Author Topic: Icing conditions  (Read 7082 times)

virtuali

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Re: Icing conditions
« Reply #15 on: September 27, 2018, 06:33:08 pm »
GSX reads the metar from Simconnect itself, it cannot read "just" the temperature, it must read the metar, because is the only way to read the Dew point.

This Simconnect metar, doesn't have anything to do with an external metar you might have seen reported either online or from a weather engine. It's an internal metar report, which is created by the simulator, so any addon needing to read weather, will get in in a metar format.

So, looking again at the code (and I think we made it intentionally), if the metar can't be read, either because it's not working, sometimes Simconnect gets stuck and doesn't report metar in time, or because the string is illegal/malformed/nonstandard, the fallback was to ALLOW deicing anyway.

That's for the reason I already explained: you CAN refuse a deicer if icing conditions has bee mistakely detected (not because GSX's fault, but because it got a bad Metar from the sim), but you cannot force-call it if no icing conditions to begin with.

So, assume an airplane like the FS Labs, were icing can be DANGEROUS on the flight and, for any reason the metar couldn't be read, what GSX should do then ? Not allowing icing, because it cannot be *sure* of the temperature/dewpoint, or allowing it anyway, since you can always refuse the service ?

I ASSUMED this was the safest choice but, of course, if it's mistakenly identified as a GSX "bug", maybe it's best to change the code, and block deicing in case of a bad metar report.

The "fix" (which is a downgrade IMHO), is already online in the current Live Update so, you can try it now.

sw34669

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Re: Icing conditions
« Reply #16 on: September 28, 2018, 01:00:08 am »

I did some more testing with this issue, default aircraft and not using activesky. Not sure where gsx is picking the temp up from but in 6 of the higher altitude airports I tested > 15-20C it offered icing.

virtuali

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Re: Icing conditions
« Reply #17 on: September 28, 2018, 02:06:12 am »
Not sure where gsx is picking the temp

Have you read my previous explanation ? It just reads the metar as provided by Simconnect. And, please, read again my last post, and read again the part that said I changed this in the current Live Udpate, to not allow deicing is the metar report was invalid or missing.

sw34669

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Re: Icing conditions
« Reply #18 on: September 29, 2018, 01:38:15 am »
Tried a normal altitude airport tonight that was actually -1C with icing reported and snow falling
asked for pushback
no de-icing offered

so there we are - de-icing offered at airports that are too hot and no de-icing offered when it's -1C

tried 3 different aircraft at CYHY (default 737/pmdg 737/747) .... all the same
tried setting weather manually to show correct temp for icing and activesky
I cant get gsx to offer icing

can you not just ask simconnect for the external temp and dew point ? Let me pass this thread onto LM for comment
Ive asked someone to have a look at this

thanks

just finished some testing ... if I use activesky which selects its own weather theme .... gsx will not offer de-icing when OAT < 4C
If i quit activesky and set the local temp in p3d manually GSX works
Not sure what the issue with malformed metars are since my aircraft and 2 other add ons all read the outside temp ok from simconnect. Can you look at this please I know a lot of us use activesky.
« Last Edit: September 29, 2018, 02:15:46 am by sw34669 »

virtuali

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Re: Icing conditions
« Reply #19 on: October 01, 2018, 02:14:36 pm »
so there we are - de-icing offered at airports that are too hot and no de-icing offered when it's -1C

No.

The "de-icing offered at airports that are too hot" shouldn't happen here because, in order to not have users mislead into thinking GSX was crazy, the current update now has changed the previous behavior, which was to *allow* deicing is the metar received from Simconnect was missing or invalid. Now, there's no deicing allowed in that case.

Which of course, hasn't fixed much (as I expected), because if an invalid metar is sent while the temperature is low, no deicing is allowed now.

THAT'S why I said the previous behavior was better, since you could always refuse deicing, but there's no way to force it.

Quote
just finished some testing ... if I use activesky which selects its own weather theme .... gsx will not offer de-icing when OAT < 4C If i quit activesky and set the local temp in p3d manually GSX works

So, the real issue is, how to deal with 3rd party products that are probably sending an invalid metar, without users being mislead it's a GSX bug ?

Quote
Not sure what the issue with malformed metars are since my aircraft and 2 other add ons all read the outside temp ok from simconnect

As I've said in my previous reply, reading the temperature alone doesn't require reading a Simconnect metar, because there's a variable for it. But order to read the Dew point, which is important to evaluate possible icing conditions, we MUST read the metar.

And no, reading the variable for the temperature, and the metar for the dew point doesn't guarantee it will work better because, if we get conflicting data (again, because of missing or invalid metar), a wrong dew point will confuse the evaluation of the possible icing conditions, since it's calculated to its relationship with the temperature.

I'll check with activesky enabled, to see if we are really getting invalid metar.