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pbelb

FSX 747-400X and VATSIM, and max auto-thottle question

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hey guys n gals,I've got a query about two probably different things....a) VATSIMI'm noticing a huge difference in performance between flying without VATSIM versus with VATSIM.if I'm flying along on a previously not connected mode, then connect to VATSIM, it seems like the plane suddenly hits a wall of molases, and acts like the air density is being made to be much more dense, therefore more difficult to fly through.I'm mostly talking about the behavior when I'm flying along at .86M and perhaps FL330 or so.what I mean is that suddenly, the plane will have trouble maintaining a certain speed/altitude, and I end up having to settle for something less.eg, right now, I'm flying VATSIM, and the FMC says FL330 should be the ceiling, and the FMC is set to fly at M.86.Well, try and do that, and the aircraft barely manages to stay above the minimum safe flying speed for that altitude.by contrast, I *never* have trouble reaching FMC suggested maximum height and cruise speed.:( max auto throttle...also, the maximum throttle settings seem to vary quite a bit, even if I'm fairly consistent in pugging in an (in)efficiency number of 60 or so.I suppose it's true that a couple of hundred thousand lbs of weight difference could help account for that performance difference in the max thrust setting, but is that all there is that's going on here?please advise.

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a) Almost certainly weather related. If you're using FSINN Beta 3 to connect to VATSIM, realize that their weather is COMPELTELY BUSTED (and they have acknowledged this, BTW). If you have ActiveSky, use that. If not, use FS's "real weather with 15 minute updates" (if you use this, ensure the "download winds aloft" is checked in the Winds page of your settings). Also, be sure you're using the wind, temperate, and pressure smoothing of Pete Dowson's latest FSUIPC.:( I'm not entirely clear what you mean. Do you mean the thrust limit, as indicated in the upper EICAS?- Bill


- William Ruppel, CYTZ, VATSIM 816871

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thank you for your reply..a) hmmm. ok. so I shouldn't use the vatsim weather. I guess I can disable their weather. have to look into that. I've just been using the 'real weather' with updates that's part of FSX, however, the default when connecting to VATSIM is to enable both weather & network. I'm using FSINN Beta 3, so I'll need to see whether I can alter that behavior.:( yes, the thrust limit. it seems to be relatively low at the beginning of the flight versus the end of the flight. perhaps it's something to do with the modelling of reality. ie: does the thrust limiter limit the max thrust the autopilot can command more at the beginning of a flight than at the end?

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a) Yes, you can alter the behavior. After you have connected to VATSIM, select the smiling sun beside the "CAVOK" row - this will reset your weather to "ideal" conditions. Then, go to FS's weather dialog, and select "Real World Weather with updates".:( Yes, the thrust limit mode (and therefore the thrust limit itself) changes depending on your mode of flight. In your pre-flight FMC programming, be sure you're entering the correct assumed temperature (or pre-computed TO and CLB modes).FYI, the thrust limit modes are: GA (go around)TO (take off)TO-1 (derated take off 1)TO-2 (derated take off 2)CLB (climb)CLB-1 (derated climb 1)CLB-2 (derated climb 2)CRZ (cruise)CON (continuous)You may override these modes in the FMC.- Bill


- William Ruppel, CYTZ, VATSIM 816871

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thank you for the info.I'm doing what you suggest for the weather, but have a further question regarding the thrust limits.I know, using the fmc, that I can easily switch between thrust limits, as you've identified them, however, what has to be done to alter the parameters of a given thrust limit?Is the temperature the only variable available for tweaking?I say that with the understanding that the trust limit is also affected by the current weight of the aircraft.thanks in advance

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re: "...so I shouldn't use the vatsim weather..." - this is not quite correct - it's fsinn that fails to deal with the vatsim weather correctly.ideally, use a weather proggy (like active sky) to process the weather data sourced from vatsim (not real world weather direct through fs) - if you use a source other than vatsim for your weather data, you risk having weather that does not match what everyone else around you on the network is using. there's nothing more likely to guarantee an unnecessary arguement resulting in supervisors getting involved that going head on with someone over which rwy is active - you MUST use vatsim weather when on vatsim (regardless of whether it matches what's actually going on outside the window) - you just need a good weather engine to process it (and that is not fsinn in this case).hth

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