OPS11IA819

NTSB incident investigation · Embraer EMB-135KL · Chicago, IL · August 8, 2011

Incident · No injuriesIncident investigationFinal report
Date
August 8, 2011, 11:00 local (16:00 UTC)
Place
Chicago, IL
Injuries
84 uninjured
Phase of flight
Approach
Aircraft
N377SKEmbraer EMB-135KLN845HKEmbraer EMB-145LR
Defining events
Approach-IFR missed approach: Air traffic eventTakeoff: Air traffic event
Weather
Visual (VMC) · Day
Status
Completed · report November 7, 2012
Report
Approved by Office Director
NTSB office
Operational Factors Division
Parties
Federal Aviation Administration, National Air Traffic Controllers Association, National Transportation Safety Board
Case key
81436

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the incident.

On this page

Probable cause

The improper air traffic control takeoff clearance issued by the local controller because of his lack of monitoring and lack of awareness of the conflicting arrival airplane.

Findings · 4

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

N377SK · Embraer EMB-135KL

Action: incorrect action selectionPersonnel issues › Action/decision · ATC personnelEmbraer EMB-135KL: 2 casesAll aircraft: 397 casesProbable cause
Info processing/decision: understanding/comprehensionPersonnel issues › Action/decision · ATC personnelEmbraer EMB-135KL: 1 caseAll aircraft: 70 casesProbable cause

N845HK · Embraer EMB-145LR

Action: incorrect action selectionPersonnel issues › Action/decision · ATC personnelEmbraer EMB-145LR: 1 caseAll aircraft: 397 casesProbable cause
Info processing/decision: understanding/comprehensionPersonnel issues › Action/decision · ATC personnelEmbraer EMB-145LR: 1 caseAll aircraft: 70 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

N377SK · Embraer EMB-135KL

N845HK · Embraer EMB-145LR

Analysis

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.

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.

Aircraft · 2

Registration
N377SK
Reported as
Embraer EMB-135KL
Category
Airplane
Serial number
145579
Engines
Rolls-Royc AE 3007A1P, 8,338 lbs thrust, turbo jetRolls-Royc AE 3007A1P, 8,338 lbs thrust, turbo jet
Damage
No damage
Flight
Part 121
Operator
Chautauqua Airlines Inc, doing business as Chautauqua Airlines
Registered owner
Chautauqua Airlines Inc
Airworthiness certificate
Standard, Transport
Departed
LSE · La Crosse, WI
Destination
ORD · Chicago, IL
Flight plan
IFR
Airport
ORD · Chicago O'Hare International, runway 32L, 9,685 × 200 ft

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Registration
N845HK
Reported as
Embraer EMB-145LR
Category
Airplane
Serial number
14500842
Engines
Rolls-Royc AE3007 SER, 7,200 horsepower, turbo fanRolls-Royc AE3007 SER, 7,200 horsepower, turbo fan
Damage
No damage
Flight
Part 121
Operator
Trans States Airlines LLC, doing business as Trans States Airlines
Registered owner
Trans States Airlines LLC
Airworthiness certificate
Standard, Transport
Departed
ORD · Chicago, IL
Destination
MLI · Moline, IL
Flight plan
IFR
Airport
ORD · Chicago O'Hare International, runway 32L, 9,685 × 200 ft, concrete

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Weather

Conditions
Visual (VMC) · Day
Wind
90° at 5 knots
Visibility
10 statute miles
Lowest ceiling
18,000 ft broken
Temperature
77 °F, dew point 66 °F
Altimeter
29.77 inHg
Observed at
ORD

Docket · 4

The files NTSB released with the investigation on September 24, 2012, on NTSB’s docket system: statements, records, photos and specialists’ reports. 694 KB in all.

Other investigations on N377SK · 1

Matched to the same aircraft by N-number and date.