Given the rigorous security screenings we go through at the airport, it seems impossible that an unticketed traveler could slip through both a TSA checkpoint and boarding line to gain access onto a plane. But that's exactly what happened on a Christmas Eve flight, and caused a holiday travel headache for the dozens of passengers on board. According to ABC News , the incident occurred on a Delta Air Lines flight from Seattle to Honolulu on Dec. 24. The plane had been taxiing for...
