Does it choose them based on weather or based on something else?

It looks at what the Ai are using first both for departure and landing. If no Ai then wind direction is used. That's why it's important to refresh Ai after a weather program initially updates the weather if you notice the wrong runway is being used. All this of course before you start RC.

 

That's the simplistic explanation. There are other factors including runways with ILS taking priority for landing but only JD could give the definitive rules.

Quick question, I have more then once noticed incorrect runway assignments given by RC, using a 3rd party weather engine set to update every 15 minutes or 40 km, in which the assigned runway does not match wind conditions (e.g. assigned to land on a runway with a strong tailwind). How do you refresh AI manually in FSX?

Advance the FSX time by one minute I believe, maybe two, and AI should refresh.

 

In FSX due to a SimConnect limitation, it appears global weather (FS worldwide) which must be used is set continually to the conditions where your aircraft is located. Therefore, as you aircraft approaches from just about 40 nm out to your destination, your destination weather follows each change based on your aircraft location for that duration. RC estimated your approach looking at the ai pattern and winds when you were 40 nm out and one more time on the way in. But the destination weather and perhaps the ai has changed since those evaluations.

 

In the Active Sky FSX versions, there is the capability of "destination weather lock" which locks the weather pattern keeping it constant at destination for a certain distance. This keeps the ai pattern and winds consistent with at the time RC evaluated the destination conditions. There is also a way that FSUIPC4 will report the weather from the AS METAR for the destination but this may not be the weather occurring there.

 

FS9 does not have this problem.

 

Beta tester bobbyjo uses in ASE the destination weather lock and that has solved the problem most times for him. Also please see the pinned topic regarding FSX ASE users.

 

I do not know if a registered FSUIC4 offers this feature.

Thank you very much for information and clarifying this for me, I will see what I can do to lock the destination weather when within approach distance to the airfield.

ASE also has a button to command the 'refresh AI traffic'. With that button there is no need anymore to assign keys within FSX for 'reload scenery' or for advancing the sim time.

Those with a user paid registration for FSUIPC can do the following (copied from the user's guide):

 

 A Traffic density set control, which sets the FS AI airline traffic density to any value from 0 to 100% according to the parameter value provided. The GA and shipping densities are adjusted to, in the same proportions, but the airline value is the guide.

A traffic density toggle control, which turns the AI airline traffic off (density = 0) if it is on, but if it is already off it turns it on, using the density value provided in the parameter or 100% if that is omitted or set zero. This also operates on the GA and shipping traffic.

 A traffic zapper control which deletes an AI aircraft close to and directly in front of the user‘s aircraft.

 

The last is handy if ai is stuck in front of you or the occasional ai occurrence supposedly protected by FS where you are waiting for ai to move that is nose-to-nose to you. Also, if you have not "reserved" a parking spot with scenery techniques you can (though unrealistically) "nuke" an ai in the parking spot you are pointing at.