Page 20 - AAPT March 2019

Feature Story
A pilot may believe they

are fully engrossed in the
system and fully aware of
their current situation and

suddenly the automated
system behaves completely
unexpectedly; the

pilot detects but does not
understand the issue …

need to duly concern themselves with
exactly how much complexity a pilot is
able to comprehend effectively.
Do aircraft systems
designers appreciate
the human dimensions
of their work?
The safety philosophy behind the
adoption of increasing onboard
automation is based on the assumption
that human error is the main cause of
accidents (Chialastri, 2012). If it is the
human that is the weak link in the chain
should it not be removed?
Chialastri argues that pilots and
machines should not be substituted
for one another but instead be
complimentary in order to achieve the
correct balance to maximise aviation
safety potential.
Although automation has
dramatically reduced the occurrence
of aviation accidents, that rate has
stagnated since the 1980s (Boeing,
2013). Following investigations into times with an already high workload and the rapid increase of air travel and the
accidents around this period it was decreased during times of low workload resultant need for reduction of costs
concluded that the human operator had (Weiner, 1989). related to better performances, lower
not been considered as a component of This indicates that aircraft automated fuel consumption, cheaper maintenance
the overall structure when designing the system designers did not appreciate and flexible pilot training — the main
automated system and that no effort had the human dimensions of their work drivers of modern cockpit design
been made to combine the human and or attempt to comply with the human (Chialastri, 2012). These factors could
machine into a cooperative unit (Dehais factors literature being produced at the explain why we are still yet to observe
et al., 2015).
This has not, however; been at the time. another marked drop in accidents per
forefront of designer’s minds. In a NASA Since the 1980s there has been million.
study of human factors in advanced a considerable increase in academic Reason (2000) lists four safety
automated aircraft, (the Boeing B-757) literature relating human factors and paradoxes based on the study of high
the pilots expressed that they felt the automation but not so much has reliability organisations, the third of
automation left them out of the loop translated into actions on the system- which applies to the attitude of aviation
and also found that the automation designer end. This may be due to a automation over past decades. Many
increased the workload during flight multitude of factors but most markedly, organisations seek to limit the variability

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