Mcdonnell Douglas DC-10-30 and Mcdonnell Douglas DC-9-82 incident near Chicago, Illinois, December 23, 1991
On December 23, 1991 at about 3:05 pm local time, 2 aircraft, Mcdonnell Douglas DC-10-30 (N142AA) and Mcdonnell Douglas DC-9-82 (N497AA), were involved in the same incident near Chicago, Illinois (Chicago O'Hare airport). No one was hurt; 315 people were on board or involved. The weather was visual conditions (good weather).
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The NTSB's probable cause their words, unchanged
THE LOCAL CONTROLLER'S NOT UNDERSTANDING READ BACK OF RADIO COMMUNICATIONS. FACTORS INCLUDE THE PILOT-IN-COMMAND OF FLIGHT 73 NOT UNDERSTANDING VERBAL INSTRUCTIONS; LOCAL CONTROLLER NOT VISUALLY IDENTIFYING THE AIRCRAFT; AND INADEQUATE SURVEILLANCE (FAA) IN THE TOWER.
THE LOCAL CONTROLLER'S NOT UNDERSTANDING READ BACK OF RADIO COMMUNICATIONS. FACTORS INCLUDE THE PILOT-IN-COMMAND OF FLIGHT 73 NOT UNDERSTANDING VERBAL INSTRUCTIONS; LOCAL CONTROLLER NOT VISUALLY IDENTIFYING THE AIRCRAFT; AND INADEQUATE SURVEILLANCE (FAA) IN THE TOWER.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- December 23, 1991 · about 3:05 pm local time
- Place
- Chicago, Illinois · Chicago O'Hare
- Type
- Incident
- Injuries
- No one was hurt; 315 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft 1
- Mcdonnell Douglas DC-10-30 · all DC-10-30s on the register
- Registration
- N142AA · registry record · serial 46714
- Damage
- Not recorded
- Flight
- Flight of an unrecorded kind · scheduled airline rules (Part 121)
- Aircraft 2
- Mcdonnell Douglas DC-9-82 · all DC-9-82s on the register
- Registration
- N497AA · no longer on the register · serial 49735
- Damage
- Not recorded
- Flight
- Flight of an unrecorded kind · scheduled airline rules (Part 121)
The NTSB's narrative for the Mcdonnell Douglas DC-10-30 final · quoted from the NTSB record
AMERICAN AIRLINES FLIGHT 73 (N142AA) WAS HOLDING IN POSITION ON RUNWAY 32R. AMERICAN AIRLINES FLIGHT 489 (N497AA) WAS CLEARED FOR TAKEOFF ON RUNWAY 9L. SHORTLY AFTER THIS, AMERICAN AIRLINES FLIGHT 873 WAS CLEARED FOR TAKEOFF ON RUNWAY 32L, FROM T1 INTERSECTION. BOTH FLIGHT 73 AND FLIGHT 873 ACKNOWLEDGED THE CLEARANCE AND INITIATED TAKEOFF ROLLS. THE LOCAL CONTROLLER DID NOT DETECT THE CONFUSION. A NEAR COLLISION OF TWO OF THE AIRCRAFT OCCURRED WHEN FLIGHT 489, IN THE INITIAL CLIMB PHASE OF FLIGHT, PASSED OVER FLIGHT 73, ON TAKEOFF ROLL, IN THE INTERSECTION OF RUNWAYS 32R AND 9L.
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 Mcdonnell Douglas DC-9-82 final · quoted from the NTSB record
AMERICAN AIRLINES FLIGHT 73 (N142AA) WAS HOLDING IN POSITION ON RUNWAY 32R. AMERICAN AIRLINES FLIGHT 489 (N497AA) WAS CLEARED FOR TAKEOFF ON RUNWAY 9L. SHORTLY AFTER THIS, AMERICAN AIRLINES FLIGHT 873 WAS CLEARED FOR TAKEOFF ON RUNWAY 32L, FROM T1 INTERSECTION. BOTH FLIGHT 73 AND FLIGHT 873 ACKNOWLEDGED THE CLEARANCE AND INITIATED TAKEOFF ROLLS. THE LOCAL CONTROLLER DID NOT DETECT THE CONFUSION. A NEAR COLLISION OF TWO OF THE AIRCRAFT OCCURRED WHEN FLIGHT 489, IN INITIAL CLIMB PHASE OF FLIGHT, PASSED OVER FLIGHT 73, ON TAKEOFF ROLL, IN THE INTERSECTION OF RUNWAYS 32R AND 9L.
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 Mcdonnell Douglas DC-10-30 from the NTSB's investigation tables, in plain English
Pilot
- Certificate: airline transport pilot
- Ratings: multi-engine land; instrument: airplane
- Flight time: 21,565 hours in all; 720 in this make and model; 216 in the last 90 days; 72 in the last 30 days
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 65,122 hours
- Last inspection: approved inspection programme, January 2, 2000
- Maximum gross weight: 554,500 lb
- Seats: 305
- Landing gear: retractable
- Engine: Ge CF6-50C2 (turbofan); 0 hours total
- Operator: American Airlines
The flight
- Destination: HNL Honolulu HI
- Flight plan: IFR
- Runway 32, 10,003 ft by 150 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 040° at 9 knots
- Visibility: 7 statute miles
- Sky: broken clouds at 2,000 ft; not recorded at 2,000 ft
- Temperature: 34°F (1°C), dew point 30°F (-1°C)
- Altimeter: 29.00 inHg
- Observation at 2:50 pm from ORD, 1 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 14 | |||
| Passengers | 207 |
The factual record for the Mcdonnell Douglas DC-9-82 from the NTSB's investigation tables, in plain English
Pilot
- Certificate: airline transport pilot
- Ratings: multi-engine land; instrument: airplane
- Flight time: 10,000 hours in all; 3,623 in this make and model; 200 in the last 90 days; 75 in the last 30 days
- Medical certificate: Class 1 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 6,624 hours
- Last inspection: approved inspection programme, January 2, 2000
- Maximum gross weight: 149,500 lb
- Seats: 149
- Landing gear: retractable
- Engine: P&W JT8D-217 (turbofan); 0 hours total
- Operator: American Airlines
The flight
- Destination: IAH Houston TX
- Flight plan: IFR
- Runway 9, 7,966 ft by 150 ft
- A second pilot was aboard
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 6 | |||
| Passengers | 88 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Other NTSB records under N142AA the same tail number, which may have belonged to a different aircraft at the time
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number CHI92IA061.