737 FMC msg (discontinuty)

[razorseal 0]

I got a msg on the FMC and it said discountunity (sp) and then the LNAV disengaged... and when I enabled the FMC again it just took made a hard turn left and steered way off course...what just happened?

[SierraDelta 1,337]

Emir,Sorry, but this one is very simple: Pilot Error .... ;-)Search the FMC manual for "discontinuity" and all will be revealed...Cheers,S

[razorseal 0]

pilot error? lol I was just sitting watching AP do all the work, what the #### did I dostupid #### computers :( :D

[Stuntie 0]

>pilot error? lol I was just sitting watching AP do all the>work, what the #### did I do>>stupid #### computers :( :DYou did nothing when you should have done something.You need to check the LEGS pages for Route Discontinuties as adding route data STARS and SIDS may (and often does) leave dicontinuities that need to be fixed. Basically the FMC needs you to confirm or edit changes between some parts ofthe route.Checking the LEGS pages should be considered part of the checklist for route programming especially after any changes to the route such as selecting an appraoch and STAR.As suggested above check the FMC manual for more info on what to look for and what to do.

[Tabs 2,790]

Emir,Was the message "DISCO INSERTED AFTER XXXX"? If so, this is due to an improperly coded SID/STAR file that has a turn in it that the FMC is having trouble calculating the right direction for. As its not possible for us to handcheck every single file that's auto generated for the database, ocassionally you'll run into this sort of thing. If you open up the LEGS page, you'll be able to see where the discontinuity is and do something to fix it.If what you saw was just something like ROUTE DISCONTINUITY and LNAV disengaging, this most likely means you've either 1. Run into a route disco that existed on the LEGS page but wasn't closed earlier in the flight, or 2. you have no further waypoints loaded. In both cases, the FMC is blind, it has no idea where you want to go, so it kicks out and holds present heading. To get back into LNAV, you need to close the disco by line selecting the next waypoint up to the top line, or enter new waypoints.

[Guest Ohio330]

I feel your pain. I tried doing what stumpy said to fix discontinuities, but all i get when trying to fix the entry is "NOT IN DATABASE"..maybe im trying to fix an unfixable route..dunno