Los Angeles Int'n'l Airport
Aircraft Accident/Incident Report

Port Hueneme, California
Monday, January 31, 2000 16:20 PST

NTSB Narrative Summary Released at Completion of Accident

The Board's full report is available at http://www.ntsb.gov/publictn/publictn.htm. On January 31, 2000, about 1621 Pacific standard time, Alaska Airlines, Inc., flight 261, a McDonnell Douglas MD-83, N963AS, crashed into the Pacific Ocean about 2.7 miles north of Anacapa Island, California. The 2 pilots, 3 cabin crewmembers, and 83 passengers on board were killed, and the airplane was destroyed by impact forces. Flight 261 was operating as a scheduled international passenger flight under the provisions of 14 Code of Federal Regulations Part 121 from Lic Gustavo Diaz Ordaz International Airport, Puerto Vallarta, Mexico, to Seattle?Tacoma International Airport, Seattle, Washington, with an intermediate stop planned at San Francisco International Airport, San Francisco, California. Visual meteorological conditions prevailed for the flight, which operated on an instrument flight rules flight plan.

NTSB Probable Cause Narrative

A loss of airplane pitch control resulting from the in-flight failure of the horizontal stabilizer trim system jackscrew assembly's acme nut threads. The thread failure was caused by excessive wear resulting from Alaska Airlines' insufficient lubrication of the jackscrew assembly. Contributing to the accident were Alaska Airlines' extended lubrication interval and the Federal Aviation Administration's (FAA) approval of that extension, which increased the likelihood that a missed or inadequate lubrication would result in excessive wear of the acme nut threads, and Alaska Airlines' extended end play check interval and the FAA's approval of that extension, which allowed the excessive wear of the acme nut threads to progress to failure without the opportunity for detection. Also contributing to the accident was the absence on the McDonnell Douglas MD-80 of a fail-safe mechanism to prevent the catastrophic effects of total acme nut thread loss.

Event Information

Type of Event Accident
Event Date 1/31/2000
Event Day of the Week Monday
Time of Event 1620
Event Time Zone Pacific Standard Time
Event City Port Hueneme
Event State CALIFORNIA
Event Country --
Zipcode of the event site --
Event Date Year 2000
Event Date Month 1
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude --
Event Location Longitude --
Event Location Airport Los Angeles Int'n'l Airport
Event Location Nearest Airport ID LAX
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles 55
Degrees magnetic from airport 290
Airport Elevation 126
Weather Briefing Completeness Full
Investigator's weather source Weather Observation Facility
Time of the weather observation
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 Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions Unknown
Sky Condition for Lowest Ceiling Unknown
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 0
Air Temperature at event time (in degrees celsius) -9
Dew Point at event time (in degress fahrenheit) -11
Wind Direction (degrees magnetic) 230
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 8
Wind Velocity Indicator --
Wind Gust Indicator Unknown
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 30.17
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury Fatal
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal 88
Injury Total Minor --
Injury Total None --
Injury Total Serious --
Injury Total All 88
Investigating Agency NTSB
NTSB Docket Number (internal use) 13648
NTSB Notification Source --
NTSB Notification Date Jan 31 2000 12:00AM
NTSB Notification Time 0
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record May 29 2003 12:32PM
User who most recently changed record NTSB\MONR
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N963AS
NTSB Number DCA00MA023
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 121: Air Carrier
Type of Flight Plan filed IFR
Flight plan Was Activated? Yes
Damage Destroyed
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Douglas
Aircraft Model MD-83
Aircraft Series Identifier MD-83
Aircraft Serial Number 53077
Certified Max Gross Weight 160000
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 --
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Jan 13 1999 12:00AM
Airframe hours since last inspection 4177
Airframe Hours 26584
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name --
Aircraft Owner Street Address --
Aircraft Owner City --
Aircraft Owner State --
Aircraft Owner Country --
Aircraft Owner Zipcode --
Operator is an individual? No
Operator Name ALASKA AIRLINES INC
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 19300 International Blvd
Operator City Seattle
Operator State WA
Operator Country USA
Operator Zip code 98188
Operator Code ASAA
Owner has at least one certificate --
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation --
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not Scheduled
Indicates Domestic or International Flight International
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 PVR
Departure City PUERTO VALLARTA
Departure State --
Departure Country MX
Departure Time 1337
Departure Time Zone PST
Destination Same as Local Flt --
Destination Airport Code SFO
Destination City SAN FRANCISCO
Destination State CA
Destination Country USA
Specific Phase of Flight Cruise
Report sent to ICAO? --
Evacuation occurred No
Date of most recent change to record May 22 2003 10:35AM
User who most recently changed record HAUT
Since inspection or accident Time of Accident
Event Location Runway Number and Location 0
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --