On top of that, most airline traffic at National is domestic, with few people changing planes.
Total airline traffic had risen 72 per cent over the last decade.
Commercial airline traffic was not expected to resume until Thursday.
The relationship between economic growth and airline traffic is also changing.
But she is already concerned about the outlook for airline traffic in the holiday season.
In the days following September 11th, all commercial and private airline traffic was grounded.
The company has entered a period when airline traffic is low and cash might be in short supply.
Seventy percent of airline traffic now goes through 31 airports.
Almost all commercial airline traffic from the United States remained cut off.
Year-to-date airline traffic is 5.9 percent above the same period last year.