Jet Crash Probe Is Concluded

Widespread maintenance deficiencies at Alaska Airlines and lax oversight by federal regulators were the main underlying factors in the crash of Flight 261 off the Ventura coast nearly three years ago, safety investigators concluded Tuesday.

In its final deliberations on the catastrophe, the National Transportation Safety Board also found that a critical component of the MD-83 jetliner lacked a fail-safe mechanism.

The safety board called on the Federal Aviation Administration to find an engineering fix that could prevent poor maintenance from leading to more accidents. There are about 2,100 airliners of similar design in service around the world, including the DC-9, the Boeing 717 and the MD-80/90 series aircraft.

The Jan. 31, 2000, crash killed all 88 people aboard the flight from Puerto Vallarta, Mexico, to San Francisco. Despite an FAA-ordered overhaul of Alaska Airlines’ practices, NTSB staff members told the board they have seen evidence of continuing maintenance problems.

“I feel in this instance, the FAA failed miserably in its oversight,” said acting NTSB Chairwoman Carol Carmody, prompting applause from dozens of relatives of the victims.

The pilots of Flight 261 had struggled with a mechanical problem for most of their trip and were preparing to divert to Los Angeles when they lost control.

The pilots had no way of knowing that the plane’s horizontal stabilizer had suddenly failed. A wing-like surface atop the tail, the stabilizer is used to control the up-and-down pitch of the nose. The MD-83 rolled on its back in a steep dive into the Pacific.

The loss of control was prompted by the failure of an internal component, a unit called the jackscrew assembly. The jackscrew is a large, threaded bolt used to raise and lower the leading edge of the stabilizer.

Investigators recovered the bolt from the ocean floor and found that there was almost no grease on it. The lack of lubrication stripped the threads of a nut that housed the jackscrew bolt and was the immediate cause of the accident, investigators concluded.

NTSB board members criticized the airline for not quickly landing Flight 261 after it became apparent that the pilots were facing a stubborn problem. Mechanics on the ground attempted to trouble-shoot the situation via radio, but they were stumped.

Board member John Goglia suggested that the airline was trying to avoid diverting the plane. “There is no doubt in my mind that pressure was being put on the captain,” he said.

Alaska Airlines issued a statement acknowledging the NTSB’s central findings and said it has completely revamped its maintenance practices and safety procedures.

“The airline agrees and concurs with many elements of the board’s review and respectfully questions others,” the statement said. “This is not, however, a time to question those judgments. This is a time to move on and to continue to focus on improving safety at Alaska and throughout the aviation industry as a whole.”

NTSB staff members said they have found evidence of ongoing problems at the airline, and recommended a new round of in-depth inspections by the FAA.

“If I was in charge, I’d look at Alaska,” said Richard Rodriguez, the lead investigator on the crash.

But a split board refused to endorse that recommendation, citing concerns that FAA inspectors are spread too thin across an industry that is reeling from economic troubles.

FAA spokesman Les Dorr defended the agency’s oversight of Alaska’s maintenance program. The NTSB criticized the FAA for granting several extensions of time intervals for jackscrew lubrication and inspection procedures, but Dorr said the extensions were “well within industry standards.” FAA officials said they would study NTSB recommendations for improvements in maintenance and a long-term engineering fix.

The MD-83 was manufactured by McDonnell Douglas, now part of Boeing. Susan Bradley, a Boeing spokeswoman, said that the company believes the design of the jackscrew is sound, but that it would cooperate in any search for improvements to make it fail-safe.

Marianne Busche of Olympia, Wash., whose son Ryan and daughter-in-law Abigail were killed in the crash, said the planes should be recalled and fixed.

“I think they need to redesign, because no one is watching over them, and there is no guarantee,” said Busche, who was among dozens of family members attending the NTSB meeting.

One woman carried a hand-lettered sign that read: “Corporate Greed Killed 88 People.”

Alaska’s statement, the only official comment by the airline, expressed “profound sorrow” to the families. But Busche said she wants an outright apology and an engineering fix.

Aeronautical engineers generally try to design backup systems for critical components, but the jackscrew unit on the MD-83 represents a relatively rare instance in which a single failure can have catastrophic consequences, said John Clark, head of the NTSB’s safety office.

Federal standards dictate that such components can fail only once in a billion flight hours, measured across a given design model. But Clark said the plane’s jackscrew failure came after about 100 million flight hours, or about one-tenth of what the standard calls for.

A redesign is needed to “take the issue off the table,” Clark said. “If something is going to be catastrophic, can we mitigate it?”

NASA has already developed some fail-safe designs for spacecraft that should be investigated to see if they can be adapted to airplanes, he added.

Other NTSB officials said their investigation showed that, with proper maintenance, the MD-83 jackscrew can continue working for decades.

But maintenance practices vary considerably from airline to airline.

Investigators said that American Airlines has about 400 aircraft with jackscrew units similar to the one on the Alaska plane and that some are in close-to-pristine condition after nearly 30 years of service. American requires frequent lubrication of the jackscrew.

But Alaska sought -- and the FAA approved -- extensions of lubrication intervals for its planes. Investigators said the last attempt to add grease to the components on the doomed plane was probably completely unsuccessful, because a port used to introduce the lubricant was found to be blocked. Alaska also obtained several extensions of the interval required for inspections of wear on the jackscrew.

FAA inspectors were overburdened and had little time to devote to hands-on oversight of the airline, which was expanding rapidly, investigator Rodriguez said.

NTSB members agonized over recommending expensive changes that could affect thousands of aircraft at a time when the industry is in financial peril.

The board called on the FAA to approve only new designs that have a backup system.

For planes currently in service, it recommended an engineering review to “eliminate the catastrophic effects” of a failure. But it stopped short of recommending that these planes be retrofitted.