Module 09A - Human Factors for B1 & B2 Certification

Comprehensive practice flashcards covering Module 09A Human Factors for EASA/GCAA Part-66 B1 and B2 certification, spanning Sub-Modules 01 through 09.

Human Factors

The study of human capabilities and limitations in the workplace, analyzing the interaction of maintenance personnel, equipment, procedures, and environmental conditions to optimize safety, efficiency, and well-being.

PEAR Model

A human factors framework that categorizes maintenance issues into four topic areas: People who do the job, Environment in which they work, Actions they perform, and Resources necessary to complete the job.

People (PEAR Model)

The individuals who perform maintenance tasks, considering their physical limitations, capabilities, mental state, emotional state, and training.

Environment (PEAR Model)

The conditions surrounding maintenance personnel, encompassing both the physical environment (such as hangar or line conditions) and the organizational culture.

Actions (PEAR Model)

The specific tasks, procedures, and behavioral actions performed by maintenance personnel to identify risk factors such as complex steps or ambiguous instructions.

Resources (PEAR Model)

Everything necessary for a technician to get the job done, including personnel, equipment, spares, tools, documentation, guidance, and physical facilities.

SHEL Model

A human factors framework developed by Elwyn Edwards and modified by Frank Hawkins, named after Software, Hardware, Environment, and Liveware, showing how human liveware interacts with each component.

Software (SHEL Model)

The non-physical aspects of a system, including maintenance procedures, maintenance manuals, checklist layouts, computer programs, and established rules.

Hardware (SHEL Model)

The physical components of a system, such as tools, test equipment, the physical structure of aircraft, flight deck design, and control and instrument layout.

Environment (SHEL Model)

The physical workplace conditions (hangar, line, climate) as well as the work environment (work patterns, management structures, public perception).

Liveware (SHEL Model)

The human being or people positioned at the center of the system, including maintenance engineers, supervisors, planners, managers, and coworkers.

Error Chain

A series of human factors problems and broken links leading up to an accident; breaking just one link prevents the accident from occurring.

Murphy's Law

The principle that "If something can go wrong, it will" (or "whatever can go wrong, will go wrong").

Complacency

The dangerous human tendency to believe that an accident will never happen to "me" or to "my Company"; identified as the deadliest of the Dirty Dozen factors.

Cornea

The clear "window" at the very front of the eye acting as a fixed focusing device, responsible for between $70\%$ and $80\%$ of the eye's total refraction.

Iris and Pupil

The colored part of the eye (iris) that regulates light entering by rapidly adjusting the aperture size of the central dark opening (pupil) by a factor of $5:1$.

Accommodation

The process by which the muscles surrounding the lens alter its shape to provide final focusing adjustment and cast a sharp image onto the retina.

Retina

The light-sensitive layer of nerve cells on the rear wall of the eyeball connected to the optic nerve, containing photoreceptor rods and cones.

Cones

Retinal photoreceptor cells that function in good light, detect fine detail, and provide color sensitivity capable of distinguishing about $1000$ different shades of color.

Rods

Retinal photoreceptor cells that cannot detect color, operate with high sensitivity in low light levels, and are rapidly impaired by hypoxia.

Visual Acuity

The ability of the human eye to discriminate sharp detail clearly at varying distances.

Hypermetropia (Hyperopia)

Long sight caused by a shorter-than-normal eyeball where incoming light focuses behind the retina, producing blurred vision when viewing close objects.

Myopia

Short sight caused by an eyeball that is longer than normal, causing light to focus in front of the retina and producing blurred vision for distant objects.

Convex Lens

An optical lens that bends light rays inwards before reaching the cornea, used to correct long-sightedness (hypermetropia).

Concave Lens

An optical lens that bends light rays outwards before entering the eye, used to correct short-sightedness (myopia).

Daltonism

Colour-defective vision (frequently termed color blindness), affecting about $8\%$ of men and $0.5\%$ of women, most commonly involving red-green confusion.

Cataracts

An eye condition characterized by clouding of the crystalline lens, usually associated with aging, leading to degraded visual clarity.

Astigmatism

A visual defect caused by an irregularly misshapen cornea, resulting in objects appearing irregularly shaped or distorted.

Glaucoma

A buildup of fluid pressure within the eyeball that can cause damage to the optic nerve and potentially lead to blindness.

Outer Ear

The external portion of the ear that collects sound vibrations and directs them down the auditory canal to the eardrum.

Middle Ear

The air-filled chamber containing two protective muscles and three tiny bones (ossicles) that transmits acoustic vibrations to the inner ear.

Ossicles

Three small bones in the middle ear that mechanically transmit sound vibrations from the eardrum to the fluid of the inner ear.

Acoustic Reflex (Aural Reflex)

An involuntary protective reflex in the middle ear where two muscles contract to shield against sounds above $80\,\text{dB}$, reducing noise by up to $20\,\text{dB}$.

Cochlea

The fluid-filled, snail-shaped structure of the inner ear connected to the ossicles, containing the basilar membrane and hair-like sensory cells.

Presbycusis

The natural, gradual reduction in hearing capability and high-frequency detection that occurs as a normal signpost of aging.

Information Processing

The mental process of receiving information through the sensory organs, analyzing it, and making it meaningful across five basic stages.

Selective Attention

A form of attention where mental effort is concentrated on a single specific input or task while filtering out competing sensory inputs.

Distraction

The diversion of attention away from a task by irrelevant stimuli; recognized as the negative side of selective attention.

Perception

The cognitive process of assembling raw sensations into a usable, coherent mental representation of the external world.

Situation Awareness

The synthesis of an accurate and up-to-date mental model of one's operational environment and state, and the ability to predict future states.

Ultra-Short-Term Memory (Sensory Storage)

The sensory memory buffer holding sensory input for up to $2\,\text{seconds}$, giving the brain sufficient time to direct attention to it.

Short-Term Memory (Working Memory)

A temporary cognitive workspace storing $5\text{ to }9$ ($7 \pm 2$) items of information for a brief duration of typically $10\text{ to }20\,\text{seconds}$.

Long-Term Memory

A permanent cognitive store with virtually unlimited capacity, retaining personal experiences, beliefs, values, motor programs, and language comprehension.

Semantic Memory

A type of long-term memory containing general, factual knowledge about the world (such as rules, concepts, and language) not tied to when or where it was learned.

Episodic Memory

A type of long-term memory containing recollections of specific personal events, past experiences, and objects associated with a specific contextual setting.

Claustrophobia

An abnormal, intense fear of being trapped in an enclosed, confined space (such as inside aircraft fuel tanks).

Diffusion of Responsibility

A social psychological phenomenon where individuals in a group feel less personal accountability to act or help because they assume others will do so.

Social Loafing

The tendency for individuals to exert less effort on a task when working in a group because they perceive their personal output is pooled with others.

Peer Pressure

The actual or perceived social pressure an individual feels to conform to the behaviors, standards, or expectations of colleagues and coworkers.

Motivation

A basic human drive that arouses, directs, and sustains purposeful behavior, reflecting the difference between what a person can do and what they will do.

External Motivation

Workplace drive that is governed by external organizational factors, namely system rewards and formal punishments.

Internal Motivation

Personal workplace drive where an individual performs tasks conscientiously out of self-desire, intrinsic interest, and personal pride.

Maslow's Hierarchy of Needs

A motivational theory structuring human needs into a pyramid: Physiological Needs, Safety & Security, Love & Belonging, Self-Esteem, and Self-Actualization.

Hawthorne Effect (Observer Effect)

A psychological reactivity phenomenon in which individuals modify or improve aspects of their performance in response to the awareness of being observed.

Organizational Culture

A company's unique philosophy, policies, standard operating procedures, training criteria, quality assurance methods, and collective norms ("the way we do things here").

Safety Culture

A set of shared beliefs, norms, attitudes, and technical practices within an organization committed to minimizing dangerous exposure to hazards.

Leadership

The role of influencing the thought and behavior of team members by motivating the team, demonstrating by example, reinforcing positive attitudes, and managing goals.

Stress

Any physical, psychological, or social force applied to a human system that causes a significant modification of its form, health, or functioning.

Stressor

Any stimulus, event, or environmental condition (classified as physical, psychological, or reactive) that triggers a stress response.

Acute Stress

Intense stress that occurs over a short duration in response to an immediate challenge, unexpected crisis, or demanding situation.

Chronic Stress

Persistent, long-duration or recurring stress caused by ongoing issues such as prolonged domestic difficulties or continuous financial problems.

Defence Strategies (Stress)

Stress-response mechanisms aimed at alleviating symptoms or anxiety rather than solving the source (e.g., denial, blaming others, alcohol, medication).

Coping Strategies (Stress)

Proactive stress-management methods where an individual directly addresses and resolves the root cause (e.g., delegating workload, prioritizing tasks).

Arousal

The overall state of physical and mental readiness and alertness of an individual for performing work, following an inverted-U performance curve.

Workload

The degree of physical and mental stimulation and demand exerted on an individual caused by the nature and complexity of a task.

Overload

A condition occurring at extremely high workload levels where an individual becomes over-aroused and performance degrades due to excessive demand.

Underload

A state occurring at low workload levels where an individual becomes under-aroused and bored, leading to degraded performance and loss of vigilance.

Fatigue

A state of physical or mental tiredness, impaired alertness, or an overwhelming need to sleep, resulting from sustained work, concentration, or sleep deprivation.

Channelled Concentration

A symptom of fatigue where an individual fixates on a single, often unimportant issue, losing situational awareness and failing to maintain an overview.

Circadian Rhythms

Internal 24-hour biological cycles linked to the day-night cycle, regulating body temperature, hunger, hormone secretion, and alertness.

Window of Circadian Low (WOCL)

The circadian period between approximately $02:00$ and $05:00$ when biological functions, alertness, body temperature, and human performance are at their lowest.

Sleep Inertia

A temporary period of grogginess, impaired memory, and mental confusion experienced immediately after waking, which can last up to $15\,\text{minutes}$.

Noise Attenuation

The reduction of acoustic energy entering the ears, achieving reductions of up to $20\,\text{dB}$ with ear plugs and up to $40\,\text{dB}$ with ear muffs.

Recommended Illumination for Repair Tasks

The baseline lighting standard required for detailed aircraft maintenance and repair tasks, set at a minimum of $75\,\text{ft-c}$ (foot-candles).

Hypothermia

The medical condition characterized by an abnormally low internal body temperature resulting from prolonged exposure to cold and wet environments.

Vibratory-Induced White Finger Syndrome (VWF)

A circulatory disorder of the hands and fingers caused by regular exposure to pneumatic tool vibrations between $50\text{ and }150\,\text{Hz}$, reducing blood flow.

Body Heat Loss Mechanisms

The physiological cooling processes of the human body, occurring normally $65\%$ by passive radiation transfer and $20\%$ by evaporative sweating.

Planning (Maintenance Tasks)

The vital pre-task preparation ensuring that qualified personnel, tools, equipment, approved data, and facilities are available at the right place and time.

Repetitive Tasks

Maintenance activities performed multiple times in a shift or week (e.g., daily life-jacket checks) that present a significant danger of complacency.

Visual Inspection

The process of examining and evaluating the physical condition of aircraft components using the human eye, optical aids (magnifiers, borescopes), and other senses.

Complex Systems

Modern aircraft systems (such as flight management computers and fly-by-wire controls) that require specialized training and strict adherence to written procedures.

Non-Destructive Inspection (NDI)

Specialized testing techniques (e.g., eddy currents, Fluorescent Penetrant Inspection) used to identify structural flaws and defects below visual thresholds.

Communication

The process of achieving shared meaning between sender and receiver, requiring sender credibility, active listening, an appropriate delivery medium, and content resonance.

Shift Handover

The vital operational exchange between outgoing and incoming personnel covering completed work, work in progress, upcoming tasks, and general technical information.

Non-Verbal Communication

The transmission of information without spoken words, through gestures, facial expressions, body language, cockpit instrument symbols, and lockout tags/placards.

Oral Communication Error Rate

The estimated baseline failure rate of spoken verbal communication in industrial work settings, estimated to be around $3\,\%$.

Direct Face-to-Face Handover

A key recommendation for improving shift transitions, ensuring direct verbal contact between outgoing and incoming personnel to prevent critical oversights.

Currency (AMT)

The ongoing obligation of an aircraft maintenance technician to stay up-to-date with new aircraft types, revised maintenance manuals, and updated procedures.

The Dirty Dozen

A list of 12 human factors identified by Transport Canada that degrade performance and cause maintenance errors, led by complacency.

Swiss Cheese Model

James Reason's accident causation model demonstrating that organizational defenses have fallible holes, and accidents happen when holes momentarily align.

Latent Failures

Dormant, hidden deficiencies within an organization (such as poor design, flawed procedures, or management decisions) that lay unnoticed until triggered.

Active Failures

Unsafe acts, slips, or mistakes committed by front-line personnel (such as technicians or pilots) that have an immediate adverse impact.

Maintenance Error Decision Aid (MEDA)

A structured investigation tool and process following the flow "Event -> Decision -> Investigation -> Prevention Strategies -> Feedback" to analyze maintenance errors.

Slip

An unintended action error occurring during execution, typically caused by attentional failures, omissions, or misordering of steps in familiar tasks.

Lapse

An unintended memory-based error where an intended action is forgotten, a technician loses their place, or an item is inadvertently omitted.

Mistake

An intentional action that proceeds according to plan, but where the plan itself is deficient due to rule-based or knowledge-based shortcomings.

Violation

An intentional deviation from established rules, standard procedures, or approved maintenance practices (categorized as routine, exceptional, or acts of sabotage).

Assertiveness

The professional ability to express thoughts, beliefs, needs, and safety concerns in an open, positive manner without being aggressive.

Window of Opportunity (Accident)

A critical period during which defense weaknesses align at all organizational levels, allowing latent and active failures to culminate in an accident.

Job Hazard Analysis (JHA)

A structured detective technique that examines the relationship between the worker, task, tools, and work environment to identify hazards before work begins.