Sign in to follow this  
Guest mbalvetti

747 FMC No pre-flt complete

Recommended Posts

Hi, after following Precisionmanual instructions on FMC programming I am not able to reach a 'pre-flt complete' situation on FMC.I remain in a pre-flt situation and even if I read both tutorial (in french and the other one listed many times in this forum I can't understand where is my error.POS ok, ZFW, reserves ok, cost index ok, trip/crz-alt ok, ref airpt ok, route ok with no discont.. all valdate and exec, v1-vr-v2 confirmed, flaps ok, rw and sid ok, perf-init page seems ok, n1 limit page ok, takeoff page okLNAV doesn't engageThanks in advance,Maurizio Balvetti

Share this post


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

If LNAV doesn't engage it means that you didn't activate the route yet. Also, a pre-flt complete message isn't shown.

Share this post


Link to post
Share on other sites

I'll just cut-n-past here. We have an Lnav discussion going a couple of posts over. This might get you started. " . . . I've seen this before too. I'm sure this is old news but I always found that (somehow) [if Lnav would not engage], I did not have a full Lnav route. Generally, either the FMC didn't like (or I didn't have) either an arrival [airport] or departure runway correctly in place. Make very sure you have RW12 (or some such) as one of the waypoints in your arrival sequence. There's gotta be a runway in there somewhere. That arrival legs page sequence can get real extended because some of the STAR arrival procedures include missed approach procedures too. (Also, maybe update your SID/STAR set from navdata or planepath? Could be messed up arrival data?)Do you have FSBuild? I use that a lot and it always gives me a usable flight plan (i.e., at least Lnav/Vnav will hook up). Also, try selecting just a Runway from the APP/DEP>APP page for the far end . . . without a STAR or even an IAP . . . just as a test flight (We really need an XB747 skin. Red with a stripe. Like that old X15! ). Generally that white, on-off-flash-of-an-Lnav-arm-indication in the FMA means that Lnav at least thinks it has an incomplete route."The point is that you also need an Lnav route set up. Just going through the pre-flight pages might not get you Lnav. Gotta have a departure airport and an arrival RUNWAY. So, complete your preflight as previous (enter your departure and arrival airports via the preflight screens, etc). Then press the ARR/DEP button on the FMC. Choose ARR (at LSK 3R? That screen is not very intuitive). Select a runway like "ILSRW28R" (or some such runway) from the right side of the screen. Don't worry about all that "Trans" stuff (for now). . . (and again, for now), whenever that EXEC button lights up, press it.Lnav will arm on the ground before TO if you have a complete route in place. Did it work?

Share this post


Link to post
Share on other sites

[/b]>The point is that you also need an Lnav route set up. Just>going through the pre-flight pages might not get you Lnav.>Gotta have a departure airport and an arrival RUNWAY. So,>complete your preflight as previous (enter your departure and>arrival airports via the preflight screens, etc). Then press>the ARR/DEP button on the FMC. Choose ARR (at LSK 3R? That>screen is not very intuitive). Select a runway like "ILSRW28R">(or some such runway) from the right side of the screen. Don't>worry about all that "Trans" stuff (for now). . . (and again,>for now), whenever that EXEC button lights up, press it.>[/b] Sorry but this is incorrect. You don't need to input an arr rwy for LNAV to engage. A "basic" rte consists of a depp/rwy and an destination plus one wpt for LNAV to engage. Pilots sometimes have no idea what ATC will provide in terms of a rwy, it's true one can plan ahead but that does not mean it is required for LNAV to engage. Sure if after that one wpt you have not selected anything then the AFDS will engage in HDG HOLD. You WILL need an arr rwy for DESCENT with E/D but this can be program ed in crz................Randy J. Smith................A PROUD MEMBER OF THE PMDG BETA TEAM[h4]Evolution is a process that results in heritable changes in a population spread over many generations[/h4]

Share this post


Link to post
Share on other sites

Maurizio, Randy has some great details to add. We're sure lucky to have someone so willing to share knowledge around. But don't worry about every detail of the potential, alternate, super duper, advanced modes of Lnav operation just yet. Just get that darn Lnav to engage first. What I set up should get you VNAV armed up too. Then you can go actually fly a mission. (Maybe Randy could help by double checking that for us too. -Randy, KIS, for the poor new guys, like me and Maurizio!-) Once you get that down, you can get fancy about setting up for an ATC joyride on the other end. But right now, go fly. Ignore ATC.

Share this post


Link to post
Share on other sites

Well I should have said "technically not correct" =P because doing it the way you suggest IS the most logical way (I do it that way) but wanted it to be clear (the beta guy in me) that the criteria is not so strict ;-)...............Randy J. Smith................A PROUD MEMBER OF THE PMDG BETA TEAM[h4]Evolution is a process that results in heritable changes in a population spread over many generations[/h4]

Share this post


Link to post
Share on other sites

mayb this was mentioned b4 but i when i had a similar problem ( Lnav didnt want to engange without any message from the FMC) i mentioned that i hadnt selected a departure Runway after selecting one everything worked fineoh and BTW: although i hadnt selected an arrival runway Lnav did work, of course after selecting a departure runway

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