Hello follow simmers.How are you?It's my first time post my questions.If i do make any mistake pls excuse me.About 2 months ago I brought a pmdg747 and I love it.However I do have some questions regrading the LNAV.This is something I had encounter.When I input all the information to FMC,I can activate VNAV and the light is stay on and activate even before the plane takeoff,however sometime I am not able to activate LNAV for some reason.For example,I am able to activate the LNAV in some routes,like the other night I flew from Tokyo to Sapporo,after the plane tookoff.ATC instruct me turn right to 060 degree,after a while ATC told me turn left to 030 degree resume own navgation,then i click on LNAV to activate it,sometime it take me few times to activate it.Like tonight I try fly from New York to Van Couver,after I tookoff the atc told me head to 135 degree,after that the atc told me resume own navgation,but this time I am not able to activate the LNAV.I need to mention I didn;t input information on dep/arr page,is it the reason why the LNAV won't activate?If so then I do not understand why when I flew from tokyo to sapporo I didn;t input the info on dep/arr page but I was able to activate the LNAV?Pls let me know when i did wrong and or sometime I miss?Thank's,the other question is how can I activate LNAV before the plane takeoff?Because I was able to activate the VNAV.Thank you.
