Boeing B727-223 incident near Des Moines, Iowa, January 4, 1991
On January 4, 1991 at about 1:30 am local time, a Boeing B727-223, registered N6821, was involved in an incident near Des Moines, Iowa (Des Moines International airport). It was a flight of an unrecorded kind under scheduled airline rules (Part 121). 2 people had minor injuries; 102 others were unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
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.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- January 4, 1991 · about 1:30 am local time
- Place
- Des Moines, Iowa · Des Moines International · map
- Type
- Incident
- Injuries
- 2 people had minor injuries; 102 others were unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Boeing B727-223
- Registration
- N6821 · no longer on the register · serial 19496
- Damage
- Not recorded
- Flight
- Flight of an unrecorded kind · scheduled airline rules (Part 121)
The NTSB's narrative final · quoted from the NTSB record
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.
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 from the NTSB's investigation tables, in plain English
Pilot
- Certificate: airline transport pilot
- Ratings: multi-engine land; instrument: airplane
- Medical certificate: Class 1
- Seat: unk
The aircraft
- Last inspection: inspection type not recorded; 0 hours since
- Maximum gross weight: 12,500 lb
- Seats: 134
- Landing gear: retractable
- Engine: Ge JT-8-D-9 (turbojet); 0 hours total
- Operator: American Airlines, INC.
The flight
- Departed from: DFW Dallas/Ft.Worth TX at 10:00 pm
- Flight plan: IFR
- Runway 7
- A second pilot was aboard
Weather at the time
- Light: night, dark
- Wind: from 240° at 5 knots
- Visibility: 20 statute miles
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
- Observation at 1:05 am from DSM, 1 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | 6 | ||
| Passengers | 1 | 96 |
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.
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 never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.