Since I rarely go to the movies now and then I have to choose carefully. Flight Plan looked really good and CNN gave it a nice review. But to save you some money, it wasn't worth the ticket. There were a ton of flaws and the movie just seemed stupid after a while.
SPOILERS
At first I thought, well this sucks, the preview already told me that her daughter is really dead and Pratt is just psycho over it. The entire plane is searched and this roller coaster nice/**** air marshall accompanies her all over the place. Pratt accuses some Arab men on board of kidnapping her daughter because she saw them across her apartment looking into their house the previous night. As it turns out, this has *absolutely nothing* to do with the film at all, except to be some random thing thrown in.
I found it retarded that two individuals, one a reluctant girlfriend accomplice, would pull off something like that. Another flaw in the whole "no one saw her with her daughter so her daughter must be dead" bit is that she was the first on the plane because she had a kid with her. Seriously, don't bother.