Originally Posted by
Stripe
After you have flown enough you will find that airlines can indeed do just that, and they do it fairly regularly. If you book a trip more than 2-3 months ahead it would be unusual to not have any intervening schedule change. Thankfully, AA is better about this than DL.
They do indeed (particularly US airlines, which seem to update their schedules very regularly as opposed to European ones which seem to do it mostly 2-3 times a year). One of my AA itineraries booked in June for travel in January with 9 segments has already experienced over a dozen schedule changes, some back and forth!!
