I have recently started receiving QNH values from RC that result in more than 500 feet variations over just a few minutes time resulting in my busting altitude. Any ideas what might be causing this?

I have recently started receiving QNH values from RC that result in more than 500 feet variations over just a few minutes time resulting in my busting altitude. Any ideas what might be causing this?

are you running a third party weather program? is it up to date?if you have a registered version of fsuipc, i think there is a way to smooth barometric pressure changes. but something is causing the change, so the trick will be to find where its coming from.jd

are you running a third party weather program? is it up to date?if you have a registered version of fsuipc, i think there is a way to smooth barometric pressure changes. but something is causing the change, so the trick will be to find where its coming from.jd

I am running the FSX real world weather.

FSX real world weather has been known to cause fluctuating winds and pressures due to missing METARS. If you use an add-on weather program that uses FSUIPC you have a feature available as follows (quoted from the FSUIPC manual):"Smooth pressure changes will limit the changes in the barometric pressure supplied by an external weather program, to 1 milliBar (or hectoPascal, or about 00.03 inches Hg) per so many seconds—the range being selectable from 1 to 30. This smoothing does not occur whilst the aircraft is on the ground, and no changes will occur whilst the simulator is paused. If you use FSMeteo, which also provides pressure smoothing, this option is disabled unless the ―Prevent external option control‖ option above is selected."If you purchase a registered FSUIPC I think it may function with FSX real-world weather but not sure. An add-on weather application will allow pressure smoothing if not directly using sim-connect but uses FSUIPC and probably will activate the FSUIPC features needed. If it directly uses sim-connect it may or may not smooth pressure changes.

I am running the FSX real world weather.

I have made the change in FSUIPC, taking the default. I'll see what that does. I have been looking at Active Sky Evolution as an alternative but am somewhat uneasy about anything more to the system. Thanks very much for the guidance.

There are currently problems in certain situations with ASE and RC4 in FSX recognizing AI patterns for the use of the active runway. If adding UT2 (FSX version Ultimate Traffic) there will be problems.ASE uses sim-connect in FSX and you must use its DWC mode as I understand it to get smoothing. This requires global weather mode which means that the weather at destination mode is the same as at your current aircraft location changing as you approach. This can disturb AI patterns. They have added service packs that now allow additional options. I am not sure whether you can use an option to let FSUIPC as an interface so you get weather smoothing without requiring DWC.If you do not need the graphics portion Active Sky 6.5 used with FSUIPC4 should not have this problem. I use 6.5 in FS9 but with the graphics portion as well. FSUIPC4 sits between your weather application (and RC as well) and FSX.This long thread will describe ASE problems encountered.http://forum.avsim.net/topic/323481-rc-slows-with-ase-dwc-mode-probable-fix/Note message 42 on page 2 of this thread.