Boeing 737-222 incident near Seattle, Washington, April 10, 1991
On April 10, 1991 at about 2:54 am local time, a Boeing 737-222, registered N9003U, suffered minor damage in an incident near Seattle, Washington (Seattle airport). It was a flight of an unrecorded kind under scheduled airline rules (Part 121). 2 people had minor injuries; 31 others were unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
TURBINE BLADE FAILURE FROM FATIGUE. FACTORS TO THE INCIDENT WERE INOPERATIVE ENGINE FIRE EXTINGUISHER, INADEQUATE SERVICE OF AIRCRAFT AND DELAYED DEPLOYMENT OF EMERGENCY SLIDE.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 10, 1991 · about 2:54 am local time
- Place
- Seattle, Washington · Seattle · map
- Type
- Incident
- Injuries
- 2 people had minor injuries; 31 others were unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Boeing 737-222 · all 737-222s on the register
- Registration
- N9003U · no longer on the register · serial 19041
- Damage
- Minor damage
- Flight
- Flight of an unrecorded kind · scheduled airline rules (Part 121)
The NTSB's narrative final · quoted from the NTSB record
DURING THE INITIAL CLIMB, THE FLIGHT CREW HEARD A LOUD BANG FOLLOWED BY AIRFRAME VIBRATIONS. THE CREW WAS NOTIFIED BY THE CONTROL TOWER THAT SMOKE AND FLAME WERE EMITTING FROM THE LEFT ENGINE. THE FLIGHT CREW DECLARED AN EMERGENCY AND WAS CLEARED TO LAND. THE PILOT DISCHARGED A BANK OF FIRE EXTINGUISHING AGENT AND SHUT THE ENGINE DOWN. THE FLIGHT LANDED WITHOUT FURTHER INCIDENT. DURING THE FOLLOW-UP INVESTIGATION, IT WAS FOUND THAT A TURBINE BLADE FAILED IN FATIGUE. THE FLIGHT CREW HAD RECEIVED AN INDICTION THAT THE FIRE EXTINGUISHING AGENT HAD DISCHARGED, HOWEVER, IT WAS LATER FOUND THAT IT DIDN'T DUE TO THE INSTALLATION OF AN INCORRECT DISCHARGE OUTLET. THE REAR EMERGENCY SLIDE ON THE RIGHT SIDE WAS SLOW IN INFLATING AND WAS NOT USABLE FOR THE EVACUATION. THE SLIDE WAS INSTALLED ON A TEST STAND AND FOUND TO OPERATE WITHIN NORMAL OPERATING PARAMETERS.
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, commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 14,075 hours in all; 188 in the last 90 days
- Medical certificate: Class 1
- Seat: unk
The aircraft
- Last inspection: inspection type not recorded; 0 hours since
- Maximum gross weight: 100,800 lb
- Seats: 100
- Landing gear: retractable
- Engine: P&W JT8D-7B (turbojet); 0 hours total
- Operator: United Airlines
The flight
- Destination: SMF Sacramento CA
- Flight plan: IFR
- Runway 16, 9,425 ft by 150 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 250° at 15 knots
- Visibility: 10 statute miles
- Sky: not recorded; scat at 3,000 ft
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 5 | |||
| Passengers | 2 | 26 |
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.