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DAL488

Airspeed tape dropping to Zero (or 45??)

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Hi Folks:I know this has been discussed before: the airspeed tape will drop to zero, resulting in an annoyance and autothrottle issues for several seconds until it indicates correctly again.I, like many others, just assumed that the problem was related to ising and that the PMDG probe heat switched may not be correctly linked to the FS9 pitot heat.However, today I experienced the issue in clear sky at FL280. I didn't bother turning on anti-ice (probe heat was already on of course), and I just waited. Sure enough it cleared after a few seconds.My concern is that this was in clear conditions, unlike the other times which were in clouds. This seems to be a regular occurrence for me, on just about every flight.And yes, I do use AS2004.An ideas?BTW, I saw that some folks turned icing off. I can't figure how to do that in FS9 or FSUIPC.Thanks,James

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I'm fairly certain this is due to random periods of severe icing implemented in FSUIPC. I was able to duplicate the zero-airspeed event several times while monitoring the wx data being supplied by FSUIPC, and every time it happened FSUIPC reported severe icing. The icing level will drop from severe after a short time (usually), explaining why application of engine A/I wasn't needed to fix the problem.The drop in indicated airspeed will totally dork the checklist sequencing in Flight Deck Companion...so I leave random icing disabled in FSUIPC.RegardsBob ScottATP IMEL Gulfstream II-III-IV-V L-300Washington, D.C.

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I have random icing turned off. But the problem persists using AS2004.

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>I have random icing turned off.Ditto. I also have random icing turned off.Interestingly enough, someone in the Active Sky forum reports the same issue with the PSS A320.So, maybe this is an AS2004 issue like is mentioned above!?!James

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It never happens with MS online weather, only with AS2004 with online updates enabled. I have not tried offline yet. The NG`s FMC Progress Page2 is a nice instrument to monitor the winds. I`ve had it up the moment the PFD freezes with 45 knots and red barberpole all the way, but there are NO changes on the RTE2, nor on the ND winds. This ghost is very stealthy.BTW I guess some addon planes might be more sensitive to things than the default planes, but AS2004 is also new on the market, and more research is needed before drawing any conclusions...things like experiencing the same thing with the default planes...not exactly my speciality :)

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I've had the same problems my self. Always happens on climb out. But on my last flight I started the default Cessna first to shut down all the system to get a cold and dark situation. I turned on the pitot heat before switching to the PMDG NG, and on that flight the problem didn't occur at all, so it might be a coincident but it could also maybe be that the PMDG panel won't turn on the pitot heat properly.

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Made an interesting discovery last night: the FS9 pitot heat will NOT turn on in the PMDG 737.I decided to add the default 737 pitot heat switch to the PMDG panel. This way, I could ensure that pitot heat was turned on. But after installing the switch, I found that the switch refused to stay in the ON position; it was like it was spring-loaded to the OFF position. I also tried the Shft-H key combo, but the switch just jumped right back to OFF.Anyway, maybe this explains why I still have the IAS dropping to zero: pitot heat is not really on.However, I do believe this is related to AS2004. I don't ever remember having this issue with FSMeteo 6.4.James

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BTW, someone in the AS2004 forum explained that he had the same problem with the PSS A320. However, after turning on pitot heat (shft-H), he hasn't had the problem since.So, once again, I'm of the opinion that if we were able to actually turn on FS9 pitot heat in the PMDG 737, this issue would be solved.James

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I saw this last night when flying up north (as in WAY up north). I am running a clean FS9 + PMDG install, nothing else added. It also glitched the panel causing the center instruments to become black holes. Night lighting on when it happened. Changed panel lights off then on and it was fixed.Ray

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No, guys, flight sim's internal pitot heat is indeed set to 1 when either or both of the PMDG 737's probe heat switches are selected on, and the FS engine anti/ice is also correctly toggled with the panel's engine A/I switch. I monitored both using FSUIPC.This is more than likely an FS and/or AS2004 issue. I suspect that in FS when severe icing is encountered, even probe heat isn't enough to save the day. We need to make sure AS can be prevented from throwing severe icing levels in on us.I too have seen some strange anomalies with night lighting...latest was a few minutes ago when there was some obvious masking of parts of the overhead panel. Undocking and redocking the O/H were enough to fix it. If a zero A/S event is accomanied by obvious program misbehavior, well then it's a horse of a different color. The times I've seen zero IAS, it was the only thing affected...and 100% of those events I monitored (three or four total) with program tracing were a direct result of random severe icing coming in via FSUIPC's weather interface.RegardsBob ScottATP IMEL Gulfstream II-III-IV-V L-300Washington. D.C.

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Bob:Are you using FSUIPC's logging feature to see what's going on? If not, what exactly in FSUIPC are you looking at?Thanks,James

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James; I have a home-grown trace utility that I use to peer into the inner workings of FS (via FSUIPC and WideFS so it runs external to the FS "server" PC). The FSUIPC logging feature will work for this purpose as well.CheersBob ScottATP IMEL Gulfstream II-III-IV-V L-300Washington, D.C.

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