Sudden speed changes cause overspeed crash

[neiljt 0]

Flying the 747 on autopilot in FS2004, I am experiencing occasional sudden jumps in speed. Although the autothrottle usually corrects these in time, every now and then the change is enough to cause a crash due to airframe stress, as the autothrottle cannot correct the speed in time.As an example, this morning, with cruise set to M0.88, the speed suddenly changed to M1.04 with an overspeed warning. As I was sitting nearby, I was able to disengage autothrottle and throttle back manually, but what usually happens is that the flight crashes and resets.I'm wondering if this might be something to do with real weather, e.g. sudden changes in wind direction/speed, or air pressure. Has anyone else experienced this, and if so, have you found a solution?Thanks :-)

[Murmur 3,941]

>I'm wondering if this might be something to do with real>weather, e.g. sudden changes in wind direction/speed, or air>pressure. Has anyone else experienced this, and if so, have>you found a solution?It's a known problem due to sudden wind shifts in FS9 weather engine. FSUIPC has an option called "Wind Smooting" that resolves the problem.Marco

[Guest]

yes, it has to do with real weather.Not all reporting stations are updated at the same time, some data can be quite old. This can lead to sudden changes in wind direction and strength during weather updates.Also, when you're over the ocean, you can at times be out of reach of any reporting station causing FS to default to no weather until you're in range of land again.This can have the same effect.FSUIPC wind smoothing can help somewhat but isn't always enough. You'll just have to stay alert and react quickly when and if it happens.

[neiljt 0]

Thanks for the responses, guys. FSUIPC was worth checking out, though it seems (in vn 3.53 anyway) ro require registration (20 Eurobucks) before I can use it to smooth wind transitions ... unless there are separate utilities that use the FSUIPC module to do this, and I will look further.I had hoped maybe there was a setting in fs9.cfg that equated to Weather - Rate of Change, that would enable a setting between "mild" (my current setting) and zero, but see nothing obvious. Or maybe this setting won't help anyway.If I don't find anything, until the next release I may just return to the Baron for now!

[ailchim 206]

I'm afraid I used to get this all the time until I paid for FSUIPC. Now I don't get it at all.The alternative of course is to fly with a bigger margin of error between your speed and the max allowed, but of course that's a bit unrealistic.You might like to think about something like ActiveSky as an alternative.Do your own research, I'm not sure if ActiveSky needs a registered FSUPIC, or if it does work with an unregistered copy, whether it is then capable of smoothing winds.ActiveSky maybe better value for money if it smooths the winds plus all the rest it does.There is an ActiveSky forum on Avsim and you should be able to get advice vis a vis FSUIPC directly from the ActiveSky authors.There are alternatives to ActiveSky, so look around.Alternatively, try here http://forums.simflight.com/viewforum.php?f=54 for the FSUIPC forum

[JSkorna 137]

Hi All,With the unregistered version of FSUIPC you get the default wind smoothing setting of 5 deg/sec. This cannot be modified. To change it, you must register your FSUIPC.Yes, AS will work well with the unregistered version of FSUIPC.One option is not to download winds aloft with FS04 Real Weather.Hope this helps,Jimhttp://www.hifisim.comhttp://sales.hifisim.com/pub-download/asv6...development.jpg http://sales.hifisim.com/pub-download/asv6-banner-proud.jpg

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[timers15 11]

Jim, does importing the flight plan into AS reduce the severe wind changes as well? It appears to me that it does ...