An increase in flights this year has helped O'Hare International Airport narrow the gap with archrival Atlanta for the title "world's busiest airport,'' and air traffic controllers in Chicago predict O'Hare will soon retake the top spot with help from a new runway opening this fall.
Hartsfield-Jackson Atlanta International Airport wrestled the top honor away from O'Hare in 2005 and has retained it since, according to the official flight count by the Federal Aviation Administration.
O'Hare previously had bragging rights to the title since the dawn of the Jet Age, when it surpassed the number of flights at Midway Airport, which had been the leader.
In the first six months of 2013, Atlanta handled 453,800 takeoffs and landings, while O'Hare accommodated 426,800 flights, a preliminary FAA tally shows.
Atlanta also is No. 1 for total passengers. A preliminary passenger count for the first half of 2013 is not yet available. But in 2012, the top airports for total passengers, behind Atlanta, were (in order) Beijing Capital International Airport, London Heathrow Airport, Tokyo International Airport and O'Hare, according to Airports Council International.
Despite a 27,000-flight cushion for Atlanta over O'Hare in the first half of this year, an increasing volume of flights at O'Hare over the last two months is trending to make it a horse race.
In May and June, Atlanta had a total of 157,000 flights to O'Hare's 154,200, for a difference of 2,800 flights over the two months.
"Hopefully, recent growth at O'Hare can be sustained," said Tony Molinaro, FAA spokesman in Chicago. "The other good news is that we have a new runway coming on line that will truly help the operation during poor weather. The runway is coming at the right time, and the tower can't wait to use it."
In 2012, 930,098 flights operated at Atlanta, versus 878,108 at O'Hare, FAA statistics show. The other airports in the top five worldwide for total flights were (in order) Dallas-Fort Worth International, Denver International and Los Angeles International, according to Airports Council International.
Among the nation's 29 busiest airports this year through May, O'Hare had the second-worst on-time performance for arriving flights, with 3 out of 10 flights parking at the gate late. Atlanta posted the sixth-best on-time rate, with 84 percent of arrivals on time, according to the U.S. Bureau of Transportation Statistics.
O'Hare's capacity to handle more flights will increase starting in mid-October when the new runway opens.
Asked whether he was going to repost a sign that says "world's busiest" on the door to the air traffic tower cab at O'Hare, Bob Flynn, the FAA's tower manager at the airport, said: "It's already on the door, don't worry."
Chicago's goal is to grow the number of O'Hare flights, while also reducing delays that make O'Hare unpopular among some fliers.
The runway expansion plan, when completed, would feature six parallel runways in an east-west layout and two crosswind runways, lining up northeast to southwest. The format replaces a pattern of intersecting runways.
Atlanta, which opened its fifth runway in 2006, has no plans pending for more runways, the FAA said.
The O'Hare runway set to open Oct. 17, called 10 Center/28 Center, will serve as an arrival runway and enable O'Hare controllers to use three arrival runways, instead of two, in reduced visibility, according to the FAA.
The extra capacity will help cut delays in bad weather, FAA officials said.
The runway opening will bring an increase in airplane noise over some suburbs and areas of Chicago, the Tribune reported in April. Areas to the north and south of the airport are expected to experience less noise, while areas to the east and west are expected to experience more.
The city has a funding commitment from the airlines to build one more runway after that, on the far south end of the airfield on land that Chicago acquired from Bensenville. The runway, 10 Right/28 Left, is scheduled to open in late 2015, according to the Chicago Department of Aviation.
No agreement has been reached on the city's plan to build a final runway north of the passenger terminals, nor to lengthen an existing runway and make related taxiway improvements.