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development of interventions suitable
for future training — is warranted.
Such additional work could validate
the assumption that by exposing pilots
in the simulator to unusual critical
events, they are likely to develop both
specific and generic strategies for dealing
with them. Ideally, such exposure
also would engender a greater sense
of self-efficacy, in turn making pilots
significantly less likely to experience
acute stress reactions after real-world
severe startle.
Humans are particularly susceptible
to acute stress reactions, and unexpected,
threatening and critical events
often present circumstances in which
some individuals fail to cope well. The
physiological stress reaction has been
shown to have severe effects on working
memory and other cognitive functions,
with constructive thoughts being
replaced by task-irrelevant, anxious
thoughts. Acute stress reaction, which
is associated with an appraisal of threat,
can create situations in some people
in which they are overwhelmed and
freeze, or institute a coping mechanism
such as freezing or denial.
Paralyzed With Fear
Acute stress reactions are common
during life’s emergencies. One only has
to see human behavior shown on the
six o’clock evening news as a disaster
unfolds somewhere around the world.
Earthquakes, floods, fires, ship sinkings,
oil rig disasters or train wrecks
often turn up a mixture of behaviors.
Studies by several researchers, 1,2,3
through eyewitness accounts and
interviews with survivors, have looked
at why some people survived a disaster
and others did not. The survivors often
have reported seeing people who were
apparently paralyzed with fear and
incapable of movement, even when
such movement would have helped
them survive.
Inaction in the face of imminent
threat especially raises concern from
the aviation safety perspective. Airline
passenger behavior during aircraft accidents,
for example, has followed similar
patterns, with some researchers 4,5
finding that even in simulated evacuation
trials, behavioral inaction was
displayed by a number of the passengers.
One study suggests that 10 to 15
percent of people typically display such
pathological behavior when faced with
life-threatening situations, 3 and real-life
examples exist such as a fatal aircraft
fire 6 after a rejected takeoff known to
have involved passive inaction among
passengers.
This inaction, which is most likely an
acute stress reaction to an overwhelmingly
threatening stimulus, may be due
to an elementary freezing mechanism
within the brain 7,8 or indeed to a coping/
defense mechanism that seeks to deny
the existence or severity of the threat. 9,10
Inaction also may be the result of the
severe startle, and experiments by other
researchers have shown that cognitive
and dexterous (that is, hand/foot
dexterity) impairments could last for up
to 30 seconds following this degree of
startle. 11,12,13,14
While these reactions could be
considered typical among a small fraction
of the “innocent” participants in an
unfolding non-aviation disaster, people
expect that professional pilots — who
are generally well trained, very experienced
and presumably endowed with
the “right stuff ” 15 — will nonchalantly,
competently and flawlessly deal with
critical emergencies to avoid disaster.
Unfortunately, this may not be the case.
Extremely high aircraft reliability
has become the norm, so official findings
after an aircraft accident or serious
FLIGHTTRAINING
incident more often are peppered with
human failings involving the pilots. In
some relatively recent fatal accidents,
the findings showed that flight crews
mishandled critical events and failed
to recover the aircraft [ASW, 8/12, p.
14; ASW, 6/10, p. 32; ASW, 3/10, p. 20;
ASW, 4/11, p. 46]. Typically, there was
some delay in acting, or incorrect action
taken, which exacerbated the problem.
Although airline pilots routinely
practice engine failures, engine fires,
depressurizations and major system
malfunctions, the types of critical events
that prevail in recent accident data are
commonly regarded as “black swan”
events, that is, highly unusual. 16 They
involved unexpected situations in which
pilots became very surprised and/or
overwhelmed. Moreover, the response
to severe startle — or subsequent acute
stress reactions of freeze or denial — is
sometimes exacerbated by the flight
crew’s conditioned expectation for
things never going wrong. This unintentional
sense of complacency is born of
the ubiquitous normality in line operations,
week-in and week-out for long
periods of time.
Reaction Process
Central to the acute stress reaction is the
person’s appraisal that some particular
stimulus is threatening. Some researchers17
have described appraisal as “an
evaluative process that determines why
and to what extent a particular transaction
or series of transactions between the
person and the environment is stressful.”
They further have suggested that
appraisal involves two distinct processes:
primary appraisal, which determines
level of threat, and secondary appraisal,
which determines an appropriate
method of coping. This process is very
rapid and appears to precede consciousthought
processing in the cortex of the
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