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d0rkiishchris

VNAV Descent issues

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I'm putting the altitude in the mcp of my first IF  of my approach long before my top of descent.  And when I reach it, it doesn't descend.  So I have to take it out of Vnav and put it into level change or a manual descent.  Whats even more strange is the descent page has become active!!  

 

Also towards the end of my flight after being miffed about the vnav not descending, I wanted to change my approach in the fmc to extend it to get down and had a console error.  

What may have caused this was me going onto a vpn just before that.  Does changing my computers IP mess up gizmo?  

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38 minutes ago, d0rkiishchris said:

What may have caused this was me going onto a vpn just before that.  Does changing my computers IP mess up gizmo?  

No.

Gizmo doesn't care about your IP or MAC address.

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7 hours ago, d0rkiishchris said:

I'm putting the altitude in the mcp of my first IF  of my approach long before my top of descent.  And when I reach it, it doesn't descend.  So I have to take it out of Vnav and put it into level change or a manual descent.  Whats even more strange is the descent page has become active!!  

 

Hi Chris,

usually the plane will start descent at the TOD as you mentioned correctly if the MCP altitude has been set to a lower level. It is also a requirement to be in VNAV at that point, it may be possible that you were still in ALT HOLD?

The whole VNAV calculation is still very frail at this point - it may work with simple approaches, but as soon as there are several or A/B restrictions on the descent, it will not work.

At this point I recommend using VNAV with caution, be ready to revert to selected autopilot modes when needed. It MAY be a consolation that VNAV isn´t used much in the descent by real pilots, but I understand that flight-simmers have grown accustomed to and like the plane doing the calculations and control inputs needed for them and we plan to finish/enhance the FMS calculation eventually.

Sorry for the inconvenience, Jan

 

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7 hours ago, Litjan said:

Hi Chris,

usually the plane will start descent at the TOD as you mentioned correctly if the MCP altitude has been set to a lower level. It is also a requirement to be in VNAV at that point, it may be possible that you were still in ALT HOLD?

The whole VNAV calculation is still very frail at this point - it may work with simple approaches, but as soon as there are several or A/B restrictions on the descent, it will not work.

At this point I recommend using VNAV with caution, be ready to revert to selected autopilot modes when needed. It MAY be a consolation that VNAV isn´t used much in the descent by real pilots, but I understand that flight-simmers have grown accustomed to and like the plane doing the calculations and control inputs needed for them and we plan to finish/enhance the FMS calculation eventually.

Sorry for the inconvenience, Jan

 

I just posted an FMC crash.  I have a screen shot.  And an FMC log file.  I don't mind if I have to descend manually.  But the FMS is crashing almost every time I make approach changes on the fly.  

console crash.jpg

ixeg fms runway change.jpg

IXEG_FMS_debug.txt

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