The Pittsburgh International Airport was packed with travelers making their way home after the Thanksgiving holiday. Despite the busy skies, several people said the travel day was smooth sailing. The TSA said air travel on Sunday could break a record for the busiest single travel day ever with an estimated 2.9 million passengers flying home. In Pittsburgh, the line for security spilled out past the ropes at one point. If you plan on flying out on Monday, there could be some weather delays and cancellations. The TSA is urging travelers to check their flight status and arrive at the airport at least two hours early.