VNAV PATH Problem

[masneoquil 66]

Hello guys,

 

I'm having a little problem with my NGX. It doesn't happen everytime, and some times it comeback to normal.

 

What happens is I'm entering the winds on the winds page and suddenly when I click for example R3 key to enter the wind for that way-point, the data doesn't get populated and the Exec button doesn't lit. I have to go to another page for that to happens. From that time on, it happens again with any data I want to change. Also I loose my vertical path and calculations and VNAV won't engage. On the legs page all time/FL data for all the waypoints are dashed, and i don't have any TD calculations.

Does someone encounter this?

 

Here are some screenshots.

 

 

 

 

EDIT: I just made the VNAV come back by adding a FL restriction into one of the waypoints at cruise. But if I do that, the FMC calculates the TD just after that waypoint, and in the case of the flight of the screenshots, almost 800 nm before!

[scandinavian13 5,192]

Does someone encounter this?

 

To me, it honestly sounds like you're jumping the gun on it. Make a change, press EXEC, and give it some time to crunch the numbers. This isn't 1 + 1 = 2 type math that the FMC is running...

 

Press EXEC and do nothing - don't click to other pages, don't adjust parameters, or anything else - just wait. I guarantee it'll repopulate without you having done anything else. Because the T/D is based off of the altitudes and profiles it calculates, it'll disappear while it recalcs everything.

[masneoquil 66]

To me, it honestly sounds like you're jumping the gun on it. Make a change, press EXEC, and give it some time to crunch the numbers. This isn't 1 + 1 = 2 type math that the FMC is running...

 

Press EXEC and do nothing - don't click to other pages, don't adjust parameters, or anything else - just wait. I guarantee it'll repopulate without you having done anything else. Because the T/D is based off of the altitudes and profiles it calculates, it'll disappear while it recalcs everything.

I know what you're talking about Kyle. I see that behavior everytime, and it does take a little time for the TD to show up.

What I'm talking about here is different. It's not only the TD, but the entire vertical flight path. I can't engage VNAV, and it doesn't show any message.

I had to climb in LVL CHG, and the entire cruse was using MCP speed selector. No VNAV at all.

But again, it doesn't happens everytime,

Maybe its a known bug. I don't know if I should open a ticket to let them know of this, but it is a show stopper cause you don't know when to start the descent.

[scandinavian13 5,192]

 

 

What I'm talking about here is different. It's not only the TD, but the entire vertical flight path. I can't engage VNAV, and it doesn't show any message.
I had to climb in LVL CHG, and the entire cruse was using MCP speed selector. No VNAV at all.
But again, it doesn't happens everytime,

 

That's weird.  Are you using saved panel states other than the defaults?

[masneoquil 66]

That's weird.  Are you using saved panel states other than the defaults?

I set to load by default the Cold and Dark panel state that came with the plane.

[scandinavian13 5,192]

I set to load by default the Cold and Dark panel state that came with the plane.

 

Dang...I was hoping you'd say it was a custom panel state.  I would've blamed it on that, and had something to work with...

 

I'd submit it to PMDG as a ticket to see what they have to say.

[masneoquil 66]

Dang...I was hoping you'd say it was a custom panel state.  I would've blamed it on that, and had something to work with...

 

I'd submit it to PMDG as a ticket to see what they have to say.

I just did that.

 

Thanks, Kyle, for your time. :Peace:

[G-CIVA 62]

I see you were trying to enter WPT WINDs during the CLB phase?? - normally this works fine for me also but occasionally I get the same issue.

 

My solution has always been to attempt to DELete the WPT WIND entry that caused the issue and go into the PERF INIT Page and overwrite the CRZ WIND entry at LSK 2R...this normally solves the issue for me.

 

I am then able to reengage VNAV for the rest of the CLB and enter the WPT WINDs after the top of climb has been captured.

[masneoquil 66]

I see you were trying to enter WPT WINDs during the CLB phase?? - normally this works fine for me also but occasionally I get the same issue.

 

My solution has always been to attempt to DELete the WPT WIND entry that caused the issue and go into the PERF INIT Page and overwrite the CRZ WIND entry at LSK 2R...this normally solves the issue for me.

 

I am then able to reengage VNAV for the rest of the CLB and enter the WPT WINDs after the top of climb has been captured.

I didn't think of that. I will try it next time it happens. Thanks!

 

Actually, I enter the wind data during preflight, before starting the engines. On that flight I took off anyway to see if VANV came back by itself but it didn't.

[Lek767 37]

Are you 100% sure you've EXEC'd the PERF INIT page? See also: http://support.precisionmanuals.com/KB/a99/v-speeds-dont-show-on-pfd-speed-tape-vnav-wont-arm-engage.aspx

[masneoquil 66]

Are you 100% sure you've EXEC'd the PERF INIT page? See also: http://support.precisionmanuals.com/KB/a99/v-speeds-dont-show-on-pfd-speed-tape-vnav-wont-arm-engage.aspx

I'm pretty sure. By the time I started entering the wind data, I have all FMC completed and ready to flight.