Boeing 737-990ER accident near Seatac, Washington, August 24, 2021
On August 24, 2021 at about 3:45 am local time, a 2015 Boeing 737-990ER, registered N479AS, was involved in an accident during taxi (from runway) near Seatac, Washington (Seattle-Tacoma Intl airport). It was flown under scheduled airline rules (Part 121). 1 person was seriously injured and 3 people had minor injuries; 130 others were unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The passenger’s use of the evacuation slide resulted in the serious injury.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 24, 2021 · about 3:45 am local time
- Place
- Seatac, Washington · Seattle-Tacoma Intl · map
- Type
- Accident
- Injuries
- 1 person was seriously injured and 3 people had minor injuries; 130 others were unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Boeing 737-990ER, built 2015 · all 737-990ERs on the register
- Registration
- N479AS · registry record · serial 60576
- Damage
- Not recorded
- Flight
- Flight · scheduled airline rules (Part 121)
The NTSB's narrative final · quoted from the NTSB record
Even though an overheated passenger cell phone was put into a battery containment bag (BCB) by the cabin crew, a large amount of smoke remained in the cabin with a strong acrid smell. As a result, the captain commanded an evacuation on taxiway A spot 6A at the Seattle-Tacoma International Airport (SEA), Seattle Washington. One passenger broke their elbow while descending on the evacuation slide.
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
What happened, in order
- Evacuation during taxi (from runway) defining event
The NTSB's findings
- Aircraft › Aircraft oper/perf/capability › (general) › (general) › Related operating info
The aircraft
- Seats: 222
- Landing gear: retractable
- Engine 1: Cfm Intl CFM56-7B27E (turbofan); 0 hours total
- Engine 2: Cfm Intl CFM56-7B27E (turbofan); 0 hours total
- Fire on the ground
- Operator: Alaska Airlines INC
The flight
- Departed from: MSY New Orleans LA at 10:43 pm
- Destination: SEA Seattle WA
- Flight plan: IFR
- A second pilot was aboard
Weather at the time
- Light: dusk
- Wind: at 4 knots
- Visibility: 10 statute miles
- Sky: broken clouds at 7,500 ft; a few clouds at 5,000 ft
- Temperature: 63°F (17°C), dew point 32°F (0°C)
- Altimeter: 29.89 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 6 | |||
| Passengers | 1 | 3 | 124 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The NTSB has not released the docket for this case yet. The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), is usually released when the investigation is nearly complete, and the list here is refreshed when it appears. Check 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.