Preliminary Information Shows The Airplanes Came Within 125 Feet Vertical And 350 Feet Horizontal

The NTSB has issued its preliminary report in a near-collision between two Embraer regional jets operating in VFR conditions near Chicago's O'Hare International Airport on August 8th. The board ascribes the incident to "controller error" in its initial findings.

NTSB Identification: OPS11IA819A/B
(A)Scheduled 14 CFR Part 121: Air Carrier operation of CHAUTAUQUA AIRLINES INC
(B)Scheduled 14 CFR Part 121: Air Carrier operation of TRANS STATES AIRLINES INC
Incident occurred Monday, August 08, 2011 in Chicago, IL
Aircraft: EMBRAER (both) 
Injuries: Unavailable

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.

On Monday, August 8, 2011, at approximately 1100 central daylight time, an air traffic control operational error occurred at Chicago-O'Hare International Airport (ORD) when Chautauqua Airlines flight 5021 (CHQ5021), an Embraer 135 regional jet, and Trans States Airlines flight 3367 (LOF3367), an Embraer 145 regional jet, passed within 125 feet vertically and 350 feet laterally above runway 32L at the extended centerline of runway 9R. Both airplanes were operating under instrument flight rules at the time of the incident and were in contact with the Chicago O'Hare air traffic control tower.

ORD arrivals to runway 9R are controlled by the North Local controller, and departures from runway 32L are controlled by the Third Local controller. 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 flight paths for these two runways intersect over runway 32L. The conflict was detected by the Third Local controller when the Chautauqua ERJ-135 was approximately 1 mile from the threshold of runway 9R. He instructed the North Local controller to tell the Chautauqua flight to discontinue the landing and go around. The Third Local controller issued a traffic alert to the Trans States ERJ-145 just as the aircraft was lifting off from runway 32L, telling the crew to "traffic alert, left to right it's an American Eagle, stay as low as you can." The crew acknowledged the instruction, stating "Yeah, we're doing that," and resumed normal climb after crossing the runway 9R final approach course.

The Chautauqua ERJ-135 was on a regularly scheduled 14 Code of Federal Regulations (CFR) part 121 passenger flight operating from La Crosse, Wisconsin to Chicago, IL with 36 passengers and 3 crew members, and the Trans States ERJ-145 was on a regularly scheduled 14 CFR part 121 passenger flight operating from Chicago, IL to Moline, IL with 42 passengers and 3 crew members. The Chautauqua flight continued to LaCrosse without further incident, and the Trans States flight returned for landing at ORD. There were no reports of injuries or damage to either aircraft. Weather conditions at the time of the incident were ceiling 20,000 feet broken, visibility 10 statute miles.

FMI: www.ntsb.gov