# NTSB OPS12IA167: Learjet 45, N570AM, Chicago, IL, December 1, 2011

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: December 1, 2011, 09:07 local (14:07 UTC)
- Place: Chicago, IL
- Coordinates: 41.779296, -87.770683 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=41.7793&lon=-87.7707&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Defining event: [Takeoff: Runway incursion veh/AC/person](https://openairdocs.org/ntsb-events/320)
- Highest injury: No injuries
- Injuries: 85 uninjured
- Status: Completed, report November 7, 2012
- Report: Approved by Office Director
- NTSB office: Operational Factors Division
- Parties: Federal Avaition Administration, Federal Avaiton Administration, Federal Avation Administration
- NTSB case key (mKey): 82486
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=OPS12IA167
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/82486/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=82486
- Page: https://openairdocs.org/ntsb/OPS12IA167

## Probable cause (aircraft 2)

The tower local controller did not ensure that the runway was clear of conflict before directing the B737 to cross the runway, and other air traffic control personnel did not effectively intervene when the separation between the two airplanes became questionable.

## Findings

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

- [Info processing/decision: identification/recognition](https://openairdocs.org/ntsb-findings/02041510): Personnel issues › Action/decision · ATC personnel (probable cause), aircraft 1
- [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · ATC personnel (probable cause), aircraft 1
- [Communication (personnel): lack of communication](https://openairdocs.org/ntsb-findings/02063510): Personnel issues › Task performance · ATC personnel (probable cause), aircraft 1
- [Info processing/decision: identification/recognition](https://openairdocs.org/ntsb-findings/02041510): Personnel issues › Action/decision · ATC personnel (probable cause), aircraft 2
- [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · ATC personnel (probable cause), aircraft 2
- [Communication (personnel): lack of communication](https://openairdocs.org/ntsb-findings/02063510): Personnel issues › Task performance · ATC personnel (probable cause), aircraft 2

## Analysis (aircraft 2)

A runway incursion occurred when a Boeing 737-700 (B737) was cleared by a tower local controller to cross a runway immediately after a Learjet 45 was cleared for takeoff on the same runway. The first officer of the B737 saw the departing Learjet and warned the captain, who stopped the B737 short of the runway edge. Air traffic control personnel did not take any actions to resolve the conflict between the two airplanes. Recorded data indicated that the Learjet passed within 287 feet laterally and 62 feet vertically of the B737.

## Factual narrative (aircraft 2)

At 0907 on December 1, 2011, a runway incursion and operational error occurred at MDW when Southwest Airlines flight 844 (SWA844), a Boeing 737-700, was cleared to cross runway 31R immediately after Gama Charters flight 17 (GAJ17), a Learjet 45, was cleared for takeoff on the same runway. After landing on runway 31C, the crew of SWA844 was instructed to cross runway 31R and contact ground control. GAJ17 was departing from runway 31R at the time, and conflicted with SWA844 as the B737 crossed the hold-short line for runway 31R at taxiway N. The first officer of SWA844 saw the Learjet departing runway 31R and warned the captain, who was at the controls, to stop. The captain stopped the B737 short of the runway edge. Air traffic control did not take any actions to resolve the conflict between the two aircraft. After the incident, the captain of SWA844 said that the departing Learjet had overflown his aircraft. Recorded FAA data indicated that the closest proximity as the Learjet passed the B737 was 287 feet laterally and 62 feet vertically. Although MDW is equipped with an Airport Surface Detection Equipment – X (ASDE-X) ground movement safety system that included conflict detection and warning capability, the system did not sound an alarm during the incident. The 0851 weather observation for MDW was wind 180 degrees at 4 knots, visibility 10 statute miles, few clouds at 15,000 feet above ground level (AGL), broken clouds at 20,000 feet AGL, broken clouds at 25,000 feet AGL, temperature 1 degree Celsius, dew point minus 4 degrees Celsius, altimeter 30.26 inches of mercury. For further information, see the Air Traffic Control Group Chairman's Factual Report included in the docket for this incident.

## Sequence of events

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

- [Takeoff: Runway incursion veh/AC/person](https://openairdocs.org/ntsb-events/320) (defining event), aircraft 1
- [Taxi: Runway incursion veh/AC/person](https://openairdocs.org/ntsb-events/320), aircraft 2

## Aircraft 1

- Registration: [N570AM](https://openairdocs.org/aircraft/N570AM), registered now, S/N 238, built 2003 (OpenAirDocs)
- Reported make and model: LEARJET INC 45
- Registry model: [Learjet 45](https://openairdocs.org/model/learjet-45) (registry code 5170805) (OpenAirDocs)
- Registry engine: [Honeywell TFE-731-SER series](https://openairdocs.org/engine/honeywell-tfe-731-ser-series) (registry code 33902, turbo-fan) (OpenAirDocs)
- Category: Airplane
- Serial number: 238
- Engines: HONEYWELL TFE-731-SER 4000 lbs thrust turbo fan; HONEYWELL TFE-731-SER 4000 lbs thrust turbo fan
- Damage: No damage
- Flight: Part 91
- Operator: Air Clayco Inc
- Registered owner: Air Clayco Inc
- Departed: Chicago, IL
- Destination: SAV, Savannah, GA
- Flight plan: IFR
- Airport: MDW, Chicago Midway, runway 31R, 5,141 × 150 ft

## Aircraft 2

- Registration: [N432WN](https://openairdocs.org/deregistered/N432WN-2024-10-04), registration cancelled 2024-10-04, S/N 33715, built 2003 (OpenAirDocs)
- Reported make and model: BOEING 737-7H4
- Registry model: [Boeing 737-7H4](https://openairdocs.org/model/boeing-737-7h4) (registry code 1384404) (OpenAirDocs)
- Registry engine: [CFM International CFM56 series](https://openairdocs.org/engine/cfm-international-cfm56-series) (registry code 13802, turbo-fan) (OpenAirDocs)
- Category: Airplane
- Serial number: 33715
- Engines: CFM INTL. CFM56 SERIES 2200 horsepower turbo fan; CFM INTL. CFM56 SERIES 2200 horsepower turbo fan
- Damage: No damage
- Flight: Part 121
- Operator: Southwest Airlines Co
- Registered owner: Southwest Airlines Co
- Departed: MSP, Minneapolis-St, MN
- Destination: Chicago, IL
- Flight plan: IFR
- Airport: MDW, Chicago Midway, runway 31C, 6,522 × 150 ft

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 4 knots
- Visibility: 10 statute miles
- Lowest ceiling: 20,000 ft broken
- Temperature: 34 °F, dew point 25 °F
- Altimeter: 30.26 inHg
- Observed at: MDW

## Docket (9 files)

The files NTSB released with the investigation on March 14, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=82486. 1.6 MB in all.

- ATC 3 - Attachment 1 - ATCT FLM VIP Arrival Checklist (item 1, .PDF, 44 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40361314&FileExtension=.PDF&FileName=ATC%203%20-%20Attachment%201%20-%20ATCT%20FLM%20VIP%20Arrival%20Checklist-Master.PDF
- ATC 3 - Attachment 2 - FAA Presidential Movement Genot RWA 11-12 VIP Movement monitoring of April 21, 2011 (item 2, .PDF, 101 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40361320&FileExtension=.PDF&FileName=ATC%203%20-%20Attachment%202%20-%20FAA%20Presidential%20Movement%20Genot%20RWA%2011-12%20VIP%20Movement%20monitoring%20of%20April%2021,%202011-Master.PDF
- ATC 3 - Attachment 3 - SWA844 Captain Statement (item 3, .PDF, 100 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40361322&FileExtension=.PDF&FileName=ATC%203%20-%20Attachment%203%20-%20SWA844%20Captain%20Statement-Master.PDF
- ATC 3 - Attachment 4 - GAJ17 Flight Crew Statement (item 4, .PDF, 47 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40361324&FileExtension=.PDF&FileName=ATC%203%20-%20Attachment%204%20-%20GAJ17%20Flight%20Crew%20Statement-Master.PDF
- ATC 3 - Attachment 5 - MDW ATCT SOP LC Assist - Duties (item 5, .PDF, 50 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40361328&FileExtension=.PDF&FileName=ATC%203%20-%20Attachment%205%20-%20MDW%20ATCT%20SOP%20LC%20Assist%20-%20Duties-Master.PDF
- ATC 3 - Attachment 6 - Flight Progress Strips (item 6, .PDF, 189 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40361338&FileExtension=.PDF&FileName=ATC%203%20-%20Attachment%206%20-%20Flight%20Progress%20Strips-Master.PDF
- ATC 3 - Attachment 7 - FAA Performance Data Analysis and Reporting System (PDARS) Data Capture (item 7, .PDF, 121 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40361340&FileExtension=.PDF&FileName=ATC%203%20-%20Attachment%207%20-%20FAA%20Performance%20Data%20Analysis%20and%20Reporting%20System%20(PDARS)%20Data%20Capture-Master.PDF
- ATC 3 - Attachment 9 - Final Operational Error Report (ATQA) MDWT11E004 (item 8, .PDF, 279 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40363037&FileExtension=.PDF&FileName=ATC%203%20-%20Attachment%209%20-%20Final%20Operational%20Error%20Report%20(ATQA)%20MDWT11E004-Master.PDF
- ATC 3 - Factual Report of Group Chairman (item 9, .PDF, 685 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40364607&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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