HelloI've been trying to no avail for the past several days to get the 747 to successfully complete a flight. For some reason, it keeps overspeeding. I have, to the best of my knowledge, correctly set up the FMC with my route and altitude data. Turned on the Flight Director on the ground, along with LNAV. Once established in the climb, turned on the AutoThrottle, VNAV, and the autopilot. It handles the climb just fine, pitching to hold the set airspeed. But as soon as it reaches its cruise altitude, it levels, and eventually overspeeds. Since I'm using FSPassengers, this is somewhat annoying to say the least. Any ideas on what I'm doing wrong??Hunter CoxEDIT:: I have noticed that the autothrottles are not holding the desired speed. The speed bug shows on the tape, but the plane just keeps accelerating.

I have had this happen to me. It is rare but it does happen. What I have done and it has worked every time is double click the VNAV button. I am not sure if it will work for you but you can give it a try.

Hunter,The A/T should be on as you line up for takeoff.Aside though, do you see anything on the speed portion of the FMA when this happens? If it's blank, the A/T is not commanding the engines, your physical throttle position is.Also, make sure control override is unchecked in the PMDG options.Read this as well.http://ops.precisionmanuals.com/wiki/PMDG_...are_and_Feeding

thanks for both of y'all's help. i did get it working earlier this evening, i just had to double click the LNAV button. Clicking it once, put the plane into its VNAV Speed mode, but the A/T never assumed control until I clicked it twice.Thanks for the help!!