VNAV / LNAV malfunction with autopilot

[gusifer 0]

Hi there,

 

I tried flying this airplane twice now, and both times when i am at cruise 350 with vnav and lnav activated it starts going crazy, goes up and down and starts doing right and left turns. tried disabling autopilot and enabling again and does the same thing.

 

can anybody help with this problema?

[scandinavian13 5,192]

http://forum.avsim.net/topic/343662-what-is-the-solution-for-s-turns-when-using-ase-with-dwc-enabled/

 

http://forum.avsim.net/topic/271606-md-11f-active-sky-advanced-and-the-s-turns-issue/

 

http://forum.avsim.net/topic/331530-overbank-and-s-turns-help/

 

http://forum.avsim.net/topic/353734-only-way-to-stop-s-turns-with-ase-buying-fsuipc/

 

and more results from Google:

https://www.google.com/search?q=site%3Aforum.avsim.net+s-turns+dwc&oq=site%3Aforum.avsim.net+s-turns+dwc&aqs=chrome.0.69i57j69i58.8752j0&sourceid=chrome&ie=UTF-8#safe=active&sclient=psy-ab&q=site:forum.avsim.net+s-turns+pmdg&oq=site:forum.avsim.net+s-turns+pmdg&gs_l=serp.3...34650.34844.0.34939.4.3.0.0.0.0.82.163.3.3.0....0.0..1c.1.20.psy-ab.E_NslPZ0_30&pbx=1&bav=on.2,or.r_cp.r_qf.&bvm=bv.49641647%2Cd.dmg%2Cpv.xjs.s.en_US.NyLNrjc7wJY.O&fp=ed0c4c3f6e03d345&biw=1280&bih=933

[gusifer 0]

I already have a registered fsuipc copy, and smoothing is active... i guess this airplane cant be used with real world weather in fsx

[scandinavian13 5,192]

 

 

i guess this airplane cant be used with real world weather in fsx

 

Works just fine for me.  I use AS2012 in DWC with the FSX turbulence setting un-checked.

[UcShrek 0]

I read the comments on all these posts but I could not find what I actually need for VNAV, because most of the people in there are having issues with LNAV, which in my case works fin with all PMDG products I have, except the 747, LNAV works fine with this product but not the VNAV, when I'm supposed to be stable at 34k AGL, (per say), it goes up and down from 32k to 36k; basically it won't stay level at requested altitude, any suggestions?

[kevinh 409]

It may be worth trying completely removing the 747 and reinstalling it. This is not something I would normally recommend as anything other than a last resort. But with the 747 it often seems to be the solution.

[Ray7675 0]

Mostly saying, for me: Completely uninstall and reinstalling the PMDG 747 will NOT solve the VNAV problem. I know this as I was experiencing this when I was flying this aircraft.

 

There's seem to be no way of solving this issue.....

[kevinh 409]

Mostly saying, for me: Completely uninstall and reinstalling the PMDG 747 will NOT solve the VNAV problem. I know this as I was experiencing this when I was flying this aircraft.

 

There's seem to be no way of solving this issue.....

The point is this is not an issue for everybody. So those who suffer from it may well have a problem relating to their installation.

 

I use the 744 a lot and rarely experience any VNAV issues like this. Occasionally VNAV does seem to lose control, and in that case switching to another vertical mode and back to VNAV can reset the sim's logic. The worst VNAV problems I see are caused when the engines roll back and the sim loses speed.

[Eric_Parker 4]

Ditto above. I fly the PMDG 747-400x a lot and yes there are issues with FSX weather. I switch back and forth between FSX and FSrealWX lite and one of the things FSX weather causes is rapid and severe wind shifts. One minute there is a 60 knot headwind and then instantly there is a 60 knot tailwind. The PMDG 747-400x struggles mightily with this problem so I use FSrealWX lite a lot.

 

Also the PMDG 747-400x is very sensitive to weight, temperature, wind speed and altitude (read density altitude) so trying to fly an 800,000 pound airplane at 40,000 feet is not going to work.

 

All these are factors to consider during flight planning. I never expect to go above 33,000 and usually fly at 30,000+/- feet for most of the route. I see a lot of airplanes on VATSIM at FL380 and above who are probably not using a payware aircraft and don't use real weather.

 

As an example I flew from ORD to LAX the other day and encountered 100+ knot headwinds over Iowa. I ended up going over South Dakota and Montana to avoid the wind having to make an unscheduled landing in Salt Lake City for fuel.

[dondormehl 0]

Gents,

 

This have nothing to do with wx or whatever. The product did not activate properly thus causing some of the modules to deactivate after a while!

 

Check system date/time for correctness. A dud CMOS battery caused my date/time to reset after restarting my new PC. I did not notice this and continued to install all my PMDG products. They all demonstrate these weird behaviours now. PMDG advises re-installing.

 

Oh, by the way, I ran FSUIPC4, AS12, Aivlasoft EFB, VA Acars and fly mostly online and never had any issues with any of my PMDG products on my old machine!

 

Check that firewall allows for acces, date/time correctness and good internet connection before activating your PMDG software!

 

Good luck!

 

Cheers,