “main” fix, then a single sequence of fixes leading to the airport or even to near a specific runway.
SIDs and STARS are named for the “main” fix with a version number attached. So the “GOFER5” is either an arrival or departure where GOFER is the “main” fix and this is version 5. After version 9, they go back to version 1. In older SIDs and STARs the main fix is actually a VOR. So the procedure identifier would be ABQ6 for one whose main fix is the ABQ VOR.
A big airport can have a dozen or more SIDs and STARs, each with 4 or occasionally 6 branches at the outside perimeter.
Now we have the background to decode that flight plan given the knowledge this flight is from Toronto to Vancouver …
From the format of the name we know URSAL3 is a departure from Toronto. URSAL is the main fix of that departure. KASED is an edge fix of the departure. From there we fly to DLH. Whose name format tells us it’s a VOR (or rarely an NDB). Next is MOT, another VOR. Then BEVEL which is an arbitrary fix. Then YXC. But not the airport as you (reasonably) surmised. It means the VOR with that identifier. Which might be on the airport that uses the same 3-latter IATA name or might be 20 miles from it. Finally at YXC we’ve hit an airway. J500 goes over/through YXC. We join J500 there and follow it however far, past however many fixes and VORs, until we get to the LOCAN fix. Then we exit the airway and go straight to BOOTH, another fix. The name CANUC5 clues us we’re about to enter a STAR. So BOOTH is an edge fix of the STAR named CANUC5. Wherein BOOTH and several other fixes funnel into the CANUC fix which then leads via a few more fixes to the immediate vicinity of Vancouver’s airport.
Bottom line: Each item’s different format serves to identify its purpose, and just like reading music or a chemical formula, it’s logical, albeit intricate, once you can speak the lingo a little bit.
The plan filed with ATC and then approved by them does not list every point you go over. It lists every place you change from one type of routing to another. Just like my instructions to get from LA to NY don’t mention Phoenix or San Antonio. Because the driver doesn’t need to do something different in those places; just stick with I-10 eastbound and you’ll be fine.
Thanks so much for that, @LSLGuy! Once again, I’ve learned more about an obscure aviation topic than I could have anywhere else. Thanks for taking the time to write all that up! It’s very much appreciated.
Right, I guess as a curious passenger, the ticketing end was usually all I saw. The way I thought of it, if I was flying to Toronto, YYZ is what I would see on my luggage tag, CYYZ is what the pilot would see on his nav charts. I had no idea of the historical origin in railway station codes.
I don’t know to what extent that was also true in Canada, but in Googling around a bit, it seems that these railway station codes have changed several times in the course of many years. I found an interesting fact: to this day, many railroad stations have IATA-assigned codes, just like airports. Thus, Union Station in downtown Toronto is YBZ. Toronto Island airport just a short distance away is YTZ. IATA seems to have a fixation for having all Toronto codes end in Z. The biggie that most people are familiar with is Pearson International, YYZ. And even the regional Buttonville airport can’t escape the tradition – it’s YKZ.
Always glad to help. Of course everythign I wrote was simplified, with exceptions here and there. And I’m far from an expert on the details of individual country practices well away from the Americas where I’ve worked.
You might find this interesting reading as an overview:
As to Canada, I’ve always been mystified why the fascination for “Y” as the first letter of the IATA and 2nd letter of the ICAO. Makes little sense to me. Some accident of history most likely.
Believe it or not, here I can actually provide some information. Also believe it or not, the “Y” stands for “Yes”! As in, “Yes, there is a weather station here” – a 1930s standard when airport codes were two letters. When IATA formed and airport codes went to three letters, Canada just stuck the “Y” in front to make the new codes. This had the added advantage of making Canadian IATA codes (somewhat) unique. From here.
In fact, as seemingly with everything else in this business, there are many exceptions. Many countries have shamelessly stolen our “Y” prefix just because it was convenient, including you guys who use YUM for Yuma, AZ, for example. Conversely, some Canadian airport codes have spilled over into the “X” and “Z” letters.
More from the above link:
As air travel increased in the 1930s, it was important to identify if an airport had a weather/radio station located on its premises for safety and landing reasons. If it did, the letter Y for “yes” was added in front of the existing radio call sign. If there were no weather stations at the airport, a W would be administered for “without.” Combining the Y from Yes and the UL radio station code, YUL was born [the present code for Trudeau International, Montreal].
When IATA formed and began requiring airports worldwide to extend their codes to three-letters (as two-letter codes were becoming scarce) during the 1940s, most of Canada’s airports had already adopted the Y for “yes” prefix due to their weather reporting and radio stations located on site.
Already familiar with the Y initial indicating an airport via its radio tower beacon system, Canada made the bold move to lay claim to the letter. Snatching it up to signify all of its airports in a uniform fashion. By saying yes to the Y, Canada firmly aligned all its commercial airports with the same letter making it the only major country to assign IATA codes in this style.
Just to add to the above (because airport codes have long fascinated me, I suppose because some of them seem so obscure) … now that we’ve explained the “Y” start of all major Canadian airport codes, the remaining two letters actually have a variety of different origins. In cases like Vancouver (YVR) or Ottawa (YOW) they’re fairly obvious mnemonics. In other cases they’re slightly less obvious – Regina (YQR) supposedly comes from “Queen city Regina”. Other occurences of the middle “Q” are just placeholders, however. Montreal (YUL) comes from the call letters of a then-nearby radio station (I think a weather reporting station). Quite a few are based on radio call signs that way. And finally, the mysterious YYZ for Toronto Pearson International actually comes from YZ being an old railway station code for the station at Malton, where the airport was subsequently built. This is the railway-station legacy that @LSLGuy mentioned, but most airport codes in Canada didn’t originate that way.
Which brings us back to the issue that the caused to OP to post.
The global number of VORs & NDBs long ago passed the total number of 3-letter combos. And the global number of fixes has long passed the number of pronounceable 5-letter words. Which means we have one identifier that was originally assumed to be unique referring to multiple places. And every person and every app that deals with this stuff has to get it right every time. As the OP’s story tells, that doesn’t always happen.
Not to mention the challenges of using the 26-letter Latin alphabet worldwide in an era where the Arabic-alphabet countries, the Chinese-style writing countries, and the Cyrillic-alphabet countries are significant players and going nowhere but up.
The whole system needs an upward compatible overhaul to, say, 8 character names for everything. Already in the USA we’ve gone through something called the High Altitude Redesign or HAR, which essentially exported the township and range section-line system off the prairies and up into the sky. So now we have fixes like “KJ45U” set out as a mesh on a regular grid across the whole USA.
