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Old 6th Apr 2004, 11:24
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rjsquirrel
 
Join Date: Jun 2002
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One possible thing to learn from this is the value of field experience weighed against the newer testing technologies that are available.

A tail rotor hub cracked, and that the crack progressed to fail the tail rotor, toss some blades and cause the crash. Conventional wisdom says that only time and experience (and crashes) will teach us how to eliminate all these critical component failures.

The newest test requirements that are used for every new helicopter (those designed in the last few years, like S-92 and AB-139) find these weak points before production starts, using induced scratches, dents and flaws on all the important parts to try to cause cracks. If a crack is caused by such a flaw, the part is redesigned by adding material, or by reshaping it until the flaw no longer causes a crack. They say that every critical bit is flawed in every critical area, increasing the number of tests quite a bit.

I saw some slides about this that had been posted, but can't find the pointer to the site.

Last edited by rjsquirrel; 6th Apr 2004 at 18:19.
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