Atlanta's Hartsfield-Jackson International Airport remains the world's busiest, "but the mix of other airports near the top is changing," The Atlanta Journal-Constitution reports. Those "changes" include a drop by Chicago O'Hare, the airport that for many years vied with Atlanta for the "world's busiest" title. 

Fox 5 of Atlanta writes "boosted by a major expansion ahead of the 2008 Summer Olympic games, Beijing Capital International Airport leaped ahead of Chicago's O'Hare in total passenger traffic last year, Airports Council International announced Thursday." The Beijing airport reported a 16.8% jump in traffic for a total of 65.3 million during 2009. That helped it jump five places to the No. 3 spot, passing O'Hare, which reported an 8.8% decline in passengers for a total of 64.4 million in 2009.

Airport Check-in: Flier traffic falls at most U.S. airports

In fact, Chicago Public Radio notes O'Hare "tumbled two spots," dropping "to No. 4, among he world's busiest airports." London's Heathrow Airport also now rates ahead of O'Hare, moving up to become the world's second busiest airport in terms of passengers for 2009. 

"You know, it was a perfect storm for Chicago," Joe Schweiterman, a transportation expert with the Chaddick Institute for Metropolitan Development at DePaul University, says to Chicago Public Radio. "We have the weak U.S. Aviation market, and the fact that we're a two-hub operation at O'Hare ... And that led to a drop that's quite alarming," he adds.

O'Hare wasn't the only U.S. airport to tumble in the rankings. The Torrance Daily Breezereports "Los Angeles International Airport was ranked as the seventh-busiest airport in the world in 2009, dropping one spot from a year earlier." Like Chicago, Beijing was one of the airports to leapfrog LAX.

"I think it's an indication of the incredible growth in Asian tourism and the post-Olympic tourism that Beijing has enjoyed," Michael Molina, deputy executive director of external affairs at LAX, tells the Daily Breeze about Beijing's jump to No. 3 from No. 8. 

As for Chicago O'Hare, there was one silver line for it in the world airport rankings. Fox 5 notes "O'Hare still bests (Beijing) Capital by aircraft movements thanks to small regional jets and private planes."

Here's the complete top 10 list (by total passengers) for 2009, according to the Journal-Constitution: 1. Atlanta (87,993,451passengers; down 2.3%); 2. London Heathrow (66,037,578; down 1.5%); 3. Beijing Capital (65,329,851, up 16.8%); 4. Chicago O'Hare (64,397,891; down 8.8%); Tokyo Haneda (61,903,656; down 7.2%); Paris Charles de Gaulle (57,884,954; down 4.9%); Los Angeles (56,518,605; down 5.5%); 8. Dallas Fort/Worth (56,030,457; down 1.9%); Frankfurt (50,932,840; down 4.7%); and Denver (50,167,485; down 2.1%).  

1. Hartsfield-Jackson Atlanta International Airport - 90,039,280