American Airlines Boeing B727-223 incident
Boeing B727-223 · Incident: airframe, component or system failure while taxiing
From Dallas Fort Worth International Airport (DFW) to an unrecorded destination
Event
- NTSB case
- CHI91IA058
- 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
- 0
- 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
Boeing B727-223
- Aircraft type
- Boeing 727
- 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
- N6821
- Operator
- American Airlines
- Onboard fatalities
- Unknown
- Route
- From Dallas Fort Worth International Airport (DFW), DALLAS/FT.WORTH, TXTo not recorded
- 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
- Taxi · from runway
- First occurrenceThe 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
- Airframe, component or system failure
- 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
- Air cond/heating/pressurization › Smoke
- Auxiliary power unit › Leak
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE AIRPLANE WAS TAXIING TO ITS ASSIGNED GATE AFTER LANDING WHEN A FLIGHT ATTENDENT INFORMED THE CAPTAIN THAT THERE WAS A FIRE IN THE REAR OF THE AIRPLANE. THE CAPTAIN IMMEDIATELY STOPPED AND THE PASSENGERS WERE DEPLANNED USING THE COMPANY'S EMERGENCY EVACUATION PROCEDURES. A FLIGHT ATTENDENT AND ONE PASSENGER RECEIVED MINOR INJURIES DURING THE EVACUATION PROCESS. NINETH-SIX PASSENGERS AND SIX OTHER AIRPLANE CREWMEMBERS DID NOT RECEIVE INJURIES. A FIRE WAS NOT PRESENT, SMOKE HAD BEEN FILLING THE PASSENGER CABIN. THE SMOKE CAME FROM THE AIR CONDITIONING/HEATING SYSTEM DUCTS. THE SMOKE WAS A RESULT OF AN OIL LEAK IN THE AIRCRAFT POWER UNIT (APU) WHICH ENTERED THE APU DUCT WORK, THE AIR CONDITIONING PACKS AND ASSOCIATED CIRCULATION DUCTING. WHEN A CERTAIN HEAT RANGE HAD BEEN SELECTED THE OIL LADEN AIR WOULD CHANGE INTO SMOKE AS IT EXITED THE CABIN HEAT DUCT OPENING.
Probable cause
AN OIL LEAK ORIGINATING FROM THE AUXILIARY POWER UNIT WHICH CREATED SMOKE IN THE PASSENGER CABIN AFTER IT PASSED THROUGH THE AIR CONDITIONING/HEATING SYSTEM EQUIPMENT AND ASSOCIATED DUCT WORK.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI91IA058
- Event ID
- 20001212X16272
- Case number
- CHI91IA058
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- 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: local date, investigation status, damage. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 1991-01-04.
- API snapshot SHA-256: d59fd7995a7e38e136bc0efe3878c5fcf2f75abc71ea6f7c15105803932f1203; retrieved 2026-09-18T18:57:35.659Z.