Re: Peruvian 757 crash -- possible cause reported

Date:         17 Nov 96 20:04:03 
From:         kls@ohare.Chicago.COM (Karl Swartz)
Organization: Chicago Software Works, Menlo Park, California
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>  In defense of the pilots, in the Caribbean case, there were conflicting
>readings, including one that the plane was going too fast. The pilots
>didn't know which one to react to.

They had three airspeed indicators.  The captain's disagreed with the
other two.  In a situation like this, a "2 out of 3" vote seems pretty
obvious.

>  In the Peruvian case, the pilot was mislead by a radar report from a
>ground station, and believed he was safely 10,000 feet high, when
>actually he was just above the water.

Aviation Week had a good article about this last week.  Apparently the
pilots eventually figured out what was wrong and were in the process
of returning to Lima, depending on the radar altimiter.  The captain
made the mistake of descending after the ground controller reported an
erroneous altitude -- in the heat of the moment, it didn't occur to
either of them that the controller's display got the altitude data
from the aircraft's transponder.

According to the article in AvLeak, the plane skipped off the water,
then a wing dipped after an engine lost partial power (probably due
to water ingestion).  The wingtip caught the water and the aircraft
cartwheeled.

In contrast to the early reports, it sounds like the AeroPeru pilots
did an excellent job of diagnosing the problem then flying the plane
with their remaining resources.  The Birgenair pilots, with fewer
failed instruments, didn't seem to have a clue.

--
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