Give American Airlines credit for trying a new method to board passengers more quickly. Airlines constantly tinker with the boarding process, and this time American says it has found a way to cut an average of two minutes from the 40 minutes to 45 minutes that it takes to board a narrowbody aircraft. American narrow bodies take off about 3,000 times a day, so two minutes per flight is a lot of time….

Aviation consultant Robert Mann said that when airlines change the boarding process, they frequently encounter a “Whac-A-Mole” syndrome, where pressing the mole down in one place means it shows up someplace else — in other words, the law of unintended consequences. For instance, Mann said, the new American policy could “create a lot of gate-level game playing behavior where, if you shed your bag, you go ahead of other people, which makes the zone number on your boarding pass irrelevant and also cuts down on their baggage fee collection.”