MB or HG altimeter
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Hi all. I know that is it possible to show/set altimeter pressure in Millibar or HG by BMS Configuration app. Since the Altimeter Pressure window reads “MB”, i’m asking whitch one is mutch more correct to use. I’ve read that the use of one instead the other depends by Nations. But, as i said, the Altimeter into the BMS cockpit reads MB for the pressure selection window.
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Hi all. I know that is it possible to show/set altimeter pressure in Millibar or HG by BMS Configuration app. Since the Altimeter Pressure window reads “MB”, i’m asking whitch one is mutch more correct to use. I’ve read that the use of one instead the other depends by Nations. But, as i said, the Altimeter into the BMS cockpit reads MB for the pressure selection window.
The efficient BMS answer would be: “The one server host uses”.
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The efficient BMS answer would be: “The one server host uses”.
Yes, i’ve noticed this in MP. I’d like to know what is more correct since the “MB” label on the instrument for every player, host included. Anyway, i’ve also noticed that values in MB usually need decimals (exemple: transition altitude 29.92 in HG, 1013.25 in MB). Since the window allows only 4 digits, does this means that the values suffer of “rounding” effect ( i can set 1013, not 1013.25)?
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does this means that the values suffer of “rounding” effect ( i can set 1013, not 1013.25)?
Yes, but ATC would never need to be that precise, because even if the actual pressure would be 1013.99, it would be rounded down to 1013. (It is always safer to have a lower setting than the actual pressure)
At sea level, IIRC, a setting of .99hPa below actual would give you an extra true altitude of ~27ft. -
Clear. Thankyou!
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Not sure about your question, to be honest. BMS? Host. Real life? ATC. I suppose it’s not about accuracy, you didn’t mention it in your first post. Or was that actually it?
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Not sure about your question, to be honest. BMS? Host. Real life? ATC. I suppose it’s not about accuracy, you didn’t mention it in your first post. Or was that actually it?
What i mean is: since the Altimeter in BMS (at least for the F-16) has the label “MB” on the QNH,QNE,QFE window, i believe that it’s correct to use Millibar. In real life maybe some Altimeter works in MB, others in HG. am i right? I understand that with BMS you can choose what type of scale to use, but it is a fiction (or not?). If the altimeters reads “MB” on this window it means that works in MB…
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Maybe the problem is that in Falcon we have only the picture of mb altimeter.
Anyway here are examples of Hg altimeters. -
Hi all. I know that is it possible to show/set altimeter pressure in Millibar or HG by BMS Configuration app. Since the Altimeter Pressure window reads “MB”, i’m asking whitch one is mutch more correct to use. I’ve read that the use of one instead the other depends by Nations. But, as i said, the Altimeter into the BMS cockpit reads MB for the pressure selection window.
Your observation is correct - “it depends”. In general, if the operating nation uses Mb then the jet will be delivered with an altimeter that indicates in Mb, and the same holds for inHg. However, if say - a USAF - jet is operating over a nation that uses Mb, then they will carry a conversion chart on a knee board so they can set their inHg indication to the ATC call in Mb (it’s easy enough to make one in a spreadsheet). I should assume that this operation goes both ways…and I should also hope that BMS would change the altimeter in the cockpit presentation between the two based on squadron selection. But I can only dream…
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Thanks for your reply m8. Clear! I’ll use MB for me and my squadron due to the BMS MB Altimeter. And for shure i will search the conversion chart so that i will be always able to set the correct value when Tower gives me HG measures!
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However, if say - a USAF - jet is operating over a nation that uses Mb, then they will carry a conversion chart on a knee board so they can set their inHg indication to the ATC call in Mb
ATC: “Descend to 3000 feet, QNH 1027”
Pilot: “Ehr, could we have that in inches?”
ATC: “Of course. Descend to 36,000 inches, QNH 1027”AFAIK, most ATC will have both hPa and InHg displayed on some piece of hardware, so on request it should be available.
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ATC: “Descend to 3000 feet, QNH 1027”
Pilot: “Ehr, could we have that in inches?”
ATC: “Of course. Descend to 36,000 inches, QNH 1027”AFAIK, most ATC will have both hPa and InHg displayed on some piece of hardware, so on request it should be available.
What surprises me is that now that most jets are software and glass in the cockpit that the STBY instruments are still one or the other…I have a conversion card because I have to pass such out at (RL) briefs on occasion. Sometimes only to be told that “my STBY alt is still in inches, so I don’t need your card”…
And I’m not aware of ATC making “QNH” calls…honestly that’s a new one on me, and I’ve been an operator (domestically) for over 30 years. “Current atlimeter xxxx mB” or “yy.yy inches”…and it’s up to the crew to employ.
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When listening to Dutch comms during e.g. Frisian Flag, where both European and USAF participate, GND or TWR gives QNH in Mb Or Hg depending on the flight calling.
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In real life maybe some Altimeter works in MB, others in HG. am i right?
If the aircraft is fitted with an AAU-34/A, its in InHg. If its fitted with an AAU-37/A, its in millibars.
I believe USAF jets are all fitted with AAU-34/A and upgrades/replacements thereof? There are COTS replacements that have a cockpit selectable setting for InHg/mb. Kellstrom make one such replacement.
You answered yourself in the opening post, it depends which country operates that F-16, as to which altimeter they selected on their purchase.
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Ok. So we can say that in RL ATCs gives MB or HG depending on Aircraft request. For now Users choose the scale, simplyfing things. Conversion table is needed when host and user uses different scale in Configurator. So the best thing we can wish to have in the future is Aircraft with different Altimeters according to RL and Own Countries and ATC with MB and HG values available on the ATC comms menù.
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If the aircraft is fitted with an AAU-34/A, its in InHg. If its fitted with an AAU-37/A, its in millibars.
I believe USAF jets are all fitted with AAU-34/A and upgrades/replacements thereof? There are COTS replacements that have a cockpit selectable setting for InHg/mb. Kellstrom make one such replacement.
You answered yourself in the opening post, it depends which country operates that F-16, as to which altimeter they selected on their purchase.
Hi BlueWolf. So the question remain: why i read MB on BMS F-16 Altimeter cockpits?
If Falcon was born as an USAF F-16C 50/52 Simulator, and if what you say is correct i’m expecting an HG Label on the Altimeter, right? For shure i’ve checked USAF Vipers and also Balkans block 50 ones. So i’m not shure that all BMS Vipers has MB label on altimeters. I’ll check -
BMS devs are not building it as a USAF simulator primarily? Which is why we have CM jets (in the BMS simulator) with a mix of european and american avionics…
The label should be ‘IN HG’ above the Barometric Counter Display.
If it bothers you, ask the devs to make it more realistic, but I wouldnt hold my breath. Then again avionics configuration was not possible before, so perhaps we will get further improvements by 4.35.
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Simply because the guy who designed the current cockpit is an european. It is not more complicated than that.
Should it have been designed by an american guy then the legend would most certainly read inhg.
It is a tiny detail gents. Both options are valid and works pretty fine use either one that works for you egardless of that tiny legend on the instrument. -
Yeah i know that it isn’t a big deal and both of them are valid options. And i understand that it’s only a texture choice. But thanks to all of you i know now that in RL it depends by aircraft build/own nation. I like to understand things about Flightsims! :mrgreen:
Being said this i think i will set MB option just in accordance with the label on the altimeter. Nothing more than this. Thanks you all! -
And I’m not aware of ATC making “QNH” calls…honestly that’s a new one on me, and I’ve been an operator (domestically) for over 30 years. “Current altimeter xxxx mB” or “yy.yy inches”…and it’s up to the crew to employ.
The phraseology I used in that joke is ICAO, where “QNH” implies hPa, “altimeter” implies InHg. I know FAA (US) and CAA (GB) have a slightly different rule book, though, and this is one of those differences.
The Brits might say “QNH xxxx Millibars”, and when it’s 999 or below, they’ll always say “QNH xxx hectopascal”.