United Airlines has begun operations with its new Bombardier CRJ 550 regional aircraft in Des Moines, offering more legroom and a separate first-class area in a 50-passenger plane. United was scheduled to begin using the planes Sunday, making Des Moines one of its first markets. The plane also has enough luggage room for every passenger to bring a roller-bag to the cabin. A self-service snack service will be available for United First passengers. United flights include service to hubs in Denver and Chicago.