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757, Nose Oscillation, FMC Exceptions

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Hi,Good to have another great PMDG bird available to fly :-). Thanks forreleasing it.Ok after that much flattery (hey its a lot for me! ;-) ) to my questions.During climb and descend with Autopilot/Autothrottle i notice thenose oscillates up & down quite a bit. The bird never settles into a steady climb or descend. Tried it with a few different speeds, altitudes. Always same effect.If i mess around in the Legs window of the FMC (adding/ removing waypoints) i often get a FMC Exception caught in DLLDraw tag 8.Any hints about the cause of these 2 things are highly appreciatedHappy flyingAndy:-)

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Andy-please provide further details that would help us resolve the issues for you:a) Regarding oscillations: What AFDS mode are you in? V/S? FLCH? VNAV? Also- what are your hardware specifications?:( Re: FMC. Please give us a step-by-step reproducing this, so we can try to nail it down.Thanks for your kind words!

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Hi LefterisThanks for your FAST response!Here my "Test"-Results. Anything more you need just let me know.Oscillations : "SPD" 250, Alt Set 15000 then "FLCH" (A/T in "CLB" Mode)I had her trimmed to a steady 2000ft/min climb before going to FLCHSpec : 2GHz P4, 1GB RAM, GeForce3 TI200, 28.32 DriversFMC : (the "Pop-up" FMC, Shift-N)Airport : KMIAComplete "Pos Init""Route"Set KMIA as Destination, "Activate" Insert "FUELR" Insert "LAX" after FUELR Now have the following in my legs window :FUELRLAXKMIARight click the button next to "LAX"Right click the button next to "KMIA"leads on my system to the mentioned exception.(please dont hold me for the (non)sense of this choice of waypoints)Andy:-)

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Guest amerton

Andy,Independantely of the choice of the wpts, you're building a FP asFUELRLAXLAXKMIAI guess not *all* possibilities have been extensively tested, i.e. don't have a route with twice the same wpt in sequence.anthonyAnthony MertonPrecision Manuals Developmenthttp://www.precisionmanuals.com

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Thanks a lot Anthony, now i know i did something dumb.I'll try to tame my mouse from now on :-)Happy flyingAndy:-)

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Hi,Thought ill ask again, whether you know a possible cause/solution for my oscillation problem?ThanksAndy:-)

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Guest andrewluck

I'm seeing a lot of FMC exceptions as well adding waypoints. I have a route saved from EGCC to EGSS as follows:CLIPYFINMABKYBUSTALORELI usually enter the waypoints to get me from LOREL to the ILS once I know what runway is at use at EGSS. Say the next waypoint is BKY.Entering BKY and pressing the button alongside EGSS to enter the waypoint results in an exception. I've also had some problems when deleting the last waypoint before the destination. You get a route discontinuity that can't be resolved.Apart from this small niggle, what can I say. You've succeeded in modelling an extremely complex piece of equipment with remarkable accuracy. Now, what we want is fuel prediction ;) Oh, we already have it.Andrew Luck18 miles SW EGSH

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Regarding oscillations: I have the exact same behaviour as Andy, both when ascending and descending (although the descent case seem more pronounced)- Bill

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