Hi,I have been fighting with the FMC to get VNAV active the last couple days and I have finally decided to ask for help. I have gotten the LNAV to work perfectly, programmed routes and all. Can anyone lay out the basic 1.2.3.4 steps of what I need to accomplish to get VNAV working.So far I've tried the following:(1) Configure route and LNAV(2) Set weights in PERF INIT(3) Set flaps and confirm flap speeds with three LSKs(4) Set cruise altitude to optimum(5) What's left to do?I've been hunting continuosly thorugh the manual and it seems like I have accomplished everything I can find. Help.-Matt

You need an OAT entry to get the VNAV to work correctly, entered (or at least verified) in the Takeoff page. Also, depending on the addons, some ATC diversions from a planned route will put you back to manual management of your vertical situation. Telling the FMC to do a climb (or descent) schedule it doesn't think the bird can pull aff does the same thing.- Dave Reed KLAS

I also did the OAT as well, I forgot to mention that. Thanks anyway though.-Matt

Matt -You don't mention exactly what your bird is doing when you fly it after all this setup, so it's hard for me to guess your prob. One other thing to check, though: after you've got everything in the FMC, go to the "Legs" page and check for valid, positive altitudes showing at your waypoints. Once done, I usually set the Capt's CDU to "VNAV", and the F/O's CDU to "Prog". Also, before commencing takeoff roll, verify FD on and A/T armed, arm VNAV, and use TO/GA keystroke (not manual throttles) for thrust setting on the takeoff.If you still don't get vertical control, you might try re-installing the 777. That last is not fun. Hope this helps!- Dave Reed

Hmmm, I never set climb waypoints with positive altitudes, that's a good idea, thanks. I have all my flightsim's uninstalled for the moment. I will be taking time during my winter break to get all this resolved. I'll print this page out and store it away for the time being. Thanks for the help,-Matt

Re " I've gotten the LNAV to work perfectly".I wish I could say the same for me.After configuring the FMC, and taking off more or less in the path to the first waypoint, sometimes LNAV is captured, sometimes not. It's really frustrating. I have to bring up the FMC panel and reconfirm the FLY FP in the route page, and press EXEC again to make the ac capture the LNAV.What's your secret?EytanLLHA

The LNAV flies a Great Circle route between waypoints, and depending on the distance to the first WP from your departure, the difference between the Great Circle's initial heading and a rhumb line course can be quite great.Assuming you're not flying a SID or DP, just fly a 45 degree intercept heading to the magenta line on the NAV display, and arm the LNAV. It will illuminate in the PFD in white if you're on the intercept, and in green once the plane is flying the LNAV route. Note that the NAV display shows the rhumb line course, and on long stages you might not see the course line accept near the terminii of that stage.- Dave Reed KLAS/AWVA 757 FO