Re: DC-9 Flight Control

From:         kls@ohare.Chicago.COM (Karl Swartz)
Organization: Chicago Software Works, Menlo Park, California
Date:         23 May 96 10:37:33 
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>Unlikely as it may seem, that fourth hyd system on the 1011 has made a
>difference.  An EAL flight was at 10K feet when the front spool on the
>number two engine broke loose and augured forward.  It destroyed lines
>to three of the four hyd systems, and damaged the fourth. They landed
>on the fourth.  AIR, there was one other similar case.  It was not
>really good design that put all those systems on the bulkhead ahead of
>the #2 fan.

Perhaps it wasn't that great a design decision, but it was good enough
to bring that Eastern L-1011 home.  Compare to the DC-10 with only
three hydraulic systems, all of them passing through the plane of the
front spool (aka fan) of the #2 engine.  When a cracked fan disk lets
loose, shrapnel (formerly the fan blades) take out all three hydraulic
systems ... an UA 232 does cartwheels in Sioux City.  Only some truly
remarkable piloting saved two-thirds of the people on board.

--
Karl Swartz	|Home	kls@chicago.com
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