Before takeoff I set my departure and arrival info into the fmc per simbrief flight plan. During the flight BATC changes the landing runway. When I enter the new info into the FMC it adds it to the bottom of the existing flight plan and now I'm going all over the place. Should I wait to load arrival info in the FMC until BATC tells me what runway ? Thanks for any help

BATC will tell you arrival procedure before top of descend. That when you enter it to FMC

In the PMDG I usually leave the arrival and approach unset until the runway picture is more settled, then load the STAR/approach when ATC gives me something usable. If you preload one runway and BATC changes it later, the cleaner fix is normally to replace the arrival from the DEP/ARR pages rather than just appending bits to the route. If it starts building a mess anyway, I just clear the bad legs and reselect the arrival instead of trying to salvage the whole sequence.

2 hours ago, bmarcoux2 said:

Before takeoff I set my departure and arrival info into the fmc per simbrief flight plan. During the flight BATC changes the landing runway. When I enter the new info into the FMC it adds it to the bottom of the existing flight plan and now I'm going all over the place. Should I wait to load arrival info in the FMC until BATC tells me what runway ? Thanks for any help

In real-world operations, and similarly when using SimBrief, the FMC is typically loaded directly from the flight plan, and in 99% of cases no changes are required. As @sd_flyer  correctly pointed out, ATC may assign a different STAR, transition, or runway if conditions change from what was originally filed.

I’m not familiar enough with BATC to comment on its specific behavior. In real operations, however, crews usually receive the digital ATIS prior to top of descent, giving them a good indication of the active runway, expected STAR, and transition. In MSFS 2020/2024, that level of advance information is often unavailable, so last-minute changes should be expected.

If the filed procedure changes and ATC provides the updated clearance in a timely manner, there is generally sufficient time to reprogram the FMC without issue. In some cases, the update requires only a few keystrokes; in others, it may involve a more extensive reconfiguration and briefing.

If you feel rushed, or if a significant change requires additional setup time, request delay vectors from ATC until you are fully prepared. That is standard real-world practice. The key is never to rush or become task-saturated. Remember, you are the pilot in command, and ATC is there to work with you—not against you.

Edited May 8May 8 by LRBS