False TAT problems with Active Sky Advanced

[ailchim 216]

I wonder if anyone else is having problems with TAT suddenly swinging from a sub-zero temperature to a high positive number, causing a loss of engine power.I can't find any reference to it on this forum.It appears from the attached post that this is happening with the 747 and the MD-11 for users of Hi Fi Simulations Active Sky Advanced, although that may be coincidence.http://forums1.avsim.net/index.php?showtopic=255228Anyone else having this problem? If so, is it in association with ASA?Mike

[downscc 1,327]

I have also seen this with the default MSFS weather (15 min downloads), and believe it to be a fault in MSFS. Add-ons like ASA or ASX might reduce the default wx wildness but don't solve it. You can smooth temperature deviations with registered FSUIPC.

[Joe L 62]

I see it also, with ASA. The MD-11 is mainly what I have been flying, but I have seen it in the the J4100 as well at lower altitudes. I do not have a cure however . . .Joe Lorenc

[downscc 1,327]

There are ways around it, but no cure. Use registered FSUIPC, and if the TAT starts diverging force a weather refresh from your weather application. Also, be sure to check the HiFi forum next door here in AVSIM. This topic has been around a long time and there is sure to be lots of advice.

[Cuddly1956 1]

Yep, trouble is if the data isn't correct to ASA from the database it falls flat as no 'obvious error' removal. I have seen TAT at 70'c and 37000 feet and at the other end of the scale minus 200'c at 10000 feet. Doesn't happen very often but when it does it's a disaster. Such is simming lol.John Ellison

[beachdog2001 21]

This is one thing that REX excels at. These temperature issues are now a thing of the past. With 2.0+ versions, I have yet to see this kind of temperature issue in many, many flights now. Actually, I never saw it much with 1.0 either. So...this issue is solvable by 3rd party developers. I am not a programmer so I have no idea what they did, but they did it over at REX.

[trisager 2]

Never seen it with either ASX or ASA, but I suppose it may depend on the area where you do your simming.Just in case your are using FSInn with FSX, positive TAT is a known problem with the weather engine in that product. Make sure that FSInn weather is completely disabled.

[ailchim 216]

Thanks for the replies.For completeness, perhaps to assist others in eliminating possible causes of their own problems:1) I have tried refreshing weather for ASA - that doesn't cure it. What does seem to cure it is switching to FSX weather via the FSX weather settings page, allowing that to load a weather set and then going back to ASA.2) I don't have FSInn.4) I do have a regeistered version of FSUIPC. This is smoothing winds which I find essential with the MD-11 but I'm not sure about temperatures until I start FSX. Of course, this isn't a smoothing issue as such, it's not that the change is too rapid, it's that it's going to an entirely unreal temperature which is causing the MD-11 engine management to think it's at the hottest & highest place on earth and then some!5) I have tried the HI-Fi Sim forum without success. They are asking what happens in the default FSX aircraft. I haven't got a clue as I have never used them and I don't fancy tooling around in one for hours waiting for this to happen - or not to happen. In any case, rather than modelling engine performance as a PMDG aircraft would, a default plane is merely likely to say "it's a bit hot in here, shall I open a window?"6) I have had this advice from a forum user W6KD, which just goes to show what a helpful bunch of people there are on here:

"I recommend the next time you see this, if you're running FSUIPC, go into the logging tab, put "34A8" into one of the offset boxes, select "FLT64" in the corresponding type dropdown box, and then check "FS Window"...this will put the current ambient temp at the acft in a window in FS. If it's abnormally high, then it's not a PMDG problem...it's the panel acting on a bad temp reported by FSX. If the OAT is normal, but you see TAT +51 on the panel, then the panel is at fault.If it's not the panel, then the next question is whether that abnormally high temp is the result of an FSX problem, or if it was written there because of an ASA problem. If you have a few gigs of disk space to play with, you can log all the SimConnect calls as Pete Dowson describes here:

http://forums.simflight.com/viewtopic.php?f=54&t=58095

When the temp anomaly occurs, shut down the sim, open the (very large) log file, and do a text search (starting at the end and working backwards) for the string "WeatherSetObservation" and you should find lines like this:CODE > 24.47553 [63, 113]WeatherSetObservation:Seconds=30, szMETAR="GLOB 231553Z 00000KT&D457NM 00000KT&A914OG 00000KT&A1829OG 00000KT&A2743NG 00000KT&A3658OG 00000KT&A5486NG 00000KT&A7315OG 00000KT&A9144NG 00000KT&A10363NG 00000KT&A11887NG 00000KT&A13411NG 00000KT&A14935NG 16KM&B-2000&D30000 1CU129&CU000FNVN000N 6CU209&CU000FMVN000N 15/13 15/10&A914 15/09&A1829 15/06&A2743 15/M05&A3658 15/M18&A5486 15/M31&A7315 15/M49&A9144 15/M59&A10363 15/M68&A11887 15/M76&A13411 15/M77&A14935 A3002"The interesting part of this long string is at the end...the "A3002" at the end is the altimeter setting, it's the series of temp layers preceding that which we are looking at:CODE &A914 15/09&A1829 15/06&A2743 15/M05&A3658 15/M18&A5486 15/M31&A7315 15/M49&A9144 15/M59&A10363 15/M68&A11887 15/M76&A13411 15/M77This is a series of temp layers...the "&A" means that it's an FS extension to the METAR, the next number is the base altitude of the layer in meters, and then you have the temp/dewpoint.So "&A914 15/09" means a layer beginning at 914m (1000 ft) with temp 15 and dewpoint 9 deg C. Likewise, "&A13411 15/M77" means a temp layer beginning at 13411m (44000 ft MSL) with temp 15, dewpoint -77.ASA sets all the temp layers the same based on acft altitude...notice that in the example above the temp is 15 deg C so all the temp dewpoint pairs are "15/something." So if you're at FL 350 on an ISA day, the temp should be -53 deg C at all levels. If it's high...i.e. 24/M79, then ASA is writing bad temps to the sim. If all the temps are OK back several minutes, then FSX is the culprit.I also note that in my example above, at the end of the string, the temps for the last layer (14935m/49000 ft) are missing from the METAR string, which makes me wonder if that could be part of the problem...the "&A14935" has no matching temp/dewpoint. Might be worth checking that one out, HiFiGuys."

I haven't tried any of that out yet.

[Airbrakes 0]

^You found the fix in item #1 you listed. It seems to be linked to the refresh rates within FS9/FSX. You don't really need to change the scenario though. If you just click on "OK", the weather should refresh itself. Be ready to deploy the speedbrakes though. :(