Learjet INC 45 and Boeing 737-7H4 incident near Chicago, Illinois, December 1, 2011
On December 1, 2011 at about 2:07 pm local time, 2 aircraft, Learjet INC 45 (N570AM) and Boeing 737-7H4 (N432WN), were involved in the same incident near Chicago, Illinois (Chicago Midway airport). No one was hurt; 85 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
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.
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.
Source: NTSB aviation accident database, copy made October 12, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- December 1, 2011 · about 2:07 pm local time · cases in 2011
- Place
- Chicago, Illinois · Chicago Midway · cases near this airport · map
- Type
- Incident
- Injuries
- No one was hurt; 85 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft 1
- Learjet INC 45
- Registration
- N570AM · registry record · serial 238
- Damage
- Not recorded
- Flight
- Flight of an unrecorded kind · general aviation rules (Part 91)
- Aircraft 2
- Boeing 737-7H4 · all 737-7H4s on the register
- Registration
- N432WN · no longer on the register · serial 33715
- Damage
- Not recorded
- Flight
- Flight · scheduled airline rules (Part 121)
The NTSB's narrative for the Learjet INC 45 final · quoted from the NTSB record
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.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The NTSB's narrative for the Boeing 737-7H4 final · quoted from the NTSB record
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.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record for the Learjet INC 45 from the NTSB's investigation tables, in plain English
What happened, in order
- Runway incursion veh/AC/person during takeoff defining event
The NTSB's findings
- cause Personnel issues › Action/decision › Info processing/decision › Identification/recognition › ATC personnel
- cause Personnel issues › Action/decision › Info processing/decision › Decision making/judgment › ATC personnel
- cause Personnel issues › Task performance › Communication (personnel) › Lack of communication › ATC personnel
The aircraft
- Seats: 12
- Landing gear: retractable
- Engine 1: Honeywell TFE-731-SER (turbofan); 0 hours total
- Engine 2: Honeywell TFE-731-SER (turbofan); 0 hours total
- Operator: Air Clayco INC
The flight
- Departed from: Chicago IL
- Destination: SAV Savannah GA
- Flight plan: IFR
- Runway 31R, 5,141 ft by 150 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 180° at 4 knots
- Visibility: 10 statute miles
- Sky: broken clouds at 20,000 ft; a few clouds at 15,000 ft
- Temperature: 34°F (1°C), dew point 25°F (-4°C)
- Altimeter: 30.26 inHg
- Observation at 2:51 pm from MDW
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 2 | |||
| Passengers | 4 |
The factual record for the Boeing 737-7H4 from the NTSB's investigation tables, in plain English
What happened, in order
- Runway incursion veh/AC/person during taxi defining event
The NTSB's findings
- cause Personnel issues › Action/decision › Info processing/decision › Identification/recognition › ATC personnel
- cause Personnel issues › Action/decision › Info processing/decision › Decision making/judgment › ATC personnel
- cause Personnel issues › Task performance › Communication (personnel) › Lack of communication › ATC personnel
The aircraft
- Seats: 140
- Landing gear: retractable
- Engine 1: Cfm Intl. CFM56 SERIES (turbofan); 0 hours total
- Engine 2: Cfm Intl. CFM56 SERIES (turbofan); 0 hours total
- Operator: Southwest Airlines CO
The flight
- Departed from: MSP Minneapolis-St MN at 2:02 pm
- Destination: Chicago IL
- Flight plan: IFR
- Runway 31C, 6,522 ft by 150 ft
- A second pilot was aboard
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Cabi | 3 | |||
| Flight crew | 2 | |||
| Passengers | 74 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The NTSB has not released the docket for this case yet. The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), is usually released when the investigation is nearly complete, and the list here is refreshed when it appears. Check at the NTSB.
Connections how this case links to the rest of the register
- N570AM on the register today · the tail number may have moved to another aircraft since
- N432WN: not on the register today · the record of its deregistration
- Boeing 737 2,894 registered today · the model family and its accident history
- Boeing 6,675 aircraft on the register
- Engine: Honeywell TFE-731-SER 291 aircraft carry this series today · as the NTSB recorded it
- Engine: Honeywell TFE-731-SER 291 aircraft carry this series today · as the NTSB recorded it
- Chicago Midway International · nearest airport
- Savannah/Hilton Head International · bound for
- Minneapolis-St Paul Intl/Wold-Chamberlain Airport · departed from
- Accidents and incidents in Illinois 2,117 since 1982 · 251 in the last ten years
- Illinois 8,049 aircraft registered
The whole map of how records connect · these connections as data: /graph/accident/OPS12IA167.json.
The bigger picture in Aviation Analytics: accidents over time since 1982, by model, by phase of flight and conditions, by place and on the map.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text does not name anyone involved, its policy at this time. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.