Garuda A300 crash, volcanic ash, and morons of the media

Date:         03 Oct 97 01:18:34 
From:         kls@ohare.Chicago.COM (Karl Swartz)
Organization: Chicago Software Works, Menlo Park, California
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The investigation into the cause of the Garuda A300 crash in Sumatra a
week ago seems to be focusing on miscommunication between the pilots
and air traffic controllers.  However, early speculation revolved
around the smoke and haze from many fires in the area.  In its report
on the crash last Saturday, the San Jose Mercury News (aka the Murky
Snooze) included the following bit of brilliance:

    An accumulation of ash has been known to clog the engines of
    aircraft flying close to volcanic eruptions, but it was not
    clear whether ash from the forest fires could have been aloft
    in sufficient concentrations to have been a factor.

Sheesh.  I guess it's too much to ask a reported to do a microscopic
bit of research before writing such drivel.  For those who may not be
familiar with volcanic ash, it consists of very fine rock fragments,
initially at temperatures of nearly 2000 F as they are emitted by the
volcano.  With a high silica content, it is an excellent abrasive, and
when reheated in the combusion chamber of a jet engine, the already
hot material can remelt and form glassy, ceramic-like deposits on the
turbine blades.

To my knowledge, combustion of wood does not produce fine particles of
rock, at any temperature.  The ash that is produced is more likely to
damage light-colored carpets than the metal used in aircraft engines.

--
Karl Swartz	|Home	kls@chicago.com
		|Work	kls@netapp.com
		|WWW	http://www.chicago.com/~kls/
Moderator of sci.aeronautics.airliners -- Unix/network work pays the bills