Groups of passengers wait at a United Airlines gate to board a flight in separate numbered lanes at O'Hare International Airport in Chicago. For airlines, every minute that a plane sits at the gate makes it more likely that the flight will be late, hurting the carrier's on-time rating and causing passengers to miss connecting flights. But the perfect boarding process remains elusive. Even an astrophysicist couldn't figure it out.
Photo by Associated Press .
published Thursday, August 1st, 2013