Originally Posted by BRJPilot

Rarely an FMS issue. Instead, it's another issue with poor training. Both on the dispatcher and pilot side. They simply don't know how to calculate fuel burns accurately. Instead of just a divert fuel number they have one for divert and "final" divert? Why? Because as the story was told, they had people on final, two miles from touching down, getting to divert fuel and diverting to an alternate many miles away. Seems ridiculous, but that's what they were taught. The final divert number is 600 lbs heavier than divert. That 600 lbs makes a big difference on a small jet like the 145. It's part of the reason why C5 flights are so weight restricted. I flew this jet for many years, LR model included, and never had issues with overweight landings like we do now.