CHICAGO – After conducting a six-month Fly Quiet Runway Rotation Test at O'Hare International Airport, the Chicago Department of Aviation (CDA) today released a report that shows 67 percent of the aircraft operations that occurred during Fly Quiet hours utilized the designated rotation runways, which provided relief to residents in communities most affected by aircraft noise.

The results of the test, which was designed to achieve a more balanced distribution of noise exposure for Chicago and suburban communities surrounding O’Hare during overnight hours, were presented at a meeting of the O’Hare Noise Compatibility Commission (ONCC) ad hoc Fly Quiet Committee.

“The CDA is committed to working with the Federal Aviation Administration, airlines and the ONCC to implement solutions that reduce the impact of jet noise at O’Hare International Airport,” said Ginger S. Evans, Commissioner. “The runway rotation test was the first of its kind ever initiated at a major airport. The feedback we received from residents, air traffic controllers, pilots and airfield crews during the runway rotation is critical to determining the next steps we take to reduce noise exposure for the communities most severely impacted.”

On average, the rotation test began at 11:16 p.m. and ended at 5:25 a.m. with an average of 65 operations occurring during that time. The number of operations and length of time spent using designated runways each evening were impacted by several factors including demand, weather conditions, runway safety inspections and routine maintenance, Federal Aviation Administration (FAA) flight checks and airline pilot requests to use certain runways.

The CDA received 6,160 surveys from 3,837 unique respondents from 84 different communities in the Chicagoland area.

The test period covered summer, fall and winter so that the impact of weather, seasonal conditions and construction schedules could be evaluated. The weekly schedule for the test utilized east-west parallel runways, as well as diagonal runways. Ten different runway configurations were utilized during the rotation test, balancing noise exposure and providing relief to communities most heavily impacted by nighttime noise. By comparison, only four designated runway configurations are utilized during the current Fly Quiet Program. The 25-week rotation schedule was successful in minimizing the impact to communities with the same operation type (arrival or departure) for two consecutive weeks.

The full report summarizes the results of the six-month test and includes information on the amount of time the rotation was utilized during overnight hours, runway configuration usage, runway utilization, public survey responses and other factors. It is available on the CDA’s website at www.flychicago.com/flyquiettest.

The rotation test was approved by the ONCC and the FAA in summer 2016 and was conducted between July 6, 2016 and December 25, 2016.

Based on the results from the six-month test, along with feedback received from residents, the FAA, airline pilots and airport operations personnel, the CDA has developed a second runway rotation test that would continue to balance nighttime noise and provide relief to the most impacted communities surrounding O’Hare. A second test would need to be approved by the FAA and ONCC before it could be implemented.