Sign in to follow this  
Guest feuersteini

747, Problems with VNAV, LNAV, Autopilot

Recommended Posts

Hello everybody,after many good flights in the PMDG 737 I have bought the PMDG 747 boxed version. But now I have a big problem.After Cockpit-preperation and FMC-preperation (Flightplan with FSNavigator)I make the takeoff with armd VNAV, LNAV, FD on, both AT. I pressed the screw TO/GA. But after aktivate the AP, the plane climb with 4000 ft or more, the speed goes near STALL, after passing the altitude, the plane climbs higher. Pressing the Altitude-Hold-button - no reaktion. The plane takes with aktivate LNAV 180

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

If I understand you correctly, you takeoff with the AP's armed. Do not turn on your AP's turned on. Autothrottle and LNAV yes, not Autopilot. Second, unless you are very light, I recommend not arming VNAV right away. Climb out speed is calculated at V2+100, and it is not very often that V2 is 150 kias or less. I sometimes have LNAV armed at takeoff because some airports have very busy SIDS (like the new ones at KATL) where there are waypoints soon after runway departure. I don't turn on the Autopilot until I am stablized after takeoff (somewhere between 500 and 800 ft AGL). Then I can do my vertical navigation by using FL CHG and airpseeds. It give me much better control. You can safely turn on VNAV above 10000'.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this