When I'm on the ground and press B the baro will set to the ASky barro setting but when I'm airborne and press B it's as P3D just defaults back to 29.92. Problem being that if the baro goes to 30.30 then ATC will tell me I'm to low. Also before the 7070 update ATC would always finish my telling the baro, now it doesn't anymore. Is this an ASky problem or is it on my end. Any suggestions.

And that's right: actual air pressure for your departure airport on the ground and up to the transition altitude (TA), which is location specific and above that standard 1013/29.92.  Coming down, you revert to actual at your destination airport at the transition level  (TL), again location specific.

 

Edited July 15, 20196 yr by ailchim

That's normal. Below FL180 it will use the actual pressure. Above FL180 it will always set it to 29.92...

Transition altitudes are different outside North America (where standard is 18'000 feet), but P3D (like FSX before) would apply the same transition altitude worldwide which is obviously wrong, ATC add-ons would rectify that and you can see on many high-end aircraft add-ons that the transition altitude of the airport you start your flight from would be indicated on the FMC. Unfortunately, you need to change it to 18'000 feet regardless of your location if you fly with P3D ATC. It is difficult to understand why this was not rectified by LM since add-on developers can do it, so could they!

When you fly above 18'000 feet and press B, P3D will automatically select 29.92 (1013) as the standard pressure. When flying below 18'000 feet, pressing B will give you the actual QNH in the region where you are. So normally when you contact P3D ATC and fly below 18'000 feet, it will tell you the QNH of your area. Anywhere above 18'000 feet that information wont be indicated as it is the standard 29.92 (1013).

When in transition ABOVE 18'000 feet simply press B and you will be OK when reaching your FL above 180 (or when you receive your clearance for a FL above 180, just select 29.92 (1013)). When descending transitioning BELOW FL180, press B it will give you the pressure in your area. If you happen to press B too early either climbing or descending before reaching 18'000 feet, your baro indication will be wrong and, hence, ATC will reprimand you for busting your altitude. The trick is that when you receive a clearance from say FL 260, "descend Altitude 12'000", the QNH will not be given by ATC (because you are above 18'000 feet), so that is when you need to press B after crossing FL180. You will notice though that after you cross 18'000, the first ATC message will include the QNH.

 

 

Edited July 16, 20196 yr by Jean-Claude

For good practice, just don't use the b button. Can't do that in real life either, you have to get the current pessure through ATIS.

Thanks everyone for the great explanation, I was getting annoyed that they were giving others the baro but not me 🙂