United cabin crew are in line for significant increases in hourly pay under a tentative five-year agreement that includes half-pay during boarding.

Starting Tuesday, travelers who fail to follow the new policy could be denied the option to check their bags or be forced to miss their flight.

With check-in chicken, travelers will intentionally delay their online check-in to the last minute in hopes of a better seat. The method relies on the fact that airlines will often charge extra for better seats, split up groups and initially assign fewer desirable seats.