- •Textbook Series
- •Contents
- •1 Basic Concepts
- •The History of Human Performance
- •The Relevance of Human Performance in Aviation
- •ICAO Requirement for the Study of Human Factors
- •The Pilot and Pilot Training
- •Aircraft Accident Statistics
- •Flight Safety
- •The Most Significant Flight Safety Equipment
- •Safety Culture
- •Reason’s Swiss Cheese Model
- •The Five Elements of Safety Culture
- •Flight Safety/Threat and Error Management
- •Threats
- •Errors
- •Undesired Aircraft States
- •Duties of Flight Crew
- •2 The Circulation System
- •Blood Circulation
- •The Blood
- •Composition of the Blood
- •Carriage of Carbon Dioxide
- •The Circulation System
- •What Can Go Wrong
- •System Failures
- •Factors Predisposing to Heart Attack
- •Insufficient Oxygen Carried
- •Carbon Monoxide
- •Smoking
- •Blood Pressure
- •Pressoreceptors and their Function Maintaining Blood Pressure
- •Function
- •Donating Blood and Aircrew
- •Pulmonary Embolism
- •Questions
- •Answers
- •3 Oxygen and Respiration
- •Oxygen Intake
- •Thresholds of Oxygen Requirements Summary
- •Hypoxic Hypoxia
- •Hypoxic Hypoxia Symptoms
- •Stages/Zones of Hypoxia
- •Factors Determining the Severity of and the Susceptibility to Hypoxic Hypoxia
- •Anaemic Hypoxia
- •Time of Useful Consciousness (TUC)
- •Times of Useful Consciousness at Various Altitudes
- •Effective Performance Time (EPT)
- •Hyperventilation
- •Symptoms of Hyperventilation
- •Hypoxia or Hyperventilation?
- •Cabin Pressurization
- •Cabin Decompression
- •Decompression Sickness (DCS)
- •DCS in Flight and Treatment
- •Questions
- •Answers
- •4 The Nervous System, Ear, Hearing and Balance
- •Introduction
- •The Nervous System
- •The Sense Organs
- •Audible Range of the Human Ear and Measurement of Sound
- •Hearing Impairment
- •The Ear and Balance
- •Problems of Balance and Disorientation
- •Somatogyral and Somatogravic Illusions
- •Alcohol and Flying
- •Motion Sickness
- •Coping with Motion Sickness
- •Questions
- •Answers
- •5 The Eye and Vision
- •Function and Structure
- •The Cornea
- •The Iris and Pupil
- •The Lens
- •The Retina
- •The Fovea and Visual Acuity
- •Light and Dark Adaptation
- •Night Vision
- •The Blind Spot
- •Stereopsis (Stereoscopic Vision)
- •Empty Visual Field Myopia
- •High Light Levels
- •Sunglasses
- •Eye Movement
- •Visual Defects
- •Use of Contact Lenses
- •Colour Vision
- •Colour Blindness
- •Vision and Speed
- •Monocular and Binocular Vision
- •Questions
- •Answers
- •6 Flying and Health
- •Flying and Health
- •Acceleration
- •G-forces
- •Effects of Positive G-force on the Human Body
- •Long Duration Negative G
- •Short Duration G-forces
- •Susceptibility and Tolerance to G-forces
- •Summary of G Tolerances
- •Barotrauma
- •Toxic Hazards
- •Body Mass Index (BMI)
- •Obesity
- •Losing Weight
- •Exercise
- •Nutrition and Food Hygiene
- •Fits
- •Faints
- •Alcohol and Alcoholism
- •Alcohol and Flying
- •Drugs and Flying
- •Psychiatric Illnesses
- •Diseases Spread by Animals and Insects
- •Sexually Transmitted Diseases
- •Personal Hygiene
- •Stroboscopic Effect
- •Radiation
- •Common Ailments and Fitness to Fly
- •Drugs and Self-medication
- •Anaesthetics and Analgesics
- •Symptoms in the Air
- •Questions
- •Answers
- •7 Stress
- •An Introduction to Stress
- •The Stress Model
- •Arousal and Performance
- •Stress Reaction and the General Adaption Syndrome (GAS)
- •Stress Factors (Stressors)
- •Physiological Stress Factors
- •External Physiological Factors
- •Internal Physiological Factors
- •Cognitive Stress Factors/Stressors
- •Non-professional Personal Factors/Stressors
- •Stress Table
- •Imaginary Stress (Anxiety)
- •Organizational Stress
- •Stress Effects
- •Coping with Stress
- •Coping with Stress on the Flight Deck
- •Stress Management Away from the Flight Deck
- •Stress Summary
- •Questions
- •Answers
- •Introduction
- •Basic Information Processing
- •Stimuli
- •Receptors and Sensory Memories/Stores
- •Attention
- •Perception
- •Perceived Mental Models
- •Three Dimensional Models
- •Short-term Memory (Working Memory)
- •Long-term Memory
- •Central Decision Maker and Response Selection
- •Motor Programmes (Skills)
- •Human Reliability, Errors and Their Generation
- •The Learning Process
- •Mental Schema
- •Questions
- •Answers
- •9 Behaviour and Motivation
- •An Introduction to Behaviour
- •Categories of Behaviour
- •Evaluating Data
- •Situational Awareness
- •Motivation
- •Questions
- •Answers
- •10 Cognition in Aviation
- •Cognition in Aviation
- •Visual Illusions
- •An Illusion of Movement
- •Other Sources of Illusions
- •Illusions When Taxiing
- •Illusions on Take-off
- •Illusions in the Cruise
- •Approach and Landing
- •Initial Judgement of Appropriate Glideslope
- •Maintenance of the Glideslope
- •Ground Proximity Judgements
- •Protective Measures against Illusions
- •Collision and the Retinal Image
- •Human Performance Cognition in Aviation
- •Special Situations
- •Spatial Orientation in Flight and the “Seat-of-the-pants”
- •Oculogravic and Oculogyral Illusions
- •Questions
- •Answers
- •11 Sleep and Fatigue
- •General
- •Biological Rhythms and Clocks
- •Body Temperature
- •Time of Day and Performance
- •Credit/Debit Systems
- •Measurement and Phases of Sleep
- •Age and Sleep
- •Naps and Microsleeps
- •Shift Work
- •Time Zone Crossing
- •Sleep Planning
- •Sleep Hygiene
- •Sleep and Alcohol
- •Sleep Disorders
- •Drugs and Sleep Management
- •Fatigue
- •Vigilance and Hypovigilance
- •Questions
- •Answers
- •12 Individual Differences and Interpersonal Relationships
- •Introduction
- •Personality
- •Interactive Style
- •The Individual’s Contribution within a Group
- •Cohesion
- •Group Decision Making
- •Improving Group Decision Making
- •Leadership
- •The Authority Gradient and Leadership Styles
- •Interacting with Other Agencies
- •Questions
- •Answers
- •13 Communication and Cooperation
- •Introduction
- •A Simple Communications Model
- •Types of Questions
- •Communications Concepts
- •Good Communications
- •Personal Communications
- •Cockpit Communications
- •Professional Languages
- •Metacommunications
- •Briefings
- •Communications to Achieve Coordination
- •Synchronization
- •Synergy in Joint Actions
- •Barriers to Crew Cooperation and Teamwork
- •Good Team Work
- •Summary
- •Miscommunication
- •Questions
- •Answers
- •14 Man and Machine
- •Introduction
- •The Conceptual Model
- •Software
- •Hardware and Automation
- •Intelligent Flight Decks
- •Colour Displays
- •System Active and Latent Failures/Errors
- •System Tolerance
- •Design-induced Errors
- •Questions
- •Answers
- •15 Decision Making and Risk
- •Introduction
- •The Mechanics of Decision Making
- •Standard Operating Procedures
- •Errors, Sources and Limits in the Decision-making Process
- •Personality Traits and Effective Crew Decision Making
- •Judgement Concept
- •Commitment
- •Questions
- •Answers
- •16 Human Factors Incident Reporting
- •Incident Reporting
- •Aeronautical Information Circulars
- •Staines Trident Accident 1972
- •17 Introduction to Crew Resource Management
- •Introduction
- •Communication
- •Hearing Versus Listening
- •Question Types
- •Methods of Communication
- •Communication Styles
- •Overload
- •Situational Awareness and Mental Models
- •Decision Making
- •Personality
- •Where We Focus Our Attention
- •How We Acquire Information
- •How We Make Decisions
- •How People Live
- •Behaviour
- •Modes of Behaviour
- •Team Skill
- •18 Specimen Questions
- •Answers to Specimen Papers
- •Revision Questions
- •Answers to Revision Questions
- •Specimen Examination Paper
- •Answers to Specimen Examination Paper
- •Explanations to Specimen Examination Paper
- •19 Glossary
- •Glossary of Terms
- •20 Index
Decision Making and Risk 15
Consider the pilot who must choose, for example, between turning back in the face of potentially bad weather (with the certainty of disappointing passengers and, perhaps, personal embarrassment), or continuing on (with the chance of getting through safely and on time but also with a chance of suffering a major disaster). The choice is clearly between two negatives: a sure loss against an uncertain possibility of a disaster. Research has found that people have a bias to favour the risky choice. Many, many pilots and passengers have died as a result of this bias (“press-on-itis”).
Interestingly, this risk-seeking tendency is reversed when the choice is framed as one between gains. Here the sure thing alternative is favoured.
The really important point is that if our pilot could have framed his choice differently as a choice between two gains (the certainty of saving lives by turning back versus the possibility of not disappointing the passengers by continuing), he/she would have been biased to make the wiser decision.
AssignTasks
Workload is shared amongst the crew by the assigning of tasks. It should not be forgotten that tasks may also be assigned to outside agencies (traffic information or diversion/holding of other aircraft by ATC).
Implement Decision
The Commander of the aircraft is responsible for supervising and monitoring the implementation of his/her decision.
Consequences
If the decision has been correct, the outcome of its implementation should be the Commander’s original objective. If not, then either the decision is incorrect or the situation has changed.
Review and Feedback
The situation is constantly changing in the air. Review of actions by the flight crew is fundamental and it should be ongoing. If the situation has changed, then the Commander should check whether the outcome of his/her decision is still valid - if it is no longer valid, the whole process starts again from the beginning. Thus the real situation is thereby continually monitored.
Standard Operating Procedures
Rule-based Behaviour is one of the things that makes aviation as safe as it is today. Wherever possible, laws, procedures, vital actions and checklists are produced for the crews to follow. This, in itself, reduces the amount of decision making that crews have to carry out.
Errors can occur at the interface between liveware and software as it is very easy for individuals to misinterpret the content of checklists, manuals, maps, charts and airport guides. In order to try to minimize these errors, Standard Operating Procedures have been introduced and, if strictly adhered to, should be successful in reducing the number of mistakes.
One disadvantage is, however, that SOPs cannot be published for every possible situation.
They are aimed at establishing a pattern of behaviour that becomes habitual. As most airlines employ the practice of standardizing equipment and procedures, it is possible for the operating habits learned on one aircraft mark or type, to be carried over to another.
Decision Making and Risk 15
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15 Decision Making and Risk
The standardization and training will allow routine tasks to be performed with less attention and effort. Design carry-over will also minimize confusion and reduce training time and costs.
SOPs should be shared by crew members and modified/updated to maintain synergy.
Errors, Sources and Limits in the Decision-making Process
Risk and Making Decision 15
The Decision-making process is prone to human error and may be limited by outside factors.
Errors
•Confirmation Bias
See Chapter 8. The best method to avoid this error is to deliberately look for information that will falsify the hypothesis rather than confirm it.
•Probability
The pilot will be heavily influenced by the probability of an occurrence. For example a bang heard on take-off could be a tyre burst, a bird strike, or an engine failure. A burst tyre is the most probable cause of a loud noise at this stage. Thus pilots may automatically carry out the initial drills for that event.
•Saliency
People often tend to focus attention most heavily on those cues that are physically salient
(loud, bright, recent, centrally visible, easy to interpret). Thus vital non-salient information may be overlooked.
•Overconfidence
An overconfidence either of personal skill or decision-making ability has been the direct cause of many bad airborne decisions. A good aviator, however experienced, is the first to admit that there is always much to learn. Overconfidence breeds complacency. Hand-in- hand with complacency is the loss of motivation to practise or learn. Performance can only deteriorate. This is sometimes known as the “Deterioration Effect”. The higher accident rate for general aviation pilots with between 1 000 and 3 000 flying hours, compared with those less experienced, is often explained by this effect.
•Fatigue/Overload
Both fatigue and overload will seriously affect decision making.
•Denial
A common aspect of human attitude when exposed to risk is that of denial. This can typically manifest itself as one of the following behavioural patterns:
•Procrastination “I’ll continue to fly on for a little longer and then decide”.
•Rationalization “It’ll all work out just fine”.
•Hope and desires “It’s bound to clear on the other side of these hills”.
•Refusal to admit “It’s not like that and anyway it can’t happen to me”.
•Status and reputation “I’m just not going to be beaten”.
•Refusal to review “It worked last time in roughly the same situation”.
Each of the above examples is a form of denial. It is a refusal to accept, admit, confront, change or decide and has been the cause of many accidents. It is fundamental that, in order for a good decision to be reached, the REAL situation is analysed, confronted and assessed.
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Decision Making and Risk 15
Limitations
•Attention
Human attention is limited or may be “funnelled” (perhaps due to stress) and thus input of information may be significantly curtailed.
•Stress
As we have already seen, stress can have a dramatic effect on both the human body and mind. Decisions made under stress are rarely of high quality.
•Lack of experience
Lack of experience will certainly slow down the decision-making process since diagnosis of the true situation will be slower than that of a skilled or an experienced pilot who will be able to rapidly correlate information from a number of sources because of the typical pattern that has been observed in the past.
In the same way, extensive familiarity with patterns of symptoms produced by particular aircraft malfunctions will allow the experienced pilot to rapidly interpret the overall situation from a potentially large number of cues indicating their individual status.
Personality Traits and Effective Crew Decision Making
The most important personality trait for effective crew decision making is stability.
Judgement Concept
It can be summarized that judgement, risk assessment and the consequential decision made in the air is based upon the:
•Pilot
•Aircraft
•Environmental conditions
•Time available
Commitment
Commitment refers to the degree of commitment to a solution when making a decision and which represents the “point of no return”.
Decision Making and Risk 15
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15 Questions
Questions
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1. |
What are the categories of risk? |
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Objective/Sudden and Subjective/Gradual |
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Sudden/Impromptu and Gradual/Planned |
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External/Objective and Internal/Subjective |
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d. |
Impromptu/Objective and Planned/Subjective |
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The Commander is ultimately responsible for all decisions made in the cockpit. |
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True |
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False |
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There is no difference between “deciding” and “decision making”. |
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True |
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False |
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A decision is “good” when: |
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it can be implemented within the available time |
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time is not an issue. The decision must be correct |
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time can be an issue but the correct perception is the important factor |
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when other members of the crew agree |
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5. |
Preparation is essential for good decision making when time is an issue. |
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True |
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False |
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6. |
One of the possible problems of preparation is: |
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action slip |
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confirmation bias |
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error of commission |
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environment capture |
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7. |
A person will tend to overestimate the frequency of: |
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a common but negative occurrence |
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a common but beneficial occurrence |
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a rare but beneficial occurrence |
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d. |
a rare but negative occurrence |
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Negative events tend to be overestimated when: |
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they are well published |
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obvious |
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under published |
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d. |
the results are unclear |
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9. |
The risk of an Airprox is normally: |
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overestimated |
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underestimated |
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discounted |
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accurately assessed |
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Evaluation of options in the decision-making process involves: |
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positive and negative considerations |
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values and costs |
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planned and impromptu considerations |
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d. |
assigning tasks |
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11. |
People tend to be biased to make a: |
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risky loss rather than a certain loss even if the expected loss from the former is |
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greater |
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risky loss rather than a certain loss even if the expected loss from the former is |
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less |
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c. |
risky loss rather than a certain loss even if the expected loss from the latter is |
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greater |
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risky loss rather than a certain loss even if the expected loss from the latter is |
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far greater |
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“Press-on-itis” is a: |
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common dilemma faced by all pilots |
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is only experienced by skilled pilots |
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c. |
only happens to inexperienced pilots |
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is rarely faced by good pilots |
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The co-pilot is responsible for monitoring the implementation of the Commander’s |
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decision. |
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True |
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False |
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14. |
People tend to focus on salient cues. |
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True |
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False |
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Fatigue/overload: |
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sometimes affects decision making |
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rarely affects decision making |
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never affects decision making |
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always affects decision making |
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In the decision-making process, what should follow “review and feedback”? |
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Assign tasks |
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Decide |
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Risk assessment |
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Diagnose and define objective |
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15 Questions
17.Man is extremely capable of accurate risk assessment.
a.True
b.False
18.Input from the crew is an important factor in the decision-making process.
a.True
b.False
19.Lack of experience will have the following effect on the decision-making process:
a.will speed it up (leaping in at the deep end)
b.slow it down
c.have no effect
d.disrupt the process
20.The decision process should include the crew.
a.True
b.False
Questions 15
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Questions 15
Questions 15
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