American Airlines McDonnell Douglas MD80 incident
McDonnell Douglas MD80 and Boeing 767 · Incident: near midair/TCAS alert/loss of separation on approach
Event
- NTSB case
- OPS09IA006
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Incident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Airline
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Aircraft 1 · McDonnell Douglas MD80
- Aircraft type
- McDonnell Douglas MD80
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- Unknown
- Operator
- American Airlines
- Onboard fatalities
- Unknown
- Route
- From St. Louis Lambert International Airport (STL), St Louis, MOTo Chicago O'Hare International Airport (ORD), Chicago, IL
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 121: Air Carrier
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Approach · IFR final approach
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Near midair/TCAS alert/loss of separation
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- None
Aircraft 2 · Boeing 767
- Aircraft type
- Boeing 767
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- Unknown
- Operator
- American Airlines
- Onboard fatalities
- Unknown
- Route
- From Dublin Airport (EIDW), DublinTo Chicago O'Hare International Airport (ORD), Chicago, IL
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 121: Air Carrier
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Approach · IFR final approach
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Near midair/TCAS alert/loss of separation
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- None
Cause areas
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
While on approach to Chicago-O'Hare International Airport, American Airlines flight 879 (AAL 879) was being radar-vectored to the final approach course for runway 28 and American Airlines flight 93 (AAL 93) was on a straight-in approach to runway 27L. Both aircraft were under control of Chicago Terminal Radar Approach Control. Because of an air traffic control oversight, AAL 879 overshot the final approach course for runway 28 and continued northbound, conflicting with AAL 93 on the runway 27L final. According to preliminary Federal Aviation Administration data, lateral separation decreased to 0.35 nautical mile and vertical separation was 0 feet before the conflict was resolved. There were no injuries or damage reported as a result of the incident, which occurred in visual meteorological conditions, with 10 statute miles of visibility and a 5500-foot ceiling.
Probable cause
The Chicago TRACON West Arrival controller's omission of a required clearance, resulting in AAL 879 overshooting the final for runway 28 and losing separation with AAL 93.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record OPS09IA006
- Event ID
- 20090604X25647
- Case number
- OPS09IA006
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (5)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, damage. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: ed971785abd809a919a5f1a8af19ebb3e6133f050bded1abbfb1252f4f6a1582; retrieved 2026-09-13T18:15:25.055Z.
- The NTSB's operator name is blank for Unknown; the operator shown is the name the NTSB's other records give its FAA operator code, AALA.