Computer-Related Incidents with Commercial Aircraft
Non-Computer-Related Automation Problems
In view of recent incidents and accidents to the Airbus A320, A330 and
A340 fly-by-wire aircraft, it is as well to remember that there has
been hydro-mechanical (analogue! :-) control automation on aircraft
for a long time, and this sort of automation can also have its problems.
One view held by many in the industry is that computers alone alleviate
more risks than they pose. A more sophisticated view would measure
on something different from an ordinal scale the risks involved in the
increasing uses of digital computers in avionics. (An ordinal scale is
a scale on which every two states are in the relation `more' or `less'
or `equally' to each other. See the classical work Foundations of
Measurement Theory, Vol. 1
by D. H. Krantz, R. D. Luce, P. Suppes,
and A. Tversky, Academic Press, 1971.)
The Boeing B737 and Airbus A320 are rival airplane series.
The A320 is the subject of many reports in this compendium.
The B737 has recently come under investigation for suspected
and reported rudder-control anomalies. Some investigators suspect
that such anomalies may have played a role in the unexplained
crashed of United Airlines Flight 585 on 3 March 1991 near Colorado
Springs, and USAir 427 on 8 September 1994 near Pittsburgh.
The NTSB has prepared an
on its investigations, released at a public meeting on
16 October 1996, which contains recommendations A-96-107
The GPS Study by the Johns Hopkins University Applied Physics Laboratory
Fly-By-Wire Anomalies in Research Aircraft