Live Traffic Cruises at Geometric Altitudes Rather Than Pressure Altitudes

Please only post bugs that are new in this build, and tag your post with #pc and/or #xbox.

Are you on Xbox, Steam or Microsoft Store version?

Are you using Developer Mode or made changes in it?
Yes, to have access to the Icing slider to adjust icing as needed

Brief description of the issue:
Live Traffic cruises at geometric altitudes rather than pressure altitude. This is increasingly apparent when you’re flying on airways as high as FL410

Provide Screenshot(s)/video(s) of the issue encountered:
In the image above, I’m at FL410 (geometric altitude of 39,950’ according to Volanta). The Live Traffic target shown above indicates 1000’ below me on TCAS flying the other way, but they actually flew 50’ above me.

Detailed steps to reproduce the issue encountered:

  1. Take CJ4 to FL410 on a cold day
  2. Watch TCAS traffic approach you going the other way (they may show 1000 feet below)
  3. Watch them fly by much closer than 1000’ apart

PC specs and/or peripheral set up if relevant:
Not relevant to this issue

Some more pictures.

TCAS Indication with traffic 1000’ below me when I’m at FL410:

True altitude shown on Volanta:

Traffic actually passing by a tiny bit above me 5 miles away:

1 Like

Oh wow, this is interesting. I fly exclusively below 10000 feet, so this is not something I’ve ever come across.
I imagine this might be more complicated in the future if and when they introduce different transition altitudes around the world. But for right now, this should be pretty straightforward.

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I think handling of standard pressure and real pressure is not correct at all. Basically at 5.000 feet MSL (or at transition altitude, depends if you’re flying VFR or IFR) you switch to standard pressure (1013 / 2992) and report flight level instead of feet then. ATC always wants you to climb to real pressure altitude! E.g. reaching an assigned FL110 with a way off real pressure (e.g. 29.50), ATC yells at you to climb or descend (depending on the pressure).
This might get really weird in combination of what you are describing. And I see you set standard pressure - maybe you should try with real pressure and report what happens then? Not that this would be right, but would confirm that MSFS completely ignores standard pressure. For now I gave up on pressing the STD button as it breaks ATC.

I think I only noticed now because I was flying the CJ4 in the mid-west prairies where:

  • Traffic is sparse, so can actually process each TCAS target one at a time
  • Traffic is predominantly East-West, so there’s no confusion on direction of flight and associated altitudes
  • I’m flying the CJ4, where the TCAS isn’t self contradictory like it is in the Aerosoft CRJ
  • I’m flying on Jet routes rather than directs, which (if other traffic also flies on jet routes), we’re being funneled close together enough to notice that we’re only 50 feet apart in altitude, not 1000.
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I’m not convinced seeing this picture, seems much more than 50 ft to me. That being said, isn’t this “please expedite climb / descent” stuff still ongoing when using offline ATC?

Traffic shows up on the TCAS as “-10” (i.e., 1000 feet below), but the traffic passes me on the right a few feet above (bear in mind that the horizontal line is actually above the horizon due to the curvature of the earth).

What I didn’t manage to get a screenshot of was the prior aircraft that passed me on the same airway with the same indication (-10), but was no more than one wingspan above me.

Obviously yes, if I would see this in real life I would say, around 1000 ft above (which in it self is still wrong, should be 1000 ft below) maybe seeing the full picture would help judging the range and relative altitude. Is it not a TCAS problem? What does flight aware show on those aircraft?

I’ll keep this topic alive with more pictures as I get them; only problem is I don’t fly often enough. :upside_down_face:

actual not an issue only with live traffic. Offline AI is also not on the correct altitude and ATC tell them constantly to increase/decrease altitude. This issue is already quite old…

use your influence and tell them to fix it :wink:

wrote Jörg that many moths ago already…

1 Like

Hi @Eefoe,

Looking for some further information from you about this issue. Are you reporting that AI traffic is incorrectly using the local altimeter setting above FL180 (e.g. 30.13 or 29.51 or whatever) and flying accordingly when they should instead be using the standard 29.92 pressure setting?