Originally Posted by
clkc86
As we were sitting, the FA announced we had 3 minutes left to get everyone on. After about 4 minutes they shut the door. A significant number of people were left on the jet way!! They nearly cut one family in two! Really glad we cut the line. Does this sort of thing happen very frequently?
No, it does not happen frequently.
I don't know why this happened but can speculate that they were given a very short notice on a release time. If they couldn't make that time (wheels up) then they'd lose it and be back on an indefinite delay. The urgency to make that time may have been increased by crew that would time out relatively soon if the delay continued.
Again, I don't know what happened on that flight but those are the only reasons I can think of which would create the urgency to depart that you described.
The flow-control (aka ATC hold) system is not an exact science. They assign times based on what they know about the weather, traffic, and the affected airport's capacity but the times are frequently no more than best guesses as their based on the best guesses for what the weather will do. They are often amended either earlier and later.