Re: over-automation with glass cockpits

From:         Jan Klier <jank@gr.hp.com>
Organization: Hewlett-Packard Company
Date:         31 Jul 96 12:29:44 
References:   1 2
Next article
View raw article
  or MIME structure

Rob Tremblay wrote:

> There is no reason that I can think of why anyone would want
> to disconnect the built in protections. They are there for my
> protection- why would I deactivate them? Having said that, however,
> many of the protections can be disabled in different ways. If I really
> wanted to stall an Airbus, I could.

  In general I would agree with you. But being a software engineer, and
knowing how many unforseen problems a computer can produce, it makes me
feel terrible uncomfortable to think that the computer has the last word.
It's just unpossible, no matter how cautious one is to predict all
situations one can come in.

  And I think there is one example for such a situation, if my information
is correct: The LH crash in Warsaw, involving an Airbus. The ATC controller
had given wrong wind information and the pilots where coming in with the
wrong configuration. As part of that, the pilots couldn't get the main
landing gear on the ground in a fashion that the pressure-on-wheels
protection would allow them to use the breaks. This in turn lead to loosing
additional runway, which they were already short on.  As far as I remember
the facts, they pilots were aware of the problem, knew how to fix it but
one of these safeguards prevented that from doing it - and that possibly,
because of a software engineer not considering the possibility of ATC
giving wrong information and other factors that might lead to a whole
chain of events which the safeguards weren't prepared for.

  Now, that's only how far I remember the story from that incident. But
independent of this, I can easily imagine an emergency situation where a
safeguard might prevent a solution that a human being is perfectly able
from executing and might therefore prevent a human being from preventing
a disaster. And it's unpossible to predict all possible emergency
situations a plane can get into - otherwise we wouldn't see new twists
developing all the time.

						Just my $0.02	Jan

--
The opinions expressed above are my own and have nothing to do with my employer
*******************************************************************************
Jan Klier             Software Design Engineer                   jank@gr.hp.com
           Hewlett Packard - Storage System Division, Greeley CO