For some reason, the PMDG aircrafts react like a fighter jet when I hit the "NAV" button. I also notice that the "Autopilot" has a hard time following commands. I have uninstalled and reinstalled the software and still the same outcome.Very frustrating!!!x(

Please sign your name at the end of your messages - its the rules.You need to be more specific if you want to tap into the wealth of knowledge available in this forum. However, I presume you have programmed the FMC correctly ? If not, the functionality of the A/P will be greatly reduced if not totally eliminated. eg if you want to use VNAV and LNAV you've got to have programmed the fmc with routes and altitudes etc. Otherwise I think you will be left with the ap just avialble for heading hold and manual alttitude changes. Also if you haven't programmed the fmc correctly and then switch the ap on it will try to achieve spurious fmc commands which may explain your strange behaviour.

Yes. I have even followed a tutorial. Programming the FMC is not the problem. I can program the Level D FMC with my eyes closed. It has to be something conflicting with the software. I tried it again today and when I hit the A/P. it shot up at an alarming ascent rate of 6500 fpm. AOA was out of sight. When I got it to settle down, I hit activated the LNAV to track the FMC course and it turned, but started descending instead of continuing to climb. Hmmmm.:-fume Stephen

It's not a problem with the software, as there are hundreds, if not thousands of us using this plane without a problem.That being said, what's you weight like? How did you load the fuel? Did you use the PMDG option menu, or did you use the FS menu?

I am positive I am programming the FMC correctly. I am using the Fuel Loader Utility and still I get the over-reactive response from the aircraft. Also, it will not follow the MCP Commands once the A/P is activated. It is so strange since as you say, thousand of simmers are flying these birds without a hitch. I am questioning the installation of a program called "RealTrim." Maybe that has something to do with it. If no luck, I will keep flying these birds with the Level D Panel which flies them perfectly!!!! Though unrealistic, and it takes away the enjoyment of flying the 737NG Panel. I cannot seem to find the problem.Stephen

Figured it out. The problem was with the FSUIPC Module. Working just fine now. Thanks.;-) Stephen

Well. It was a struck of luck that I flew somewhat decent. I actually still have the problem. #### things will just not fly right. Oh well. When I hit the A/P it seems as if it is trying to find the track and the wings oscillate up and down to make center. Then upon LNAV command the aircraft banks to start turn but descends at the same time.