# NTSB OPS11IA819: Embraer EMB-135KL, N377SK, Chicago, IL, August 8, 2011

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: August 8, 2011, 11:00 local (16:00 UTC)
- Place: Chicago, IL
- Coordinates: 41.889591, -87.62088 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=41.8896&lon=-87.6209&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Defining events: [Approach-IFR missed approach: Air traffic event](https://openairdocs.org/ntsb-events/100); [Takeoff: Air traffic event](https://openairdocs.org/ntsb-events/100)
- Highest injury: No injuries
- Injuries: 84 uninjured
- 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
- NTSB case key (mKey): 81436
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=OPS11IA819
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/81436/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=81436
- Page: https://openairdocs.org/ntsb/OPS11IA819

## Probable cause (aircraft 2)

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

NTSB's coded findings; those marked are part of the probable cause.

- [Action: incorrect action selection](https://openairdocs.org/ntsb-findings/02041010): Personnel issues › Action/decision · ATC personnel (probable cause), aircraft 1; cases with it: [Embraer EMB-135KL, 2 cases](https://openairdocs.org/ntsb-findings/02041010/cases.md?model=3260302), [All aircraft, 397 cases](https://openairdocs.org/ntsb-findings/02041010/cases.md)
- [Info processing/decision: understanding/comprehension](https://openairdocs.org/ntsb-findings/02041515): Personnel issues › Action/decision · ATC personnel (probable cause), aircraft 1; cases with it: [Embraer EMB-135KL, 1 case](https://openairdocs.org/ntsb-findings/02041515/cases.md?model=3260302), [All aircraft, 70 cases](https://openairdocs.org/ntsb-findings/02041515/cases.md)
- [Action: incorrect action selection](https://openairdocs.org/ntsb-findings/02041010): Personnel issues › Action/decision · ATC personnel (probable cause), aircraft 2; cases with it: [Embraer EMB-145LR, 1 case](https://openairdocs.org/ntsb-findings/02041010/cases.md?model=3260212), [All aircraft, 397 cases](https://openairdocs.org/ntsb-findings/02041010/cases.md)
- [Info processing/decision: understanding/comprehension](https://openairdocs.org/ntsb-findings/02041515): Personnel issues › Action/decision · ATC personnel (probable cause), aircraft 2; cases with it: [Embraer EMB-145LR, 1 case](https://openairdocs.org/ntsb-findings/02041515/cases.md?model=3260212), [All aircraft, 70 cases](https://openairdocs.org/ntsb-findings/02041515/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Approach-IFR missed approach: Air traffic event](https://openairdocs.org/ntsb-events/100) (defining event), aircraft 1; cases with it: [Embraer EMB-135KL, 1 case](https://openairdocs.org/ntsb-events/100/sequence.md?model=3260302), [All aircraft, 115 cases](https://openairdocs.org/ntsb-events/100/sequence.md)
- [Takeoff: Air traffic event](https://openairdocs.org/ntsb-events/100) (defining event), aircraft 2; cases with it: [Embraer EMB-145LR, 4 cases](https://openairdocs.org/ntsb-events/100/sequence.md?model=3260212), [All aircraft, 115 cases](https://openairdocs.org/ntsb-events/100/sequence.md)

## Analysis (aircraft 2)

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 (aircraft 2)

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 1

- Registration: [N377SK](https://openairdocs.org/deregistered/N377SK-2018-03-30), registration cancelled 2018-03-30, S/N 145579, built 2002 (OpenAirDocs)
- Reported make and model: EMBRAER EMB-135KL
- Registry model: [Embraer EMB-135KL](https://openairdocs.org/model/embraer-emb-135kl) (registry code 3260302) (OpenAirDocs)
- Registry engine: [Rolls-Royce AE-3007A1P](https://openairdocs.org/engine/rolls-royce-ae-3007a1p) (registry code 54571, turbo-fan) (OpenAirDocs)
- Category: Airplane
- Serial number: 145579
- Engines: ROLLS-ROYC AE 3007A1P 8338 lbs thrust turbo jet; ROLLS-ROYC AE 3007A1P 8338 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

## Aircraft 2

- Registration: [N845HK](https://openairdocs.org/deregistered/N845HK-2021-04-12), registration cancelled 2021-04-12, S/N 14500842, built 2004 (OpenAirDocs)
- Reported make and model: EMBRAER EMB-145LR
- Registry model: [Embraer EMB-145LR](https://openairdocs.org/model/embraer-emb-145lr) (registry code 3260212) (OpenAirDocs)
- Registry engine: [Rolls-Royce AE3007 series](https://openairdocs.org/engine/rolls-royce-ae3007-series) (registry code 54582, turbo-fan) (OpenAirDocs)
- Category: Airplane
- Serial number: 14500842
- Engines: ROLLS-ROYC AE3007 SER 7200 horsepower turbo fan; ROLLS-ROYC AE3007 SER 7200 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

## 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

## Other investigations on N377SK (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB CEN11IA270](https://openairdocs.org/ntsb/CEN11IA270), Apr 3, 2011: Embraer EMB-135KL (N377SK), Dubuque, IA, incident, minor damage. Probable cause: The airport authorities' improper decision to deactivate the jet bridge braking system which created an unsafe condition by the gate agents not being able to stop the bridge from impacting the…

## Docket (4 files)

The files NTSB released with the investigation on September 24, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=81436. 694 KB in all.

- ATC 3 - Daily Record of Facility Operations (item 1, .PDF, 76 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40370838&FileExtension=.PDF&FileName=ATC%203%20-%20Daily%20Record%20of%20Facility%20Operations-Master.PDF
- ATC 3 - Position Logs (item 2, .PDF, 436 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40370839&FileExtension=.PDF&FileName=ATC%203%20-%20Position%20Logs-Master.PDF
- ATC 3 - Crew Statements (item 3, .PDF, 33 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40372302&FileExtension=.PDF&FileName=ATC%203%20-%20Crew%20Statements-Master.PDF
- ATC 3 - Factual Report of Group Chairman (item 4, .PDF, 149 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40372343&FileExtension=.PDF&FileName=ATC%203%20-%20Factual%20Report%20of%20Group%20Chairman-Master.PDF

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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