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vc10man

VNAV FMC Message

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Loading a flightplan via PFPX, yet I get this message occasionally at some Add-on Airports, and as a result do not get the Take-Off Ref speeds, nor do I see any FLs in the Legs Pages.

Not sure if I'm doing something wrong, so can anyone assist, kindly, and put me right?

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2 hours ago, harvester21 said:

Hi Rick, what message?

How silly of me to have missed out the obvious!!! Mia Culpa. I had forgotten I inserted it in the Sub-Title.

FMC message is PERF/VNAV Unavailable., hence do not see any FLs for the VNAV to track.

 

Edited by vc10man
Image Insert

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The FCOM search feature using "perf/vnav unavailable" as search string revealed this gem:  VNAV selected without gross weight, cost index or cruise altitude entered.  I bet a coffee that you haven't clicked on the weights appearing with a ">" symbol next to them.

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Hi Dan. Appreciate your response.

However, I have now more than a 100 flights with the Queen under my belt. Invariably, while GSX is doing the catering, after the IRS has aligned realistically, and I have selected the quantity of fuel as calculated by PFPX+ 10% extra for the route plan, I input the ZFW, the CI, and the CL, and if it is a long-haul, inevitably, I will see a flag in the FMC to opt for a lower CL for the fuel loaded.

This has occurred twice and both times at a Thai Creations add-on airport. Does not happen at say, an FSDT add-on.

That is not to say it wasn't my faux pax that I missed one of those data inputs, because while at CL currently, I checked in the PERF INIT page and lo and behold, the ZFW was amiss. Input that that and lo and behold I now have FLs on the Legs pages.

 

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It is a stretch to imagine how scenery would effect the operation of the FMC,  other than what is in the navdata it is quite unaware of any scenery.  It will be interesting if it can be reproduced at will with a set of specific steps... keep an eye on it.

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I accept your theory, Dan. The reason I alluded to the airport add-on was because the Runway was displaying a different No. to one that RAAS was calling out, or what was in the recently-updated AIRAC Cycle Navdata.

But now that you have clued-me up, will monitor it.

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3 hours ago, vc10man said:

the Runway was displaying a different No. to one that RAAS was calling out

When runway numbers change you can run the free MakeRwys tool to build the new list that RAAS uses.  I run it a couple of times a year anyway.

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7 hours ago, downscc said:

When runway numbers change you can run the free MakeRwys tool to build the new list that RAAS uses.  I run it a couple of times a year anyway.

Thanks, Dan, Never used that tool, but will have go at it.

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