this movie simply doesn't work

I've probably seen it five times. For some reason I watch it too often.
The general movie is very alike to Panic Room, this movie feels like Panic Room expect it takes place in the air. The movie was also released after Panic Room and both star Jodie Foster in a similar plot, did I already mention it takes place in the air?
Panic Room and Flight Plan share a lot of story elements, even the name could be considered a imitation of their each.
Flight = Panic, Plan = Room
it's just too close I think. But thats not the point.

The movie feels totally like a late 90's psychological/crime thriller but it was made in 2005. Thats the problem. It is not able to jump over it's own shadow and taking some chances!
It's like wearing a thick coat of make-up, to the point of not being able to move your face anymore and showing some expression.

A girl gets abducted in a situation that simply suggest the pure impossibility of that happening. So you got a basic suspense scenario set up. What does the plot do next in this scenario? Is the woman completely crazy? How do you sustain the suspense of this scenario?
I have no idea! Because the possibility of either: It happened (child got abducted), or it did not happen (the woman is crazy) is not possibly to be extended to a deeper complex level in such circumstances.
I near expected a supernatural explanation to this whole movie.
But theres nothing supernatural about this movie. Maybe it should had have!

It's just a women in a plane and a child got abducted. No element in this movie does justify the situation to make it more believable than it is if it would really happen. Theres just no reason for this scenario.

I love watching this movie. But watching this movie is something a kin to watching paint dry. I get absolutely nothing out of it and eventually I loose interest. Panic Room on the other hand is extremely suspenseful and keeps me glued to the action happening the whole movie.

As you might have noticed: The attempt to describe this movie, why it lacks and what does not work, is about as describing as watching this movie is.