Suggestion for more realistic QNH / altimeter behavior

1st Official Post

    Hello,

    I’ve been using Aerofly FS Global for quite a while and I’m really impressed with the overall simulation quality, especially the flight feeling and performance. However, I noticed a small inconsistency regarding the altimeter and QNH system. At the moment, when QNH is changed, the altimeter behavior doesn’t always seem to fully match a physically accurate atmospheric model like in real aviation. This can sometimes create a slight mismatch during approach and landing phases. In real aviation, QNH adjusts the altimeter reference to mean sea level pressure, and all approach procedures (ILS, PAPI, minimums) are consistently based on this value. If possible, future updates could improve realism by: Making the local pressure (QNH) model more physically accurate Ensuring the altimeter responds in a more consistent way Improving altitude reference consistency during approach/landing Overall, the simulator is excellent, this would just be a small improvement that could take the realism even further.

    Thank you.

    • Official Post

    The altimeter behavior is fully simulated and reflects real world behavior.

    However pressure changes of the atmosphere do not happen yet, so the correct QNH to set is always 1013hpa or 29.92inHg. If you set this pressure setting in the altimeter, which it already is by default, then the barometric readings should be correct at all times. If you use a pressure setting from real world weather, well then it's just going to be an incorrect altimeter setting for the sim with all consequences that result from that.

    TLDR; It's working correctly for the simulated weather condition.

    Quote from Jet-Pack (IPACS)

    The altimeter behavior is fully simulated and reflects real world behavior.

    However pressure changes of the atmosphere do not happen yet, so the correct QNH to set is always 1013hpa or 29.92inHg. If you set this pressure setting in the altimeter, which it already is by default, then the barometric readings should be correct at all times. If you use a pressure setting from real world weather, well then it's just going to be an incorrect altimeter setting for the sim with all consequences that result from that.

    TLDR; It's working correctly for the simulated weather condition.

    For example, in the MCDU approach page, the QNH value is entered. It would be great if, when we enter something like 1008, the altitude automatically behaves as if it were based on 1013. For instance, if we set the barometer to 1008, but we entered 1008 in the MCDU approach page, then when we switch the barometer to 1013, there should be an altitude discrepancy. You could simulate it this way. Alternatively, there should be an option in the weather settings where we can manually enter the QNH value we want. The simulator could then adjust the altitude based on the value we input. The goal is to improve realism instead of always staying at 1013.

  • Post by Small Planes (April 23, 2026 at 10:46 AM).

    This post was deleted by the author themselves (April 23, 2026 at 11:14 AM).
    • Official Post
    Quote from poyraz_tr51

    For example, in the MCDU approach page, the QNH value is entered. It would be great if, when we enter something like 1008, the altitude automatically behaves as if it were based on 1013. For instance, if we set the barometer to 1008, but we entered 1008 in the MCDU approach page, then when we switch the barometer to 1013, there should be an altitude discrepancy. You could simulate it this way. Alternatively, there should be an option in the weather settings where we can manually enter the QNH value we want. The simulator could then adjust the altitude based on the value we input. The goal is to improve realism instead of always staying at 1013.

    I think you're confusing things a bit here.

    In the real world, if I enter a QNH value in the MCDU that does not affect the atmosphere at all. It does however tell the aircraft to anticipate a change in altitude when you switch from STD pressure to QNH at the transition level and it does tell the aircraft that the air pressure is lower and thus the landing distance may be higher than on a standard day. If we implement changes in the simulated air pressure of the atmosphere then that will be a separate menu in the settings which works for all aircraft not just those which happen to have an MCDU. The MCDU entry needs to be independent to fully simulate the effects of entering incorrect data for example. Same with takeoff weight for example. If you enter 100t too low takeoff weight the indicated V-speeds are lower than what the aircraft needs and we already full simulate this, which allows you to practice your skills and avoid tailstrikes like these: (at 8:50 roughly)

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    Quote from Jet-Pack (IPACS)

    I think you're confusing things a bit here.

    In the real world, if I enter a QNH value in the MCDU that does not affect the atmosphere at all. It does however tell the aircraft to anticipate a change in altitude when you switch from STD pressure to QNH at the transition level and it does tell the aircraft that the air pressure is lower and thus the landing distance may be higher than on a standard day. If we implement changes in the simulated air pressure of the atmosphere then that will be a separate menu in the settings which works for all aircraft not just those which happen to have an MCDU. The MCDU entry needs to be independent to fully simulate the effects of entering incorrect data for example. Same with takeoff weight for example. If you enter 100t too low takeoff weight the indicated V-speeds are lower than what the aircraft needs and we already full simulate this, which allows you to practice your skills and avoid tailstrikes like these: (at 8:50 roughly)

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    If so, you could add this to the settings menu just like turbulence and wind, with both manual and automatic options. What I mean is: it shouldn’t stay fixed at 1013 all the time. For example, if we go into the settings and set it to a value like 1005, then we would also need to set 1005 in the aircraft to read the correct altitude. It should be a feature similar to how we can manually adjust wind and turbulence.

    • Official Post
    Quote from poyraz_tr51

    If so, you could add this to the settings menu just like turbulence and wind, with both manual and automatic options. What I mean is: it shouldn’t stay fixed at 1013 all the time. For example, if we go into the settings and set it to a value like 1005, then we would also need to set 1005 in the aircraft to read the correct altitude. It should be a feature similar to how we can manually adjust wind and turbulence.

    Yes but that's easier said than done and has impacts on many things all at once. E.g. passing missions if the altitude is no longer geometric but barometric instead, descent planning, starting flights, time skip, resuming a flight, changing the pressure mid flight, air traffic flight altitudes, etc. etc.

    Quote from Jet-Pack (IPACS)

    Yes but that's easier said than done and has impacts on many things all at once. E.g. passing missions if the altitude is no longer geometric but barometric instead, descent planning, starting flights, time skip, resuming a flight, changing the pressure mid flight, air traffic flight altitudes, etc. etc.

    So, can you tell me if this feature might be available in the future?

    Since this is the suggestion forum, wouldn't it be easier to have the sim default to its current level as far as fuel burn/barometric setting etc, and then have an advanced mode the user can click and then choose to have more realistic features. I could be completely wrong since I've never heard it from a dev, but on other forums, they say fuel burn was blocked because users were submitting support tickets complaining about running out of fuel.

    It would seem there needs to be a balance between the bulk of users that don't care and want to fly, and those looking for the option of a more realistic experience.

    Even back in FS9, you could tick unlimited fuel, and turn off real weather.