Hello!I just bought the boeing 737-800 PMDG version. I have spent alot of time in the FMC, its all new to me, and i have followed the tutorials following with the PMDG aircraft.However i struggle with putting up my own flight route in the FMC. I want to fly from ESSA to EGGL, and when i enter "UN873" under the via section the FMC tells me that the input value is invalid. I have followed alot of guides on youtube, and when i try to do what they´re doing i can get it working, but not on my own.I plan my routes whitin FSX.What am i doing wrong?What is the correct way to set up your own flightpath?I dont need an indepth answer as im new to this. To start with im happy to get the route working in the FMC.Thanks for your time and answer.

Your best bet is to post your question in the PMDG Forum. http://forum.avsim.net/forum/432-pmdg-737ngx/

I doubt PMDG will respond to this inquiry. It's a valid FSX question. Programming the FMC is not difficult but it can be overwhelming at the beginning. I did a Google search for ICAO EGGL and it identifies it as London but I think the more appropriate ICAO would be EGLL. My FSBuild does not identify EGGL as a valid ICAO and won't provide me a valid flight plan. I did an FSBuild flight plan from EGGL - Stockholm to EGLL - London Heathrow and it identified the Route as U873, not UN873. Try that. UN873 or U873 is a high altitude oceanic flight route. PMDG will probably recognize U873.Best regards,Jim

What am i doing wrong?

Also, remember to check your AIRAC versions (both the aircraft and the one used to build the Flightplan). Between updates, some waypoints and airways change and that can also be a cause of why your FP isn't working on the 737's FMC.

FSBuild, ESSA to EGLL auto build. Latest AIRAC versionsESSA DKR N872 ALS P999 DHE UZ303 OKOKO UP155 SOMVA UP44 ARTOV UL620 MANGO UL980 LAM.BIG3D EGLL

You should not fly from Lambourne to Biggin for the Heathrow arrival, it should be the LAM3A STAR (think its still 3A, don't have the chart infront of me right now). The LAM-BIG STAR is a stack swap STAR that is tactically used by ATC to alleviate congestion in certain holds to spread around the traffic. They should not be used for flight planning. All the Heathrow STARs contain stack swap alternates because it was something we did fairly routinely most notably between BNN and OCK or LAM and BIG due to a spike in traffic at one of the holds.

Addressing the OP's oringal question:Did you have an waypoint on UN873 as the last waypoint before putting UN873 in the "via" heading? The FMC needs to know where to start an end an airway. So you need to have a waypoint on the airway as the "to" waypoint. Then enter the airway in the "via" slot. Then enter the waypoint you'll exit in the next "to" entry.Addressing the OP's oringal question:Did you have an waypoint on UN873 as the last waypoint before putting UN873 in the "via" heading? The FMC needs to know where to start an end an airway. So you need to have a waypoint on the airway as the "to" waypoint. Then enter the airway in the "via" slot. Then enter the waypoint you'll exit in the next "to" entry.

atco is correct. BIG3D, BIG1E, and BIG1G are "for use only as directed by ATC and must not be used for flight planning purposes."

Strict Standards: Declaration of group_forum_breadcrumb::sendOutput() should be compatible with that of output::sendOutput() in /opt/webdocs/newsite/forum/hooks/group_forum_breadcrumb_d29bf565a59f776807044fd19e49258a.php on line 107

Addressing the OP's oringal question:Did you have an waypoint on UN873 as the last waypoint before putting UN873 in the "via" heading? The FMC needs to know where to start an end an airway. So you need to have a waypoint on the airway as the "to" waypoint. Then enter the airway in the "via" slot. Then enter the waypoint you'll exit in the next "to" entry.Addressing the OP's oringal question:Did you have an waypoint on UN873 as the last waypoint before putting UN873 in the "via" heading? The FMC needs to know where to start an end an airway. So you need to have a waypoint on the airway as the "to" waypoint. Then enter the airway in the "via" slot. Then enter the waypoint you'll exit in the next "to" entry.

That is wrong, in the RTE page, on the left side you can enter your airway, UN873, for example, before entering a waypoint.Strict Standards: Declaration of group_forum_breadcrumb::sendOutput() should be compatible with that of output::sendOutput() in /opt/webdocs/newsite/forum/hooks/group_forum_breadcrumb_d29bf565a59f776807044fd19e49258a.php on line 107

Addressing the OP's oringal question:Did you have an waypoint on UN873 as the last waypoint before putting UN873 in the "via" heading? The FMC needs to know where to start an end an airway. So you need to have a waypoint on the airway as the "to" waypoint. Then enter the airway in the "via" slot. Then enter the waypoint you'll exit in the next "to" entry.Addressing the OP's oringal question:Did you have an waypoint on UN873 as the last waypoint before putting UN873 in the "via" heading? The FMC needs to know where to start an end an airway. So you need to have a waypoint on the airway as the "to" waypoint. Then enter the airway in the "via" slot. Then enter the waypoint you'll exit in the next "to" entry.

That is wrong, in the RTE page, on the left side you can enter your airway, UN873, for example, before entering a waypoint.