Seattle-Tacoma Int. Airport
Aircraft Accident/Incident Report

Seattle, Washington 98188
Sunday, April 17, 1994 18:55 PDT

NTSB Narrative Summary Released at Completion of Accident

DURING THE LANDING/TAXI SEQUENCE, THE LEFT MAIN GEAR WHEEL HUB EXPERIENCED A FATIGUE FRACTURE. THE CRACKS WHICH LED TO THE FRACTURE ORIGINATED IN THE HUB GREASE DAM GROOVE. THE FRACTURING OF THE HUB DAMAGED OTHER BRAKE COMPENENTS, WHICH ALLOWED HYDRAULIC FLUID TO LEAK ONTO A HOT BRAKE PAD, WHERE IT WAS IGNITED.

NTSB Probable Cause Narrative

THE FATIGUE FRACTURE OF A MAIN GEAR WHEEL HUB.

Event Information

Type of Event Incident
Event Date 4/17/1994
Event Day of the Week Sunday
Time of Event 1855
Event Time Zone Pacific Daylight Time
Event City SEATTLE
Event State WASHINGTON
Event Country --
Zipcode of the event site 98188
Event Date Year 1994
Event Date Month 4
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport SEATTLE-TACOMA INT.
Event Location Nearest Airport ID SEA
Indicates whether the acc/inc occurred off or on an airport On Airport
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation 430
Weather Briefing Completeness Unknown
Investigator's weather source Pilot
Time of the weather observation 0
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID
Elevation of weather observation facility 0
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation
Lighting Conditions Dusk
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 17000
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 20
Air Temperature at event time (in degrees celsius) 17
Dew Point at event time (in degress fahrenheit) 10
Wind Direction (degrees magnetic) 340
Variable Wind Indicator Unknown
Wind Speed (knots) 3
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None 139
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 5012
NTSB Notification Source --
NTSB Notification Date Apr 17 1994 12:00AM
NTSB Notification Time 1910
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 6 2000 11:03AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N931AS
NTSB Number SEA94IA103
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 121: Air Carrier
Type of Flight Plan filed IFR
Flight plan Was Activated? --
Damage Minor
Aircraft Fire Ground
Aircraft Explosion None
Aircraft Manufacturer's Full Name MCDONNELL DOUGLAS
Aircraft Model MD-83
Aircraft Series Identifier MD-83
Aircraft Serial Number 49232
Certified Max Gross Weight 149500
Aircraft Category Airplane
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 147
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Apr 13 1994 12:00AM
Airframe hours since last inspection 41
Airframe Hours 25773
ELT Installed Unknown
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name ALASKA AIRLINES
Aircraft Owner Street Address P.O. BOX 68900
Aircraft Owner City SEATTLE
Aircraft Owner State WA
Aircraft Owner Country
Aircraft Owner Zipcode 98168
Operator is an individual? --
Operator Name
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address
Operator City
Operator State
Operator Country
Operator Zip code
Operator Code ASAA
Owner has at least one certificate Yes - certificate holder
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Unknown
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not Scheduled
Indicates Domestic or International Flight Domestic
Operator carrying Pax/Cargo/Mail Passenger Only
Type of Flying (Per_Bus / Primary) Unknown
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code SFO
Departure City SAN FRANCISCO
Departure State CA
Departure Country
Departure Time 1655
Departure Time Zone PDT
Destination Same as Local Flt crash at destination city
Destination Airport Code
Destination City
Destination State
Destination Country
Specific Phase of Flight Taxi
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:30AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 34R
Runway Length 11900
Runway Width 150
Sight Seeing flight No
Air Medical Flight No
Medical Flight --