>As part of our recurrency training we shall be giving the pilots a short
>talk on error chains. I have not yet been briefed as to the content of the
>company course, but I am trying to find any freely avilable papers on the
>subject to expand the company brief and to give the pilots something of
>interest to take home to read at their leasure.
Good request, Peter!
>From my perspective, the concept of the error chain is a way to help crews
understand the workings of situation awareness. Part of maintaining good
SA involves building mental relationships between the various events which
occur before and during a flight. These events involve the aircraft, the
other crew members, ATC, the company, cabin crew, passengers, weather, and
all the other dimensions of the aviation world.
Many times, these events are unrelated and when taken together amount to
nothing. Sometimes, however, the cumulative effects can be important. A
simple example:
A crew finds themselves inbound to an airport when the anit-skid system
(aircraft event) fails. Not a problem. Checking the conditions at the
destination they find that it is unexpectedly raining (weather event)
creating a wet runway situation. Time to check the landing distance
charts. Closer to destination, the controller advises that the primary
runway is closed (ATC event) and they will be required to land on a
shorter, crosswind runway. Time to think about an alternate.
Each of the above events can be a link in an error chain if the crew does
not recognize what is happening and respond effectively. Keep in mind that
the name "error chain" can be misleading for crews because the links
themselves are not crew errors (though some might be); rather, they can
lead the crew into making an error which places the flight at risk. The
key is for the crew to be alert to the individual events as they occur and
be able to "put two and two together" to recognize the potentially adverse
relationships between them.
Most accidents and serious incidents are the result of many small events,
none of which would have caused the event alone. It is the combination
which creates an environment fertile for disaster.
>From a training perspective, the careful addition of these events
(typically called event sets) to a LOFT or other simulator experience is an
excellent way to allow a crew to practice their ability to recognize error
chains as they build, and give the instructor an opportunity to help them
improve their skills.
Not to blow my own horn (well maybe a little), I did a paper on this
process which you can find at:
http://users.why.net/neilkrey/pubs/sfpaper/simuflit.html
It are some rather large graphics in this paper which will take a little
time to load, but they help you step through the process of planning,
recognizing events which deviate from the plan, and then responding
effectively.
Best regards,
Neil Krey
neilkrey_at_why.net
http://users.why.net/neilkrey/