# Incident 20151219023779I: 2015 Boeing 737-990ER, Seattle, WA, December 19, 2015

- Type: FAA incident report (Accident/Incident Data System), as reported
- Date: December 19, 2015, 08:33 local time
- Place: Seattle, WA
- Airport: Seattle-Tacoma International
- Damage: No damage
- Phase of flight: Landing: Touchdown
- Operating rules: Air carrier (Part 121)
- Operator: ASAA
- Location: 47.4636° N, 122.3133° W: From the FAA
- Nearby events: https://openairdocs.org/map.md?lat=47.4636&lon=-122.3133&mi=10
- Aircraft: N477AS, registered now (https://openairdocs.org/aircraft/N477AS) (OpenAirDocs)
- Registry model: Boeing 737-990ER (registry code 13848CE, https://openairdocs.org/model/boeing-737-990er) (OpenAirDocs)
- Registry engine: CFM International CFM56-7B27E series (registry code 13078, https://openairdocs.org/engine/cfm-international-cfm56-7b27e-series) (OpenAirDocs)
- Reported make and model: 2015 BOEING 737-990ER
- People aboard: 153
- Fatal injuries: 0
- Other injuries: 0
- Pilot certificates: Airline transport
- Pilot flight hours: 21,882 total, 1,082 in this make and model, 210 in the last 90 days
- NTSB investigation: [NTSB DCA16IA036](https://openairdocs.org/ntsb/DCA16IA036) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/20151219023779I

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

ON SATURDAY, DECEMBER 19, 2015, AT 0831 PACIFIC STANDARD TIME, ALASKA

AIRLINES FLIGHT 27, A BOEING 737-990ER, WAS CLEARED TO LAND ON RUNWAY 16

CENTER (16C) AT THE SEATTLE-TACOMA INTERNATIONAL AIRPORT, SEATAC, WA, BUT

MISTAKENLY LANDED ON TAXIWAY TANGO, WHICH PARALLELS THE RUNWAY.

THE FLIGHT WAS IN CONTACT WITH SEATTLE TERMINAL RADAR AIR TRAFFIC CONTROL

AND WAS CLEARED FOR THE INSTRUMENT LANDING SYSTEM (ILS) APPROACH TO RUNWAY 16 RIGHT (16R). AT 5 NAUTICAL MILES FROM THE AIRPORT IN VISUAL

METEOROLOGICAL CONDITIONS, THE SEATTLE AIR TRAFFIC CONTROL TOWER (ATCT)

OFFERED FLIGHT 27 A SIDE STEP TO THE PARALLEL 16C. THE CAPTAIN, WHO WAS THE

PILOT FLYING, AGREED TO THIS ROUTINE MANEUVER, AND MANUALLY FLEW THE

AIRCRAFT TO THE LEFT TO ALIGN WITH 16C. THE FIRST OFFICER ACKNOWLEDGED THE

CLEARANCE FOR A VISUAL APPROACH AND LANDING ON 16C, AND TURNED HIS

ATTENTION TO RE-TUNING THE ILS RECEIVER RADIOS FOR THE RUNWAY CHANGE.

AS THE AIRCRAFT WAS TOUCHING DOWN, BOTH CREWMEMBERS REALIZED THEY WERE NOT ON RWY16C. THE AIRCRAFT TOUCHED DOWN NORMALLY ON THE 9,400 FOOT BY

180 FOOT PAVED TAXIWAY, TANGO, WHICH IS PARALLEL TO AND BETWEEN 16C AND 16R.

## The NTSB's investigation of this event (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB DCA16IA036](https://openairdocs.org/ntsb/DCA16IA036), Dec 19, 2015: Boeing 737 (N477AS), Seattle, WA, incident, no damage. Probable cause: the flight crew's misidentification of the taxiway as the landing runway.

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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