As you see in the pic, the PMDG 737 has problems to keep the course so it flies parallel to the course. Why?
My best guess would be an incorrect starting position entered in the FMC.
You could also have an offset entered in the INIT REF / INDEX page in the FMC
The IRS was wrong? Sure it it possible but that would have been the first time with the 737. At the end of the flight (to KORD) the course was corrected and exactly as it should be.
The IRS wouldn’t have been wrong, but the initial position that was entered may have been.
During the flight, it would have updated it’s internal position constantly, which may explain why it was only noticeable at the start.
Without a lot more information it is impossible to assist. Exactly how did you get into this position? After the last waypoint?
Mathijs Kok
PMDG
I think something is being overlooked here. What is that map from? It very likely is not a problem with the plane but with how the map program is plotting its position. I have seen that before with a different moving map program. The navigation display in the 737 showed me dead on course but there was an offset in the map program.
That is the stock map, available off the in sim toolbar.
It is the map of MSFS 2020. The official map.
I dont know when it exactly starts. It happened slowly it seems. And then the 737 flew parallel to the course and later it corrected the course and it flew right following the course. This happen btw rarely but sometimes it happen.
We have no reports similar to this in our support system at this moment, so I really would not know what to say.
Mathijs Kok
PMDG
Is the sid shown in the VfR map? If not you have different starting points and you would fly in parallel until you reach a waypoint that is shown in the VFR map. Also are the Route the same in the FMC and Worldmap