Incorrect Altitude in ATC

[veldthui 0]

Anyone else noticed that once you get above 18,000' and using ATC it is called out that you are actually 300' above where the gauges and PFD say you are. If you are 21,000' it will call out something like "at FL213 climbing for FL280". It should be calling out at FL210.Thought it was a timing issue but have checked each time and it is the same. Have changed over to STD as well so it is not that.http://www.virtualpilots.org/signatures/vpa475.png

[downscc 1,327]

I suspect that the MSFS ATC code is using your absolute altitude, you can check this by turning on the lat/lon readout (SHIFT+Z) and comparing that altitude with the ATC. When you change to 29.92 you use pressure altitide as a reference but pressure altitude and absolute altitude are different except when the air mass is standard.

[Tabs 2,790]

John,Passing 18,000, you need to press B to reset the internal FS altimeter to 29.92 and then press the "STD" switch on the EFIS control panel...

[michal 44]

Just for your information, ATC is always getting your altitude from your transponder which is based on the 29.92" pressure setting. This is so your own potential erroneous altimeter setting would not interfere with their operations. ATC ground computers then do their own recalculation to ajust for local barometer setting if such operation is necessary.Michael J.http://img142.imageshack.us/img142/9320/apollo17vf7.jpg

[Tabs 2,790]

Barometer setting doesn't matter above transition altitude though, everyone standardizes on 29.92/1013 above that.

[Peter Clark 21]

Not setting the barometer to 29.92 above transition alt does matter though. I would suspect the OPs problem is that they didn't select STD crossing through transition, so though their altimeter was reading FL350 (say), they were really at 35,300 because of a mis-set Kollsman window, thus triggering the "Hey, check your altitude" call from ATC.

[michal 44]

>Barometer setting doesn't matter above transition altitude>though, everyone standardizes on 29.92/1013 above that.My point was that ATC gets your altitude 'standarized to 29.92' no matter what altitude you are at.Michael J.http://img142.imageshack.us/img142/9320/apollo17vf7.jpg

[Peter Clark 21]

RW transponders always send back to ATC pressure altitude, but I don't think we're talking about RW transponders here....

[downscc 1,327]

I agree... I think MSFS uses absolute altitude. I just finished a flight at FL410 and the absolute altitude was about 43000. This is normal.Real world ATC always wants you to confirm altitude on initial contact or after hand-off. It's automatic, "Redbird 56 checking in at Two-Three-Zero."

[veldthui 0]

>John,>>Passing 18,000, you need to press B to reset the internal FS>altimeter to 29.92 and then press the "STD" switch on the EFIS>control panel...I have done that and get the same result. It does not matter what it is set to. Also to the other comments, this is not ATC saying that I am 300' high. This is "me" calling out to ATC on initial contact when changing frequencies. ATC have never bugged me about being 300' above altitude.http://www.virtualpilots.org/signatures/vpa475.png

[Peter Clark 21]

I disagree, leave your altimeter at 30.92 or 28.92 and climb into a flight level, MSFS ATC will give you altitude warnings until you reset your altimeter to 29.92 and climb or descend appropritately. Unless you're saying that even though you're set to 29.92 MSFS ATC is actively looking for the corrected altitude, which would make some sense in how they code the ATC system, but it would be just as easy to have an "if then elseif then " loop. Either way, MSFS ATC will yell at you about your altitude if you don't have 29.92 above 18,000 feet.

[veldthui 0]

It seems the new version has fixed whatever problem it was as it is now reporting the correct FL each time.http://www.virtualpilots.org/signatures/vpa475.png