How to calculate weights in 787

[Hyper14 4]

Hi, I'm kind new to the 787 and I have some questions regarding the weight and balance configuration. I usually import my data from simbrief, but I noticed that only changes the info in the FMC, not the actual payload. So I look at the numbers in simbrief and I set them in the weight and balance tab. Even If I have the tanks full or the weights exactly like I should, I always get an insufficient fuel message. Any idea what I should do, or any tutorial that can help?

Edited October 29, 2023 by Hyper14

[YMMB 234]

Not sure if this helps however some things that if answered could guide others with more knowledge...

In Simbrief have you chosen the appropriate model of 787 before generating the flight plan, ie 787-10,9, 8.

Were there unusually high head winds that could bring up a fuel warning pre-flight?

If you did go ahead and complete the flight ignoring the initial fuel warning was there sufficient fuel to make it?

[MattNischan 3,870]

10 hours ago, Hyper14 said:

but I noticed that only changes the info in the FMC, not the actual payload.

It does actually update the payload, however, there is a sim bug with the weight and balance panel where if the payload is updated outside that panel, it isn't reflected in the panel itself.

[Hyper14 4]

7 hours ago, YMMB said:

Not sure if this helps however some things that if answered could guide others with more knowledge...

In Simbrief have you chosen the appropriate model of 787 before generating the flight plan, ie 787-10,9, 8.

Were there unusually high head winds that could bring up a fuel warning pre-flight?

If you did go ahead and complete the flight ignoring the initial fuel warning was there sufficient fuel to make it?

Yes, I selected the model I was using( I used the default 787 and the horizon sim 787-9) and I completed the flight with a bit a fuel left( maybe enough for some go-arounds) 

[Hyper14 4]

2 hours ago, MattNischan said:

It does actually update the payload, however, there is a sim bug with the weight and balance panel where if the payload is updated outside that panel, it isn't reflected in the panel itself.

Ohh, so the fuel quantity actually changes but I just doesn't show on the panel? So I could just import the weights and not modify the weights and balance panel and I would be fine?

[Fiorentoni 4,381]

2 hours ago, Hyper14 said:

Ohh, so the fuel quantity actually changes but I just doesn't show on the panel? So I could just import the weights and not modify the weights and balance panel and I would be fine?

Yes. You can see that the fuel changes on the MFD screen. Fuel is sensed and not taken from the FMC, so if that changes, you know the actual w&b did update.