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Brunei DCA CPL(A) Human Performance study materials
Brunei DCA CPL(A) Human Performance study resources

Brunei DCA CPL(A) Human Performance practice questions

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Question 1Human Factors Foundations and Aviation Psychology

Which component of human information processing is responsible for selecting which sensory inputs receive conscious attention?

  1. Short-term memory
  2. Long-term memory
  3. Perception Correct answer.
  4. Motor programme

Explanation

Perception is the interpretive stage in which incoming sensory data are organised and given meaning, and it determines which stimuli are attended to and which are filtered out. Memory stores and motor programmes operate downstream of this selection process. Attention itself is a limited resource that gates what perception will process.

Question 2Human Factors Foundations and Aviation Psychology

A pilot's scan of the instruments is described as a 'T' pattern. This is best understood as an example of:

  1. A breakdown of motor coordination
  2. An innate reflex present from birth
  3. A long-term memory failure under stress
  4. A learned perceptual schema that guides attention efficiently Correct answer.

Explanation

A scan pattern is a learned schema, built through training and experience, that allows a pilot to sample instruments in a structured and efficient order rather than randomly. Schemas reduce the load on limited attentional resources. They are acquired rather than innate, and they represent effective perception rather than failure.

Question 3Human Factors Foundations and Aviation Psychology

According to the widely used model of working memory, which component is responsible for temporarily holding and manipulating verbal and numerical information?

  1. The visuospatial sketchpad
  2. The episodic buffer
  3. The central executive
  4. The phonological loop Correct answer.

Explanation

The phonological loop is the subsystem that holds speech-based and numerical material for short periods through rehearsal. The visuospatial sketchpad handles imagery, the central executive allocates attention, and the episodic buffer integrates information across modalities.

Question 4Human Factors Foundations and Aviation Psychology

A pilot is heavily loaded with radio calls and checklist reading while also trying to remember a heading. Performance on the heading task deteriorates. This is best explained by:

  1. Competition for limited capacity in the phonological loop Correct answer.
  2. Reduced visual acuity in the flight deck
  3. Permanent loss of the heading from long-term memory
  4. Failure of the motor programme for the controls

Explanation

Verbal radio calls and spoken rehearsal of a heading both draw on the same phonological store, so concurrent verbal tasks compete for limited capacity. This interference degrades retention of the heading. The effect is a capacity limitation in working memory, not a permanent memory loss or a sensory problem.

Question 5Human Factors Foundations and Aviation Psychology

Which statement best describes the capacity of long-term memory in the human information processing model?

  1. It holds roughly seven items for about twenty seconds
  2. It can hold only one item at a time
  3. It is cleared completely during each sleep cycle
  4. It has effectively unlimited capacity and stores information in organised networks Correct answer.

Explanation

Long-term memory is generally modelled as having essentially unlimited capacity, with information stored in organised associative networks that support recognition and recall. The limited-duration, limited-capacity store is short-term or working memory. Long-term memory is not wiped each night.

Question 6Human Factors Foundations and Aviation Psychology

An experienced pilot recognises a familiar approach configuration almost instantly without consciously analysing each instrument. This primarily reflects:

  1. Pattern recognition using well-developed schemas Correct answer.
  2. Random guessing under time pressure
  3. Loss of situational awareness
  4. Deliberate step-by-step calculation

Explanation

Expertise allows a pilot to match the current situation against stored schemas, enabling rapid recognition rather than slow serial analysis. This pattern recognition is efficient and frees mental capacity for other tasks. It is not a random process nor a loss of awareness.

Question 7Human Factors Foundations and Aviation Psychology

In decision-making, 'confirmation bias' refers to the tendency to:

  1. Overestimate the time available for a task
  2. Choose the first option that comes to mind
  3. Defer all decisions to another crew member
  4. Seek and favour information that supports an existing belief Correct answer.

Explanation

Confirmation bias is the tendency to search for, interpret, and recall information in a way that confirms pre-existing beliefs while discounting contradictory evidence. It can cause a pilot to persist with an incorrect diagnosis. It is distinct from other biases such as availability or plan continuation.

Question 8Human Factors Foundations and Aviation Psychology

A pilot who has invested heavily in a diversion decision continues with it even when new weather information makes it clearly unsuitable. This behaviour is best described as:

  1. Plan continuation bias Correct answer.
  2. Anchoring on the first radio call
  3. Complacency
  4. Availability bias

Explanation

Plan continuation bias is the tendency to keep following an established plan despite changing conditions that should prompt revision. The prior commitment makes abandoning the plan psychologically costly. Availability bias and anchoring involve how information is recalled or weighted, not persistence with a chosen course of action.

Question 9Human Factors Foundations and Aviation Psychology

Which of the following is the most characteristic feature of a skill-based error?

  1. A slip or lapse during a routine, well-practised action Correct answer.
  2. A deliberate violation of a standard procedure
  3. A misdiagnosis of an unfamiliar system failure
  4. A wrong decision made from incomplete knowledge

Explanation

Skill-based errors occur during routine, highly practised actions and typically take the form of slips (wrong execution) or lapses (omitted step). They arise from attentional failure rather than lack of knowledge. Mistakes involving diagnosis or decision-making belong to higher rule- or knowledge-based levels.

Question 10Human Factors Foundations and Aviation Psychology

A pilot intends to set the altimeter to the correct pressure but sets a transposed value, later noticing the error. This is best classified as:

  1. A skill-based slip Correct answer.
  2. A deliberate violation
  3. A knowledge-based mistake
  4. A communication error

Explanation

The action was routine and well practised, but execution deviated from intention, which is the defining characteristic of a slip. The pilot knew the correct action and intended to perform it. Mistakes involve faulty intention or knowledge rather than faulty execution.

Question 11Human Factors Foundations and Aviation Psychology

The 'Swiss cheese' model of accident causation suggests that:

  1. Human error is the only relevant causal factor
  2. Accidents occur when weaknesses in several defensive layers align Correct answer.
  3. A single failed barrier always causes an accident
  4. Accidents are purely random events

Explanation

The model depicts defences as slices of cheese with holes representing latent weaknesses and active failures; an accident occurs only when holes in successive layers momentarily line up. This emphasises systemic defences rather than a single cause. It shows that multiple contributing factors must align.

Question 12Human Factors Foundations and Aviation Psychology

Which of the following best illustrates a latent condition in an aviation system?

  1. A confusing aircraft manual produced by an organisation months before a flight Correct answer.
  2. A sudden radio failure in flight
  3. A gust of wind during landing
  4. A pilot misreading a dial during approach

Explanation

Latent conditions are organisational or design weaknesses present long before an event that increase the likelihood of error by front-line operators. A confusing manual is a pre-existing organisational product. Misreading a dial is an active failure, while a radio failure or gust is an environmental or technical event.

Question 13Human Factors Foundations and Aviation Psychology

Which of the following is the best description of 'situational awareness' in flight operations?

  1. The ability to recall checklist items from memory
  2. The physical skill of manipulating the controls smoothly
  3. The tendency to follow standard operating procedures
  4. The perception and comprehension of relevant elements in the environment and projection of their future state Correct answer.

Explanation

Situational awareness comprises three levels: perceiving relevant elements, comprehending their meaning, and projecting their future status. It is a cognitive construct distinct from memory recall or manual skill. Procedural compliance supports it but is not equivalent to it.

Question 14Human Factors Foundations and Aviation Psychology

A pilot becomes absorbed in reprogramming the flight management system and fails to notice a change in heading clearance. This loss of situational awareness is best attributed to:

  1. Attention tunnelling on a single task Correct answer.
  2. A failure of the motor programme
  3. Excessive long-term memory capacity
  4. Improved perceptual filtering

Explanation

Fixation on one task narrows attention so that other relevant cues go unnoticed, a classic form of attention tunnelling. The pilot's resources are consumed by the programming task. Long-term memory capacity and motor programming are not the limiting factors here.

Question 15Human Factors Foundations and Aviation Psychology

Which statement about stress and pilot performance is most accurate?

  1. Arousal has no measurable effect on performance
  2. Performance improves continuously as arousal increases
  3. Only physical stressors affect performance
  4. Moderate arousal can improve performance, but very high arousal typically degrades it Correct answer.

Explanation

The relationship between arousal and performance is often described as an inverted U, in which moderate arousal optimises performance while very low or very high arousal impairs it. High stress narrows attention and disrupts complex tasks. Both psychological and physical stressors are relevant.

Question 16Human Factors Foundations and Aviation Psychology

A pilot under acute stress reports a narrowed field of attention and reduced ability to process peripheral information. This phenomenon is known as:

  1. Perceptual narrowing Correct answer.
  2. Memory consolidation
  3. Habituation
  4. Sensory adaptation

Explanation

Under high stress, attention tends to narrow toward central cues, reducing the processing of peripheral information, which is termed perceptual narrowing. This can cause important peripheral cues to be missed. Consolidation, habituation, and sensory adaptation describe different processes.

Question 17Human Factors Foundations and Aviation Psychology

Which of the following best describes the effect of fatigue on human performance in aviation?

  1. Slower reaction times, increased variability of performance, and impaired attention Correct answer.
  2. Enhanced memory recall under workload
  3. Faster decision-making with fewer errors
  4. Improved vigilance during long flights

Explanation

Fatigue degrades performance by slowing reactions, increasing inconsistency, and impairing attention and vigilance. These effects are particularly dangerous in long, monotonous flights. Fatigue does not enhance vigilance, memory, or decision accuracy.

Question 18Human Factors Foundations and Aviation Psychology

A pilot flying a long night sector after a short sleep period begins to experience brief involuntary lapses into sleep. These episodes are best described as:

  1. Circadian adaptation
  2. Hypoxia
  3. Spatial disorientation
  4. Microsleeps Correct answer.

Explanation

Microsleeps are brief involuntary episodes of sleep that occur despite efforts to stay awake, commonly associated with fatigue and sleep deprivation. They pose a serious risk because the pilot may be unaware of them. They are distinct from circadian adaptation, hypoxia, or spatial disorientation.

Question 19Human Factors Foundations and Aviation Psychology

Which of the following is the most reliable sign of inadequate oxygen supply at altitude?

  1. Immediate loss of consciousness without warning in all cases
  2. A persistent cough
  3. A sudden sharp pain in the joints
  4. Impaired judgement and euphoria that the pilot may not recognise Correct answer.

Explanation

Hypoxia commonly produces euphoria, impaired judgement, and reduced self-awareness, so the affected pilot may not recognise the danger. This insidious quality makes it particularly hazardous. Joint pain and cough are not typical early signs, and unconsciousness is not always instantaneous.

Question 20Human Factors Foundations and Aviation Psychology

In the context of crew resource management, 'assertiveness' by a first officer is best described as:

  1. The tendency to remain silent to avoid conflict
  2. The ability to state concerns clearly and persistently when safety is at risk Correct answer.
  3. The willingness to accept all decisions without question
  4. The habit of overriding the captain without discussion

Explanation

Assertiveness in CRM means expressing safety-relevant concerns clearly, respectfully, and persistently until they are acknowledged. It supports the gradient of authority and prevents errors from going unchallenged. It is not silence, unilateral override, or passive acceptance.

Question 21Basic Aviation Physiology and the Body's Response to Flight

At a constant cabin altitude, which change most directly reduces the oxygen saturation of arterial blood?

  1. A rise in the partial pressure of carbon dioxide in the alveoli
  2. An increase in the ambient humidity of the cabin air
  3. A decrease in the nitrogen content of the cabin air
  4. A fall in the partial pressure of oxygen in the alveoli Correct answer.

Explanation

Haemoglobin saturation depends mainly on the partial pressure of oxygen in the alveoli, which drives diffusion into the blood. When alveolar oxygen pressure falls, as at altitude, the saturation curve drops steeply. Carbon dioxide and humidity affect breathing and comfort but not the primary gradient in this way.

Question 22Basic Aviation Physiology and the Body's Response to Flight

What is the main function of the alveoli in the lungs?

  1. To generate the pressure that drives ventilation
  2. To exchange oxygen and carbon dioxide between air and blood Correct answer.
  3. To produce surfactant that lubricates the airways
  4. To filter particulate matter from the inspired air

Explanation

Alveoli are thin-walled sacs surrounded by capillaries where gas diffuses down its pressure gradient. Oxygen enters the blood and carbon dioxide leaves it across this membrane. Filtration, surfactant production and pressure generation belong to other structures or processes.

Question 23Basic Aviation Physiology and the Body's Response to Flight

During a rapid decompression at high altitude, the time of useful consciousness is shortened mainly because of which effect?

  1. An immediate loss of cabin pressure warning systems
  2. A rapid fall in the oxygen pressure in the blood and tissues Correct answer.
  3. A sudden increase in blood carbon dioxide levels
  4. A reflex closure of the airways

Explanation

Rapid decompression causes an abrupt drop in alveolar oxygen pressure, so blood leaving the lungs is poorly oxygenated. Brain tissue has little oxygen reserve, so useful consciousness fades quickly. Carbon dioxide does not rise acutely in this setting, and airway closure is not the mechanism.

Question 24Basic Aviation Physiology and the Body's Response to Flight

Which statement best describes hypoxia in the aviation context?

  1. An excess of carbon dioxide in the blood caused by rebreathing
  2. An abnormal increase in the oxygen-carrying capacity of the blood
  3. A reduction in blood pressure on standing up
  4. A condition in which the tissues receive insufficient oxygen for their needs Correct answer.

Explanation

Hypoxia is a general shortage of oxygen at the tissue level, whatever the cause. In flight it commonly results from reduced oxygen pressure at altitude. It is distinct from hypercapnia, from postural hypotension and from polycythaemia.

Question 25Basic Aviation Physiology and the Body's Response to Flight

A pilot breathing 100 percent oxygen at 40 000 feet is protected against hypoxia primarily because the oxygen pressure delivered is adequate. Which statement explains this?

  1. The partial pressure of oxygen in the alveoli remains high enough to saturate haemoglobin Correct answer.
  2. The oxygen dissolves the nitrogen in the blood
  3. The oxygen raises the carbon dioxide level in the blood
  4. The oxygen reduces the breathing rate to conserve oxygen

Explanation

Breathing pure oxygen raises the fraction of oxygen in the alveoli, so the alveolar oxygen pressure stays high even when ambient pressure is low. This maintains haemoglobin saturation and tissue oxygenation. It does not dissolve nitrogen or alter carbon dioxide in the way described.

Question 26Basic Aviation Physiology and the Body's Response to Flight

Which symptom is most typical of the early stage of hypoxia in a healthy pilot?

  1. Severe chest pain radiating to the arm
  2. A sudden increase in visual acuity
  3. A marked slowing of the heart rate with fainting
  4. Euphoria and a reduced awareness of one's own performance Correct answer.

Explanation

Early hypoxia often produces a sense of well-being, impaired judgement and reduced self-criticism before obvious physical signs appear. This makes self-detection unreliable. Chest pain and fainting are not typical early features in a healthy pilot.

Question 27Basic Aviation Physiology and the Body's Response to Flight

What is the principal effect of hyperventilation on the blood?

  1. It lowers the carbon dioxide level and raises the blood pH Correct answer.
  2. It reduces the oxygen pressure in the alveoli
  3. It raises the carbon dioxide level and lowers the blood pH
  4. It increases the oxygen-carrying capacity of haemoglobin

Explanation

Hyperventilation removes carbon dioxide faster than it is produced, so the arterial carbon dioxide level falls. This makes the blood more alkaline, a state called hypocapnia. Oxygen carriage is not increased and alveolar oxygen pressure is not reduced by the breathing itself.

Question 28Basic Aviation Physiology and the Body's Response to Flight

A pilot who has been hyperventilating becomes dizzy and has tingling in the fingers. Which action is most appropriate?

  1. Breathe faster to blow off more carbon dioxide
  2. Ignore the symptoms and continue the flight unchanged
  3. Hold the breath for as long as possible
  4. Slow the breathing rate and, if needed, rebreathe from a bag while checking oxygen supply Correct answer.

Explanation

The symptoms fit hypocapnia from excessive ventilation, so slowing the breathing helps restore carbon dioxide levels. Because hypoxia can cause similar symptoms and can also provoke overbreathing, oxygen supply should be checked. Simply ignoring symptoms is unsafe.

Question 29Basic Aviation Physiology and the Body's Response to Flight

Which structure in the inner ear provides the sense of balance and spatial orientation used in flight?

  1. The Eustachian tube
  2. The eardrum
  3. The cochlea
  4. The vestibular apparatus Correct answer.

Explanation

The vestibular apparatus contains the semicircular canals and otolith organs that detect rotation and linear acceleration. These signals underpin balance and orientation. The cochlea serves hearing, while the eardrum and Eustachian tube are part of the sound-conduction and pressure-equalising system.

Question 30Basic Aviation Physiology and the Body's Response to Flight

During a prolonged constant-rate turn without visual reference, a pilot may feel that the turn has stopped. This illusion is caused by which mechanism?

  1. Adaptation of the fluid and hairs in the semicircular canals Correct answer.
  2. A sudden drop in cabin pressure
  3. A failure of the otolith organs to detect gravity
  4. A reduction in blood flow to the retina

Explanation

The semicircular canals respond to angular acceleration, not to a steady rate of turn. After the initial acceleration, the fluid and hair cells adapt, so the brain no longer receives a turning signal and the pilot may believe the aircraft is straight and level. This is the basis of the leans illusion.

Question 31Basic Aviation Physiology and the Body's Response to Flight

What causes the somatogravic illusion during a rapid acceleration on take-off?

  1. The otolith organs interpret the acceleration as a pitch-up attitude Correct answer.
  2. The eyes overestimate the aircraft's climb rate
  3. The ears detect a change in cabin pressure as a climb
  4. The semicircular canals detect the acceleration as a roll

Explanation

The otolith organs sense the resultant of gravity and linear acceleration. During strong forward acceleration the resultant tilts backward, which the brain may interpret as a nose-up attitude, tempting the pilot to push forward. This illusion is strongest without visual reference.

Question 32Basic Aviation Physiology and the Body's Response to Flight

Which action best helps a pilot resist spatial disorientation during flight in cloud?

  1. Trust bodily sensations when they conflict with the instruments
  2. Make rapid head movements to clear the vestibular signal
  3. Close the eyes briefly to reset the sense of balance
  4. Rely on the flight instruments and maintain a disciplined instrument scan Correct answer.

Explanation

Without external visual reference, vestibular sensations are unreliable, so the instruments are the only trustworthy attitude source. A disciplined scan and cross-check reduce the chance of acting on a false sensation. Trusting sensations or making abrupt head movements increases the risk.

Question 33Basic Aviation Physiology and the Body's Response to Flight

Which statement correctly describes the effect of increasing altitude on the partial pressure of oxygen in the air?

  1. It stays constant while only the percentage of oxygen changes
  2. It falls only above 10 000 feet
  3. It rises because the air becomes less dense
  4. It falls in proportion to the fall in atmospheric pressure Correct answer.

Explanation

The proportion of oxygen in dry air stays near 21 percent, but the total pressure falls with altitude. Since partial pressure is the product of fraction and total pressure, the oxygen partial pressure falls as atmospheric pressure falls. The change begins at any altitude, not only above 10 000 feet.

Question 34Basic Aviation Physiology and the Body's Response to Flight

A pilot flying unpressurised at 12 000 feet begins to feel drowsy and has difficulty concentrating. Which explanation is most likely?

  1. Hypoglycaemia caused by the cold cabin
  2. Hypercapnia from rebreathing cabin air
  3. Mild hypoxia from the reduced oxygen partial pressure at that altitude Correct answer.
  4. Decompression sickness from dissolved nitrogen

Explanation

Above about 10 000 feet without supplemental oxygen, alveolar oxygen pressure falls enough to impair mental performance in many people. Drowsiness and poor concentration are typical early signs. The other conditions have different causes and would not be expected simply from this altitude.

Question 35Basic Aviation Physiology and the Body's Response to Flight

What is the purpose of the pressurisation system in a transport aircraft cabin?

  1. To maintain a cabin pressure equivalent to a moderate altitude Correct answer.
  2. To supply pure oxygen to all occupants continuously
  3. To keep the cabin at sea-level pressure at all times
  4. To remove all carbon dioxide from the cabin air

Explanation

Pressurisation keeps the cabin at a pressure equivalent to a moderate altitude, typically around 6 000 to 8 000 feet, which keeps oxygen pressure adequate without excessive structural stress. It does not supply pure oxygen or keep the cabin at sea level. Carbon dioxide removal is handled by ventilation.

Question 36Basic Aviation Physiology and the Body's Response to Flight

Which statement about the effects of positive G on the body is correct?

  1. Blood is displaced toward the lower body, reducing blood pressure at the brain Correct answer.
  2. Blood is displaced toward the head, raising cerebral blood pressure
  3. Heart rate falls sharply and consciousness is unaffected
  4. Vision improves because retinal blood flow increases

Explanation

Positive G acts along the head-to-foot axis, so blood pools in the lower body and venous return falls. Cerebral blood pressure drops, which can cause grey-out or loss of consciousness if sustained. Vision does not improve and heart rate usually rises as a compensatory response.

Question 37Basic Aviation Physiology and the Body's Response to Flight

What is the main purpose of the anti-G straining manoeuvre?

  1. To raise blood pressure and maintain blood flow to the brain during high G Correct answer.
  2. To reduce the effect of noise on hearing
  3. To equalise pressure in the middle ear
  4. To increase the oxygen content of the blood

Explanation

The manoeuvre combines muscle tensing with controlled breathing to raise intrathoracic and arterial pressure. This helps keep blood flowing to the brain when positive G would otherwise cause pooling. It does not change blood oxygen content, hearing or ear pressure.

Question 38Basic Aviation Physiology and the Body's Response to Flight

Which effect is associated with exposure to sustained negative G?

  1. Blood engorgement of the head and face with possible red-out Correct answer.
  2. A fall in heart rate below resting levels
  3. Pooling of blood in the legs with grey-out
  4. A decrease in the oxygen partial pressure of the cabin

Explanation

Negative G drives blood toward the head, causing facial congestion and a reddening of vision known as red-out. The pooling in the legs and grey-out belong to positive G. Heart rate and cabin oxygen pressure are not directly determined by the G direction in this way.

Question 39Basic Aviation Physiology and the Body's Response to Flight

Which factor most increases a pilot's susceptibility to decompression sickness during flight?

  1. Eating a large meal before flight
  2. Wearing a tight-fitting helmet
  3. Flying in a cold cabin
  4. Flying shortly after scuba diving Correct answer.

Explanation

Scuba diving loads the tissues with dissolved nitrogen, and flying soon afterwards exposes the body to reduced pressure that can release bubbles. A suitable surface interval is therefore required before flight. Helmets, meals and cold cabins are not established causes of decompression sickness.

Question 40Basic Aviation Physiology and the Body's Response to Flight

What is the primary cause of barotrauma of the ear during descent?

  1. Prolonged exposure to engine noise
  2. Excessive oxygen in the middle ear
  3. A rapid increase in blood pressure
  4. Failure to equalise the pressure difference across the eardrum Correct answer.

Explanation

During descent, cabin pressure rises and the eardrum is pushed inward unless the Eustachian tube admits air to the middle ear. If equalisation is delayed by congestion or poor technique, the pressure difference causes pain and injury. Oxygen, blood pressure and noise are not the cause.

Question 41Basic Aviation Physiology and the Body's Response to Flight

Which technique is most appropriate for equalising middle-ear pressure during a descent?

  1. Blocking both ears with the fingers
  2. Swallowing, yawning or performing a gentle Valsalva manoeuvre Correct answer.
  3. Keeping the mouth open and breathing rapidly
  4. Holding the breath and straining as hard as possible

Explanation

Swallowing and yawning open the Eustachian tube, and a gentle Valsalva manoeuvre helps air enter the middle ear. Forceful straining can damage the ear, and the other actions do not open the tube. Equalising early and often during descent is the key.

Question 42Basic Aviation Physiology and the Body's Response to Flight

How does the body normally respond to a fall in the oxygen level of the blood?

  1. The body stops producing red blood cells
  2. Breathing rate and depth increase through chemoreceptor stimulation Correct answer.
  3. Breathing rate falls to conserve oxygen
  4. The heart rate falls to reduce oxygen demand

Explanation

Chemoreceptors detect a fall in arterial oxygen and stimulate an increase in ventilation, raising alveolar oxygen pressure. Heart rate typically rises rather than falls. Over a longer period, red cell production may increase as an adaptation.

Question 43Basic Aviation Physiology and the Body's Response to Flight

A pilot notices a gradual onset of headache, fatigue and slight breathlessness during a long flight at moderate cabin altitude. Which assessment is most reasonable?

  1. Increase cabin altitude to improve comfort
  2. Remove the oxygen mask to test the response
  3. Consider mild hypoxia or dehydration and check oxygen equipment and cabin altitude Correct answer.
  4. Assume the symptoms are purely psychological and continue

Explanation

Headache, fatigue and breathlessness can arise from mild hypoxia, dehydration or fatigue, so the pilot should check the oxygen supply and cabin altitude and take corrective action. Dismissing the symptoms or worsening the exposure is unsafe. Removing oxygen would not be a sensible test.

Question 44Basic Aviation Physiology and the Body's Response to Flight

Which combination best explains why a pilot may fail to recognise their own hypoxia?

  1. Impaired judgement and euphoria develop before obvious physical signs Correct answer.
  2. Hypoxia always causes severe pain that distracts the pilot
  3. The symptoms appear only after landing
  4. Oxygen saturation rises as hypoxia develops

Explanation

Hypoxia impairs the very mental functions needed to notice it, and early euphoria reduces self-criticism. This is why oxygen discipline and monitoring are more reliable than self-assessment. Severe pain is not typical, and saturation falls rather than rises.

Question 45The Nervous System and Sensory Illusions (Vision, Hearing, Vestibular and Somatosensory)

Which part of the eye contains the photoreceptors that convert light into nerve signals?

  1. The cornea
  2. The retina Correct answer.
  3. The sclera
  4. The lens

Explanation

The retina lines the back of the eye and holds the rods and cones, which are the photoreceptor cells that transduce light into electrical signals. The other structures mainly protect the eye or help focus light onto the retina.

Question 46The Nervous System and Sensory Illusions (Vision, Hearing, Vestibular and Somatosensory)

Rods in the human retina are specialised for which function?

  1. Low-light detection of movement Correct answer.
  2. Focusing the image on the fovea
  3. Colour discrimination in bright light
  4. Sharp central vision

Explanation

Rods are highly sensitive to dim light and are concentrated in the peripheral retina, where they detect movement and shapes but give no colour information. Cones, by contrast, serve colour and high-acuity central vision.

Question 47The Nervous System and Sensory Illusions (Vision, Hearing, Vestibular and Somatosensory)

Pilots flying at night are advised to use off-centre viewing. What is the main reason for this technique?

  1. It places the image on the rod-rich peripheral retina Correct answer.
  2. It relaxes the ciliary muscle to prevent fatigue
  3. It improves colour perception of runway lights
  4. It reduces glare from cockpit instruments

Explanation

At night the fovea, which is cone-dominated, is relatively insensitive, while rods in the periphery detect faint light. Looking slightly to one side of a dim object places its image on rod-rich retina, improving detection.

Question 48The Nervous System and Sensory Illusions (Vision, Hearing, Vestibular and Somatosensory)

Dark adaptation after exposure to bright light is slowest during which phase?

  1. The rod-cone break
  2. The first minute, when cones adapt
  3. The final rod-dominated phase Correct answer.
  4. The cone plateau between about five and ten minutes

Explanation

Dark adaptation has an initial rapid cone phase followed by a much slower rod phase that can take 20 to 30 minutes or more to complete. The final rod-dominated stage therefore accounts for most of the total adaptation time.

Question 49The Nervous System and Sensory Illusions (Vision, Hearing, Vestibular and Somatosensory)

Which statement best describes a common visual illusion during the approach to land at night?

  1. A narrower-than-usual runway makes the aircraft appear too high
  2. A wider-than-usual runway makes the aircraft appear too low Correct answer.
  3. Bright runway lighting makes the aircraft appear too high
  4. An upsloping runway makes the aircraft appear too high

Explanation

A runway that appears wider than normal leads the pilot to judge the aircraft as lower than it actually is, prompting a high approach. Conversely, a narrow runway creates the illusion of being too high.

Question 50The Nervous System and Sensory Illusions (Vision, Hearing, Vestibular and Somatosensory)

A pilot on final approach sees a runway that slopes upward away from the threshold. What illusion is likely?

  1. The aircraft appears lower than it is
  2. The aircraft appears higher than it is Correct answer.
  3. The runway appears shorter than it is
  4. The runway appears narrower than it is

Explanation

An upsloping runway presents a surface that rises into the field of view, so the pilot tends to perceive the aircraft as higher than its true path. The natural correction is to fly lower, risking an undershoot.