Aviation accidents and incidents, particularly civilian airplane crashes or incidents threatening a crash or requiring an emergency landing, are a common theme in fiction. Films centered on such incidents make up a substantial subset of the disaster film genre, and influence how other stories within the genre are told. Works in this genre encompass both fictional depictions of the incidents themselves, and depictions of consequences such as investigations, lawsuits, and the effect on the lives of persons involved. A subgenre, the "plane crash survival movie", involves characters placed in a dangerous environment by an initial airplane crash. Airplane crashes have been described as "the easy and obvious device" for dramatically incorporating an airplane into the plot of a film, and as "a Ho