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FLIGHTTRAINING
Results of Startle Experiment in Boeing 737 Simulator
Stimulus Altitude
(AGL)
student became unresponsive, and the
instructor pilot had to physically hit the
student to get him to release his iron grip
on the controls. A successful recovery
was finally made close to bailout altitude.
Denial
Denial also is an emotionally focused
coping mechanism, and, like freezing,
a very rudimentary human process.
If a person appraises the stimulus as
being particularly threatening, and
this mechanism is implicitly invoked,
then the stressful stimulus may simply
be ignored.
Denial also appears to have a
subconscious strategic purpose. This
is remarkably common, particularly in
people with life-threatening illnesses.
Approach 1
Lowest Alt During Go-Around
With Stimulus
Approach 2
Lowest Alt During Go-Around
Without Stimulus
240 ft 170 170
240 ft 170 140
240 ft 170 190
240 ft 160 110
240 ft 160 170
240 ft 150 180
240 ft 150 160
240 ft 150 170
240 ft 150 170
240 ft 140 170
240 ft 140 160
240 ft 200 170
240 ft 220 160
240 ft 86 140
240 ft 66 150
240 ft 56 180
240 ft 0 (landed) 150
240 ft 0 (landed) 190
Alt = altitude, AGL = above ground level
Note: The 18 participating type-rated pilots descended 36.1 ft on average during their delayed reaction
to the startle stimulus induced by the researchers on their first approach.
Source: Wayne Martin, Patrick Murray and Paul Bates
Figure 2
Many would ignore the symptoms for
some time rather than confront the
stressful issue of their mortality.
Denying the threat’s existence can
be very effective in relieving stress;
however, continual reappraisal and
dynamic denial are required for this
coping mechanism to persist. Dynamic
denial occurs when the flow of
critical information is not continually
processed as part of this pathological,
acute-stress coping mechanism.
While this could be problematic
when situations such as deteriorating
weather or aircraft status compound
the threat, the more immediate
stressors — those conducive to dynamic
denial — generally are of greater
concern in critical events. So dynamic
denial could have severe implications
in airborne critical events because of
the careful analysis and logical problem
solving required.
The airline pilot interviews for
the thesis revealed that short-term
denial was relatively prevalent during
these events, with participants reporting
that some level of denial had been
experienced in 15 of the 45 events they
recalled. This was generally short-term
denial, and it did not turn out to be of
catastrophic consequence. However, it
raises the question of how many fatal
accidents have involved denial, with the
pilots never achieving recovery or with
recovery being delayed too long.
The pilots’ interview responses also
indicated that such brief periods of
denial were not unusual, although in all
of the situations that interviewees discussed,
denial was quickly overcome as
rational processing kicked in. Dynamic
denial, if it had persisted, could have
been particularly detrimental to the
outcome of the situation, although it
is impossible to tell from accident data
whether denial was involved. However,
there are several examples of instances
in which pilots took no action at a time
when intervention was required, indicating
that dynamic denial is at least a
possibility. Further research in this area
is required.
One subject specialist 23 even has
described a pathological taxonomy
of seven different stages: denial of
personal relevance, denial of urgency,
denial of vulnerability, denial of affect,
denial of affect relevance, denial of
threatening information and denial of
information. While the early stages are
mildly concerning in the aviation context,
the latter stages — when threatening
information or all information is
denied — are particularly worrisome in
the aviation safety context.
32 | FLIGHT SAFETY FOUNDATION | AEROSAFETYWORLD | MAY 2013