Two Embraer regional jets under air traffic control guidance came close to colliding at the Chicago O'Hare international airport on 8 August in clear weather, an incident that appears very similar to a near-collision in the same location on 16 May.
According to the US National Transportation Safety Board (NTSB) preliminary report issued on 25 August, Chautauqua airlines Flight 5021, an Embraer ERJ-135 with 36 passengers and 3 crew, passed within 38m (125ft) vertically and 106m laterally of Trans States airlines Flight 3367, an ERJ-145 with 42 passengers and three crew, above runway 32L at 1100 local time that day.
"The Chautauqua ERJ-135 was on final approach to land on runway 9R when the Trans States ERJ-145 was cleared for takeoff from runway 32L," the NTSB said, adding that the flight paths for the two runways intersect over runway 32L.
Investigators say the local controller working the Trans States flight detected the conflict when the Chautauqua aircraft was approximately 1mi from the threshold of runway 9R. He instructed the local controller handling the Chautauqua arrival to "discontinue the landing and go around" and radioed the departing Trans States aircraft, which had just lifted off, "traffic alert, left to right, stay as low as you can," according to the report.
There were no injuries to the passengers or crew on either aircraft, and the Trans States flight continued on to its destination of Moline, Illinois.
The incident bears a striking resemblance to a near-miss in clear weather between a SkyWest CRJ200 and an ExpressJet ERJ-145 over runway 32R at O'Hare on the morning of 16 May.
In that incident, the NTSB says SkyWest flight 6958 was landing on runway 9R as ExpressJet flight 6075 was departing runway 32L. "The aircraft came within approximately 480ft [146m] laterally and 275ft [84m] vertically of each other while over runway 32L," says the NTSB.