I'm sorry to say that this film highlights the problem with trying to recount "true" stories on the screen.
Whilst the events of that tragic day need to be told, I'm not sure that this film does the passengers and crew of that flight any service at all.
The following comments about this film may appear controversial, but please remember I am comment in the FILM and not the people involved in the real events.
The film itself is little more than a montage of people making phone calls to say goodbye to people. The terrorists who hijacked the plane appeared unconvincing and didn't seem to make much of an attempt to stop the passengers from calling people and getting themselves organised.
The plane is hijacked quite early in the film and even after the passengers decide that they must act they spent another half hour making calls, you can't help but think that if they had organised themselves earlier that they might have had more success retaking the plane.
The passengers never really seem to be in direct personal jeopardy, particularly with odds of about 1:10 (including the terrorist flying the plane) and yet they seem too paralysed with fear to do anything. If this was a fictional story, then Stephen Segal would kick everyones ass and all would end happily ever after! This is the problem with true stories, they are rarely really as dramatic as they sound in real life.
They spend more time debating what to do than actually doing anything! Please remember that this was a dramatisation about events that we don't really know about. The director necessarily had to use some artistic licence in making this film and yet could have used more to establish a bit more tension.
In all, a disappointing film where nothing really happens.