So you don't have to, I went to see "Flightplan" this weekend. Here's a rundown of the film in all it's logic-hating glory --

The movie opens with Jodie Foster (or as the kids call her, JoFo) in a subway station with a stunned look like she probably had after realizing she agreed to star in Nell. She perks up when she sees her husband. The scene cuts to her at the morgue. The coroner walks out and tells her that when she's done to punch in her code on the casket (there's a little electronic keypad built into the front) and then call for him. Cutting back and forth between her and her husband going to their apartment, and her in front of the casket with her husband's body in it. In their apartment she asks him not to go upstairs. Considering that later on we find out he died by falling out of a window in their apartment, I think we're supposed to take these scenes as delusions. At the morgue, Jodie freezes up and the coroner comes in and explains by international law a casket can not be transported without it being secured with a code.

Then Jodie is in her daughter's room. It's night and a nightlight by the bed is shining hundreds of little airpline shapes throught the room. You see, because this movie takes place on an airplane. In film terms, this is referred to as nineshadowing. A bit of exposition about moving to New York (they're in Germany) and the girl goes to sleep. Jodie Foster walks to her daughter's bedroom window and sees two creepy guys in the apartment across the way studying for their final exam in Advanced Placement How To Look Suspicious. She turns to her daughter, then turns back, and they're gone.

At the airport they're looking at the super-duper double-decker jumbo jet they'll be flying on. The daughter asks if her mother built the plane. Jodie exposits that she built the engines that run the plane. They walk to get on the plane and the daughter asks if she can hold onto her ticket. Inside the plane they are the only ones inside. No crew, no other passengers. When the other passengers start tumbling in the daughter is sitting on the floor playing with a toy airplane, so none of the passengers see her. After everyone is loaded in, the daughter looks out the window to see cargo being loaded onto the plane, including her father's casket. So Jodie Foster leans over to try and confort her and further obscure her from other passengers. This is all like that episode of Fawlty Towers where the staff tries to hide Manuel's rat from the health inspector, only less plausible.

They've taken off and most of the passengers are asleep. JoFo tells her daughter that there are some empty rows in the back, and if she wants she can stretch out back there. JoFo then falls to sleep, dreaming of the new diamond studded Oscar-holder the salary from this movie will buy her.

Jodie Foster wakes up, and turns to see her daughter's seat is empty. No big deal, she gets up and goes back to the empty rows. Hmmm, not there. She starts checking the bathrooms, the kitchen, the stairs between the decks. This goes on for tens of minutes as she builds to a full-blown panic. Eventually she starts banging on the cockpit door demanding to see the captain. In a close-up we see a gun suddenly pointed at her head. We pull back to see the talkative passenger that was sitting next to her is holding it. It seems he's the flight marshal.

We cut to a scene with the whole crew, the air marshal, the captain, and our Ms. Foster. One of the stewardesses (who looks like a redheaded fish) explains that she did a head count and everyone's been accounted for, plus there's no such person in the passenger log. None of the crew claims to have seen the girl. Jodie spouts off all the different places on the plane she could be
Things the bad guys, when devising their brilliant plan, had to hope would go smoothly.
The mother lets the daughter hold the ticket (and assumedly the boarding pass) so that she can't produce it for the captain as proof of her daughter's existance.
The mother would be let on first so no one can see the daughter walking down the aisle.
The mother decides to go to sleep and is not spending the time thinking about her late husband, working on funeral arrangements, or catching up on the story line in "Uncanny X-Men"
The person who takes the daughter doesn't wake up either the daughter or mother in the process.
None of the other passengers is suspicious when a sleeping child passenger is carried out of her seat. Sure, they wouldn't be thinking kidnapping while they're several miles above the earth, but possibly attempted sexual assault.
The crew doesn't bat an eye when someone brings the little girl down into avionics. You know, the part of the plan that's keeping 400+ people from crashing into the Atlantic Ocean.
Not a single person remembering seeing the daughter. This includes: passengers who enjoy people-watching, passengers who are nervous getting on plane and look around to keep distracted, passengers who upon seeing cute little moppets ask a million questions ("How old is she?" "What's her name?"), passengers looking for a few hours sleep and assessing how many noisy kids are in their general vacinity.
Not a single crew member remembering the daughter. Yes, they see hundreds of passengers each flight, but kids tend to stand out as needing extra attention.
The captain not ordering the air marshal to handcuff the mother to her seat when she starts going crazy.
Allowing the mother to rile other passengers (including the Arab gentlemen) without getting knocked out for the remainder of the flight or getting her neck broken.
The mother being of sound enough mind to devise a plan to get into the luggage hold and being able to do so without drawing the attention of any of the crew.
When the mother searches avionics that she won't look down to see her daughter lying there in relatively plain sight.
The mother being able to scrounge around the luggage hold without killing herself in the process.
The mother deicding to check the casket for her daughter even though only she knows the code and on top of that it's been strapped tight.
The mother having the presence of mind to remember the code for the casket.
The mother not immediately closing the casket when she sees her dead husband.
The air marshal getting there before she closes the casket.
The mother not going berserk like Ralphie from "A Christmas Story" when the air marshal has the gun on her, thus preventing her from looking for her daughter further.
The captain buying into the ludicrous story the marhsal gave that the mother is actually a hijacker and this was all a clever ruse to scare the passengers. Also that the only person she'll talk to is the air marshal.
Nobody in the crew deciding to play hero and take the mother out when it was clear she wasn't holding any detonator.
That as the crew passes by her to disembark that she doesn't say anything to jeopardize this awesome plan.
And even when she DID say something to the captain talking about her missing child, that he's too much of a lunkhead to think, "Wow, even Fermat couldn't get all of this to add up."
That the FBI, BlackOps, or whomever doesn't see the air marshal through a telescopic lens holding the detonator and sending a "they don't pay us to miss" shot straight through his cranium.