Re: Boeing 777 - Totally Irresponsible?

Date:         27 Dec 96 13:32:19 
From:         "john r." <john@guava.demon.co.uk>
Organization: silence
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In article <airliners.1996.2792@ohare.Chicago.COM>, "Bernie Gracy, Jr."
<bgracy@worldnet.att.net> writes
>The keynote speaker of the 1996 Pacific Northwest Software Quality
>Conference reviewed the 10^9 (ten to the ninth power) problem.  Years of
>testing a PC program are required to believe that it won't fail within a
>week of release.  To meet the FAA standard of 10^9 hours of failure free
>operation would require 100 years of testing assuming that one could
>execute 1 test/sec (there are about 10^7 seconds in a work-year).
>
>He went on to say that because of the millions of lines of code written
>for the 777 that it would be impossible to test all of the failure
>conditions, and therefore was irresponsible to design and deploy such an
>aircraft.  He vowed never to fly on one...
>
>How was the 777 tested?  Is it safe?  Or is it "unsafe at any airspeed?"

You might be interested to know that the 777 has a Jesus switch above
the captain. If all goes wrong with the flying controls, hitting the
switch connects analog control column inputs to analog control surface
actuators, so dumping all your digits.

Crew do this in training. I have been told it then behaves like a normal
plane and takes skill to fly.

--
  _J_O_H_N____R_E_L_P_H____________   john@guava.demon.co.uk