False TAT temperature indication with PMDG MD-11

[vjs_tiger 0]

No question there. I have never seen it without ASA. I have used REX for over 300+ flight hours since the summer and never once did I see 40C at FL38. :( It is most definitely an ASA program IMHO.

exactly !!!

[JSkorna 137]

Hi,You are assuming way too much in comment #6. I said that there were no updates on this issue from us, only because you asked to hear something. That doesn't mean we are not working on things, no different then the folks that are waiting for a cloud pop fix with FS9.Thanks,

[ailchim 216]

My mistake in understanding what you said then, apologies.Thanks for the further update and indeed for the efforts you are making on our behalf.Just one point - I do seem to be a lone voice on this but I do seem only get this problem after restarting a saved flight. That may be a complete red herring but it does seem to be my experience.

[aentwis 61]

It appears there is a problem in general with VATSIM/FSInn weather and FSX, being a simconnect/FSX issue, as I understand it. There is also an option we can set in ASA, as on page 29 of the ASA manual "Use VATSIM online weather"...VATSIM Online Weather: Selecting this option instructs ASA to use VATSIM as the weather data source for weather updates of your current and destination weather. A flight plan must be in use.Someone mentioned previously in this thread that there was a problem if a flight plan was loaded in ASA... Assuming that the logic requires a flight plan to be loaded before VATSIM weather can be use, this could be the source of erroneous data leading to the TAT issues? A stab in the dark...Could those with the issues please confirm that this option is not set on their installations of ASA. Just to rule out the possibility that ASA is not being fed VATSIM weather data unnecessarily. As I understood it, one doesn't need to be online with VATSIM to be able to get the weather server's data... then again, I may be wrong...Just looking to see if there is a common denominator with those experiencing the problem of high TAT...Andrew

[ailchim 216]

No, not using Vatsim at all and that option is unchecked in my ASA settings

[Chris Wright 0]

...and as noted umpteen times, it happens in fs9 too so it isn't a simconnect issue!

[ailchim 216]

Another snippet of information which may or not be relevant, which may or may not spark a thought in somone's head.I have had a really bad attack - with a resumed saved flight, with a flightplan loaded into ASA, as always in my case.I tried refreshing ASA, I tried closing ASA & restarting it, I tried closing FSX AND ASA and restarting both. No effect, the problem occurred identically on each iteration.I tried adopting FSX weather and closing ASA. That cleared the problem but as soon as I restarted ASA, it was back.I loaded a fixed, historical ASA weather file - as it happens pretty close to the one which would have been used when I started the flight, one day before I resumed it. Bingo, no further problem.I convinced that in my case, this is to do with ASA trying to apply new weather updates over a saved situation. My current solution is as above. It would be interesting to see if it works for anyone else.

[Turbine777 13]

Another snippet of information which may or not be relevant, which may or may not spark a thought in somone's head.I have had a really bad attack - with a resumed saved flight, with a flightplan loaded into ASA, as always in my case.I tried refreshing ASA, I tried closing ASA & restarting it, I tried closing FSX AND ASA and restarting both. No effect, the problem occurred identically on each iteration.I tried adopting FSX weather and closing ASA. That cleared the problem but as soon as I restarted ASA, it was back.I loaded a fixed, historical ASA weather file - as it happens pretty close to the one which would have been used when I started the flight, one day before I resumed it. Bingo, no further problem.I convinced that in my case, this is to do with ASA trying to apply new weather updates over a saved situation. My current solution is as above. It would be interesting to see if it works for anyone else.

I agree. Although I have not pin pointed this particular issue with saved flights. They do get corrupt all the time and I have a list of insanely weird things that have happened and it ended up being a saved flight. Now a days when something strange happens, that's the first thing I check. Good thinking.

[JHepburn 0]

I agree. Although I have not pin pointed this particular issue with saved flights. They do get corrupt all the time and I have a list of insanely weird things that have happened and it ended up being a saved flight. Now a days when something strange happens, that's the first thing I check. Good thinking.

Not limited to MD-11. I had this happen twice during a single flight in the JS41 last night. At 22k ft, I went from -12 TAT to 27 TAT for about 5 minutes and then went back.

[Guest imagegear]

Not limited to MD-11. I had this happen twice during a single flight in the JS41 last night. At 22k ft, I went from -12 TAT to 27 TAT for about 5 minutes and then went back.

I think we have more than one problem here and they also happen on default aircraft although it seems to be over a slower range.I run the PMDG 747X and it has brought me down on a number of occasions, once on vectoring for 27R at EGLL, it was'nt pretty.Problem 1It would appear to me that there are at least two applications competing to deliver weather to FSX. I have disabled FSInn weather, disabled FSX weather, and did not start ASA this morning and I still had cloud, temperature and winds on the ground. So it's coming from somewhere. As soon as I started ASA I have the rapidly changing ASI and Mach values above FL250. Consequently I suggest that the unknown weather must be competing with ASA. Problem 2.....and they may be relatedI set up to have the OAT in a window as delivered from FSUIPC prior to engine start and recognised a realistic OAT value of -1. However TAT in the default B738 was showing +7. According to my research the following should be true that at Ground Level TAT should equal or be close to OAT (as delivered from FSUIPC) possibly with a bit of solar radiation if we have got that realistic in sim weather. As I climbed out the value in the B738 TAT stayed at around +7 all the way to FL120 before dropping slowly to -34 at FL340.I suspect the high altitude value is correct based on the following but the lower values are not modelled correctly in the sim.SAT is Static Air Temperature, that is, the temperature of the 'free' air unaffected by your speed. OAT and SAT are essentially the same. Forward speed causes the air to compress as a function of Mach Number OR TAS, either may be used to calculate the Ram Air Temperature (RAT) / Total Air Temperature (TAT), or Indicated Outside Air Temperature (IOAT).TAT = SAT X (1 + .2 X M^2), ORTAT = SAT X (TAS / 87.1)^2,Where TAS is in Knots, SAT and TAT are in Degrees Absolute, and M = Mach Number. The formulae may be reversed to convert TAT to SAT. (RAT differs from TAT by dint of the efficiency of the Temperature measuring probe).OAT, SAT, RAT, and TAT are used in conjunction with Calibrated Airspeed (CAS) or Mach Number to calculate TAS. If CAS is used in the calculation, Pressure Height must also be known.RAT/TAT usually determines the upper limit of the icing range of temperatures, OAT/SAT usually determines the lower limit.So two problems I think, combining to give some very unpredictable TAT indications.Imagegear

[JSkorna 137]

Hi,I'll respond to #1 knowing that any saved flight in FS also has a saved .wx file associated with it. So that is where the "weather" is coming from.Thanks,

[Ratherbflyin 9]

I have the same problem with Flight1's Mustang. I've noticed that it only happens to me in the higher elevations, i.e. when approaching FL280 and higher. I am unable to climb to assigned flight level until the TAT returns to normal and I am usually about to stall just trying to maintain altitude.

[JHepburn 0]

Hi,I'll respond to #1 knowing that any saved flight in FS also has a saved .wx file associated with it. So that is where the "weather" is coming from.Thanks,

Hey Jim,I never load a saved flight, and I still see this issue. I don't think that is the sole culprit, although it may contribute in individual cases.

[JSkorna 137]

Hi Jeff,You always start from the Plan a Flight Screen?

[russert 0]

Hey Jim,I never load a saved flight, and I still see this issue. I don't think that is the sole culprit, although it may contribute in individual cases.

Jeff,Even loading up FSX loads a saved flight -- the flight that has been saved as default. If you go to advanced weather and there are no layers under the temperature, visibility, pressure, etc, then I guess my fix was an isolated case. I'd still give it a look at though because I haven't seen the terrible TAT problem in months, and I usually do a flight every day.