The absence of a northwest diagonal runway from the lineup in O'Hare International Airport's latest overnight flight rotation is causing sleepless nights in some neighborhoods, residents said Friday.
Chicago's Aviation Department launched its third rotation test in late July without using diagonal Runway 15/33, which is slated to be decommissioned either March 29 or May 24, officials explained at a O'Hare Noise Compatibility Commission meeting.
The schedule includes parallel runways and two diagonal ones that weren't used heavily at night before and it's affecting towns such as Des Plaines and Elmhurst.
Landings on diagonal Runway 4-Right/22-Left are "really affecting my family in terms of disrupting our sleep over sustained periods of time," said Carol Snyder, who has two high-school-age kids and lives in north Elmhurst.
"I know we're expected to share in some of the pain but this is inequitable."
O'Hare shifted to a mainly east-west parallel runway system in 2013, which sent significant air traffic over Bensenville and Wood Dale and nearby communities.
The third rotation is no "panacea," Bensenville Village Manager Evan Summers said, because the village is still hard-hit by the jet cacophony. But, he said, it does provide predictability, which residents need.
"When Test 3 is closely followed, our residents can expect to have one week of nighttime noise and then some relief the following week," Summers said.
The runway rotation, which ends in mid-October, is intended to evenly distribute night jet noise over the region.
Planners will use data from the trial to formulate a 2½-year temporary rotation that would last until a final and sixth parallel runway opens in fall 2020 on the north airfield.
"It turns out without 15/33, it does appear to put a big burden on the 4/22s," Mount Prospect Mayor and ONCC Chairwoman Arlene Juracek said. "So part of the discussion is whether that 50/50 split between parallel and diagonal is really the way we want to go" for the temporary rotation.
"We're starting to get into some creative discussions, always with the idea of equity."
Meanwhile Elgin resident Ed Piotrowski, who lives 35 miles away from O'Hare, said he's suffering from an influx of jets. "They're making their turns right over my house," he told ONCC members.
The unexpected noise likely came from planes using the airport's most northerly runway in east flow conditions, officials said.
Also Friday, a draft Chicago Department of Aviation report on the second runway rotation from late April to mid-July indicated that on average, the rotation began at 11:32 p.m. and ended at 5:14 a.m.
Wind direction, storms, runway maintenance and pilots requesting longer runways can affect the scheduling, but 55 percent of aircraft used the designated rotation runways during the test, according to the draft.
The most-used runway for departures during the second test were 28-Right/10-Left and 15/33. For arrivals, the heaviest deployment was on Runways 28-Right/10-Left and 10-Center/28-Center.