Drawing up an overnight runway rotation plan at O'Hare International Airport is a thankless task at best, but it's proving to be an even knottier problem this time around with the absence of some key runways.
O'Hare Noise Compatibility Commission members could vote this month on a fourth rotation lasting from 2018 to fall 2020 that's intended to evenly spread jet noise around the region.
Available runways to use in the rotation are shrinking as Chicago intends to decommission a large diagonal runway (15/33) in 2018. And two smaller diagonal runways, 4-Left/22-Right and 4-Right/22-Left, will be closed for some months because of construction and repairs in 2018 and 2019, respectively, officials said at a ONCC Fly Quiet committee meeting Monday.
Another variable is how long the Federal Aviation Administration will take to conduct an environmental assessment of the fourth rotation if approved. The process involves public hearings and could last up to a year.
Residents in Elmhurst have pushed back against use of 4-Right/22-Left in the rotation, which kept them sleepless, while Des Plaines homeowners have objected to wake-up calls from planes using 4-Left/22-Right.
But with either of those runways out of the picture, it means more of a racket for Bensenville and Wood Dale residents as the airport shifts to putting aircraft on a pair of long, parallel runways (10-Center/28-Center and 10-Left/28-Right).
"We're a little concerned about that," Bensenville Village Manager Evan Summers said, adding he hoped construction schedules could be tweaked to speed up the work.
"It doesn't seem the right time to work on the 4/22s," FAIR Allocation for Runways member Al Rapp remarked.
Also Monday, planners released data from the third rotation test. Findings included the fact that the average rotation started at 11:10 p.m. and ended at 5:13 a.m.
For nighttime departures, the busiest runway was 10L/28R with 50 percent utilization, followed by 4R/22L with 16 percent. For night arrivals, most landings came to 10C/28C with 51 percent, followed by 4L/22R with 19 percent.
The Fly Quiet committee next meets Nov. 17. If members approve a rotation plan, it could go to a vote before the full board Dec. 1.
The fourth rotation would last until a new parallel runway is built on the north airfield in fall 2020.