Many numbers are considered lucky, unlucky, superstitious, or somehow unique. It varies regionally, religiously, culturally, historically, or by country. Some numbers are directly associated with a particular event that resonates positively or negatively. Fortunately, I am not superstitious, which is just as well: I was born on Friday the 13th. What about 666—the so-called ‘number of the beast’—on US flights?