Weird FL with PSXT

[kiek 1,215]

2 hours ago, artox67 said:

Well, those rules are the same for every plane. So please explain, why it works on VATSIM, there I see the correct FL but not in PSXT?

Well VSATSIM is not the topic here, but I assume it is because  VATSIM is a closed user group and you all work with the same local QNH. (BTW I have more than 1000 hours in a LevelD-767 at VATSIM)..

Back on topic,

2 hours ago, artox67 said:

If a plane 10NM ahead of me, we should have the same altitude 39000 + 7*30= 39210 feet.

ONLY if the altimeter in the plane in front of you  works with the same local QNH as your plane. The plane in front of you works with the QNH shown in the PSXT_MSFS app, but again, WHAT is the the local QNH in MSFS that drives the altimeter in your user plane?  

Edited October 30, 2022 by kiek

[artox67 0]

I double checked it now.

The underlying local QNH is 1020. But regardless which local QNH is used, the difference are always + - 300-400 feet.

[kiek 1,215]

2 hours ago, artox67 said:

I double checked it now.

The underlying local QNH is 1020. But regardless which local QNH is used, the difference are always + - 300-400 feet.

Good,  calculate the difference between the underlying local QNH and the QNH in PSXT_MSFS.

[artox67 0]

I'm not sure if I'm smart enough to follow you, or we talk about completely different things.

My understanding is, if an aircraft 10NM away from me on FL 390, and I'm on FL 370 it should show me in the TCAS +20 and not +22 or +18 e.g. When both on STD setting for QNH

[kiek 1,215]

1 minute ago, artox67 said:

My understanding is, if an aircraft 10NM away from me on FL 390, and I'm on FL 370 it should show me in the TCAS +20 and not +22 or +18 e.g. When both on STD setting for QNH

No that is a misunderstanding!

That is only true if both aircraft have the same local QNH. Altimeters work on barometric pressure, you know.

In real live that is always the case because both aircraft are closeby. 

But with PSXT + RT, the spawn aircraft have the QNH from the Real Time data (shown in the GUI of PSXT_MSFS), while you with your user aircraft have the QNH of the weather set in MSFS. If that is live weather it should be the same, or close by, maybe 1 hPa difference.  That's why I have asked you a few times to compare the QNH in MSFS with the QNH in PSXT_MSFS. If they are not the same that would be the cause of you seeing +1700 instead of +2000.

I recommend to study some literature about altimeters and the difference between altitudes and flight levels.

[kiwi971 0]

hello

I think I understood what you were saying before but as you can see on the image I am in real weather the QNH is the same everywhere and yet the traffic has an altitude between 700ft and 1000ft difference with my device and the QNH is the same everywhere

 

Edited December 3, 2022 by kiek

[kiek 1,215]

Is that traffic flying at your flightlevel?

What aircraft are you flying?

[kiwi971 0]

yes the traffic is flying at my flight level

I use the PMDG 737 800

Edited December 3, 2022 by kiek

[kiwi971 0]

I am currently in flight and there is a 1000 foot difference between my plane and the traffic. I fly at level 400 and traffic flies at level 380 on my TCAS while on real traffic it is at level 370 and for QNH is the same PSXT: 1017 Real traffic: 1017 and MSFS: 1017

Edited December 3, 2022 by kiek

[kiek 1,215]

On 12/2/2022 at 10:32 AM, kiwi971 said:

I am currently in flight and there is a 1000 foot difference between my plane and the traffic. I fly at level 400 and traffic flies at level 380 on my TCAS while on real traffic it is at level 370 and for QNH is the same PSXT: 1017 Real traffic: 1017 and MSFS: 1017

With an aircraft in RT at FL370 and you at FL400 one would expect to see -30 in the TCAS . You see  -20, with is 1000 feet wrong indeed. The  corresponding PSXT aircraft in your Sim is at at FL370 at QNH 1017  (37120 ft altitude).

Weird...

It looks like a problem in the your plane. Even if  PSXT would mistakenly calculate with 1013 it would never give a difference more then 4 * 30= 120 feet.

Edited December 3, 2022 by kiek

[kiwi971 0]

I will try with another plane to see if the problem comes from PMDG

Edited December 3, 2022 by kiek

[artox67 0]

I assume I found the issue (on my PC) 

The Real Traffic Launcher shouldn't minimize during the flight. When I keep the window open (back behind the MSFS e.g.) the QNH will be updated.

When I minimized the window it will not.

[kiek 1,215]

3 hours ago, artox67 said:

When I minimized the window it will not.

Interesting, but are you sure?

[artox67 0]

1 hour ago, kiek said:

Interesting, but are you sure?

I tested it now over a couple of weeks, and yes, I'm sure.

The only thing of course I didn't know is, is it only me.

[ckukmale 30]

Might be related to this.