De-Icing Temp trigger

[Brent Beale]

What conditions trigger the use of de-icing in GSX (i.e. minimum OAT) temp?  I'm still getting asked if I need de-icing at 8 C and I'm wondering if that is normal.

Regards
Brent

[virtuali]

- Temperature must be below 8°C

AND

- Dew point must be within 2°C of Temperature (OR higher) OR It's raining/snowing

[Brent Beale]

Umberto - thank you for your quick response.

I had a flight this morning with an OAT of 17C and dewpoint 4C - GSX asked if I wanted de-icing.  Should I be seeing this?  I'm using the latest update.

Brent

[virtuali]

I had a flight this morning with an OAT of 17C and dewpoint 4C - GSX asked if I wanted de-icing.  Should I be seeing this?  I'm using the latest update.

It's not possible that you would be asked for de-icing if OAT is more than 8C.

Of course, GSX ask the sim for the OAT, using the standard Simconnect call to request Metar so, the only possible explanation is that, for some reason, the value the sim reported wasn't the one you were looking at, or the call to Metar failed for some reason (interference from a 3rd party weather engine, maybe ? ).

Enabling logging in GSX will show failures to obtain the Metar update in the Couatl.LOG file.

[Brent Beale]

This problem is persisting on my installation.  The example below shows the weather at 17C, dewpoint -3 which coincides with the NOAA metar.  Incidentally, I am using OPus on FSX.



I've attached the log file to see if you are able to spot anything not quite right.

Regards
Brent

[virtuali]

This problem is persisting on my installation.  The example below shows the weather at 17C, dewpoint -3 which coincides with the NOAA metar.  Incidentally, I am using OPus on FSX.

As I suspected, you are using a 3rd party weather engine so, the only possible explanation is that, the temperature reported by the FSX Metar, wasn't the one you read from that program.

Please note that, I'm indicating "FSX Metar", which doesn't have anything to do with the real world Metar. FSX Metar is just a report of the weather has it's happening in FSX, reported through Simconnect, which happens to use the standard Metar format, which we decode using a standard Metar reporting utility. It's entirely disconnected from the real world Metar.

The point of 3rd party weather engines is, usually, download the real Metar reports, and set the same conditions in FSX, using several methods (Simconnect, FSUIPC, proprietary).

So, if everything works correctly, a proper Simconnect client, like GSX, should be able to ask the FSX Metar through Simconnect, which some weather engine has translated from real world, and get the same report as the real world one, because the same conditions has been set in the sim.

Try with NO 3rd party weather engine enabled, and just set the weather manually in FSX, and see if GSX is working correctly.

[Brent Beale]

I've done as you requested (setting the weather manually in FSX) and the ice detection works as you described.  The odd thing is that it works fine using Opus some flights and others not as I would expect with similar temp and dew point values in each case.

 From your perspective, how can I express what is happening with the Opus weather engine to the developer?

[virtuali]

From your perspective, how can I express what is happening with the Opus weather engine to the developer?

Yes, it seems the problem here is that, in some cases, Opus is not setting the weather in FSX as it should, which affects Metar reports obtained with Simconnect. Perhaps the Time and Time zone has some effect on this, since we ask for Metar using the sim local time, local day of the year and local time zone.

[Brent Beale]

I'm trying to understand.  If Opus isn't passing the weather to FSX why does the aircraft show the correct temps and pressure, etc.?

[virtuali]

I'm trying to understand.  If Opus isn't passing the weather to FSX why does the aircraft show the correct temps and pressure, etc.?

It depends how the aircraft gauges read the weather. They might use:

- The airplane gauge variables ( such as A:AMBIENT TEMPERATURE in XML gauges or the equivalent in C++)

- FSUIPC (which calls Simconnect)

- Simconnect directly

Now, through Simconnect, there are TWO different ways to get informations on the weather, either by checking the airplane simulation variables, or by asking for a proper Metar report, which is a different kind of request.

GSX uses the Metar report method, because it's the ONLY way to get the Dew Point for the sim, which is important to detect icing properly.

So, the real question is, why if there's Opus involved, the Metar obtained by Simconnect doesn't agree with the airplane variables ? GSX doesn't have any idea who's setting the weather, it's only asks for it using the proper Simconnect method as a Metar, and it does it directly and, as you said yourself, it works when not using Opus.