I created a flight in Simbrief from LAX to ORD and loaded it into the aircraft via the MSFS Load flight plan functionality. Entered the Departure, Arrival and Approach info. In looking at the STAR and Approach phases in the FMC the altitudes and speeds at the various waypoints do not make sense. Drop to 2000 ft 35 miles out, then you have to be above 4000 15 miles out. Speeds are all 240 right up to approach. Anyone else having issues like this and if so any clues on what is going on here. I’ve had a couple of flights where I’ve had to manually adjust altitude and speeds to simulate a normal arrival and approach as the FMS is not calculating things correctly.
I’ve noticed VNAV seems to be flakey at calculating TOD especially on the STAR. ATC always descends me ahead of TOD marker which always seems too late. The pmdg 737 (comaprable boeing FMC etc) does a superior job of VNAV. The 787 only ever seems to be on the VNAV PATH on approach, which is kind of too late for meaningful VNAV PATH descents. It spends most of it’s life on VNAV SPD. It does seem to adhere to constraints though. I must go scrutinise the flightplan more next time.
Yep. I’ve had a few flights with issues, and I think a few that were OK. Hope they can sort this out. Hopefully they are aware of this - seems like a glaring issue and I don’t feel like spending 30 minutes with ZenDesk or whatever. I agree that the PMDG 737 VNAV is very good. My flight was into KORD 10C.
KLAX/24L N0484F390 ORCKA5 LAS J146 DVC DCT HBU/N0483F410 J146 GLD DCT PWE DCT IRK BENKY6 KORD/10C
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IMHO SimBrief is not always correct. The routing SimBrief has given you is strange. The STAR route exit is in the opposite direction of the ILS approach entry. This means the aircraft flies by KORD outbound, turns around, flies back over KORD to the ILS entry, and then turns around again to enter to ILS. Try calculating the TOD with all these turns! This even looks strange to me on the SimBrief pdf map.
This route is imported and loaded into the 787 FMC as-is. And the autopilot will fly the aircraft as directed.
To “fix” this route, in the FMC I deleted the STAR, added waypoint BYLAW after RYELY, and deleted the discontinuity. The TOD was recalculated to descend from 37,000 ft to 9,000 over 96 nm which seems about right.
I always compare the SID, STAR, and approach charts to the flight plan. Does everything make sense? Would I plan the route differently?
I have no idea WHY SimBrief chose the routing it gave you. I think SimBrief (and SkyVector) use a different flight planning algorithm not used by other flight planners. It chooses the most recent routes flown IRL between the departure and destination. These routes would reflect any weather or ATC traffic flow routing which may not be the optimal time or distance. The various flight planners are good tools for creating routes but they always should be checked using the actual charts.
Both in MSFS and IRL the ATC climb/descent instructions often do not match the calculated VNAV path. In general, the pilot has to decide to fly according to ATC instructions or to VNAV although the climb/descent speeds are used for fuel economy and engine efficiency.
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Hey thanks for this information. Usually, but now always, I use Plan mode on the FMC to check the routing at least for discos and totally weird routing like U-turns. I did not do that this time. Looking at the FMC at arrival things did look screwy from then on, but I kept on trying to deal with it. My experience is that SB is pretty reliable, which is why I’ve gotten a little lazy. Or when I’m in a hurry chasing ATC which was the case for this one. But a good lesson that it’s not 100%. I guess if I’m willing to deal with a situation mid-flight, or just shut down I could continue to do that, but since I am part of a virtual airline, I should follow protocol.
Yes - on occasion ATC does not follow my my VNAV path - and I can usually accommodate that. (be easier with a copilot through :)).
Thanks for your help! I was thinking that I would switch over to the Kuro 788 to see if that was better, but I probably don’t have to do that. I did install it so I’ll play with it a bit, but not expecting miracles when the flight plan is crazy.
Thanks again - very good explanation and thanks for taking the time to load up my FP and check it out.
Looks like your system is identical to mine except I have the RTX 3080 Ti.
Thx! Your comment reminded me to update my profile with my new GPU.
MSFS flight planning has had a number of bugs and fixes over the years but there is more left to do. For example, I recreated your flight plan in SimBrief and imported it into MSFS World Map. The flight map looked identical to the SimBrief map except for some reason, the destination approach didn’t load. I had to manually add it. I changed the SID and STAR to “direct” and then changed them back to what they were. The World Map “cut” the STAR in half to have a direct route to the approach without all the turns. When I started the flight, the FMC imported the flight plan without the World Map changes. (Bug ???) After updating the FMC to reflect the World Map changes I checked the inflight NAVLOG and the VFR Map. The VFR Map correctly showed the updated flight plan. However, the NAVLOG still showed the old flight plan. (Bug ???) What flight plan would be used by MSFS ATC? I discovered that ATC used my updated flight plan from the FMC as shown on the VFR Map. (!!!) I’ll try this flight plan again after the next update to see if there are any improvements.
So I read somewhere in the 787 WT documentation that you save the SB flight plan without SIDS or STARS using the SB downloader. Then load that into World Map, then add those back into the FMC. That’s what I’ve been doing and it’s worked well, with a few exceptions which were likely SB issues as you pointed out.
I use Navigraph and Avilisoft EFB for flight following, and don’t use the MSFS map or log stuff at all.
I use Simbrief to plan flights and also in-game ATC. My issue arises when ATC requests a descent; I have to use the flight change button. However, the speed doesn’t automatically adjust based on the Simbrief route. Is there a way to manually change my altitude via autopilot and then return to VNAV with speed automatically controlled?
Hi,
Just replying to this post to let the writers know that things are not any better with SimBrief in MSFS 2024 especially with the 787.
There are now multiple models of the plane available.
Here is my write up of this issue if you want to file with me a formal bug report: