A jackscrew with inadequate lubrication was discovered yesterday during a check of an Alaska Airlines jet, less than a week after federal...
A jackscrew with inadequate lubrication was discovered yesterday during a check of an Alaska Airlines jet, less than a week after federal officials opened an investigation into an earlier report of a jackscrew that had not been greased.
The discovery, confirmed by Alaska and federal air-safety officials, came during a fleetwide inspection of Alaska’s MD-80 jets. The airline ordered the inspection last week after The Seattle Times disclosed the earlier incident, in which three Alaska mechanics reported finding an ungreased jackscrew on an MD-83 jet on Jan. 10.
In addition, the airline acknowledged yesterday that an Alaska inspector involved in the January incident is the same employee who crossed out an order to replace the jackscrew that ultimately failed during the deadly crash of Alaska Flight 261 in January 2000.
The failure of the jackscrew — a part in the tail section that helps control the plane’s angle of flight — led to the Flight 261 crash off Southern California, killing all 88 passengers and crew. Federal investigators found the jackscrew had not been adequately lubricated, causing excessive wear.
The latest problem was discovered in Seattle early yesterday during an overnight check, said Laura Brown, a spokeswoman for the Federal Aviation Administration (FAA) in Washington, D.C.
The jackscrew lacked adequate lubrication in the middle, although it had grease at both ends, Brown said.
Alaska spokeswoman Caroline Boren said the plane was temporarily grounded and that the airline conducted tests that showed no excessive wear of the jackscrew.
“There were no indications that this jackscrew was unsafe or unairworthy,” she said.
The FAA last week opened an investigation into the Jan. 10 jackscrew incident, saying it would question mechanics and examine Alaska’s maintenance practices.
Incident in dispute
Alaska disputed the three mechanics’ reports, concluding the jackscrew had been properly lubricated during a major maintenance check in November. The check took place at AAR Aircraft Services, a contract repair station in Oklahoma City that does heavy-maintenance work for the airline.
Sources familiar with the November check told The Times that the work in Oklahoma City was overseen by Alaska inspector Ron Hensel, who in 1997 crossed out an order to replace the jackscrew on the plane that crashed during Flight 261. The sources spoke on condition of anonymity because the matter is under investigation.
Boren confirmed last night that Hensel oversaw the so-called “OK to close” during the November maintenance check. Under federal regulations, Alaska is legally responsible for maintenance at the Oklahoma facility and is required to have inspectors there to assure that the work is done properly.
As part of that check, Hensel ensured that an AAR inspector had signed off the work card for the jackscrew lubrication, Boren said.
Hensel, reached by phone at AAR in Oklahoma City, responded “no comment” and then hung up.
In 1997, Hensel reviewed a work order to replace the jackscrew on an MD-83 jet undergoing a major maintenance check in Oakland, Calif. The order had been issued by Alaska mechanic John Liotine, who concluded that the jackscrew was too worn to remain on the plane.
Hensel ordered new wear tests that found the jackscrew to be well under its wear limit. He crossed out Liotine’s order to replace the part.
At the time, the plane was nearing a deadline to be returned to passenger service and a new jackscrew was not readily available. The jackscrew was not checked for wear again before it failed 28 months later during Flight 261.
The plane plunged into the Pacific Ocean off Southern California, en route from Puerto Vallarta, Mexico, to San Francisco and Seattle.
After the crash, the FBI and a federal grand jury in San Francisco conducted an investigation into the 1997 inspection to determine whether the wear tests were actually done. No charges were filed.
Hensel told federal investigators that he acted properly when he canceled the jackscrew-replacement order because Liotine had erred when he concluded the part had reached its wear limit.
Hensel was questioned by Alaska after the Jan. 10 incident about the work performed in Oklahoma City, sources said.
At that time, he said he couldn’t remember details of the work, the sources said. But he told company officials that if anyone would be careful about a jackscrew, he would be because of what he went through after the Flight 261 crash, the sources said.
AAR Aircraft also performed the last inspection of the inadequately lubricated jackscrew discovered yesterday, Boren said. Hensel was not involved in that inspection, which occurred in August, she said.
More frequent lubrication
After the crash, the FAA ordered that jackscrews be lubricated every 650 flight hours. Alaska had been lubricating its jackscrews about every 2,550 hours before the crash. MD-80 planes have a unique jackscrew with no backup system.
The new lubrication interval lowered the likelihood that a jackscrew would become severely worn before a problem was discovered. It would take 81 days for a plane flying eight hours a day to reach 650 flight hours.
In the Jan. 10 inspection, the mechanics found no excessive wear of the jackscrew and put new grease on the mechanism. That plane had been flying for about 2 ½ months since the November inspection in Oklahoma City. Grease should still be visible on the entire jackscrew after that amount of time, according to maintenance experts.
The plane that was inspected yesterday had not reached 650 flight hours since its jackscrew was last checked, the FAA’s Brown said.
Alaska spokeswoman Boren said that under FAA rules, the airline normally would record the jackscrew’s condition, lubricate it and return the plane to passenger service.
But in order to conduct a comprehensive evaluation, Alaska decided to remove the jackscrew and replace it with a new one before putting the plane back in service, Boren said.
Alaska also contacted Boeing, which merged in 1997 with McDonnell Douglas, the maker of the MD-80, as well as the jackscrew’s manufacturer, to review the findings related to the jackscrew, Boren said.
The FAA had an inspector at Alaska’s Seattle hangar at the time the problem was discovered, Boren said.
As part of its investigation, the FAA is also looking into another jackscrew incident two weeks ago that raised questions about Alaska’s lubrication procedures. The jackscrew was replaced when a mechanic reported an unusual noise in the mechanism.
Alaska CEO Bill Ayer ordered inspections of all 26 of Alaska’s MD-80 series planes last week to make sure they had been properly lubricated.
Boren said Alaska had examined 10 other jackscrews and all were found to be in normal condition. She said the inspections were being conducted on an expedited basis and would be completed by the end of the week.
Brown said the FAA had found no reason to order the immediate grounding of Alaska’s MD-80 fleet. She said the critical issue is whether excessive wear is found on a jackscrew.
Steve Miletich: 206-464-3302 or firstname.lastname@example.org