Grumpy Old Geeks Topics Flight numbers Topic Flight numbers 3 mentions in 1 episode The hosts discuss how airlines assign numbers to flights and return routes. Mentions 197: Last Night in Sweden Feb 20, 2017 1:03:13 What does your flight number mean? 1:03:30 Flights going eastbound or north are assigned even numbers. 1:03:46 Return flights between destinations are often assigned numbers that is one higher or lower.