Logged on with ATC, they are seeing me 1000 above, I am at FL340 and they see me up at FL350
Interesting. And this is on PilotEdge? Flying live weather or a preset?
(It really would be cool if Asobo could have specifically tested with all the major services before any of the releases went out, I will admit.)
PilotEdge using Live Weather. It works fine with Presets as was the work around before. which I assume is because the altimeter is 29.92 across the board
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I’m hopping onto the PilotEdge discord server to ask some technical questions, see if anyone can help…
@Bishop398 “Plane Altitude” may be a bit farther off from “Indicated Altitude” than I first thought on my flight yesterday done during climb in the CRJ.
At the moment, I am cruising at 7000 feet indicated altitude with live weather active in the G1000 172. Pressure is 30.04, and the altimeter is synced to that. Indicated altitude is 7000, pressure altitude is 6850, (which perfectly matches on the altimeter if I change the baro to 29.92).
OAT is 11C and Plane Altiude is 7180. This does not appear to be a bug, because that matches the calculation for True Altitude on my E6B app, if I plug in the current values for indicated altitude, pressure, temperature and the altitude of the pressure reporting source, (which in this case is 955 feet).
It appears that either indicated (not pressure) altitude or plane altitude may be taking temperature into account?
If VATSIM does, in fact, use the plane altitude simvar below transition altitude, I can see why there might still be a bit of a discrepancy between what a controller sees, and what the pilot sees on the altimeter. A 180 foot difference will not usually draw ATC’s attention (at least not in the r/w), but 300 feet (or more) certainly will
yeah in this case we are looking at a discrepancy of roughly 1000ft or more which is not normal
It would depend on where a 1000 foot difference is seen. Apparently, there is still an issue with the built in MSFS ATC not “seeing” altitude correctly, but there should not be such a major difference when flying on Vatsim since HF2
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Ive heard reports that VATSIM works correctly but I can not confirm. I’m on the PilotEdge network and there it is still not showing the correct altitude using Live Weather up at the flight levels. Hopefully we will hear back from them soon, might be something that needs to be adjusted.
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Pilot Edge would need to use the MSFS simvar “pressure altitude” at the flight levels. From what I have seen since HF2 released, that now works 100 pecent correctly when the altimeter is set to STD.
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For me altitude is still an issue. Just using the standard ATC, for example, it tells me to set altimeter to 30.03, but then tells me that I’m at the wrong altitude. I had to set it to 29.42 in order to get ATC to think i was at the correct altitude. This takes lots of guess work.
Please see the known issues in the current hotfix changelog, where it mentions in-sim ATC radar altitude issues.
-Matt | Working Title
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Ahh, thanks. I never saw release notes, but by changing the URI for .14 release notes I found them.
So do I get this right.
A temporary workaround to use Vatsim would be, to just switch to custom weather (as it is based on the ISA atmosphere) leave the pressure in the weather setting at the default 1013 and set the aircrafts altimeter to the local QNH the Vatsim ATC gives me? (and yes switch to Standard at the respective trans alt).
Thanks
My understanding of the current state is that what you should do for VATSIM at this time is:
- use live weather
- use STD above transition altitude, as normal, so your indicated altitude matches pressure altitude
- use the MSFS barometer setting below transition altitude if it differs from the VATSIM barometer setting, to ensure your indicated altitude is relatively close to your true altitude
(However I could be incorrect, as the only VATSIM flight I’ve been on recently – as wingman in a formation flight so I wasn’t the one dealing with the radio – had no active air traffic controllers in the area, so cannot confirm personally that it’s working as expected.)
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Just put in the remarks “MSFS 2020 - Altitude bug may be present”
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Ah thanks… that does not sound too hard to do… you pretty much ignore the ATC QNH and press B below the trans. alt., the rest is as usual.
If someone else could confirm this please… I might try myself later or tomorrow when I get to fly again.
True and indicated altitude rarely match, only in standard atmosphere will the indicated altitude be the true altitude. If the atmosphere is non-standard they simply won’t match, setting the altimeter to the correct QNH is not gonna solve that.
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Which is why (if it were my call to make), I would like to see online network clients use the simvar “indicated altitude”. It would solve all of the inconsistencies, and would effectively emulate exactly how things work in the real world where ATC is concerned.
R/W transponders always transmit pressure altitude, referenced to 29.92. When an aircraft is flying below the transition altitude, the ATC computers that drive the controllers’ display scopes will automatically apply a barometric conversion to the reported Mode C pressure altitude, using the pressure from whichever METAR-reporting station is closest to the aircraft’s current position.
This will result in the ATC controller seeing the same “indicated” altitude for a specific aircraft as the pilot of that same aircraft sees - assuming the pilot has also set his altimeter to the closest airport pressure, and the altimeter is within calibration limits.
Above the transition altitude, all aircraft in flight will be using 29.92 in/hg (or 1013 hPa) as their altimeter setting, so ATC transponder returns on controller scopes can use the reported pressure altitude directly without conversion.
In the real world, both the altimeter in the aircraft, and ATC controllers on the ground, are applying only a barometric correction to pressure altitude - without taking temperature into account. Since no temperature compensation is being used by either party, the resulting “indicated” altitude, will not be the same as “true” altitude unless atmospheric conditions are exactly ISA.
Effectively, since r/w ATC controllers are monitoring “indicated” altitude, (below the flight levels) then IMO, online ATC networks like Vatsim, IVAO and Pilot Edge should do the same - at least where their clients that interface with MSFS are concerned.
Agree, I didn’t check yet but it seems altimetry in FS2020 is working correct now so its up to VATSIM etc. to update their clients I suppose?
Can confirm I did a VATSIM flight EDDM to EGLL today with service online both above and below transition altitude. The QNH reading in the sim happened to match what VATSIM was issuing anyway but absolutely no problems with altitudes below the transition level doing it the way recommended.
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