WHERE DO flight numbers come from? Do they hold some hidden meaning?
Yes and no. Ordinarily, flights going eastbound are assigned even numbers; those headed westbound get odd numbers. Another habit is giving lower, one- or two-digit numbers to more prestigious, long-distance routes. If there’s a flight 1 in an airline’s timetable, it’s the stuff of London–New York.
Numbers might also be grouped geographically. At United, transpacific flights use three-digit numbers beginning with 8, which is considered a lucky number in some Asian cultures. Four-digit sequences starting with a 3 or higher are, most of the time, indications of a code-share flight.
The Secret Lives of Flight Numbers.: