National Transportation Safety Board
Aviation Incident Final Report

 

 

Location:

Seattle, WA

Incident Number:

DCA16IA036

Date & Time:

12/19/2015, 0831 PST

Registration:

N477AS

Aircraft:

BOEING 737

Aircraft Damage:

None

Defining Event:

Wrong surface or wrong airport

Injuries:

153 None

Flight Conducted Under:

Part 121: Air Carrier - Scheduled

Analysis

 

The flight crew inadvertently landed on a taxiway that ran parallel to the intended landing runway. About 5 miles from the runway and having been cleared to land on runway 16R, the tower controller asked if the flight would like to sidestep to runway 16C which had recently opened. The flight crew accepted and visually lined up with taxiway T, instead of the intended landing runway 16C. Although visual meteorological conditions were present, the sun was reflecting off taxiway T resulting in the flight crew visually focusing on it during landing. The flight crew and controller did not recognize the error until after landing.

 

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this incident to be:
 

the flight crew's misidentification of the taxiway as the landing runway.

 

Findings

Personnel issues

Identification/recognition - Flight crew (Cause)

Environmental issues

Glare - Effect on personnel

Factual Information

 

On December 19, 2015, about 0831 pacific standard time, Alaska Airlines flight 27, a Boeing 737 airplane, N477AS, landed on taxiway T instead of the intended runway 16C at the Seattle-Tacoma International Airport (SEA), Seattle, Washington. There were no injuries to the 153 passengers and crew onboard and the airplane was not damaged. The flight was conducted under the provisions of 14 Code of Federal Regulations Part 121 as a regularly scheduled passenger flight from Chicago O'Hare International Airport (ORD), Chicago, Illinois, to SEA. Visual meteorological conditions prevailed at the time of the incident.

The captain reported that the descent and approach were normal. They had been cleared for the instrument landing system (ILS) approach to runway 16R. Just inside of 5 miles, the tower controller offered runway 16C that had recently opened. The captain lined up the airplane to land on what he believed was 16C. He noted that runways 16C and 16R and taxiway T were wet and reflected the morning sun, whereas 16L and the terminal were in a shadowed area and not readily visible. He further noted that the distance from 16L to 16C is less than the distance between 16C and 16R so it may appear that 16C is the left runway with taxiway T being the middle runway. The captain suggested that runway lead-in lights should remain on to prevent future similar events.

The first officer reported that both pilots were focused on landing what they thought was runway 16C, but was taxiway T. Although the first officer had retuned the captain's ILS for 16C, he was puzzled that the flightpath indicator showed on-glideslope while the localizer showed off course. Although he casually mentioned the discrepancy, since they were visually aligned with the runway, he did not give it further attention. The first officer noted that he had been focused too much on secondary tasks and neglected the big picture of ensuring the airplane was lined up on the proper runway.

 

 

History of Flight

Landing-flare/touchdown

Wrong surface or wrong airport (Defining event)

 

 

Pilot Information

Certificate:

Airline Transport; Commercial; Flight Engineer

Age:

58, Male

Airplane Rating(s):

Multi-engine Land; Single-engine Land; Single-engine Sea

Seat Occupied:

Left

Other Aircraft Rating(s):

None

Restraint Used:

 

Instrument Rating(s):

Airplane

Second Pilot Present:

Yes

Instructor Rating(s):

Airplane Single-engine

Toxicology Performed:

No

Medical Certification:

Class 1 With Waivers/Limitations

Last FAA Medical Exam:

10/05/2015

Occupational Pilot:

Yes

Last Flight Review or Equivalent:

06/12/2015

Flight Time:

(Estimated) 21882 hours (Total, all aircraft), 12328 hours (Total, this make and model)

 

 

Co-Pilot Information

Certificate:

Airline Transport; Commercial

Age:

41, Male

Airplane Rating(s):

Multi-engine Land; Single-engine Land

Seat Occupied:

Right

Other Aircraft Rating(s):

None

Restraint Used:

 

Instrument Rating(s):

Airplane

Second Pilot Present:

Yes

Instructor Rating(s):

Airplane Multi-engine; Instrument Airplane

Toxicology Performed:

No

Medical Certification:

Class 1 Without Waivers/Limitations

Last FAA Medical Exam:

01/06/2015

Occupational Pilot:

Yes

Last Flight Review or Equivalent:

04/30/2015

Flight Time:

(Estimated) , 949 hours (Total, this make and model)

 

 

Aircraft and Owner/Operator Information

Aircraft Make:

BOEING

Registration:

N477AS

Model/Series:

737 990ER

Aircraft Category:

Airplane

Year of Manufacture:

2015

Amateur Built:

No

Airworthiness Certificate:

Transport

Serial Number:

40716

Landing Gear Type:

Retractable - Tricycle

Seats:

191

Date/Type of Last Inspection:

01/16/2015, Continuous Airworthiness

Certified Max Gross Wt.:

188200 lbs

Time Since Last Inspection:

1986 Hours

Engines:

2 Turbo Fan

Airframe Total Time:

1986 Hours as of last inspection

Engine Manufacturer:

CFM International

ELT:

Installed, not activated

Engine Model/Series:

CFM56-7B27E

Registered Owner:

Alaska Airlines

Rated Power:

27000 lbs

Operator:

ALASKA AIRLINES INC

Operating Certificate(s) Held:

Flag carrier (121)

Operator Does Business As:

 

Operator Designator Code:

ASAA

 

Meteorological Information and Flight Plan

Conditions at Accident Site:

Visual Conditions

Condition of Light:

Dawn

Observation Facility, Elevation:

KSEA, 434 ft msl

Distance from Accident Site:

1 Nautical Miles

Observation Time:

0753 PST

Direction from Accident Site:

181°

Lowest Cloud Condition:

Few / 1600 ft agl

Visibility

10 Miles

Lowest Ceiling:

Broken / 2500 ft agl

Visibility (RVR):

 

Wind Speed/Gusts:

7 knots /

Turbulence Type Forecast/Actual:

None / None

Wind Direction:

140°

Turbulence Severity Forecast/Actual:

N/A / N/A

Altimeter Setting:

29.9 inches Hg

Temperature/Dew Point:

3°C / 2°C

Precipitation and Obscuration:

No Obscuration; No Precipitation

Departure Point:

CHICAGO, IL (ORD)

Type of Flight Plan Filed:

IFR

Destination:

Seattle, WA (SEA)

Type of Clearance:

IFR

Departure Time:

0617 CST

Type of Airspace:

Class B

 

Airport Information

Airport:

SEATTLE-TACOMA INTL (SEA)

Runway Surface Type:

Concrete

Airport Elevation:

432 ft

Runway Surface Condition:

Wet

Runway Used:

16C

IFR Approach:

ILS; Sidestep

Runway Length/Width:

9426 ft / 150 ft

VFR Approach/Landing:

Straight-in

 

Wreckage and Impact Information

Crew Injuries:

6 None

Aircraft Damage:

None

Passenger Injuries:

147 None

Aircraft Fire:

None

Ground Injuries:

N/A

Aircraft Explosion:

None

Total Injuries:

153 None

Latitude, Longitude:

47.463611, -122.313333 (est)

 


 


Administrative Information

Investigator In Charge (IIC):

Timothy LeBaron

Report Date:

06/08/2020

Additional Participating Persons:

Robert Hendrickson; Federal Aviation Administration; Washington, DC

Publish Date:

06/08/2020

Note:

The NTSB did not travel to the scene of this incident.

Investigation Docket:

http://dms.ntsb.gov/pubdms/search/dockList.cfm?mKey=92491