From: werner@cs.utexas.edu (Werner Uhrig)
Newsgroups: sci.aeronautics
Subject: Re: Crash causes and faults [Long] (was Re: El Al 747...)
Date: 10 Oct 1992 04:35:30 -0500
Organization: CS Dept, University of Texas at Austin
NNTP-Posting-Host: dimebox.cs.utexas.edu


In article <1992Oct9.191642.23055@athena.mit.edu> cid@athena.mit.edu (Derek H Cedillo) writes:
>In article <1992Oct9.102012.21752@cactus.org> rdd@cactus.org (Robert Dorsett) writes:
>>In article <1992Oct9.035126.14109@athena.mit.edu> cid@athena.mit.edu (Derek H Cedillo) writes:
>>>In article <167@newave.newave.mn.org> john@newave.newave.mn.org (John A. Weeks III) writes:
>>>>In <1992Oct7.005552.5844@athena.mit.edu> cid@athena.mit.edu (Derek H Cedillo):
>>>>> I think boeing may have made a big boo-boo somewhere.

	that was "baby-talk", not typically used in a professional discussion
	forum; at least one does not leave such a "suggestion" standing in the
	room, without AT THE SAME TIME following it (better would be PRECEDING 
	it) with a technical justification.


>>>To me, 2 aircaft that lose 2 engines on the same wing shortly
>>>after take-off within 10 months of eachother is a boo-boo.

	it took someone'c omplaint to make you state that justification.


>>>Especially when both ended so fatally.  

	"especially" has no foundation and thus, this does not have technical
	relevance.


>>To me, uninformed conclusions before they even have a death count is a 
>>"boo-boo."  I call your boo-boo "coincidence," until the forensic evidence
>>suggests otherwise.  
>
>Does the idea of a service bulletin put out by boeing and the FAA 
>about engine mount pins failing have any impact?

	not without further supporting evidence, no!

	does the fact that both captain's were occupying the LEFT seat
	have any relevance?!?

>15 such pins have been found recently to have cracks in them that could
>lead to thier failure.  

	Boing (and everyone else, obviously) should definitely "hold
	their breath" waiting for investigators' reports, digging into
	that direction; which means "don't form an opinion (and hype a
	LIKELY boo-boo) until the reports are in!"


>>I can think of at least five common-cause-of-failure possibilities...

>Your bird strike has some possiblilites, but still good odds against it.

	it wasn't "his bird strike" - and, man, are you quick at figuring
	odds.  frightening !


>Although not any  engines are "bird-Proof" a large amount of them 
>are made to be.  Engines are designed for bird strikes in mind, and
>a great deal goes into making sure tragic loss of power doesnt arise
>from a bird strike.  I worked for GE this summer and aided in some
>testing.  If the engine is struck by a bird, or even multiple ones
>it would still take a lot to make the engine break apart and fall off
>the wing and affect the other engine.  

	your inexperience shows:  where there is one bird, there are
	flocks of them;  birds enough for all engines....  though they
	tend to be found more on side of the fuselage than on both
	sides, most likely ...

>As far as sabatoge goes, this is unlikely.  A cargo plane is not
>the likely target of a terrorist attack.  Who are they going to affect?

	what the hell do you know what the Israelis put into that plane?
	and, besides, one dead transport, is better than 10 years of
	failure, no ?!?  (no, I haven't heard anything yet that would
	have me believe that to be the most likely cause)


>Unless they planned on doing this with the precise location of the crash
>(the apartment complex)...maybe.

	bah!  you got a case of "rambling on"...


>Preventative maintanence is a good possibility, especially when 
>cracks were found in other pins.  If there were some, they should 
>have been detected.  Good point.

	bah!  the more precise the instruments get, the more minute
	the cracks they CAN discover, the more cracks WILL BE discovered.
	Only after persistent catastrophic failures of a component should
	we "know to suspect"; but not enough parallels have as of yet (that
	I know) been establish to make this "a rash of TWO"...

	I have "not the foggiest" as to what the incidence rate might be
	(and severity of the cracks) at which one would/should "get exited";
	does anyone?


>Pilot error is a real tough call.  Like I mentioned earlier, 747's are
>very heavy, especially when filled with cargo.  Without much altitude
>its hard to recover, actually it is a 1/billion chance.
>As far as a pilot error causing engines to fail and fall off,
>this is obviously ludicrous. But I dont think this is what you meant right?

	bah!  more rambling:  "real tough", "747s are very heavy, especially
	when filled with cargo", "without much altitude, it's hard to recover".
	"1/billion chance"....

	disconnect your keyboard, please!


	[ more of the same deleted; I started a KILL-file for this group; please
	  add me to yours, as I don't think I will contribute much of "basic value"
	  to this group; I'm just likely to, on occassion, tell someone to
	  "stop smoking that stuff" (with apologies to most readers) ]


				Cheers,		---Werner
-- 
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