Stress

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• Cell damage - especially within the brain.

• Heat stroke.

• Coma.

• The body loses water through the skin, lungs and kidneys.

Should the blood temperature rise to approximately 43°C (110°F), death will result.

Note: Generally speaking the mind and body need an average of 2 weeks to acclimatise to a hot
and humid environment.

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Stress
Extreme Cold Stress
If the core temperature drops to approximately 35°C shivering declines and eventually ceases.

The e ects of extreme cold are:

• Uncontrollable shivering and an associated need for more oxygen. Around 34.5°C, the
shivering that will have started earlier will tend to cease.

• Cell damage - especially of the brain.

• Sleepiness associated with a feeling of contentment or apathy.

• Circulatory impairment and degradation of the sensory nerves.

• Severe damage to the skin and tissues (frostbite).

• Coma.

• Death.

It is important to stress that the e ects of exposure to extreme temperatures are not restricted
to the more dramatic conditions described above. Smaller temperature variations within these
limits can have a detrimental e ect on a person’s ability to perform a task.

Internal Physiological Factors

The most important of these factors are:

• Hunger.
• Thirst.
• Fatigue.
• Lack of sleep.
• Pain.

With the exception of pain, these factors are normally within the control of aircrew. It is of
fundamental importance that crews ensure they never start a period of duty with any of these
internal physiological stressors.

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The Brain’s Ability to Adapt to Physiological Stressors

Repeated exposure to moderate levels of stress from the environment will cause the body to
adapt to the stress in order to reduce its impact. For example if an individual lives close to a
busy airport the sounds may not be noticed a er a time, whereas a visitor might well comment
on the noise levels. This ability is limited and varies from person to person.

Cognitive Stress Factors/Stressors

These di er from physiological stressors since they depend on the operator’s professional
knowledge, experience and skill.
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They can occur in the cockpit under the following conditions:

Stress

• When the situation facing the pilot is unexpected and no procedure exists to resolve it.

• When the solution to the unexpected problem is realized but the pilot has insu cient time,
or is unable to apply the solution. This can occur when the pilot is “overloaded”.

• When the solution is applied but the results are not as expected and the problem remains
unsolved.

Level of Cognitive Stress

This will depend upon:

• The individual’s inborn and learnt characteristics. A pilot may be easily stressed in such
a situation either because of his personal character traits and sensitivity to stress or the
realisation that he/she possess insu cient knowledge to solve the new problem.

• The time available to solve the problem. In a dynamic situation, a lack of time is, in itself, an
additional source of stress and will o en lead to risk taking.

Non-professional Personal Factors/Stressors

In our modern, complex lives we are subjected to a plethora of life stresses and o en nd
that we are unable to ‘switch o ’ so that, inevitably, we carry these stresses from home to the
workplace and vice versa.

Bereavement
The loss of a spouse, partner or child has been found to lead to higher levels of stress than
any other event. Some airlines will ensure that a pilot su ering such a loss is removed from
ying duties for a time as they are aware that the pilot’s stress level will be so high that his/her
performance and reactions could be severely degraded.

Domestic Stress
Stress at home can a ect the pilot at work and equally stress at work can a ect the pilot’s
home life. Pilots su ering from domestic stress should be aware that this can a ect their
concentration and performance when at the controls of an aircra . Aircrew must try and use
all available facilities to ensure that they are not being a ected by this form of stress.

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Non-professional Personal Factors/Stressor Table
Evidence indicates there is a relationship between stress and health and some evidence for a
correlation between non-professional stress and the risk of an accident.

Although the stress level caused by a particular stressor will di er from one individual to
another, it is possible to make a general assessment of stress levels.

The table below gives a suggested weighting for various incidents in an average westerner’s
life. When applying such weighting to other cultures there will be some marked di erences.
Aircrew must remain sensitive to these cultural di erences.

As stress is cumulative, all of the events experienced should be added to give an indication of

7
the total stress acting on any one person.

Stress
Stress Table
Death of a spouse, partner, or child 100
Divorce 73
Marital separation 65
Death of a close family member 63
Personal injury or illness 53
Marriage 50
Loss of job 47
Retirement 45
Pregnancy 40
Sexual problems 40
Birth 39
Change of nancial situation 38
Son or daughter leaving home 29
Change of eating habits 25
Change of residence 20
Taking on a bank loan or HP debt 17
Vacations 13
Minor violations of the law 11

This list is not a complete catalogue of all events which may cause stress and the weighting
given will vary according to the personal background and cultural system in which the individual
was raised. As a guide only, to indicate your own stress level, add together the marks for each
event occurring in your life in the last six months.

Scoring:

Below 60 marks: a life unusually free of stress.

60 - 80 marks: normal amount of stress.
80 - 100 marks: stress in life is rather high.
100+ marks: under serious amount of stress.

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Imaginary Stress (Anxiety)

Both human beings and animals can su er from stress without there being a stressor present.
It is the anxiety that a future risk exists together with the feeling of an inability to cope or
lack of self-con dence. An example of this natural response is when a dog is taken to the vet,
having experienced pain during a previous visit. The animal shows signs of anxiety even though
no stressor exists. Some of us have similar feelings about a visit to the dentist. Inevitably anxiety
will a ect our performance.

Unpleasant events in life may be apparently completely forgotten but the anxiety associated
with them can be brought to the surface by one of the senses (a scene, noise, smell) and distort
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perception. This anxious apprehension can be strong enough so as to trigger the GAS response.
Stress

Organizational Stress
The Organization
In the aviation industry today, nancial pressures on companies can cause pilots to work under
considerable pressure. Small unserviceabilities may be carried, duty hours stretched to the limit,
checks rushed to make a slot time, and there are many other examples. As an extreme example
of stress generated by poor management, the president of an airline which was in nancial
di culties, instructed pilots to y below the legal minima in bad weather. They were also
instructed to ignore maximum take-o weights and reduce minimum fuel reserves. As a direct
result of these decisions the airline su ered three serious accidents in a short period.

If management continually exerts pressure on its employees to operate in ways that are more
consistent with short-term monetary concerns than with safety and good practice, then the
whole company will develop ‘organizational stress’.

The symptoms will manifest themselves as:

• Poor industrial relations.

• Absenteeism.
• An increased accident/incident rate.

Aircrew and the Organization

Work stress may be caused by a sudden high work load such as an emergency. The stress
experienced will be increased if the pilot is unsure how to react or feels inadequately trained
for the speci c situation. Realistic simulator training is essential to reduce the impact of any
emergency.

Stress may also arise from a long-term high work load. Airlines operate in a competitive world
and must make maximum use of sta and equipment. An aircra and crew standing idle
are not producing revenue. Even with the advances of modern ATC there will be times when
airspace and airports become overcrowded. Add to this technical delays and additional stress
is created.

Rostering of crews can also lead to stress problems. A particular pilot may have to perform an
excessive number of night ights and su er undue disruption to his home life. This, in turn,
leads to further cumulative stress.

Poor relationships and/or communications with management and colleagues, both on and o
the ight deck, leads to stress. Some cockpit voice recordings, listened to a er accidents, have
detected crew members arguing on the ight deck just prior to the accident.

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Organizational Stress Sources in Pilots
A survey of commercial pilots showed some of the main sources of stress to be:

• A lack of control or disruption of events in their lives.

• Scheduling and rostering.
• Insu cient hands-on ying.
• Anxiety over courses/checks.
• Home to work interface.
• Career prospects and achievements.
• Lack of responsibility and decision making.
• Fatigue and ying patterns.

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Of signi cance in the above list is insu cient ying. The modern airliner is most e ciently and

Stress
economically operated by automatic control, indeed it is the policy of many airlines that the
ight management system should operate the aircra for more than 96% of its ight time.
Whilst modern systems and their back-ups are undoubtedly extremely reliable, many pilots
are worried that the systems may fail and are unsure of their ability to manage the aircra
themselves. A pilot ying the maximum allowable duty hours may have very little actual hands-
on time per month.

Stress Effects
Stress has e ects on the body, the mind, and the health and thus the performance of the
individual. The short-term e ects of a sudden source of stress will be caused by the ‘ ght or
ight’ response.

Performance
Figure 7.5 shows the relationship between stress and performance. Like the arousal/
performance graph it is an inverted U curve, however, there is a “break point”.

When there is little or no stress, there is a drop in vigilance and performance is poor. As stress
increases performance increases up to the optimum - the “break point”- a er which, if stress
continues to rise, performance is degraded.

PERFORMANCE BREAKPOINT

STRESS LEVEL

NO MEDIUM INTENSE
STRESS STRESS STRESS
MOTIVATION

Figure 7.5 Comparison of performance and stress levels

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Health Effects
The long-term e ects of chronic stress damage a person’s health. The e ects are usually seen
earliest in the gastrointestinal system, and symptoms include nausea, indigestion, diarrhoea
and, a er an extended period of time, ulcers. There is evidence of a connection between stress
and coronary heart disease and high blood pressure. Those who su er stress have a higher
than normal risk of getting of asthma, headaches, sleep disorders and neuroses. They also
are much more likely to have allergies, skin diseases and tend to su er more from colds and
in uenza.

Behavioural Effects
When under stress the individual will exhibit restlessness, trembling, or may have a nervous
7

laugh. There will be a tendency to take longer over tasks and there may well be excessive
changes in appetite and an increase in smoking or drinking.
Stress

Moods swings are also a common symptom of stress. Some individuals become aggressive in
the cockpit towards other members of the crew and/or outside agencies (ATC). On the other
hand, others submit to the situation with an air of resentfulness and frustration. Either way
there is a loss of exibility. Alternatively, there are some individuals who react to stress by a
tendency to rush into decisions. Fewer parameters are taken into account and, therefore, the
risk of errors is increased.

Cognitive Effects
Stress has a major e ect on the thought process with forgetfulness being an early symptom.
The ability to think and to concentrate is reduced and there is an inability to determine
priorities or make decisions. Correct actions are forgotten and procedures learnt in the past
are substituted. This is known as regression.

Fixation or “mental block,” is another symptom, where it becomes impossible to review what
has been done and consider other solutions.

A further cognitive e ect is con rmation bias, which is discussed further in Chapter 8. This is a
compulsive and repeated search for information to con rm a decision reached.

Stress causes the mind to limit its attention to only those factors it feels it can cope with and
to ignore additional inputs which may be vital in assessing a situation accurately. This loss of
situational awareness and “not being able to see the wood for the trees” has been the root
cause of many accidents.

In one case, when debriefed a er escaping successfully from a burning aircra , passengers
reported how quiet everything around them seemed to be. It was stress that caused them to
concentrate only on their escape, the screams around them were never registered.

It is commonly accepted that auditory information is the rst to be discarded under extreme
stress.

Coping with Stress

Stress Awareness
In order to cope with stress it is fundamental that there is an awareness that the problem
exists. An individual who recognizes the fact that he/she is su ering from stress is a long way
along the road to identifying the source(s) and overcoming the problem. Once recognized, the
object is to change our attitudes or our environment in order to re-establish harmony between
the two.

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7
Among any population there is a wide variation in how stress is perceived. At one extreme,
individuals suppress knowledge of problems and thereby appear not to perceive them or
require stress coping strategies. At the other extreme are those who are highly sensitive to
problems and will anticipate di culties not perceived by others and employ coping strategies
to avoid the stress experience.

Coping strategies may be classi ed into three categories:

• Action Coping.
• Cognitive Coping.
• Symptom Directed Coping.

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Action Coping

Stress
In action coping the individual attempts to reduce stress by taking some action. He reduces the
level of demand by either removing the problem or changes the situation so that it becomes
less demanding. For example a pilot asked to y in marginal conditions could refuse, thus
removing the immediate stressor. However, this action could lead to another stressor - loss of
employment.

The demand could be changed, however, by delaying take-o for a few hours when the weather
is forecast to improve. In this case, reducing the perceived demand of the original task, without
substituting another stressor. The individual may also hand over some tasks, either to other
crew members, or to Air Tra c Control by asking for, as an example, assistance in navigation.

The individual may remove himself from the stress situation by changing his job, or in the case
of domestic stress, by divorce. These methods may, however, only substitute one source of
stress for another. Clearly in many cases it is impossible to undertake this kind of solution.

Cognitive Coping
As action coping cannot change some situations, cognitive coping involves reducing the impact
of stress on the individual. Our brain can employ ‘defence mechanisms’ which operate outside
our conscious awareness; a system of repression or denial to prevent the conscious brain from
even becoming aware of the stressor.

Other strategies involve rationalization or detachment which may change the perceived
magnitude of the problem. “Pretend it’s a simulator detail the same as the one you did last
week” will enable the conscious mind to perceive the problem as having a solution.

Symptom Directed Coping

Some of the symptoms of stress may be relieved by the use of drugs. In this context the drugs
may be relatively simple such as co ee or tea. Other cases may be eased by the use of alcohol
or tobacco.

It must be emphasized that only the symptoms are treated by this form of coping and that the
stressor(s) will remain until addressed separately.

Coping with Stress on the Flight Deck

Coping is the process whereby the individual either adjusts to the perceived demand of
the situation or changes the situation itself. Some coping changes appear to be carried out
unconsciously; it is only if they are unsuccessful that we consciously take note of the stressor.
To reduce the e ect of stress in ight involves mainly psychological mechanisms and includes
behavioural patterns which can be learned.

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Individually one must learn and acquire experience to develop automatic responses which cost
little in energy and strongly resist stress:

• A thoroughly professional approach to training will increase the range of responses available
to the individual and will reduce the chances of meeting unknown situations. Hence the
emphasis on regular simulator ights when any emergency can be practised in a safe
environment.

• One should learn from the past, including the experience of others.

• Thorough pre ight brie ng and preparation will allow the individual to anticipate events.
The pilot must be prepared for all incidents which could, plausibly, arise during the ight.
7
Stress

Crew Resource Management (CRM) will teach techniques for sharing and allocating tasks
to prevent any one individual becoming overloaded and will highlight the e ective use of all
members’ knowledge to increase the range of possible responses. It should improve everyone’s
awareness of the situation, and, by combined e orts, allow for the creation of new ideas.

A good atmosphere on the ight deck is a great help in a stressful situation and humour can
be an e ective antidote to stress.

There are ve major guidelines to prevent stress a ecting safety:

• Keep it simple and basic - y the aircra .

• Accept the situation - do not attempt to conceal the facts or danger.
• Use all crew resources (group support).
• The captain (unless incapacitated) must make the decisions and control the situation.
• Never give up: there is always a suitable response.

Stress Management Away from the Flight Deck

The success of any stress management programme will be determined by the individual’s
willingness to recognize the source of his/her stress and the determination to do something
about it. A good stress management programme should be both:

• Preventative ( nding ways to keep stress levels to a minimum)

and

• Curative (providing ways of reducing existing levels of stress)

Helpful techniques can include:

• Health and Fitness Programmes

Regular physical exercise reduces tension and anxiety and makes it much easier to withstand
fatigue. Physical tness also improves cognitive function and improves reaction times.

• Relaxation Techniques
Meditation, self-hypnosis, yoga, and biofeedback can all help to reduce tension by mental
and physical (muscle) relaxation or control of heart rate and blood pressure.

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• Religious Practice
For many people some form of religious practice will help to cope with stress, particularly if
it is a major life event such as bereavement, accident or chronic illness. There are, however,
some possible dangers if the particular belief is of a fatalistic nature. “It is in the hands of
God” may prevent some individuals from trying to resolve their own problems.

• Counselling Techniques
Many individuals will bene t not only from professional counselling but also from just
talking to their friends or colleagues. It will help to reduce feelings of inadequacy if they
know that others nd a particular task di cult.

The basic principle behind counselling is that, since stress is caused by an individual’s perception

7
of a situation, the stress will be reduced if the individual can be made to change the way he/

Stress
she perceives or reacts to the situation by changing or modifying his/her beliefs or assumptions
about the event (cognitive coping). Counselling may also assist an individual to see that some
behavioural change may be necessary (action coping), and help bring about that change.

An individual, such as a pilot, who must demonstrate authority and control in his work may
show some reluctance to ‘admit’ that he is experiencing problems with stress. He may fear that
the admission of being under stress might be interpreted as weakness or a lack of competence.
All pilots should be aware that stress can in uence performance on the ight deck, particularly
in an emergency, and take positive steps to deal with the stress if they feel they are a ected
by it.

Note: Evidence that people under stress o en smoke more, overeat or increase alcohol/ca eine
consumption has led to the theory that apparent self-abusive behaviours may actually be forms
of stress management.

Stress Summary
Stress is simply a fact of life. We all require some stress to activate our nervous system, to
stimulate us and allow us to adapt. It is only when the stress is high or sudden that it can
become destructive and may exceed our abilities to adapt. Stress encountered in our daily lives
is cumulative and depletes our reserves. However, a lack of stimuli may be just as bad since this
encourages anxiety.

Although it is extremely di cult to eliminate stress, we can, through training and other
techniques, increase our resistance to it. Stress coping can be either short-term (action coping)
or long-term Stress Management (a change of lifestyle or counselling) depending on the
situation. The rst step is, however, to recognize and admit to oneself that the condition exists.

Although the stress mechanism is mainly physiological and triggered as a defence mechanism
to help us survive, coping strategies to deal with stress are mainly psychological.

To increase stress tolerance the chief weapons in your armoury are:

• Experience (fewer unexpected situations).

• Learning (re ex responses are performed correctly, even under stress).

• CRM (using all resources available).

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