Originally Posted by
buckeyefanflyer
I have been monitoring airine schedules for over 45 years, in the 1960's into the 1990's, for westbound and southbound flights, flight numbers were usually odd, and eastbound and northbound used even flight numbers. Classic exampes flight 1 and 2. Not sure why this was changed but it a usually a mix now.
Would be interesting to know how long it took to get to having four digit flight numbers. For example, did it start with no digits, and a flight name instead of a number? And I wonder if we will need five digit flight numbers someday...