OT?: Safety checks ordered on controls in 1,100 airliners

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What are the dozens suspect parts? Are they all from the stabilizer? The report doesn't say.

Safety checks ordered on controls in 1,100 airliners

Source: Birmingham Post Publication date: Feb 16, 2000

Technicians are to examine more than a dozen suspect parts from MD- 80 series passenger jets to try to prevent another accident like that of Alaska Airlines Flight 261 in which all 88 people died when it crashed.

The suspect parts were being sent to a federal aviation safety laboratory in Washington for study after airlines were ordered to inspect the stabiliser control mechanism in almost 1,100 aircraft.

It followed the discovery of problems in that part of the Alaska Airlines MD-83 which crashed into the Pacific off Los Angeles on January 31.

The crew lost control of the plane while trying to fix a problem with the stabiliser, a tail part that controls the plane's up-and- down motion.

The control is similar in MD-80, MD-90, DC-9 and Boeing 717 planes, the types of planes inspected under Federal Aviation Administration orders.

Airlines were on Friday given 72 hours to inspect the planes, which meant the work had to be completed by Monday. Final reports may not be completed for a day or so.

Also on Monday, the FAA said 13 suspect jackscrews had been removed from planes and sent to Washington, where the FAA was to turn them over to the National Transportation Safety Board for analysis and signs of wear.

The jackscrew raises and lowers the stabiliser, moving the plane's nose up or down. The replaced jackscrews were found to have grit or metal shavings in their lubricant, the FAA said.

Publication date: Feb 16, 2000 ) 2000, NewsReal, Inc.

link

http://beta.newsreal.com/cgi-bin/NewsService?osform_template=pages/newsrealStory&ID=newsreal&storypath=News/Story_2000_02_16.NRdb@2@13@3@130&path=News/Category.NRdb@2@18

-- Carl Jenkins (Somewherepress@aol.com), February 16, 2000

Answers

Carl, The last tally I read last night was that 27 airplanes were now seen to have problems as a result of the inspections; Alaska led the count with eight, followed by Delta with six.

I posted this link on another thread, but I think the article from Aviation Now is good enough that it bears repeating--excellent photos, diagrams, and charts, plus it goes into more detail of what NTSB has discovered from CVR and DFDR.

-- Rachel Gibson (rgibson@hotmail.com), February 16, 2000.


Hi Rachel, Excellent Link. I'm no aircraft engineer but I have one question. The autopilot was turned on just before the first descent leading to the fatal plunge. Is there any evidence that event contributed to the crash?

-- Carl Jenkins (Somewherepress@aol.com), February 16, 2000.

Your link didn't work for me, Rachel.

-- Squirrel Hunter (nuts@upina.cellrelaytower), February 16, 2000.

Squirrel, try this:

http://www.aviationnow.com/TwoShare/getPage/AWContent/AWST/awst_main_h eadlinenews

Carl, discussion by experts at this site and on the aviation safety sites has dwelled only briefly on the role of the autopilot...the general gist seems to be to wait for more info. As you read the article I'm linking to here you can see there is some question about a "control" the pilots discussed with ground maintenance while they were at cruise. I'm searching for manufacturer of jackscrew/gimbal nut and for designer of onboard PLC's, but the amount of digging required takes time. I'm sure others here can advise better.

-- Rachel Gibson (rgibson@hotmail.com), February 16, 2000.


There's more. Boeing and Parker Hannifin are in the news these days because of a court quarrel they are having with US Airways (?) over the construction of the rudder in the airplane that crashed at Pittsburg in 1994 (Flt 427). The argument revolves around the role of pilots and the responsibility of the manufacturer when a part in the tail of the airplane jams. I mention it because possible similarities to the present disaster may evolve. May, I say.

-- Rachel Gibson (rgibson@hotmail.com), February 16, 2000.


Rachel --

Important observation. Not only that, the situation you describe closely parallels the problems Pieter posts on, from Australia, in which the heatwave (subsiding now?) coincided with 3 generator outages, AND a nationwide strike by the electrical workers union.

IN THAT LIGHT, now check out the thread on the independent truckers striking in Miami and the cargo containers being left on the docks and product not getting delivered -- "all as a result" (or not) of high diesel prices. Its' like reverse synergy ..... things falling apart in more directions at once -- so problems are replicating and compounding faster than they can be effectively addressed. As in the case of the truckers in Miami, it almost begins to lok Humpty Dumpty -- like the pieces don't want to go back together again.

-- Squirrel Hunter (nuts@upina.cellrelaytower), February 16, 2000.


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