US Air Transport Assn. warned of crowding at airports over the 12-day period starting Nov. 16 and ending Nov. 27 as an average of 2.3 million passengers fly daily during the country's Thanksgiving holiday period, up 4% over last year.

"Two things most concern us," ATA President and CEO James May said. "Number one, the weather, and number two, the capacity of the airspace ... We are all of us somewhat at the mercy of the weather." He added that "senior-level" airline executives would be "directly in touch" with FAA "more frequently" via conference calls than in past years. "We want to make sure really heavy-hitting decision-makers are involved" in the calls so that carriers can respond quickly to delays and other issues, he told reporters in Washington on Nov. 12.

May said FAA has promised to implement "operational improvements" at the crowded New York airports, including giving carriers the ability to perform "dual runway operations" that will increase system capacity, in time for the holiday rush. But he warned that security checkpoint lines will be "longer" and noted that "rookie travelers" who don't ordinarily fly likely will slow throughput.

He projected load factors of "roughly 90%" during the period, up 10 points from the already-high average of 80% through the first three quarters of 2007. "At 90% load factors, there's very little room for error," he said, noting that airlines will have minimal flexibility if weather forces flight cancellations.

He encouraged passengers to arrive at airports 2 hr. early for domestic flights and 3 hr. early for international flights. His advice to passengers: "If you always expect the worst and you don't have the worst, then you'll be in a little more positive frame of mind."