FSUIPC influencing in-sim airspeeds

[Ocelotfr]

Hello Pete,

Strange one this. I fly FSX Steam Edition and use REX Sky Force 3D for weather. I noticed while flying the Qualitywings B757 that airspeed, which is normally set to IAS in the sim, became True. That is to say that setting a Mach number of 0.81 sent the plane to 525 knots as shown on the speed ribbon at 36000 feet, resulting in a chronic over speed. Normally, the over speed in this configuration should be around 340 knots. So I tried with a FSX stock B737 and with an indicated airspeed of 318 knots, the Mach number is only 0.47. Where it gets interesting is that disabling all weather and setting all weather off in FSUIPC v.4.972 (unregistered) instantly corrects the problem, with the speed ribbon behaving as it should. My only thought on the matter is that REX Sky Force 3D could be the culprit, or that I need to register FSUIPC. Your views would really be appreciated.

Alan Walker

[Pete Dowson]

41 minutes ago, Ocelotfr said:

Where it gets interesting is that disabling all weather and setting all weather off in FSUIPC v.4.972 (unregistered) instantly corrects the problem,

If FSUIPC is not registered, there are no weather features available to users other than logging it, so you can't change anything. There is no way it is influencing the weather unless there is an external program using its interface to do this, and you can't "set it off" if so. even in a registered install.

The relationship between airspeed and mach is complex, but depends very much on air density which in turn relates to the pressure (hence altitude). Check the QNH when this happens -- it it probably rather low (but I might need correcting on this).

If the problem is solely with the QW B757 then you'd probably need to ask in their Support Forum.

Pete

 

 

[Ocelotfr]

Quote

Thank you Pete. As you rightly say, a program must be influencing this, and my eyes are turning to REX Sky Force 3D, as it's only after having installed it recently that the problem became apparent. I've checked the QNH during the flights and the reading, depending upon the weather scenario, is low; the aircraft barometer set to 'standard', however. I'll try to drill down into the problem, but thanks again for your reply. It's much appreciated.

Alan

 

[Schtick1964]

I have experienced the exact same issue. I recently started using FSRealWx 3.0 which, I believe, uses FSUIPC. I can only cruise along in my TDS B737-800 at FL380 at mach .47 with an indicated airspeed of 320kts. My ground speed is slightly higher. When I go to the FSUIPC panel and press clear all weather the issue disappears. I'm now able to cruise at M080 (approx. 260kts indicated at FL380) with my ground speed at a normal 450kts. I'll admit I have not registered my version of FSUIPC. Is this the source of the issue?

[Pete Dowson]

3 hours ago, Schtick1964 said:

I'll admit I have not registered my version of FSUIPC. Is this the source of the issue?

Why not read the previous answer in this thread?

To repeat: an unregistered FSUIPC does nothing whatsoever by itself! It merely acts as an interface into the Sim for other programs. I think you must look to the weather program you are using. That's the only purpose of installing it unregistered!

Have you checked the reported weather each time?  Weather conditions can affect indicated airspeed too.  Maybe your weather program is setting extreme values.

Anyway, you are lucky I spotted your post. You do realise you added to a 26 month old thread?

Pete

 

[Schtick1964]

Hi Pete. I was actually surprised to find someone had experienced the same issue as I was seeing. I had not dealt with the indicated airspeed/mach number situation for the longest time as I have been flying low and slow in a C208 where the indicated/true issue doesn't show up. The actual upper winds in one of my recent high level flights did not produce the ground speed I was achieving as well as the fact that I couldn't get over M0.47 without exceeding the over-speed value. I'll have to get the version of FSUIPC registered and see if that makes a difference. I'll also have to tweak FSRealWx and see if I'm missing something there.

 

[Pete Dowson]

7 hours ago, Schtick1964 said:

I'll have to get the version of FSUIPC registered and see if that makes a difference.

That will only allow you new facilities for assigning and calibrating controls and operating many other options like traffic limiting or zapping, etc etc.  It would also allow you to use any of the many Lua plug-ins available to provide other services.

BUT it will do nothing by itself about weather. That is a matter solely between your weather program and the flight sim receiving its instructions!

So, your problem, if it really is one, should really be more properly directed to the support for the weather program you are using.

Pete

 

[Schtick1964]

Thanks Pete.