Introduction

The world has changed significantly for air travellers in the 1990s. New generation aircraft, such as the Airbus A319/320/321/330/340 series and the Boeing B777 are now in service. These aircraft are `fly-by-wire'-- their primary flight control is achieved through computers. The basic maneuvering commands which a pilot gives to one of these aircraft through the flight controls is transformed into a series of inputs to a computer, which calculates how the physical flight controls shall be displaced to achieve a maneuver, in the context of the current flight environment. While large commercial air transport aircraft have had hydraulically- aided controls for along time, and military air forces have been flying their aircraft under computer control for equally as long, many people including myself believe that the use of computer primary flight control in commercial transports heralds a new era, in which scientists concerned with specification and verification of computer systems, as well as passengers concerned with personal safety, should renew their interest.

It would be pleasant to say there have been no accidents. Unfortunately, as with many new types of aircraft, the Airbus A320/A330/A340 series has had its share. There have been fatal accidents with A320 aircraft in Bangalore, India; in Habsheim, in Alsace in France; near Strasbourg, also in Alsace in France; and in Warsaw, Poland. An A330 crashed on a test flight in Toulouse, killing Airbus's chief test pilot as well as the other crew on board. An A340 suffered serious problems with its flight management computer system en route from Tokyo to Heathrow, and further significant problems on approach to Heathrow. In late 1995 and early 1996, the B757 (not a fly-by-wire aircraft) suffered its first two fatal accidents in a decade and a half of service.

Even transport aircraft which are not fly-by-wire have nowadays their share of safety-critical computer-based systems. New-generation flight management and guidance systems (the so-called `glass cockpit') and Full-Authority Digital Engine Controls (FADEC) are found on most newly-built aircraft.

I collect here a series of comments and papers referring to recent computer- related accidents from various experts and not-so-experts. The collection was originally restricted to fly-by-wire aircraft, but has since broadened to include other computer-related or maybe-computer-related incidents. This page will grow with time. I sincerely hope not by much.

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