someone on the plane got "chaotic", stewardess cannot help, pilot wanted to calm situation down, got taken as hostage, imho even small bomb like lighter may make hole into the windows then the pressure got down, pilot got treats if copilot will not let them in to kidnap the plane bomb will be activated, copilot instead of giving plane to hands of terrorists so they can target any bigger city, decided to get down and meanwhile emptied the wings from fuel to lower the damage on the ground ... if not like that, at least good plot for movie
r.i.p. at the first place anyway ...