I liked it!
Of course scary airplane movies are a favorite of mine, but I thought it was really good! It totally kept my attention the whole way through. I love Lacey Chabert and thought her acting was superb....and the plot actually made sense and created a worthwhile mystery.
I could've done without the rude flight attendant, who was played way over the top, but other than her, good cast and good story....and good ending!!