The Federal Aviation Administration said to be prepared for delays this week it will mark one of the busiest periods in history for the nation's airports.The FAA said it projects over 50,000 flights will take off on Tuesday, marking the busiest day during the seven-day holiday travel period. Over 49,000 flights are projected to take off on Wednesday and Sunday this week.Thanksgiving Day itself is expected to be the least busy day this week, with almost 26,000 flights in the air.Volume is the second-leading cause of flight days in the United States, only trailing weather, the FAA said. As of Nov. 17, 16.1% of flight delays in the U.S. were caused by volume. With high traffic volumes and not enough air traffic control employees, the FAA will have to implement measures that could delay some flights from taking off.RELATED STORY | Forget about Black Friday; plumbers are getting ready for Brown FridayFAA administrator Michael Whitaker said it would be implementing Traffic Flow Management where air traffic is most crowded. He added that staffing shortages would continue through the Thanksgiving holiday, but the FAA is "working diligently to make sure these initiatives can operate as efficiently as possible."The weather could be a cause for delays for those flying through Salt Lake City, which is a major Delta Air Lines hub. The area is under a winter storm warning on Tuesday."Our thousands of air traffic professionals are ready for the increased volume this week and through the holiday season," said Whitaker. "We're closely watching the weather, which is, of course, the biggest source of delays, and we'll do our best to work around that. Our Command Center in Virginia has real-time engagement with all of the airlines to find the most efficient, safe path around weather as it occurs."RELATED STORY | Transportation officials expecting busiest holiday travel season yetThe Transportation Security Administration expects to screen over 18 million passengers this week. Sunday is projected to have the largest number of passengers with the agency expecting to conduct over 3 million screenings. Sunday could approach a record for the nation's airports, as TSA exceeded 3 million screenings in a single day for the first time on July 7.