hellojust a few questions about the 737ngx i dont know what i am doing wrong with that beautiful bird : i cannot on engage de vnav button after take off.. no green light.. Lnav is ok.in the fms , i ve all the things complete and ok: the route, the weight ..... etc... and all the fms is set , the speed v1 vr v2 calculate and okbut no speeds v1 v2 vr on the PFD... it stay in yellow and no speed .....so no annoucements i am sure i doing something wrong, but even i read the manuals ( start up and the tutorial too )any help appreciatethanks in advance and nice flights to you allPierre af

Common is to forget to execute performance initializations on the FMS. And of course make sure the V speeds are actually entered on the respective CDU page. As for VNAV it's a little hard to troubleshoot with no information at all. There are a few conditions that will or will not allow engagement. Did you follow the intro flight step by step? I haven't done it so far to be honest but a quick check revealed that it also includes arming VNAV on ground. So if it's not working there, then something went wrong before. And that is most likely during FMS initialization I would guess.

Can you engage the autopilot at all?Has your ADIRU initialized completely before you move the aircraft. You have the option to set realistic (10min), 30sec. or instant initialization in the PMDG aircraft options. If it happens to be set on realistic, then you can't move the aircraft for 10 minutes and you won't have any Vspeeds showing on the PFD.Do you have your IRS selectors set to NAV? If you have left them on ALIGN, you won't have Vspeeds.Do you have your Departure runway set in the FMS? If you have your RTE complete, but haven't set the departure runway in the DEP/ARR pages, you won't have any Vspeeds.If you happen to change your departure runway just before you takeoff, you will also get the message on the SP of the CDU, "Vspeeds deleted" and you will have to reset you Vspeeds on the Takeoff page of the CDU.Make sure that your "Standby Power" and "Transfer Bus" switches are both set to "Auto"I would go over the tutorial carefully. You have left something out.Just some things to check. Bob

It happened to me on my first try and I couldn't figure it out, I had saved the panel at that point when VNAV would not engage, and when I reloaded it, I could engage the VNAV button. It could be a bug, but maybe I had made a mistake, but I had changed nothing when I reloaded the panel. It has not happened again, so I am assuming that I had done something wrong... BTW, you may have to set the runway elevation on the pedestal if it is not almost zero. You certainly have to do it if you are going to land on a runway at 2500 ft elevation. Henri

thanks for the quick answers.i ve read al the posts and i ve done all your recommandations but nothing... vnav no green lightmy fms seems correct.. and i can engage the AP and vnav and AT ......and no vsppeed on pfd... just the message yellow no speed...i will go to night better on the tutorial again !!thanks anyway and if i found solution i let you know..pierre

Henriwhat do you mean and how you saved the panel?on the pedestal runway elevation?

Henriwhat do you mean and how you saved the panel?on the pedestal runway elevation?

No, you can save the panel settings in the FMC and reload them later from the FMC. Henri

ok thanks for the answeranother strange in the flight but sure its myself ..i fly lfpo lfpg short flight: take off rwy 26 lfpo and strange things i dont know why speed on pfd and vnav button ok now !! yupie !!but suddenly during the sid AT went off. and impossible to control the speed ever via speed button or fms in route page or crz page... the bird is flying 270 kts alone.. speedbrakes doesnt make him to slow down... just a few kts...but he follow the flightplan in fms..need to read again the tuto or go back to flight school :):)Pierre