In the customizable HUD at the bottom of the screen if you select pressure the reading doesn’t change regardless of temperature or altitude. Am I missing something?
@Swang007 do you know anything about this?
That’s air pressure, right? I never use it, but it seems like air pressure would go down the higher you go.
1013,25hpa is the standard pressure used by planes above transition altitude (5000ft in Europe). Below transition altitude, they use QNH (pressure at MSL).
Nowdays, everything is Controlled by CPC (Cabin pressure Controller) which controls outflow valve.
Hope it helps
It doesn’t change with altitude.
So you mean that’s cabin pressure?
That’s strange. There’s supposed to be less air pressure at higher altitudes.
Yes - pressure reduces with altitude but it has nothing to do with it. To calculate the altitude, the plane should know how high it is from " something ".
Static probes will calculate the pressure in the area where the plane is.
It will then compare this pressure with 1013,25 hpa (Standard pressure). So each and every plane flying has the same reference: 1013,25 hpa. Of course, during landing, it uses MSL (Main Sea Level Pressure). That pressure is called QNH so when you land, your altimeter will show the altitude of the airport above MSL.
Hope it helps! 😉
Pressure does change with altitude!
You set a pressure in the altimeter which then uses that to calculate the altitude of the aircraft above the ground. Close to the ground you use a local preassure (QNH https://en.wikipedia.org/wiki/QNH), this is the pressure usually at the airport you are taking off from, or landing at. It is given to you by ATC and available in ATIS and the METAR (e.g. you see Q1016 in the METAR). Once above a certain height you use standard pressure (STD) which is 1013 hPa or 29.92 inHg.
From my notes:
However, I don’t know how this works in IF. Although QNH values are shown in the METAR this doesn’t seem to match the local QNH value at the airport you are at, and doesn’t allow you to change it.
Exactly! Thanks ATK for all these details 😉
Thanks everyone for your input, I just did a series of test flights varying altitudes above ground and sea level and also temperature. It won’t even move a mercury inch so as far as I can tell it’s cabin pressure and so unless there is a way of depressing cabin pressure then it’s just pointless. Any thoughts is there a way of changing that to outside air pressure?
1013 hectopascal or 29.92inches is the standard. Transitiation altitude / level is different in every country in Europe.
Standard is used so wherever you fly while cruising everybody will be at the same true altitude and like that the minimum vertical seperation is maintained. This has nothing to do with the CPC!
Yes nothing to do with CPC but cabin altitude is controlled by CPC by opening/closing outflow valve. Nothing to do with QNH/QNE.
I don’t know why I wrote that lol
One simple fact… It doesn’t change so it’s pointless
For a game like IF I don’t think it’s important if the pressure changes or not, if it was the cabin it should also decrease.
No cabin pressure must be held at 1013 hpa.
Please show me that…??
If cabin pressure is not held then by the time the aircraft reaches 32,000 ft anyone on board would have lost consciousness as the air is too thin at that altitude.
This post was flagged by the community and is temporarily hidden.
As rotate sais the cabin pressure doesn’t go higher then around 8000 feet, in the newer aircraft it’s even lower around 6500.
The pressure doesn’t stay at 0 feet. If you depart or land on an airport with 5000 feet elevation the cabin pressure will never reach 0 as it takes the landing elevation as reference for pressurization.