Because I'm a nerd...

[minitour]

Because I'm a nerd, I've been sitting up all night typing out "checklists" and all sorts of useless information to study while I'm home for the next week or two. It occured to me that I should check AWOS at the airport (across the street) because the wx looks like crap. Anyhow, something came over me and I checked airnav.com and found out that there are actually ATIS frequencies that have phone numbers (wow)! So I got the number for OKC and ORD and called. This is what I got...questions to follow

ORD Information G 0956 zulu
Wind 190 at 4
Visibility 6 Mist
Cieling 2,500 Overcast
Temperature 9 Dew Point 7
Altimeter 30.37
Arrivals expect Vectors ILS Runway 14R Approach
Departures expect Runway 27L

OKC Information B 0952 zulu automated observation
Wind 140 at 12
Visibility 1/4
Indefinite Cieling 100 Feet
Temperature 14 Dep Point 14
Altimeter 30.28
ILS Runway 35 R approach in use
Landing and departing runway 17L and runway 17R

...other than the notams (taxiway/runway closures) that was it.

A few things I've come to notice in the past 8 months that maybe you guys (esp. ATCers) could help me out with.

Some ATIS are humans and some are "automated" computer voices. Is there a reason for this? With the computerized ones, do you program it to say what it says or does it get the information off of a METAR or something else? If you don't program it, how does it know what runways/approaches to use?

With the O'Hare ATIS, is there a reason that you would think it is beneficial to have arrivals on 14R and departures on 27L. If my figures are right, that would give arrivals a headwind component of around 3 and a crosswind component of around 3 or 4. Clearly no big deal, but for departures would this not give them a tailwind component? I realize (if the numbers are right on my chart) that it is only 1 knot, but could this make a difference for larger planes?

With the OKC ATIS, they are using ILS 35R and "landing and departing" 17R/L. Okay, I can understand this one. 35R is the only ILS that is Cat II (maybe even III but II for sure - too lazy to look). Is this common then to have a departing runway the exact oposite of the landing runway?

For you ATCers out there, this one is for you:

I've noticed that at "busier" airports (CLE/PIT/Im sure others too) they have an Arrival ATIS and a Departure ATIS. Is there a real benefit to this? I would think the ATIS would have the same information for both arrivals and departures, but I could be wrong. If you are at a facility that does this, is there a specific thing that goes on one vs. the other?

Okay, I think I'm done being nerdy for one night. Thanks for any help/answers y'all can give.

-mini

 

[Vector4fun]

Mini,


Can't answer all your questions, but will tackle a few. The computer-voiced ATIS is a "Digital ATIS". We have a pair of computer terminals at the Flight Data position that run an old DOS based "windowing" system. We can call up either FDIO, (Flight Data In/Output), which is how we access flight plans in the NAS or HOST computers at the Centers, a PDC (Pre Departure Clearance ??) program, which allows up to send IFR clearances to certain airlines and corporate operators via ACARS or printers at the gates; or, finally, DATIS. We normally have FDIO and PDC running on one terminal, and DATIS running on the second terminal.

The DATIS program receives all the hourly and special observations automatically. We can edit the observations to correct a mistake if we notice it, normally we just edit/delete the remarks because they're not relevant or important. Then we use a "page" in the program that has all the common variables on it. ie runways in use, runways/taxiways closed, approaches in use, hazardous WX, bird activity, TFRs, etc., etc. These variables are programmable and customizeable for each airport. We can also just type an odd NOTAM into one window for inclusion. Finally, we review the new ATIS on a speaker, and hit another key to transmit it. Sounds complicated, but in fact much easier and quicker than creating a voice recording. If there are no changes from one hour to the next, (other than WX) I can create a new ATIS in about 5 seconds. I don't know why any moderate sized or larger facility doesn't have it.

The main reason for separate Dep/Arr ATIS messages is that at the largest airports, the ATIS can get so long that nobody listens to the whole thing. We try to shorten them a bit by only including the relevant info.

It would NOT be common to have ILS approaches advertised to 35R, and departures using 17L, except the WX explains the situation. They are below Cat I mins, and you said 35R was the only Cat II runway. (Don't have any OKC plates here) But the wind is 170012, which means most departures would require 17L/R because of the tailwind component.

I have no idea how/why ORD does anything they do. It must work though.

 

[IFlyGC]

Mini,

You're not a "nerd"...you're trying to learn more about the world we work in....you should be commended for it.

I'm not an ATC guy but I can shed some light on a few things for you.

It the smaller airports, the automated voice on the ATIS is just the feed from the ASOS/AWOS on the field. They flip the switch before going home for the night. The other version at the larger airports is referred to on charts as D-ATIS....it allows certain aircraft to download the text version directly into the cockpit to save time having to listen to...the...really...slow...man...talking. I 'think' the information is typed in by a controller, but I'm sure someone will correct me on that!

It's quite common for a large airport to use different runways for arrivals and depatrures. 10kts of tailwind is usually ok for take-off depending on the companies operating specifications (ops-specs) and the limits of the aircraft.

The difference between the arrival and departure atis (in CLE at least) is normally just a letter. Occasionally there will be an extra nugget of wisdom (such as de-ice procedures for the departing aircraft) but not much difference comes to mind. I'm at work again tonight....I'll look a little closer at them for ya.

Oh, and if your a true nerd, I'm sure you already know about 1-877-ANY AWOS. You can get every awos out there with this little beauty!

 

[Dr Pokenhiemer]

The computerized voice says whatever is typed to it. At BNA, on home game days it says, "Advise on initial contact you have Echo. Go Titans!"

Go to your local tower sometime if you have the chance. Due to secruity they may not let you in right now, but maybe you can atleast talk to someone for a few minutes.

 

[Vector4fun]

Just a side note. Does anybody remember that old DOS accessory program that used to come with SoundBlaster sound cards? The one that "read" lines of text in a computer voice? I swear, (though I have no technical knowledge of the fact) that they used or adapted that program for DATIS. It acts and "feels" the same, including having to deliberately miss-spell certain words to get the program to pronounce them properly.


The DOS windowing program is sort of like GEM, if anyone remember that.

 

[sonofaeagle]

Dr. Spatzo?

 

[avbug]

...with information wilkey...

 

[Av8tor]

Check out http://www.anyawos.com/ (877) 269- 2967 you can live weather at almost any airport in the country from your phone.

 

[Loafman]

If you just want to scare your fellow crewmember sometime, when it's time for the approach, pull up the D-ATIS for KMWN. It's always interesting.

The current observation is: KMWN 161356Z 33032G37KT 1/8SM FZFG BKN000 BKN100 M06/M06 RMK VRY LGT ICG FZFG BKN000 SUN DMLY VSBL