Class D and ATIS vs ASOS

[Matthew]

I bounce between 3 Class D airports.

Two broadcast ASOS, but the third (I'm pretty sure it's also the busiest of the three) broadcasts ATIS.

Is there any particular reason for one information packet over the other?

 

[Captain]

Cost. AWOS is cheapest, ASOS is next and ATIS costs most. That's my guess.

 

[Inverted]

My guess would be airports that didn't start out as class D. There is really no reason not to have an ATIS if there is a tower there. AWOS and ASOS are completely automated where as ATIS is a recording from ATC.

 

[kkoran]

My guess would be airports that didn't start out as class D. There is really no reason not to have an ATIS if there is a tower there. AWOS and ASOS are completely automated where as ATIS is a recording from ATC.

Cost.

 

[gismo]

My guess would be airports that didn't start out as class D. There is really no reason not to have an ATIS if there is a tower there. AWOS and ASOS are completely automated where as ATIS is a recording from ATC.

I think ATIS requires a "certified" weather observer. Also ASOS/AWOS works when the tower is closed and that might be an advantage for an airport with a part time tower.

 

[FormanFlyer]

Cost would be my guess as well.

I know that airports are funded via combination of Fed/Local money, but beyond that I'm pretty weak on how this works.

How is it decided that an airport will get a tower, become class D,C,B, or move up/down a class? Is it simply based off money available or is there a standard/regulation that says if you reach X amount of traffic volume per day or year you become obligated to have a tower/become class D,C,B?

It's almost embarrassing to realize how much I don't know about how airports work vs how much I know about airplanes themselves.

 

[John Baker]

I was going to make a long winded post about coastal airports needing ATIS over AWAS or ASOS, then I realized I don't know all that much about it. It's the weather, it's the altimeter setting, it's airport information. As long as it sounds like the airport is 1200, I'm happy.

-John

 

[roncachamp]

I bounce between 3 Class D airports.

Two broadcast ASOS, but the third (I'm pretty sure it's also the busiest of the three) broadcasts ATIS.

Is there any particular reason for one information packet over the other?

Probably just the activity levels at the less busy airports.

 

[roncachamp]

I think ATIS requires a "certified" weather observer. Also ASOS/AWOS works when the tower is closed and that might be an advantage for an airport with a part time tower.

Yes, ATIS requires a "certified" weather observer, and that observer is more likely to be an ASOS/AWOS than a human.

 

[Inverted]

Yes, ATIS requires a "certified" weather observer, and that observer is more likely to be an ASOS/AWOS than a human.

This. Thats why I say there is really no cost increase I can see from having ATIS at an airport. All Class D airports will have an ASOS or AWOS for when the tower is closed anyway.

 

[roncachamp]

This. Thats why I say there is really no cost increase I can see from having ATIS at an airport. All Class D airports will have an ASOS or AWOS for when the tower is closed anyway.

Maybe. There may still be a control tower in some forsaken Class D airspace that has no ASOS or AWOS. I'm not aware of any of those, but I do know of airports with ASOS/AWOS that have no weather broadcast when the tower is closed.

 

[Unbeliever]

All Class D airports will have an ASOS or AWOS for when the tower is closed anyway.

KEMT. No Automated weather.

They've been trying to install one for quite a while now. I think it's been 9 months since the hardware was installed and working, but there was an issue getting the observations to the tower, so still no automated observations.

The next door neighbor class D KPOC also doesn't have automated observations.

ATIS only at KTOA also.

That's just my recollection of stuff in the Los Angeles Basin. All 3 of those are Class D.

--Carlos V.

 

[Pilawt]

KVUO has had ASOS for a number of years. During hours that our temporary tower was operating over the past year (it just closed for keeps last week), the ASOS was not real time, rather only repeated the hourly 50 after the hour) sequence. The tower controllers were responsible for providing real-time wind and altimeter.

There was no notice of change in the ASOS operation. Most local pilots were unaware that the ASOS was no longer real-time, even though it sounded the same as always. Guess they never compared their instrument panel clock with the time recited by the recording.

 

[kkoran]

This. Thats why I say there is really no cost increase I can see from having ATIS at an airport. All Class D airports will have an ASOS or AWOS for when the tower is closed anyway.

They'd still have to purchase ATIS equipment. The system the ASOS or AWOS uses to transmit can't be used for an ATIS.

 

[kkoran]

This. Thats why I say there is really no cost increase I can see from having ATIS at an airport. All Class D airports will have an ASOS or AWOS for when the tower is closed anyway.

They'd still have to purchase ATIS equipment. The system used to transmit the ASOS/AWOS observation can't be used as an ATIS.

 

[roncachamp]

They'd still have to purchase ATIS equipment.

ASOS broadcast equipment must be purchased as well.

The system the ASOS or AWOS uses to transmit can't be used for an ATIS.

According to the Instrument Procedures Handbook, it can:

AUTOMATIC TERMINAL
INFORMATION SERVICE AND DIGITAL ATIS​

The automatic terminal information service (ATIS) is

another valuable tool for gaining weather information. ATIS
is available at most airports that have an operating control
tower, which means the reports on the ATIS frequency are
only available during the regular hours of tower operation.
At some airports that operate part-time towers,ASOS/AWSS
information is broadcast over the ATIS frequency when the
tower is closed. This service is available only at those airports
that have both an ASOS/AWSS on the field and an
ATIS-ASOS/AWSS interface switch installed in the tower.​

​

​

 

[kkoran]

ASOS broadcast equipment must be purchased as well.



According to the Instrument Procedures Handbook, it can:

AUTOMATIC TERMINAL
INFORMATION SERVICE AND DIGITAL ATIS​

The automatic terminal information service (ATIS) is

another valuable tool for gaining weather information. ATIS
is available at most airports that have an operating control
tower, which means the reports on the ATIS frequency are
only available during the regular hours of tower operation.
At some airports that operate part-time towers,ASOS/AWSS
information is broadcast over the ATIS frequency when the
tower is closed. This service is available only at those airports
that have both an ASOS/AWSS on the field and an
ATIS-ASOS/AWSS interface switch installed in the tower.​

​

​

The two airports in that the OP frequents that broadcast the ASOS already have the equipment so the cost isn't an issue.

 

[Captain]

The two airports in that the OP frequents that broadcast the ASOS already have the equipment so the cost isn't an issue.

I'm thinking the order goes like this...

Super rural airport with a tight budget installs an AWOS.

As operations increase they switch over to an ASOS. I don't even really know the difference, but as a pilot I know I can always pick up an ASOS much further away than an AWOS. Due to the I surmise an ASOS has a more powerful xmitter and is therefore more expensive.

As operations step up even more a tower gets installed. It stands to reason any airport getting a tower installed is large enough to at that point already have an ASOS.

So, the folks working the tower have the ASOS equipment to give them the weather. If the airport authority springs for the ATIS equipment (tape recorder, xmitter, ect) then the tower has an ATIS. Now they can record the weather, landing runway and local NOTAMs. They can even say 'Merry Christmas' every now and again too.

If the airport want to go nuts with it they can even spring for the automated voice to broadcast the ATIS message.

 

[comanche]

KAUS (Austin, TX) is a class C airport. Tower operates 24/7, but it only has a part time ATIS. Why? Money? What does it become when ATIS is not working? What do you tell the approach control that you have ASOS if that is what information is presented when ATIS is not working?

Been away from flying for several years and just getting back into it. Thanks.

 

[Captain]

I'd imagine it gets real quiet in AUS in the middle of the night. I'm thinking the tower guys find it easier to inform each pilot active runway that update the ATIS each hour. So the ASOS goes on and the hourly tapings cease.

Just inform approach or tower on initial call up that you 'have the weather' if ATIS is off and ASOS is on.

 

[kkoran]

I'd imagine it gets real quiet in AUS in the middle of the night. I'm thinking the tower guys find it easier to inform each pilot active runway that update the ATIS each hour. So the ASOS goes on and the hourly tapings cease.

Just inform approach or tower on initial call up that you 'have the weather' if ATIS is off and ASOS is on.

BINGO!

 

[Inverted]

KAUS (Austin, TX) is a class C airport. Tower operates 24/7, but it only has a part time ATIS. Why? Money? What does it become when ATIS is not working? What do you tell the approach control that you have ASOS if that is what information is presented when ATIS is not working?

Been away from flying for several years and just getting back into it. Thanks.

I always just say I have the "one minute wx" if it isn't an ATIS....

 

[Unbeliever]

KEMT. No Automated weather.

They've been trying to install one for quite a while now. I think it's been 9 months since the hardware was installed and working, but there was an issue getting the observations to the tower, so still no automated observations.

I'm going to have to withdraw KEMT. They finally got the ASOS officially on line on May 1, 2012.

Still no automatic observations yet to NOAA when the tower is closed, but hopefully they're working on that certification now.

--Carlos V.

 

[flyingcheesehead]

Maybe. There may still be a control tower in some forsaken Class D airspace that has no ASOS or AWOS. I'm not aware of any of those, but I do know of airports with ASOS/AWOS that have no weather broadcast when the tower is closed.

Not sure if this is still the case (I don't think it is), but it used to be that at UES the ATIS/ASOS frequency did not broadcast while the tower was open - The tower would just read you the weather. Then, at night, the ASOS was on. Pretty stupid if you ask me, but maybe the contract towers get paid per contact...

What I'm used to is the home 'drome, where there's ATIS while the tower/TRACON are open, and ASOS when they're not. It's augmented by a recording at the end of the robotic ASOS broadcast that I've heard so many times I could probably (and may well actually! ) recite it in my sleep: "Madison Tower hours of operation are 6 AM to 11 PM local time. Common traffic advisory frequency is 119.3 and is monitored by crash, fire and rescue. Pilot-controlled lighting is available on 119.3. ILS 18 and 21 are selected. IFR departures contact Chicago Center on 135.45 for clearance..." followed by NOTAMs.

 

[kkoran]

Not sure if this is still the case (I don't think it is), but it used to be that at UES the ATIS/ASOS frequency did not broadcast while the tower was open - The tower would just read you the weather. Then, at night, the ASOS was on. Pretty stupid if you ask me, but maybe the contract towers get paid per contact...

What I'm used to is the home 'drome, where there's ATIS while the tower/TRACON are open, and ASOS when they're not. It's augmented by a recording at the end of the robotic ASOS broadcast that I've heard so many times I could probably (and may well actually! ) recite it in my sleep: "Madison Tower hours of operation are 6 AM to 11 PM local time. Common traffic advisory frequency is 119.3 and is monitored by crash, fire and rescue. Pilot-controlled lighting is available on 119.3. ILS 18 and 21 are selected. IFR departures contact Chicago Center on 135.45 for clearance..." followed by NOTAMs.

JO7210.3X, 10-4-1
h. During the hours of operation, part-time towers that have ATIS capabilities and ASOS/AWOS ground to air broadcast capability, must ensure that the latest METAR/SPECI weather sequence is broadcast only on ATIS. ASOS/AWOS must not be allowed to broadcast weather concurrent with ATIS.

i. During the hours of nonoperation, part-time towers that have ATIS capabilities should record for continuous broadcast the following information:

NOTE-
Those facilities that have ASOS/AWOS broadcast capability must allow the automated weather report to be broadcast on the ASOS/AWOS frequency in the one minute update mode and include the applicable information in subparas 10-4-1h, 1 thru 5 at the time of closing.

1. The local tower hours of operation.

2. ASOS/AWOS frequency.

3. The appropriate common traffic advisory frequency (CTAF).

4. The frequency for operating radio controlled approach lights.

5. The FAA facility and frequency for additional information.

EXAMPLE-
(Name of tower) tower hours of operation are (time) local time to (time) local time. The frequency for automated weather is (frequency). The common traffic advisory frequency is (frequency). Pilot operated approach lighting is available on (frequency). For additional information contact (name of approach control or center) on (frequency).

http://www.faa.gov/air_traffic/publications/atpubs/FAC/1004.html#1004.html.1

 

[roncachamp]

What I'm used to is the home 'drome, where there's ATIS while the tower/TRACON are open, and ASOS when they're not. It's augmented by a recording at the end of the robotic ASOS broadcast that I've heard so many times I could probably (and may well actually! ) recite it in my sleep: "Madison Tower hours of operation are 6 AM to 11 PM local time. Common traffic advisory frequency is 119.3 and is monitored by crash, fire and rescue. Pilot-controlled lighting is available on 119.3. ILS 18 and 21 are selected. IFR departures contact Chicago Center on 135.45 for clearance..." followed by NOTAMs.

I don't think NOTAMs belong there. A NOTAM that gets cleared during the night stays there until the tower opens. A new NOTAM may go unnoticed because the pilot received them all over the robo ATIS and assumes it's up to date.

 

[flyingcheesehead]

I don't think NOTAMs belong there. A NOTAM that gets cleared during the night stays there until the tower opens. A new NOTAM may go unnoticed because the pilot received them all over the robo ATIS and assumes it's up to date.

These aren't things that are going to go away during the night - It's usually things like taxiway closures and the like, and it's helpful to get it from an extra source. They have some such NOTAMs on the ATIS during the day as well. It's never a complete list of all the NOTAMs for the airport, and I don't think anybody expects it to be.

 

[roncachamp]

These aren't things that are going to go away during the night - It's usually things like taxiway closures and the like, and it's helpful to get it from an extra source. They have some such NOTAMs on the ATIS during the day as well. It's never a complete list of all the NOTAMs for the airport, and I don't think anybody expects it to be.

So the need to go to another source for current NOTAMs exists whether or not they've been put on the overnight recording.

 

[Captain]

NOTAMS schmotams. Who reads those things anyway? AD CLSD is about the only thing that raises my eyebrow.


Edit to add: I keed.

 

[flyingcheesehead]

So the need to go to another source for current NOTAMs exists whether or not they've been put on the overnight recording.

Yup - But in the event somebody doesn't do that, at least they'll be prevented from driving their airplane into wet concrete and causing both themselves and the airport management and other users a lot of headaches...