Not really a 1 minute turn. Sure, it is 1 minute from the scheduled boarding time, but in reality those planes don't need more than 10 minutes to board. I fly out of MHK and it seems like most flights have a scheduled 30-35 minutes between plan arrival and the next one leaving. If the arriving plane is anywhere close to on time, the departure is on time. American knows the true time it takes to turn and is willing to schedule the flights like that. They don't want to publish a later boarding time because they don't want the passengers to cut it too close and of course there is a decent chance that the plane arrives 10 minutes early and they can start boarding 30 minutes ahead.