to do so in poor weather and with reduced visibility. During good weather, up to 150 planes an hour will be able to take off from the runway, according to the Federal Aviation Administration.

The impact will be felt far way, especially in smaller airports around the country whose regional jets to Chicago were the first flights to get delayed, hurting those airports’ attempts to offer reliable one-stop service to the other side of the country.

Aviation consultant Greg Principato said that while he was president of Airports Council International – North America, from 2005 until earlier this year, he heard repeatedly from small airport directors that the construction project at O’Hare was one of the most important issues for them.

“For a lot of those small communities it’s going tothe U.S. Department of Transportation.

That represents a slip of three places in the rankings over the same period a year earlier, when O’Hare’s on-time rate was 77 percent.

City aviation officials had to overcome numerous challenges to get to this midway point in the project.

For the new runway alone, they had to relocate a cemetery and its 1,500 graves, a section of railroad line, a waterway that had to be moved twice, two large cargo facilities and an aircraft fueling station.

The city has also had to negotiate hard with American and United, which are helping bankroll the expansion project. The airlines sued Chicago in 2011 to stop it from issuing bonds to finance the project, arguing that the city was violating a lease the gives them authority to review