The question is.....do all airlines use a different system of numbering their flights or are they all kind of on the same type of system. I have noticed on more than one airline that real low number flights are usually international or longer range - the higher the number the shorter???
Like NW has flights like 65, (or two digit #) which go from DTW to places in Japan or Amsterdam.....while 4-digit # are many times Dc9 flights of fairly short distance (MEM-ATL, MEM-GPT, etc), and 3-digit (like flights# 535, 995, etc) are medium-length like DTW-MIA
Didn't United have a flight #1 which was super long - like LAX to Australia or somewhere like that? And Delta uses # 3000 and up I think for their commuter flights which are usually short.