Thursday, February 19, 2009

ATIS Identifiers

In a recent comment reader ZuluDelta wrote:

I have noticed that the occasional aircraft reports that it is "with Juliet" or "Oscar, Tango, Papa, India, Uniform, Kilo" One checked in "with Whiskey"! Perhaps in some future blog, you could elaborate on what these secret codes are.

I almost think that with a name like ZuluDelta, this person might be kidding, but I always err on the side of treating a question as serious. Plus this is an easy one to answer, so it allows me to fill in a day on the blog without incurring the wrath of Texans by saying something inadvertently critical about one of their freeway ramps.

When an airport has a control tower, whether it's in Texas or not, there is almost always a published frequency that broadcasts a continuously repeating recorded message called the Automated Terminal Information Something. I think it's "Service," and I'm deliberately not looking it up to demonstrate how I don't care. We call it "the ATIS," pronounced Eh-Tiss. It might sound something like this:

This is Somewhere Airport Information Charlie, recorded at one nine three zero zulu. Wind three two zero at one four gusting two zero. Sky clear. Visibility fifteen miles. Altimeter three zero one four. IFR approach is a visual approach runway two zero. Active runways two zero and three five. Note One: Echo three taxiway is restricted to aircraft wingspan under 50 feet. Note Two: construction equipment operating west of runway 01/35. Vehicles will remain 400' from runway at all times. Inform Somewhere Tower on initial contact you have information Charlie.

The recording is often made by a human, just one of the controllers in the tower who checks the current conditions, presses a button on the machine and talks into the recorder. You can hear the regular hubbub of tower activity in the background, and there are stories about things audible on the ATIS that shouldn't be. Sometimes the conditions are coded in machine readable form and the ATIS is provided by a mechanical voice.

Either way, the ATIS is updated as required to keep up with changes in the information, usually at least once an hour. Every time it is changed, the information letter is incremented. So the first one in the morning is Alfa, then Bravo, then Charlie and so on through the radio alphabet. That way you need only listen long enough to hear the letter, called the identifier, to know if you have the latest information.

You tune the ATIS frequency and come in somewhere in the middle of that, drumming your pen impatiently on your kneeboard as they waddle through all the taxiway closure stuff when all you want to know is which approach plate to get out. You copy down the information and then call up the controller and "prove" that you have done your homework by specifying which ATIS information you have. If you don't say, or if you say but they weren't paying attention, they will ask you to "Confirm you have Quebec." If they've changed it between your picking it up and your calling them, sometimes they say "Information Romeo is now current. Inform when you have Romeo" and make you go listen again before they will talk to you.

Pilots and controllers get mileage out of making fun of the names of the letters. I've heard ATIS recordings that advertise "Information Echo-co-co-o" and I'm sure the story about the passenger named Mike or Charlie who asks "why did he ask if I was with you?" Here's a PilotsofAmerica forum thread on silly ATIS messages.

Here's an MP3 of an ATIS recording from Ferihegy airport (I think it's in the Czech Republic in Hungary). Here's live ATIS from Bankstown, Australia, if their tower is open when you click it. This last one contains profanity, and it may or may not have ever been actually broadcast but it perfectly demonstrates the mechanical ATIS voice. And it's very funny if you don't mind hearing a few words that shouldn't be said on the radio.


Julien said...

One specificity of Australia, or at least something done in Australia differently from North America, is that the ATIS identifier Zulu is only used for the ATIS message broadcasted after tower hours, i.e. when a controlled airport turns back into a CTAF(R). Information typically contains preferred runway and circuit direction as well as local weather conditions if the airport has the right equipment.

Anonymous said...

Thank you, Aviatrix. Now it is all clear to me.

The aircraft landing "with Whiskey" at LAS was a private jet tearing in quite late at night. It seemed reasonable to me that perhaps some high roller was close to running out of his favourite beverage and had dispatched the crew out to resupply him, "with Whiskey".

However today, once again listening to LAS, ATC enquired of a United flight if they were "with Oscar". The Oscar I immediately thought of was the movie Award that I believe is coming up this weekend, which had some limited plausibility and the other Oscar I thought of was "Oscar the Grouch" from Sesame Street.

United said that they were indeed "with Oscar", and shortly after a SouthWest flight said that they were "with Oscar" too. What to think?

I was getting more and more confused. However now the mystery has been put to rest.

Thank you again.

P.S. Zulu Delta are the phonetics for the last two letters in my Amateur Radio callsign. Sorry, I did not mean to mislead you.

Anonymous said...

In Canada it might be pronounced "Eh Tis", but in the U.S.I think its pronounced "ay tis". :)

Anonymous said...

ZD: The phonetics are the same for HAM and Aviation radio (as well as US Military IIRC). :)

At my home airport the ATIS doesn't recycle when the tower opens, they just move onto the next letter (IIRC, again). If they closed with D, they open with E and so on. And for a reason I probably should know but don't, the ATIS always seems to update around 56 past the hour in the US. I never understood why 56, and not say, on the hour.

Colin said...

You have "alfa" in the post instead of "alpha."

Here in Southern California the Camarillo airport (KCMA) is too close to the Oxnard airport (KOXR). They can have dramatically different weather, but pilots often confuse one with the other, straying into the wrong airspace and so on. (And there's a military base next to Oxnard...)

So Oxnard's ATIS uses the letters Alpha to Mike and the Camarillo ATIS uses November to Zulu. If you call Oxnard and say you have Oscar (the grouch), they kindly remind you where THEY are, where YOU might be, and perhaps that you need to check your frequency. For something.

Anonymous said...

colin: gotta be carful over that airbase airspace too, 'tis restricted, don't want to be on the wrong side of the PCH while flying up the coast, lest you find some very unhappy lads joining you in formation.

Side: you wouldn't happen to be a CFI at SMO would you?

Aviatrix said...

In Canada it might be pronounced "Eh Tis", but in the U.S.I think its pronounced "ay tis".

Grin. I did that on purpose because "ay" could be pronounced as "eye", but everyone knows how Canadians say "eh."

I love hearing all your local procedures with ATIS identifiers. Boundary Bay airport used to skip "Delta" because there was an airpark called Delta only two miles away.

And I spell alfa that way when it's for the radio, as opposed to the Greek letter α. Lots of people do. I get slightly more google hits on 'alfa bravo' than 'alpha bravo'.

Anonymous said...

Just for information, Ferihegy airport is the main airport of Budapest which is the capital of Hungary. So, it is not in the Czech Republic, although in a immediately neighbouring country ... :-)

Thanks for your great blog, by the way!

Marko from Germany (with an affiliation to Budapest)

Michael said...

In Alice Springs the ATIS is heard through the VOR or NDB. And for some reason its impossible to hear the letter of the code they are saying.

Dont know why, and every pilot somehow cant hear it either. and when it finally can be heard over the scratchy idents, someone makes a radio call as your are listening. gets very frustrating sometimes.

jinksto said...

Heh... I giggled the use of "eh"TIS..well, chuckled anyway... I don't think I can giggle.

My favorite ATIS was for a small airport that went something like "runway three six is CLOSED for construction. Landing traffic should use the grass parallel to runway three six.... no... we're not kidding."

nec Timide said...


Interesting, I had a long amateur radio conversation with a lad near Alice Springs one day while stuck in traffic. Never could understand his callsign, I couldn't even determine if he was using international phonetics or a local variety as some HAMs do. Maybe it's the water?

Aviatrix said...

Ferihegy airport is the main airport of Budapest which is the capital of Hungary.

Thanks for that, Marko. I found the link on a page with the .cz extension and was too lazy to investigate, knowing that one of my readers would know, and might have a story to go with it.

I know I already said this, but I am so loving the responses to this blog entry. Thank you for requesting it, Zulu Delta!

Anonymous said...

In Canada it might be pronounced "Eh Tis", but in the U.S.I think its pronounced "ay tis".

Grin. I did that on purpose because "ay" could be pronounced as "eye", but everyone knows how Canadians say "eh."

Glad you caught the joke.:)

Anonymous said...

If you want to hear acual ATIS for Warsaw "Okecie" airport, (capital of Poland), you can use phone +48 22 650 21 11