[BC] Gaffe City

[RichardBJohnson at comcast.net]

Once you touch software, you open up a big can of worms.
Think about fly-by-wire airplanes! Airbus Industries, during
an air show, had an Airbus A-320 fail to obey the pilots, killing
them instead. Of course Airbus blamed the pilots, but it turns
out they removed and "lost" the flight-data recorder so nobody
knows. That same aircraft type crashed during certification
testing because the test pilots deliberately disabled two of the
triple-redundant hydraulic systems, as specified by the test
plan. The computer decided that the two identical hydraulic
pressure readings were the correct ones! Therefore they only
applied zero pressure to the flight controls. That same aircraft
type crashed while departing Kennedy Airport because the
pilots ripped the tail off while flying in turbulence. It turns out
that the tail was made of paper (Nomex), had no spars, and
was just strong enough to keep the airplane straight on an
aborted takeoff. That's all the regulations required, so that's
what they designed it to do. After all, the flight control system
will prevent any excessive air loads to be transferred to the tail
(it didn't).

Recently, a Boeing 777, which although it has mechanical flight-
control backup, landed short of a runway in England because
the flight control system simply shut down the engines.
Investigators will eventually find some way to blame the pilots,
but right now it seems that some three of the triple-redundant
engine control systems decided to do the same thing at the
same time. Three identical computers, running identical
software does not produce a triple-redundant system as
required by regulations. However, that's what they use.

One of the most expensive software blunders occurred when
the French Aerospace Consortium had a guidance computer
reset during launch of several very expensive satellites. It seems
that it encountered a divide-by-zero error! The total cost of that
launch was about US$2.3 billion. A billion here, a billion there,
and pretty soon you are talking about real money!

Now, to help you sleep soundly during your next flight,
I will tell you that when I was waiting in Austin, Texas for
a 767 aircraft to be fixed so it could depart, I observed
the booting of the first officer's flight-director. It uses
Windows CE!


--
Cheers,
Richard B. Johnson

  -------------- Original message ----------------------
From: Reader <reader at oldradio.com>
 > the 
<http://www.infoworld.com/article/08/01/21/03FE-25-tech-failures_1.html>"Top
 > 25 tech slipups of all time," is dedicated to keeping the technology
 > industry from losing its collective memory about its biggest blunders.