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craig_read

Strange FMC Altitudes Issue

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Hi,

 

I've had this a few times now and it seems to be somewhat random in when it occurs.  But I'm programming the FMC for a flight, everything is going fine, however I can't engage VNAV at the gate.  When I look at the FMC the FMC generated altitudes appear in the legs page, they flicker once, then disappear.  No matter what I do I can't get them to stay there!  I've tried re-aligning the ADIRU but nothing seems to make a difference.  Basically once it's done this once it just continues to do it all the time.

 

The only way I can get out of it is to restart the flight completely, loading P3D again and then it's fine again.  Is anyone else seeing this?

 

Cheers

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http://www.avsim.com/topic/432377-vnav-preditced-altitude-not-show-on-fmc/

 

This post seems to be similar:

 

IRS Aligned, flight plan entered weights set, perf page set with cruise altitude set.

 

GR WT

260.5

FUEL

56.4KG CALC

ZFW

204.1

RES

10.4

CRZ ALT

340

COST INDEX

95

CRZ CG

7.5%

STEP SIZE

RVSM

 

Seems ok to me, this is how I've always set it up and I've had no problems.

 

When I look at the Legs page I see the speeds and altitudes for a split second then they disappear.

 

On VNAV Page 2 my step at flickers between 0241z/1739NM and NONE, and it won't settle, FL360 sits within limits for the cruise.

 

Setting the step to 0 calms the page, when I go back to the legs again I see the speeds and altitudes, they flicker then disappear. I can turn on VNAV and it illuminates, only to disarm moments later. Manually setting the STEP to 2000 makes no difference either.

 

PROG page flickers, that is ETA and FUEL (values and top labels), DTG and TO do not.. TO T/C indicated at 2321z/ 113NM this too is flickering.

 

Manually entering the step climbs into the LEGS page again puts the altitudes back temporarily and then they disappear again.

 

Can someone enlighten me as to why it's doing this?

 

I've also just tried to save the panel state and it won't let me, I put TEST into the scratch pad, select the filename field and nothing... sometimes it temporarily illuminates EXEC but then it extinguishes and I can't save it.. hmmm...

 

Yep definitely broken it won't let me load panel states either.. restarting P3D again :P

 

Cheers

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It's being caused by selecting specific transitions I think. If I leave the transition out from the approach it works fine, with it the routing (magenta line) jumps around and never settles.

 

Obviously the majority of transitions it is fine with.

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Navigraph AIRAC 1602 when originally released was messed up and was corrected a couple of days later. Their website still shows V 1 but it is different from the original release. You might want to download and install 1602 now. Possibly that could help. If that does not solve the problem that is an avenue to a solution that can be eliminated.

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Navigraph AIRAC 1602 when originally released was messed up and was corrected a couple of days later. Their website still shows V 1 but it is different from the original release. You might want to download and install 1602 now. Possibly that could help. If that does not solve the problem that is an avenue to a solution that can be eliminated.

My FMC Nav app shows I have 1602 V1 installed, I'll probably wait till the next version and go from there.. at the moment I am having to fly the transition on fixes.. not a problem but it would be nice to be able to programme it properly.. Thanks for the suggestion though I will try this on the ground shortly!

 

Cheers

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