Re: ETOPS

From:         kls@ohare.Chicago.COM (Karl Swartz)
Organization: Chicago Software Works, Menlo Park, California
Date:         12 Oct 96 02:36:03 
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>How right you are. See Martinair 767 and three 757 in short order!

I assume you mean to suggest that the Martinair incident and the three
757 crashes all show that twins are less safe than airliners with more
than two engines.  If so, how do you substantiate that?

The Martinair 767 involved a bizarre failure of the electronic flight
instruments.  The same sort of failure could just as easily happen to
the four-engined 747-400 or A340, which have even more sophisticated
flight decks.

The final report on the American 757 crash at Cali says pilot error
was the primary cause, though conflicting information in the printed
charts versus the FMS were a major contributor.  Again, this has no
correlation whatsoever with the number of engines on the aircraft.

The Dominican Alas (Birgenair) 757 which crashed near Puerto Plata
went down due to a plugged airpseed sensor and failure of the pilots
to recognize and properly respond to the problem, compounded by less
than adequate documention of the problem and resolution in the flight
manual.  A single-engined Cessna 172 or an eight-engined B-52 could
suffer the same problem.

The circumstances of the AeroPeru 757 crash are shrouded in over 500
ft of water and an incredible outpouring of misinformation from the
authorities, moreso than usual.  However, if any of the descriptions
can be even slightly trusted, aspects of it sound vaguely reminiscent
of both the Martinair 767 incident and the Dominican 757 crash.  Once
again, the number of engines appears to have nothing to do with the
crash.

ETOPS may be more or less safe than long flights with three- or more
engined planes, but the cases you cite provide no evidence one way or
the other.

--
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