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Aloft winds


acc33
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I´m experiencing problems with aloft winds when flying off-line or on-line (ivao) using fs2004 and unregistered fsuipc.

A "dramatic" wind changes (in speed & direction) occurs suddently and several times mainly over an area with 2 or more airports; recently, for example, over LFPG and EGLL area. The result, the aircraft goes to overspeed or to a very low speed, because with these "dramatic" changes, the autopilot doesn't had time to correct to the desire setpoint.

One partner told me that the problem lies on the fs2004's interpretation of weather from different stations, and with a registered version of fsuipc, the problem will be solved by its capabilities of "wind smoothing". Other partner told me that the "wind smoothing" capability of the registered version of fsuipc doesn´t work on fs2004.

So, with this confusion and before buying the key for fsuipc:

With a Registered version of the fsuipc, the "wind smoothing" capability will work on fs2004 on-line and off-line??? in order to avoid "dramatic" aloft wind changes.

Thanks in advance for any answer

Bst Rgds

Alberto

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One partner told me that the problem lies on the fs2004's interpretation of weather from different stations, and with a registered version of fsuipc, the problem will be solved by its capabilities of "wind smoothing". Other partner told me that the "wind smoothing" capability of the registered version of fsuipc doesn´t work on fs2004.

Wind smoothing is one of the more popular features in FSUIPC and it most certainly does work on FS2004. If your "other partner" has experienced problems with this he/shw most certainly has not come here to report them.

With a Registered version of the fsuipc, the "wind smoothing" capability will work on fs2004 on-line and off-line??? in order to avoid "dramatic" aloft wind changes.

The wind smoothing facility is designed to work with any source of weather. I don't fly on-line myself, but I don't know of any way the on-line weather programs can subvert the smoothing algorithm.

But you shouldn't let me persuade you. Get some other on-line fliers actually using FSUIPC to tell you. There must be many.

Regards,

Pete

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I have an interesting problem which could be related to the "it doesn't work" comment.

I've recently gone FS9 (following a HD corruption), from a very stable and well customised FS2002 setup (FSUIPC 3.47).

So, I'm now running FS9.1 with FSUIPC 3.51 (registered), and I've noticed that with wind smoothing switched on, aircraft like the PSS Airbus (which used to be well behaved in FS2002) don't correct for the wind properly in FS9 - the aircraft weathervanes into the wind, and slowly drifts off course, in an upwind direction (relative to the crosswind component of the reported wind).

When the aircraft comes within about 3 miles of the next (flyby) waypoint, it pulls this very hairy "S-turn" across the fix, before heading to the next fix, slowly drifting off course again. Rinse, lather, repeat!

This applies whether I'm flying offline with FS9 downloaded weather, or online with VATSIM (Squawkbox 3) weather. No ASV or any other WX addon.

As soon as I switch the wind smoothing off, the aircraft becomes true to the the route being commanded by the autopilot - but of course, back to the very wild changes in the winds aloft while in the cruise. (Which seem amplified with SB3 WX!)

Becuase of the recent system rebuild, the last FSUIPC I have is 3.47 (so I've not been able to "back out" a point release, back to 3.50, like some others tried).

Pete, if there's anything you need in terms of logging or want me to try out, please let me know.

Thanks!

Mike

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So, I'm now running FS9.1 with FSUIPC 3.51 (registered), and I've noticed that with wind smoothing switched on, aircraft like the PSS Airbus (which used to be well behaved in FS2002) don't correct for the wind properly in FS9 - the aircraft weathervanes into the wind, and slowly drifts off course, in an upwind direction (relative to the crosswind component of the reported wind).

Are you using ASV at all?

Either way, please check the Interim Versions announcement at the top of the Forum and try version 3.511. This, by default, reverses a "fix" I put into 3.51 which seems to have some unwanted side effects.

Pete

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So far, it looks like 3.511 fixes this problem with the PSS 'buses as well, from the testing I've done with FS9 weather in the last hour.

So, it looks to be another similar symptom to what's been described in the "3.51 & Winds" thread.

Ah, sorry, I saw and answered your first message first!

It should depend more on the source of the weather than the aircraft being used. Where is your weather from, please?

Pete

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Hi Pete, the good news having just done two test flights in the PSS Airbus, is that 3.511 seems to fix this NAV "drift" (probably being caused by an erroneous crosswind correction) with both the default FS9 downloaded "real-world" weather, and the VATSIM-supplied Squawkbox 3 weather.

Both flights were plodding between London and Manchester and vv.

Interestingly, I didn't seem to be able to reproduce the NAV "drift" observed under 3.51 when using the FS9 GPS and the default King Air, but I only did a short test flight, and at a lower altitude, so maybe it was less apparent, and I need to repeat this experiment.

So, could it be in someway isolated to add on aircraft products, regardless of weather source?

Cheers,

Mike

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Interestingly, I didn't seem to be able to reproduce the NAV "drift" observed under 3.51 when using the FS9 GPS and the default King Air...

So, could it be in someway isolated to add on aircraft products, regardless of weather source?

It may simply be that some navigational controls are using FS-computed wind component vectors (crosswind and headwind), whilst others are deriving these themselves. I would have thought that, for realism, a GPS method would be based on point-to-point computation in any case.

Regards,

Pete

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Hi,

I've posted two updates to FSUIPC in the top announcement here as part of an attempt to get the wind smoothing system working correctly (again). Please try them out and let me know what you think. I've reproduced the notes about them here, below, so you can see what is going on.

Best regards

Pete

===============================================

FSUIPC.DLL Versions 3.511 and 3.512

I've posted two test versions at the same time in an attempt to find out if they both behave the same, wind-wise, or if one is better than the other. I am testing here, but wider usage is needed, please.

The 3.51 fix in the wind smoothing algorithm which additionally makes the wind direction written to offset 2DE0 have the correct effect at the aircraft, now appears to be in error. The direct wind control facilities at offsets 2DE0 and 2DE8 are used by ASV (optionally, but defaulted). The fix applied to get the apparently correct effect at the aircraft via these offsets has the unfortunate side effect of making FS set incorrect crosswind and head/tail wind components.

Worse, even weithout anything using direct wind control, with Wind Smoothing is enabled, the same, "corrected" algorithm is used and again applies the incorrect wind components -- although then these don't appear to be read as such by navigational instruments.

I cannot make a lot of sense of all this at present, though after a couple of days of investigation it does appear to me that FS's wind simulation is rather different when the aircraft is on the ground than when it is in the air. I can 'fix' things on the ground, and in the air, but with different algorithms. Although I can detect the difference ("aircraft on ground") I cannot actually implement both fixes because the wind changes have a delayed effect on the aircraft. I've tried, but no matter what I do, things get screwed up for a while just after take-off, i.e. at the worst possible time.

So I'm abandoning the attempts to get the wind control working on the ground. Hopefully I'll be able to do better with the next version of FS, as and when.

Just by way of explanation of what the original change in 3.51 was all about: the problem in 3.50 and before with the wind direction written to 2DE0 was that the effect actually implemented in FS at the aircraft was a wind 180 degrees opposite, as could be found by turning a static ground aircraft into wind as measured on its ASI. The fix in 3.51 certainly fixed that, and quite a bit of exposure here (as 3.507) failed to detect the airborne inconsistencies which arose.

The differences between 3.511 and 3.512 are in how much "fiddling" FSUIPC does with the winds inside FS when smoothing or providing direct control. Over the last two days I think I've proven to myself that some of the things I was changing don't matter, and may make things worse, so 3.512 eliminates that part of the code.

Please try both 3.511 (without "AircraftWindRev=Yes") and 3.512 (it doesn't have that parameter), and let me know which you find better, if you notice any difference at all. Thanks!

Regards

Pete

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