Altimeters during Preflight and Approach Checklist

[thaine 5]

Hei Bryan,

 

I experience the following during the Preflight- and Approach Checklist. During the items of verifying the altimeter settings, the FO replies/challenges always 1 hPa to little.

 

Preflight: Lets say the QNH is 1024 hPa set at all altimeters. After I read the setting, the FO replies 1023 hPa. The voice recognition gets the right number, which is visible in the green text window.

 

Same for the approach checklist. The FO challenges a QNH with an offset of 1 hPa. So if the QNH is 1009, set on all altimeters, the FO challenges me with "Altimeters 1008".

 

Any Idea what could cause this?

[byork 2,258]

Hi Rafeel,

 

Not sure... on my system the FO reads back the correct number.

 

Are you using any programs that interfere with weather?

 

Note that FS2Crew does not "read" the alt setting value out of the NGX itself, but rather out of FSX.

[thaine 5]

Ah ok,

 

That could be the issue. I use ASE on a second computer that feeds the weather into FSX. Normally I use the QNH values from the ASE report or whatever the VATSIM ATIS tells me. ASE is using the weather from the VATSIM servers and they do agree most of the time. Maybe something gets mixed up on the way into FSX. I will check next time what the QNH in FSX is by setting the altimeters automatically via the "B"-key.

[byork 2,258]

Good plan.

 

Cheers,

[thaine 5]

During yesterdays flight, I was setting the altimeters automatically (B-key) during the preflight procedures. The FO answered with the correct QNH during the checklist.

Then, during the approach procedures I was preselecting the QNH manually according to what ASE told me. And this time the FO challenged me with the correct QNH during the approach checklist.

 

Here's what I think that happened: If I remember correct, ASE updates my weather every 15 mins; I need to check that for the next flight. I'm not quite sure how often the VATSIM weather is updated. I think that the offset was caused by the weather being updated in between me checking the value at ASE and the checklists. So that the FO had a newer value of the QNH compared to the one that I got some minutes before.

[SKeller 5]

Sorry for bringing up this "old" topic again. But I'm having the same issue. I always press the B-key when the F/O calls Transition Level during descent, and yet the F/O reads the altimeter setting wrong by 1 unit (e.g. 1010 instead of the 1011 displayed in the PFD). I'm using OpusFSX for weather, but if you say that FS2Crew reads the QNH from FSX, shouldn't the F/O call always match the value on the PFD as long as I press B?

 

Opus weather reports 1011, IVAO Metar reports 1011, PFD displays 1011, but F/O says 1010.

 

Not a big thing, I'm just curious whether there might be a fix.

 

Thanks and best regards,

Stefan

[byork 2,258]

In this instance, FS2Crew is reading not the value in the display (because that piece of data is not accessible via the SDK)... instead, FS2Crew is reading the pressure outside the aircraft.

[SKeller 5]

Hi Bryan,

 

Thanks for your response. But where does the PFD get its value from then? This sounds as if there were two different sources for the pressure readouts. (I'm just trying to understand...)

 

Best regards,

Stefan

[Don t moderate me this way 882]

In "default" weather (exactly 29.92 in) hitting "B" gives me a gauge reading of 29.91. So I guess there's (just) a(nother) quirk in the FSX internals.