O'HARE — Planes landed and took off as promised just 37 percent of time during the first full week of a test to rotate the O'Hare Airport runways used at night to give Northwest Side residents some relief from jet noise.
Data released by the Chicago Department of Aviation show that a series of severe summer storms July 10-17 prompted air traffic controllers and airport officials to direct planes away from the runways designated for use as part of the rotation plan, according to the data.
Assistant Commissioner Aaron Frame said it was "too soon to tell" based on the data whether the rotation plan would give residents of areas surrounding the airport a break from the roar that some contend has made it impossible for them to get an uninterrupted night of sleep since an east-west runway opened in 2013.
"We're definitely learning as we go," Frame said. "We are working with a number of stakeholders to ensure this plan is a success."
A six-month test of the weekly rotation plan started July 6.
Because storms can play havoc with the winds at O'Hare — forcing planes to change directions so they can land safely against the wind — planes can be directed to use a second set of runways as part of the rotation.
Between July 10-17, planes used the alternate runway configuration in the rotation 24 percent of the time.
That means the approximately 80 planes that land and take off at O'Hare every night followed the rotation 61 percent of the time July 10-17, according to the data.
During the first four days of the rotation — when the weather was far calmer — 82 percent of planes landed and took off from the first-choice runways in the rotation plan.
The voluntary restrictions on nighttime operations at O'Hare, known as Fly Quiet, encourage pilots and air traffic controllers to fly over expressways, industrial areas and forest preserves to reduce the noise over residential areas from 10 p.m.-7 a.m. each night.
From July 10-17, 74 percent of planes followed those guidelines, including those planes that took off and landed while the rotation was in effect, typically from midnight to 5:30 a.m.
The schedule of which runways set be in use at night is available online, so people will know what to expect, officials said.
The success of the rotation will also be judged by the results of online surveys that ask residents whether the plan is making a difference in their quality of life, officials said.
Chicago Aviation Commissioner Ginger Evans has touted the rotation plan as a "big breakthrough" in city officials' effort to reduce the jet noise that prompted more than 4 million complaints in 2015 and another 500,000 complaints since the beginning of 2016.
The results of the rotation plan are scheduled to be published each week in an effort to be as transparent as possible, Frame said.
But data on the runway rotation plan is not yet available for July 17-24.
The rotation includes a diagonal runway on the west side of the airport until 2019, when it is slated to be demolished as part of the final phase of the airport expansion.
City officials have steadfastly rejected pleas from members of the Fair Allocation in Runways Coalition to keep the runways in service at O'Hare as the only way to reduce jet noise over the Northwest Side.
Members of the coalition gave the first weeks of the rotation plan a mixed review.
In a letter to O'Hare Noise Compatibility Commission Chairwoman Arlene Juracek, coalition leader Helen Rosenberg wrote city officials that some members of the group "are getting relief for the first time in almost three years."
But Rosenberg told the aviation officials that the survey that will be used to judge the plan was lacking because the questions "do not accurately capture life on the ground, experienced by those who are supposed to benefit from the current Fly Quiet rotation."
"This survey could be much, much stronger if the [Chicago Department of Aviation] is genuinely sincere about collecting our real, lived experiences on the ground and making decisions that permanently improve the quality of our health and lives," Rosenberg wrote.
In her response to the coalition, Juracek said the group should have offered its feedback on the survey before the pilot program was implemented.
But group member Daniel Dwyer said the coalition's representative did offer input, but city officials chose not to include the group's suggestions.
After the pilot program ends Dec. 25, the O'Hare Noise Compatibility Commission and city aviation officials will decide whether to make the rotation permanent.
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