Other mistake: In the scene where they are 1st landing at Bangor it is known that there is no electricity at the airport. If you look closely during the landing you will see that the runway lights are on. (00:50:40)
Factual error: When initially investigating the missing people and the condition of the airplane, Brian looks at a screen that gives the airplane's transponder code (or "squawk") as 7777. An airliner would never be squawking that code, since this particular code is reserved for military interceptor operations.