National Transportation Safety Board Public Hearing

Alaska Airlines Flight 261 — December 10, 2002 Washington DC

By Frank Boksanske, AMFA National Safety and Standards Director

December 11, 2002

The National Transportation Safety Board held its “Sunshine Meeting” on the January 2000 Alaska Airlines Flight 261 accident on December 10, 2002, in Washington D.C. The hearing began with a brief introduction by acting Board Chairman,Carol S. Carmody. The following Board members were present as well: John Hammerschmidt, John Goglia, and George W. Black, Jr.

Richard Rodriguez, Investigator-in-Charge, began with an overview of the accident. Presentations followed by Jeff Guzzetti, Systems Group Chairman – Lubrication and End Play Inspection and Jackscrew Overhaul Assemblies Procedures; Joseph Epperson, Materials Group Chairman - Metallurgical Findings; Joseph Kolly, Ph.D., Grease Group Chairman – Investigation of Lubricating Grease; Jana Price, Ph.D., Statistical End Play Data Study; Richard Rodriguez, Investigator-in-Charge – Alaska Airlines Maintenance Program and FAA Oversight; John Clark, Director, Office of Aviation Safety – Design and Certification of the MD80 Horizontal Stabilizer Trim System; Captain Dave Iren, Operations – Flight Crew Decision Making. The board presentation may be viewed on the following NTSB web site: http://www.ntsb.gov/default.htm linking to “Investigation of Alaska Airlines Flight 261.”

Following is the probable cause resulting in the demise of Flt 261 that crashed in the Pacific Ocean 2.7 miles north of Anacapa Island, California, nearly three years ago.

“The National Transportation Safety Board determines that the probable cause of this accident was 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 was (1) Alaska Airlines’ extended lubrication interval, and the FAA’s approval of that extension, which increased the likelihood that an unperformed or inadequate lubrication would result in excessive wear of the acme nut threads; and (2) 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. Contributing also to the accident was the absence on the MD-80 of a fail-safe mechanism to prevent the catastrophic effects of total acme nut thread loss.”

The AMFA investigation concluded with a letter of submission submitted August 15, 2002, to the NTSB Investigator-in-Charge, Mr. Richard Rodriquez. The letter states, in part:

“AMFA believes the certification of the MD-80 aircraft was without adequate redundancy.”

“AMFA believes that Alaska Airlines compromised critical leadership positions, as required per part 119.65 of the Code of Federal Regulations (CFR, by not filling the vacancies of qualified personnel for each of the three dedicated Director positions.”

“AMFA believes that the MSG-3 (Maintenance Steering Group Three) is flawed, in that it allowed the extension of maintenance intervals to escalate beyond a reasonable requisite.”

“Alaska Airlines received FAA approval to drop the 3600 flight hour (FH) and the “whichever comes first” requirement of the MSG-3 Maintenance Review Board (MRB) interval for the MD-80 C1 check. To date, ASA is still required only to meet the 15-month interval to the MD-80 C1 check, regardless of flight hours.”

“FAA staffing and training of qualified inspectors was insufficient in providing adequate surveillance of Alaska Airlines under the Air Transportation Oversight System (ATOS) program, in that it allowed numerous discrepancies to exist in the maintenance and inspection programs as brought out in the FAA’s “Special Inspection,” and Alaska Airlines own Audit.”

“Insufficient lubrication of the acme nut and screw assembly through the actions of the MG-3 process, and the decisions of the Reliability Analysis Program, (RAP) in the unrealistic extension of maintenance intervals, without sufficient data, led to the accelerated wear rate of the horizontal stabilizer acme nut and screw assembly.”

For the complete AMFA letter of submission to the NTSB, please visit our national website at www.amfanatl.org and link to Safety and Standards.

National Safety and Standards has received many positive comments from aviation experts regarding the contribution of the AMFA team, as to probable cause findings of ASA 261, highlighting their professionalism and integrity that was displayed throughout the investigation as well.

In ending, I wish to express our sincere appreciation and thanks to the AMFA accident investigation team, under the leadership of David Patrick, for their role in the investigation. The following Alaska Airlines Technicians represented AMFA in the investigation: David Patrick, “party coordinator”; Kevin Kruse, Human Factors; Gerald Cline, Structures; John Pollom, Structures; Lance Seyer, Records; Kurt Pagenkopf, Structures; Bruce Wood, Grease; and Louie Key, Structures.

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