Barometric pressure setting


When i’m flying in the a320neo, I change the altimeter to whatever my departure airport gives over ATC, once above 18000ft I switch to standard or 29.92??, once nearing arrival airport ATC gives me local reading and I switch again.

My question is if I descend below 18000ft, say half way through my journey, how do I find out what I should set the altimeter to or does it not matter?


Find an ATIS signal at an airport closeby. It’s definitely more critical for landings, you are often given it by ATC before landing, and often enroute too it would seem.
If I’m using live weather I sometimes just look up the Metar info online for an airport too just to get a ballpark figure in the sim (which is sometimes slightly different to real life despite live weather).
I usually leave it on std until under 18k ft then just switch it to ATC communicated value.
Not sure what happens IRL.

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As you descend below 18,000, your next ATC contact should give you an altimeter setting. I know that when I’m using Flight Following on a GA flight, every new controller after a handoff will give me that info if I’m below 18,000, but above that, they don’t bother.

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Button b sets the current air pressure


Ah yes didn’t think to tune Atis for nearby airports.

I just started a world tour doing short trips in the Cirrus sr22, I stay at around 4-5000ft to take in the scenery, Im not sure its so important in small aircraft, especially if Im using visual guidance and manual landing?

IRL trivia - ATC doesn’t give altimeter @FL180 and above because 29.92 is the standard. When you are given descent below FL180 it is a requirement for ATC to give the current altimeter. (I believe it is also a requirement to give you updated altimeter if it changes during your time with that ATC sector, but that was from a few years ago).

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Normally this would be given in the atis from the field, or on initial contact. Here in Europe it can differ from airfield to airfield what the transition level is.

A good rule of thumb when you are not certain if you have to calibrate or not:
If you’re cleared to decent to FLIGHTLEVEL XXX it means in standard pressure. If you are cleared to decent to XXX FEET you have to calibrate at latest when you reach the altitude

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Good point AwesomeBlack533 - My info is from and for ATC in the US. Thanks for reminding me this is a world wide forum. I’ll do better at clarifying where the info applies…

The standard button is just a shortcut to 29.92 in Hg / 1013.25 hPa.

Unfortunately, if I tune on ATIS freq before the SIM gives me this option via its ATC window I do not receive any info. And the MSFS ATC gives this option for destination airport only after landing when it is a bit late:))) Also, they give us the " final" info about wind and pressure when they give us clearance to land, usually on final and this is too late for one and the only crew member a board - no time to enter them into FMS to calculate landing speeds:))) Why their ATC does not give us an option to select ATIS before or when they clear us to approach, I have no idea. I use “b” button to enter current pressure to altimeter just because there are no way (at least if I fly with real weather) to receive this info from their virtual dispatchers in a proper time. Even when they tell us to “expedite” they do not always brief us about pressure, so, only “b” helps.

ATIS is limited by reception distance. You’ll get it closer to your destination.

If you’re using FBW A20NX, in the FMS panel, you can go to MCDU>ATSU>AOC> WX Request, enter location ID and then click SEND.

After about 15 sec, you can RETURN, then go to RECEIVED MSGS and get your altimeter setting at the destination to program in altimeter to your arrival Perf menu.

The thing to note is if you’re in US, you should be using the local altimeter setting for the altitude at which you’re flying. The above procedure will help you get your approach perf numbers. It won’t necessarily give you the altimeter setting that you should be flying until you join final.

To get your local altimeter, you can manually tune a closer ATIS, pick it up during a handoff lower than FL180 or run a wx request for a closer location.

Thank you, I use C4J mod. This option works in this mod and helps, but not every time and not for every airport.

… or use b when you duck below FL180. Which is what you already said. :grin:

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As for “you can manually tune a closer ATIS” it does not work for me. Thats the problem. I enter the freq for this ATIS and receive nothing. I have to select ATIS via the ATC menu to receive the info. And if ATIS is not available via that menu for that airport, my manual tuning does not help. I did not check it with the latest sim update, but I am sure they did not repair this.

Imagine that you are flying from Orlando, Florida, USA to New York City but your route has you descending below FL180 closer to Washington, DC. What I mean by “manually tuning a closer ATIS” is get the altimeter by looking up the aviation maps and charts to get the ATIS frequency for Washington Dulles (not JFK) and get the local weather.

In the US, is a good resource.

You will need to make sure “AI controls radio” is off.

I’m not sure I was clear as to what I was suggesting you try.

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Thank you for your patience. This is exactly what I do. When I tune this ATIS taken from charts NOTHING HAPPENS:))) I receive nothing! Silence:))) Untill the same freq appears via the menu:))) Even if I do this staying in the airport. If I tune the same freq via menu - I receive the info:))) I do not know is this a bag or something is wrong with my MSFS installation - I do not have time to investigate or report properly. I know how to use radio - I am a radiooperator IRL and I have flying experience IRL.

Ah. Sorry, there are a number of people new to Aviation on the forums and I was not quite sure what your level of experience was.

Sorry to overexplain. I don’t have this issue that you’re having. I’m able to manually dial in frequencies and receive local ATIS.

I don’t know why manually tuning the radio isn’t working. It’s either an issue of VHF range, so about 25 NM max in-sim, or the frequency published on the chart does not match the in-sim frequency - which happens a lot on both vox/data and ILS frequencies.

The way to confirm the actual in-sim frequency is to use an external EFB like LittleNavMap that reads the sim NavDatabase. It will show you all the frequencies associated with the field in the COM tab.

In-sim database, especially if you’re using the stock NavBlue, sometimes is not reflective of Charts from another data provider, like Jeppensen for example. Always use a utility that reads directly from the NavDatabase in use.

The other factor that folks may miss is that depending upon the aircraft radio interface, you can have up four frequencies, but only two active at any given time (one per COM radio). One may have tuned the correct frequency, but not made it active.

The additional oddity is in the ATC/radio window; if you’re tuning the ATIS while staying with the current Control facility (Approach, Center, etc), make sure you’re tuning ATIS on the second COM radio, made it active, and you’re clicking on the correct tab in the ATC/radio window so you see the appropriate choices or hear the ATIS/ASOS/AWOS prerecorded message stream.

Thank you. I’ll try one more time one day:) For the first time I faced this situation when I was going to listen ATIS again after I received already the msg via menu option. I forgot some figures and decided to go to ATIS channel manually and listen. As I knew already the freq from the menu I entered it via radio page ( on FMS on C4J) and… nothing happened. After this I activated ATIS on the same freq via menu again and my info arrived (without text in the ATC menu, voice only). I changed the freq manually to another freq, than entered it manually again and info was not arriving. After this I stopped all attempts to use radio in MSFS manually. But it was before few latest sim and world updates, may be it is working now. I’ll check.