A while ago I read a post about how to easily set the expected QNH before you actually switch to it from STD. I can't find that post anymore... Anyone knows the answer?

Tune to the ATIS frequency of Your destination Airport.

Alternative open the Weather window in the tool bar and use the Metar function - QNH is to be found as "Qxxxx" f.ex. "Q1016".

3 minutes ago, Wothan said:

Tune to the ATIS frequency of Your destination Airport.

Alternative open the Weather window in the tool bar and use the Metar function - QNH is to be found as "Qxxxx" f.ex. "Q1016".

Thanks but I now how to read METAR and where to get the current QNH. 😉 I am asking about a tip how to enter it (in my case in the Fenix) before I have to switch from STD to current QNH. So that when I switch it is already set correctly. I read a tip about this a few weeks ago but can't find it anymore.

I believe @tup61 is not asking how to get the current QNH but how to pre-set it so that it will be available once switching out of STD. It also sounds as if this question is specific to Airbus.

 

 

The real bus will not change altitude in cruise if you change the pressure. I suppose they modeled it correctly 

I think in the Boeing you could pre select it so that when you come out of STD it’s at the pre selected QNH… from what I remember it’s either Boeing or Airbus 

I had this last night flying the Fenix, and it's likely behaving as it should do. I set the QNH and the other requirements on the approach page, but despite me not checking  when i tried to move from STD to the QNH it kept reverting to STD. It was only once i was below 4000ft ( which i guess was when i should have changed it, did it then work ok). this was on approach to 25R EBBR

On the other hand, i could be totally wrong, and just ignore me .

12 minutes ago, ha5mvo said:

The real bus will not change altitude in cruise if you change the pressure. I suppose they modeled it correctly 

Er...? Don't really know what this has to do with my question... 😉

7 minutes ago, Ridvan Celik said:

I think in the Boeing you could pre select it so that when you come out of STD it’s at the pre selected QNH… from what I remember it’s either Boeing or Airbus 

That's certainly not as it works in the Airbus.

3 minutes ago, Car147 said:

It was only once i was below 4000ft ( which i guess was when i should have changed it, did it then work ok). this was on approach to 25R EBBR

Afaik the QNH doesn't automatically switch to the one set in the MCDU. You have to set it manually.

10 minutes ago, tup61 said:

Er...? Don't really know what this has to do with my question... 😉

I believe I actually answered it.

just prior to TOD, set up the arrival pressure, than switch it back to standard.

In transition simply switch to the preselected pressure.

As I said, when changing the barometric pressure the plane ( that’s how it’s on the real one) will maintain altitude and won’t hunt down for the new barometric altitude as you change the setting.

Edited June 12, 20223 yr by ha5mvo

In the FENIX it is even simpler 🙂 - hit "B" when at the transition level...  Compare to ATIS reported QNH or METAR ( the EFB has it available for you too ).

Sometimes with airfields near the final approach path you can get a QNH ( using the hit "B" method ) which differs from your destination airfield QNH, so, make sure you check it against ATIS / METAR and keep hitting "B" up to the FAF.

Edited June 12, 20223 yr by jcomm

4 minutes ago, jcomm said:

In the FENIX it is even simpler 🙂 - hit "B" when at transition level...  Compare to ATIS reported QNH or METAR ( the EFB has it available for you too ).

There’s a caveat. If the point of transition is somewhat further from the airport, which is likely with say, 18k transition, the pressure at this point might be slightly different than in the actual port of arrival.

10 minutes ago, ha5mvo said:

I believe I actually answered it.

just prior to TOD, set up the arrival pressure, than switch it back to standard.

In transition simply switch to the preselected pressure.

Ooo, LOL, sorry, I now know what you mean! 🙂 That's how you can do it indeed! But the post I read was about how to preset QNH during descent already. It involved switching to another mode and such. Maybe I Just have to switch from managed to selected mode but I remember the instructions being a bit more complicated. 😉

7 minutes ago, jcomm said:

In the FENIX it is even simpler 🙂 - hit "B" when at transition level...  Compare to ATIS reported QNH or METAR ( the EFB has it available for you too ).

Nah, that's cheating. 😉

Edited June 12, 20223 yr by tup61

On Boeing aircraft, the QNH can be pre-set to the value gleaned from the ATIS. Once ATC clears you to descent beyond the transition level, press STD and voila.

On the Airbus, the QNH cannot be pre-set. The value entered on the Approach page is used by the FMGC for profile computation, but has no effect on the reading of the altimeter. Once cleared below the transition level (which is alway higher than the transition altitude to account for pressures lower than 1013 hPa), push for STD and set the QNH (from the ATIS, and the controller will tell you when clearing you below TA). 

Edited June 12, 20223 yr by psychedelic_tortilla

1 minute ago, ha5mvo said:

There’s a caveat. If the point of transition is somewhat further from the airport, which is likely with say, 18k transition, the pressure at this point might be slightly different than in the actual port of arrival.

That's why I rather don't set it before TOD! 

1 hour ago, ha5mvo said:

There’s a caveat. If the point of transition is somewhat further from the airport, which is likely with say, 18k transition, the pressure at this point might be slightly different than in the actual port of arrival.

Yep, mentioned that too in my suggestion 🙂