Re: The causal factor...

Sakuma_at_BDZ.crane.jal.co.jp
Fri, 9 Oct 98 13:31:20 +0900

Dear Don :
Please allow me to intervene between you and Graham. You have provided us with
a good material for discussing human errors. As a starting point, let me
present here my own definition of human errors as follows.
"Human error is defined as a part of normal human behaviour in which the
expected level of performance cannot be achieved because (1) the performance of
human brain is lowered, or (2) the expected level of performance is too high."
In your lightning strikes case, the expectation of social public for the
airline industry(not necessarily for individual pilot) is to fly passengers
from point A to B safely and efficiently. If the safe flight cannot be
accomplished due to the effect of lightning strikes, we must say that the
failure to forecast severe lightning conditions is a human error by any
professional personnel who has responsibility in the airline organization. I
know that forecasting the turbulance or lightning condition is very difficult
for us even with current advanced forecasting technology, but would never be
"Mission Imposible" for human beings. In fact, even now, some airline is
reportedly challenging this difficult job as one of the major company
objectives. To be noted here is that to be blamed is not human error itself but
insufficient human effort to reduce or control human errors. Making errors is
not intentional while the lack of human effort is an intentional part of human
behaviour. To err is an inevitable result of human challenge for realizing
difficult dreams. Human error may never be eliminated since humans are destined
to never stop challenging. In this meaning, I think Graham's belief that human
error is a contributory factor in 100% of aircraft accidents may help encourage
relevant people to make effort to reduce and control human errors which may
appear in every human behaviours. Once again, we could not eliminate human
errors but could prevent accident by reducing or controling human errors. Only
intentional negligence for accident prevention should be blamed.
Hidetake Sakuma
Hidetake Sakuma

> Graham,
> If lightning strikes an airliner, and the airliner subsequently blow ups
> (don't laugh, at least one DC-8 went down this way) is the human still a
> contributory factor to the fatal accident? If you sight our inability to
> predict where lightning will strike or that they took-off when there were
> clouds in the sky then maybe it is human error. However, I would hardly
> believe that humans could be "contributory" factors in accidents 100% of
> the time. I think we need to be careful to catagorize what we believe are
> controllable cirsumstances vs. uncontrollable, necessary risks vs.
> unnecessary risks, etc. If we understood exactly how mother nature worked
> we'd probably eliminate many accidents. But only if one includes our
> general lack of understanding of weather as a human error can we really say
> that human's are partly to blame for 100% of accidents. And for weather
> forecasters: forecasts can only be as good as the models that create them,
> which can only be as good as the research and understanding of our weather
> systems. An inaccurate weather forecast is seldom the result of a human
> error! It is a result of a lack of ability to produce models that will
> account for all atmospheric anomalies. If you call this human error, all
> you're saying is that we just aren't smart enough when it comes to weather
> forecasting. In the presence of ALL available information, if a error
> occurs in forecasting, how can it be labled human error?
> Just some thoughts for discussion.
> Don
> At 08:15 AM 10/8/98 +1000, you wrote:
> >
> >"Statistics show that approximately 65 percent of all fatal air carrier
> >accidents list human error as a probable cause," said Dr. Herman Rediess,
> >director of the Office of Aviation Research."
> >
> >By probable cause, are we talking about primary cause or causal factors?
> >
> >If it is the latter, do we count ATC, Maintenance, design atc. as human
> error?
> >
> >At the risk of sounding pedantic, I believe human error is a contributory
> >factor in 100% of aircraft accidents. This does not aim to legitimise human
> >error, but to remind us of the importance of work in the area.
> >
> >Air traffic controllers, weather forecasters, maintenance engineers,
> >designers etc. are all human and therefore prone to human error.
> >
> >If we are talking about primary cause then that is a different matter, but
> >then let me pose this question:
> >
> >If an airliner has a crash in Australia (God forbid), who will determine
> >what contribution it has to accident statistics that are based on primary
> >cause? The Australian Bureau of Air Safety which investigates accidents in
> >Australia stopped using 'primary cause' years ago and now only uses
> >'Findings' and 'Significant Factors'.
> >
> >
> >
> >
> >
> >Dr. Graham Braithwaite
> >Department of Aviation
> >University of New South Wales
> >Sydney 2052
> >Australia
> >
> >Tel: +61 (0) 2 9385 6757
> >Fax: +61 (0) 2 9385 6637
> >Mobile: 0414 736 467
> >