Because Simbrief’s default airframes are in the end not that realistic and evidently haven’t been set up properly. That’s why basically every third-party flight sim aircraft maker (for PC sims) creates custom airframes.
E.g. for ETOPS - it has every aircraft set to 60 minutes. Which is false beyond any recognition.
In Simbrief, what does it give for the number of passengers and cargo? Did you actually input values for them?
Another possibility is something went wrong when I shared it - here’s the link again: SimBrief - Dispatch
It’s because it cares about reserves and stuff. Not only is fuel burn generally less in IF, but you also don’t need to care about that in 99% of cases.
16 hours is no problem as long as you’re not picking ridiculous speeds.
Same issue there’s something wrong somewhere I guess
Actually Qatar airlines seems to use 200lr for this route which is QR920 callsign and single flight. Based on flight aware link I’ve shared if you care to notice it
I got this bug where you can’t import if it gets ridiculously long flights where it gives you invalid dates. Still not resolved btw Unable to import FPL when Simbrief shows Invalid date
have you used the kml file thing from flight radar there seems to be way too many waypoints?
yeah too many waypoints, can’t exceed 200 or 250 i think. Also genreally just really complicated, hope it gets resolved tho
Yeah I remember hearing they were switching back to the 777-200LR for the Northern Summer.
Guys have you ever tried the B77W EGLL to YSSY? That flight would be around 19 hour flight and I’ve already tried it
Well here’s the thing irl they don’t use random waypoint fixes but mostly connect through standard airways and named intersections unless they deviate from their flight plan using off route waypoints. it could be little tricky to figure it out but mapping them visually helps me quite a bit. Here you can see those airways connecting over black sea.
In your case load the kml file to simbrief and map them visually with airways and waypoints enabled so you should be able to figure it out more accurately.
This worked before 
I’m sure it’ll work fine I’m just not sure wy it stoppde working after 25.1 since this would be a lot of work for a flightplan with well over 500 waypoints
You don’t have to enter the waypoints just connect the fixes maybe I can do it for you? You can dm me the kml file and I’ll figure it out?
It’s easier than you think
Yeahh I know ow to do it, but the bug is just kinda annoying, thanks for the offer though
