Event OPS11IA819

Factual narrative

On Monday, August 8, at approximately 1100 central daylight time, a near mid air collision (NMAC) occurred at Chicago O’Hare International Airport (ORD) when Chautauqua Airlines flight 5021 (CHQ5021), an ERJ-135 regional jet en route from La Crosse, Wisconsin to ORD, passed in close proximity to Trans State Airlines (LOF3367), an Embraer 145 departing ORD for Moline, IL. Both aircraft were on regularly scheduled 14 Code of Federal Regulations Part 121 passenger flights and under control of ORD airport traffic control tower (ATCT) at the time of the incident. There was no damage reported to either aircraft, or any injuries to passengers or crew. At approximately 1058, CHQ5021 contacted the ORD north local controller (NLC) and was provided the current wind, given clearance to land on runway 9R, and advised that traffic would be departing runway 9R prior to his arrival. At 1059:32, the NLC instructed CHQ5021 “… go around, climb and maintain 2500, fly runway heading.” The NLC then instructed CHQ5021 to”…turn left heading 040 and remain with me.” CHQ5021 then returned and landed on runway 9R without further incident. At 1058:07, the ORD Third Local Controller (3LC) issued LOF3367 the current wind and a takeoff clearance for runway 32L. At 1059:27, the 3LC instructed LOF3367 “…traffic alert, left to right, it’s an American Eagle stay as low as you can.” The pilot immediately responded, “Yeah, we’re doing that.” At approximately 1100, the 3LC controller instructed LOF3367 to “…fly heading 330 and contact departure.” LOF3367 acknowledged the frequency change, and the 3LC responded, “sorry about that.” Radar data indicated that CHQ5021 passed about 125 feet above and 350 feet in front of LOF3367. LOF3367 then changed to departure frequency and continued the remainder of the flight without further incident. The Chicago O’Hare International Airport weather for August 8, 2011 was obtained from the KORD Automatic Surface Observation System (ASOS). KORD weather at 1051 was wind calm, visibility 10 statute miles, scattered clouds at 25,000 feet, temperature 26 degrees Celsius, dew point 18 degrees Celsius, and altimeter setting 29.79 inches of mercury. For further information, see the Air Traffic Control Group Chairman's Report in the docket for this case. A near-midair collision occurred when an Embraer ERJ-145 regional jet departing from runway 32L passed within close proximity to an Embraer ERJ-135 regional jet on approach to runway 9R. The local controller had cleared the ERJ-145 for takeoff without ensuring that adequate spacing existed between the ERJ-145 and the approaching ERJ-135. The ERJ-135 was instructed to go around, but the two airplanes passed within 125 feet vertically and 350 feet horizontally of each other above runway 32L. When interviewed, the local controller stated that he had overlooked the arriving airplane during his scan, possibly because he was distracted by coordination requirements affecting two other airplanes. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12

NTSB Findings

Hierarchical cause / factor breakdown from the FAA bulk avdata database. Each finding tagged C (Cause) or F (Factor).

• C Personnel issues-Action/decision-Action-Incorrect action selection-ATC personnel - C
• C Personnel issues-Action/decision-Info processing/decision-Understanding/comprehension-ATC personnel - C
• C Personnel issues-Action/decision-Action-Incorrect action selection-ATC personnel - C
• C Personnel issues-Action/decision-Info processing/decision-Understanding/comprehension-ATC personnel - C