Alaska Airlines steps up jet greasing maintenance

Alaska Airlines has sharply increased how often it lubricates its MD-80-series jetliners after excessive wear was recently found in tail components in two planes.

Alaska's lubrication procedures and frequency of inspections have been a major focus of the investigation by the National Transportation Safety Board (NTSB) into the January 2000 crash of Alaska Flight 261.

The airline's recent discovery of worn bearings in two planes heightened the safety board's interest, because investigators think lack of lubrication of a key component contributed to the crash in which 88 people died.

"We've reviewed and lowered lubrication intervals for all components to the lowest, most conservative levels in the industry," Alaska spokesman Jack Evans said yesterday.

All components requiring lubrication on Alaska's 31 MD-80 jets — nose to tail — will be greased under the new schedule, Evans said.

Evans said Alaska voluntarily contacted the Federal Aviation Administration (FAA) after it discovered the worn bearings in the course of its reliability program, which looks for trends in the carrier's maintenance program.

He said Alaska had planned for some time to lubricate more often as the carrier switches to new industry maintenance standards. But when wear problems with the bearings were found, Alaska accelerated its plans, Evans said.

The worn bearings were found over the past few months in the rudder-trim tabs of the two MD-80s. One bearing fell apart when it was removed; the other showed unusual wear, a company official said.

The rudder-trim tab is a backup system to the rudder, which is attached to the vertical stabilizer in the tail section. It allows the pilot to mechanically move the rudder, which controls the side-to-side movements of the plane. The rudder can be manually operated if the trim tab fails.

"It's not a safety-of-flight issue," said Boeing spokeswoman Liz Verdier. Boeing merged with McDonnell Douglas, the maker of the MD-80 series, in 1997.

But the safety board, concerned about the worn bearings, asked the FAA and Alaska to look into the matter, sources with both agencies said.

"It's the principle of the thing," said a government official close to the safety board. "Why is there no grease on this thing?"

The switch came weeks after the Air Line Pilots Association, in a report to the safety board on Flight 261, criticized Alaska's frequency of inspections on the plane that crashed, saying they were relaxed without proper study.

The pilots association is a party to the safety board's investigation, which is expected to conclude by the end of the year.

The safety board, in a draft report on Flight 261, has concluded that a lack of lubrication in critical areas of the MD-83's jackscrew assembly led to the crash.

The jackscrew is a 2-foot-long, 1-1/2-inch-diameter threaded shaft that moves up and down through a stationary gimbal nut, raising and lowering the leading edge of the stabilizer, the winglike structure on the tail that controls much of the up-and-down pitch of the plane's nose.

Alaska spokesman Evans said that lack of lubrication is one possibility for the worn bearings, but that "any number of factors" could have caused the excessive wear.

Bearings "do wear out from time to time," Evans said. "But because it is difficult to determine the specific cause, we took the most conservative possible approach to addressing it," he said.

Even before taking that step, Alaska inspected and lubricated all rudder-tab bearings on its MD-80s, and randomly analyzed 12 bearings without finding problems, Evans said.

The FAA, which has been under scrutiny for its oversight of Alaska, is preparing briefing papers on the worn bearings in response to inquiries from the safety board, sources in the FAA regional office in Renton said.

"It has a lot of energy in the office," said one FAA inspector.

FAA spokesman Mike Fergus confirmed that the safety board has asked questions about the incidents.

"The NTSB is asking what the history of it was," he said.

Fergus said the worn bearings didn't involve "safety of flight," but Alaska's lubrication of its MD-80s appeared to be the concern.

Steve Miletich: 206-464-3302 or smiletich@seattletimes.com.