MD-80 Accidents: Possible Common Link Found?

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Found this on Free Republic. Looking at the facts presented and ignoring the hyperbole, if the assertion about NTSB is correct, the politcal fallout from this is going to be interesting. Implied, of course, is that those stabilizers were not manufactured to MD/Boeing specifications.

[start quotes] Investigators at the National Transportation Safety Board now believe that manufacturing problems in China caused the crash of an MD-83 airliner last month, killing all 88 Americans on board. If their suspicions are borne out, Alaska Air Flight 261 could become a powerful symbol for all that has gone wrong with President Clinton's failed policy of appeasement toward China, as well as a tragic monument to the shortsightedness of major U.S. exporters such as Boeing, who have shipped jobs overseas relentlessly in pursuit of the phantom Chinese market. [end quotes]

Link: "FR: Casualties of the Clinton-China Connection"

-- redeye in ohio (not@work.com), February 25, 2000

Answers

I don't think that argument is sustainable. If it took ten years for the defect to show up then that was pretty good workmanship in my books.
These items are not install and forget (like aprt in a satellite that is not accessible after launch).
These items need to be inspected, checked, lubricated etc. etc. after so many hours of use. Their quality must be checked before they are installed in the plane. Blaming it on the manufacturer is a cheesy excuse. my 2"

-- spaceman spiff (spiff@space.com), February 25, 2000.

Here, learn more about Free Republic (and what it's "news" is really all about):

LINK

pan

-- panjandrum (panjandrum@samfoote.net), February 25, 2000.


PTB(pass the buck)

-- canthappen (n@ysayer.com), February 25, 2000.

I did say "Looking at the facts presented and ignoring the hyperbole..."

I find that there is useful information to be found in many places. Solon and FR both included, along with many others. It is useful to separate the opinions and the positions from the facts.

One point to consider: neither the Clinton admin. nor NTSB has anything that I can see to gain by blaiming a Chinese subcontractor, not in light of Clinton admin. policies towards that country. If anything, I'd expect NTSB to bury this sort of conclusion until Clinton gets MFN for China passed!

How might this conclusion have been arrived at? Metallurgical problems which simply took years and flight hours to surface. If the alloys used in those gimbals and jackscrews were not quite as specified, let aone in some but not all cases, for that to be determined would have required metallurgical analysis way beyond simply examining tolerances.

-- redeye in ohio (not@work.com), February 25, 2000.


As a metallurgical engineer I can answer your conjecture about a failure showing up after ten years. This is definitely possible - it would be called a fatigue failure. This is a common occurrence in metal parts that last a long time and have cyclical loads. The aircraft industry has very strict fatigue life standards for many aircraft components - the very existence of safe, inexpensive air travel would be impossible without the ability of engineers to test and predict the life of structural components.

The problem with fatigue life is that it is statistical in nature, and therefore relies on probabilities. It is always possible that the part failed "early" even though it was manufactured properly. There are many variables that influence fatigue life. The first thing that must be determined is whether the loads that the part was subjected to were in the range where fatigue is possible. Then we can discuss whether a failure after ten years could be due to Chinese manufacturing processes, etc. or whether it was something else.

-- Lazarus Long (lazlongk@aol.com), February 25, 2000.



Lazarus,

A non-metallurgical and non-engineer to boot thanks you for your input!

Now, in days, weeks or longerto come we can see if there was anything to this article's statement about NTSB's conclusions thus far. That is, if these conclusions hold, and are not treated like Flight 800 was (in my opinion).

-- redeye in ohio (cannot@work.com), February 25, 2000.


I'm not going to suggest that I have the faintest idea of what happened to the MD80's, however, I do have a question. How can fatigue failure on the metal parts, given that the failure might not show up for ten years, coincidentally start failing at pretty much the same time? It might be plausible if each of the planes' air travel time were almost identical, which doesn't seem probable. Just a thought..

-- Trish (adler2@webtv.net), February 25, 2000.

Two things to remember here.

1: China stated making MD-80 components in the late 1980's or early 1990's.

2: The jackscrew installed in AK261 at the time of the crash was manufactured in 1979.

As much as I don't like the US aviation industry giving away manufacturing know-how to the Chinese (who are building whole MD-90's right now no US jobs involved), the failed part was not of Chinese manufacture.

Unless they're delivering parts via time machine. ;)

WW

-- Wildweasel (vtmldm@epix.net), February 25, 2000.


According to the Sacbee website of the Sacremento Bee today, 13 MD- 80s have had problems since the crash of the Alaska Airlines plane. The article also stated that eighteen (18) jackscrews have been replaced. IMHO, these planes seem to be having a LOT of problems all of a sudden.

-- Lurkess (Lurkess@Lurking.XNet), February 25, 2000.

My neighbor and good friend flies md-80s for american airlines and is very aware needless to say of the problem. He told me that american had inspected all subject aircraft and found no unusual problems. apparently the alaska air is a fairly late modle and yes he did think the evidence is related to manufacturing discrepincies by the chinese. He also has had many good laughs at the "y2k speculations and the md-80 malfuctions".

-- jd (jda@pos.com), February 26, 2000.


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