Flight 261: A Year Later

It has been a year since an Alaska Airlines jet plunged into the sea off the coast of Ventura County, and federal investigators are still sorting through clues to determine how--and why--the crash occurred.

Many of the facts are known.

Shortly after takeoff from Puerto Vallarta, Mexico, on Jan. 31, 2000, for a scheduled flight to San Francisco and Seattle, the cockpit crew began having problems with the MD-83’s stabilizer--the flat, wing-like part of the tail that largely controls the up-and-down pitch of the nose.

As Flight 261 continued, those problems worsened, prompting a decision to attempt an emergency landing at Los Angeles International Airport. But it was too late.

An extremely loud bang--apparently the sound of the horizontal stabilizer breaking away--echoed through the plane.

“Mayday!” co-pilot William Tansky shouted as the plane dove and rolled over on its back.

“Push! Push! Push!” pilot Ted Thompson yelled back, apparently asking Tansky to help him shove the control yokes forward in an effort to raise the nose of the inverted plane.

But experts say that without the stabilizer, the plane was doomed, hopelessly out of balance and lacking any controls that could have pulled it out of the dive.

“Here we go,” Thompson said.

A second later, the jetliner slammed into the ocean near Anacapa Island, killing all 88 on board.

National Transportation Safety Board investigators recovered much of the fragmented wreckage from the ocean floor. Several of the key pieces examined during the investigation were from the jackscrew mechanism that raises and lowers the leading edge of the stabilizer. The threads of the gimbal nut through which the jackscrew moves had been stripped off, and no grease was found on the jackscrew.

Hearings on the crash were held last month in Washington. Questions were raised about the design of the jackscrew mechanism, the effectiveness of maintenance procedures at Alaska and the oversight of that maintenance by the Federal Aviation Administration.

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Officials from the FAA, which certified the jackscrew’s design, said it provides strength that far exceeds any anticipated loads that may be placed on the mechanism.

They said the jackscrew and gimbal nut also have a necessary form of redundancy--a double helix of spiraling threads, like the alternately red and white stripes on a barber pole. Each set, they said, is capable of bearing the full stabilizer load.

Nonetheless, the jackscrew mechanism on Flight 261 failed.

Michael O’Neil, an FAA engineer, said that certification of a design assumes that the system will be maintained properly. Such maintenance, he said, would include adequate lubrication.

In the months before the crash, Alaska had received permission to extend the time between greasings from Boeing Co., which had taken over the operations of McDonnell Douglas, the company that designed and built the plane. The FAA said it signed off on this “escalation” of the greasing intervals.

Alaska also had received permission from Boeing, starting in 1997, to substitute a new lubricant for the one it had been using.

NTSB investigators are looking into whether the old and new greases are compatible--whether residue from the old grease may have caused the new grease to break down. Although no grease was found on the part of the recovered jackscrew that moved through the gimbal nut, small amounts of the old grease were found on the ends of the screw.

The lack of lubrication on much of the jackscrew intensified questions about Alaska’s maintenance procedures that date back to 1998. That’s when a federal grand jury in San Francisco began investigating allegations that records had been falsified at the airline’s maintenance facility in Oakland.

The probe spread to Seattle six weeks after the crash, when 64 mechanics there signed a letter to the company alleging that a supervisor had pressured them to sign off on substandard maintenance work.

Some of these mechanics, contacted by The Times, said that several jets had been returned to service despite concerns that further repairs might be needed. The allegations did not involve the plane that crashed.

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Many of these mechanics expressed doubts about the thoroughness of FAA oversight of Alaska’s maintenance operations. The FBI and the Department of Transportation inspector general’s office--responsible for determining whether any criminal activity contributed to the crash--queried some of the mechanics about Alaska’s maintenance practices, also asking them whether the FAA had been doing its assigned job of making sure the work is done right.

Last spring, the FAA conducted a special “white glove” inspection of Alaska’s maintenance program. On May 2, the agency announced that it had found “serious breakdowns” in the carrier’s procedures for assuring proper repairs.

The agency warned that it might have to shut down Alaska’s heavy maintenance program, but it backed away from that threat June 29, saying Alaska had come up with an acceptable plan to correct the shortcomings. Nonetheless, on Dec. 2, the FAA recommended that Alaska be fined almost $1 million for sloppy maintenance and for flying planes with inoperative equipment.

NTSB investigators at last month’s hearings in Washington said they have been sifting through mountains of evidence--wreckage recovered from the sea, maintenance records, eyewitness reports and studies done by experts in everything from metallurgy to the performance of pilots under stress.

The NTSB is not shy about naming names. In the past, it has pointed fingers at the FAA, airlines, pilots and others--less to assess blame than to pinpoint errors in the hope that they can be corrected.

Sometime later this year, the NTSB will point its finger again, issuing its final report on the crash of Flight 261.

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A Failed Jackscrew

Federal investigators are still looking into the cause of the crash of Alaska Airlines Flight 261. Much of the wreckage was recovered from the ocean floor. Several of the key pieces were from the jackscrew mechanism that raises and lowers the leading edge of the horizontal stabilizer. The threads of the gimbal nut through which the jackscrew moves had been stripped off, and no grease was found on the jackscrew.

Nut Assembly:

Jackscrew turns up or down inside the nut assembly, raising or lowering stabilizer.

Source: Boeing Co.; compiled by RICHARD O’REILLY/ Los Angeles Times