'Human
performance Factors' is one of the main causal factor in the majority
of aircraft accidents. If the accident rate is to be decreased ,Human
Factors issues in aviation need to be better understood and
appreciated and proactively applied. By proactive application it is
meant that Human Factors knowledge should be applied and integrated
during the systems design and certification process and all
operational and workplace design, that is, before the systems and the
people become operational.
The human element is the most flexible, adaptable and valuable part in
the aviation system. "Human Errors " leading to air accidents and near
misses is of no help in their prevention because though probing into
the causes may lead us to WHERE the system breakdown has occurred but
no guidance as to WHY it has broken down. A human error may be due to
design procedures in the system, inadequate training or poor standard
operating procedures and checklists being maintained. The contemporary
SAFETY thinking requires that the human error should be the starting
point rather the stop rule in the event of incident or accident and
their prevention.
In 1975 Hawkins elaborated the interface of human factors, that is,
the live ware with the hardware or machines and software, that is, the
procedures, symbiology etc. and the environment in his very famous
SHEL MODEL depicted below.
The boundaries in the interface between these various systems are not
smooth as can be seen in the model. And any mismatch in them can lead
to incident or accident. To achieve matching in the various aspects a
clear understanding of the central component in the model i.e. the
Human component is paramount. The limitations of the human being in
terms of physical size and shape, the physical needs, their input
characteristics like efficiency, skills, well being in work place,
health and fatigue, their information processing skills and
boundaries, their output characteristics and environmental tolerances.
The human
being or the human factor is the hub of the SHEL model and all the
remaining components must be adapted and matched to this central
component.
To understand the importance of 'Human Factor' in aviation ,let us
look into the causal factors in a few air crashes.
1. In December 1972- an L1011 crashed in the Florida Everglades. On
investigation it was found that duties were not properly allocated and
the whole flight crew became preoccupied with a landing gear indicator
light bulb which led to the accident.
2. In 1974, a B707 crashed during approach in Pago-Pago in Samoa, with
a loss of 96 lives. A visual illusion related to black hole phenomenon
was a causal factor.
3.In 1974, a DC10 crashed because a cargo door failed, it opened and
blew out during take off.
4.In 1987 an MD 80 crashed on take off in Detroit. The pilots had not
set the flaps, thus violating the standard operating procedures.
In the recent years air traffic has incrasead multi folds all over the
world.The introduction of huge,wide bodied larger and faster aircraft
together with an increasing number of smaller aircraft has required
ATC to handle a greater variety of aircraft in the same designated
airspace with greater stress levels than before.Also in many parts of
the world , future Air Traffic demands are expected to exceed the
capabilities of current ATC systems, which must hence evolve or be
replaced to operate safely and efficiently to match the demands.
Sectorization of the airspace is not the perfect solution in today's
growing traffic scenario because of extra co-ordination and liasion
work involved. The solutions that can be devised which can take careof
the Human Factors are-
-
the
provision of better data to ATC
-
more
replacement of manual functions with automation
-
well kept
automated data handling and presentation
-
More
automated assistance for cognitive human tasks such as problem
solving and decision making
-
more
flexible use of airspace, based on operational requirements rather
than geographical boundaries
-
A change
from short- term, tactical interventions which solve problems that
arise, to strategic preplanning of efficient traffic flows to
prevent problems from arising
Today, we
need to design and devise aviation systems taking care of the
requirements and limitations of the ‘Human performance factors’. The
applicability of these factors are required in all technological
innovations such as satellite based navigational systems like PBN. We
need to identify all the Human factor consequences and to resolve the
associated problems not only of display, control, integration inter
faces, communications, understanding, memory, but also of team roles,
attitudes, norms and ethos to achieve the SAFETY we are looking for
.Ultimately we require a system where in there are so many safety
chains so that human performance error become the first safety ring
break-down and does not lead to breaking down of all rings and leading
to accidents and incidents.