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Human Performance

Q1: The majority of aviation accidents are caused by ^t40q1

DE · FR

Answer

B)

Explanation

The correct answer is B because statistical analyses consistently show that roughly 70-80% of aviation accidents have human error as a primary or contributing cause, including poor judgment, loss of situational awareness, and inadequate decision-making.

Q2: The "swiss cheese model" can be used to explain the ^t40q2

DE · FR

Answer

D)

Explanation

The correct answer is D because James Reason's Swiss Cheese Model shows how accidents result from an error chain — multiple defensive layers (represented as slices of cheese) each have weaknesses ("holes"), and an accident occurs only when these holes align simultaneously to let a hazard pass through all barriers.

Q3: What is the percentage of oxygen in the atmosphere at 6000 ft? ^t40q3

DE · FR

Answer

B)

Explanation

The correct answer is B because the composition of atmospheric gases remains constant at approximately 21% oxygen regardless of altitude — it is the partial pressure of oxygen that decreases as you climb, not the percentage.

Q4: Which is the percentage of nitrogen in the atmosphere? ^t40q4

DE · FR

Answer

C)

Explanation

The correct answer is C because nitrogen constitutes approximately 78% of the atmosphere and remains physiologically inert under normal flight conditions, though it becomes relevant in decompression sickness after diving.

Q5: At which altitude is the atmospheric pressure approximately half the MSL value (1013 hPa)? ^t40q5

DE · FR

Answer

D)

Explanation

The correct answer is D because at approximately 18,000 ft the atmospheric pressure drops to about 500 hPa, which is roughly half of the standard sea-level value of 1013.25 hPa, and this also means the partial pressure of oxygen is halved.

Key Terms

MSL = Mean Sea Level ### Q6: Air consists of oxygen, nitrogen and other gases. Which is the approximate percentage of other gases? ^t40q6

DE · FR

Answer

B)

Explanation

The correct answer is B because after oxygen (21%) and nitrogen (78%), the remaining approximately 1% consists of trace gases — mainly argon (about 0.93%) with small amounts of carbon dioxide, neon, and helium.

Q7: Carbon monoxide poisoning can be caused by ^t40q7

DE · FR

Answer

C)

Explanation

The correct answer is C because cigarette smoke contains carbon monoxide (CO) from incomplete combustion, and CO binds to haemoglobin with approximately 200 times the affinity of oxygen, reducing the blood's oxygen-carrying capacity.

Q8: What does the term "Red-out" mean? ^t40q8

DE · FR

Answer

A)

Explanation

The correct answer is A because red-out occurs during sustained negative g-forces (such as in a pushover or bunt manoeuvre), which force blood into the head and eyes, engorging the retinal blood vessels and creating a red-tinted visual field.

Q9: Which of these is NOT a symptom of hyperventilaton? ^t40q9

DE · FR

Answer

A)

Explanation

The correct answer is A because cyanosis (blue discolouration of skin and lips) is caused by low blood oxygen levels and is a sign of hypoxia, not hyperventilation. Hyperventilation actually increases blood oxygen levels while decreasing CO2.

Q10: Which of these symptoms may indicate hypoxia? ^t40q10

DE · FR

Answer

A)

Explanation

The correct answer is A because cyanosis — the bluish discolouration of lips, fingertips, and nail beds — is a classic clinical sign of hypoxia caused by an increased proportion of deoxygenated haemoglobin in the blood.

Q11: Which of the human senses is most influenced by hypoxia? ^t40q11

DE · FR

Answer

A)

Explanation

The correct answer is A because the retina has an exceptionally high oxygen demand, making vision the first sense to degrade under hypoxic conditions — night vision can deteriorate noticeably at altitudes as low as 5,000 ft.

Q12: From which altitude on does the body usually react to the decreasing atmospheric pressure? ^t40q12

DE · FR

Answer

B)

Explanation

The correct answer is B because at approximately 7,000 ft the body begins to show measurable physiological responses to reduced oxygen partial pressure, such as increased heart rate and breathing rate, though a healthy person can still compensate.

Q13: Which altitude marks the lower limit where the the body is unable to completely compensate the effects of the low atmospheric pressure? ^t40q13

DE · FR

Answer

D)

Explanation

The correct answer is D because above approximately 12,000 ft the body's compensatory mechanisms — increased breathing and heart rate — are no longer sufficient to maintain adequate blood oxygen saturation, and hypoxic symptoms become increasingly apparent.

Q14: What is the function of the red blood cells (erythrocytes)? ^t40q14

DE · FR

Answer

D)

Explanation

The correct answer is D because red blood cells contain haemoglobin, an iron-rich protein that binds oxygen in the lungs and delivers it to tissues throughout the body, making them the primary oxygen transport mechanism.

Q15: Which of these accounts for the blood coagulation? ^t40q15

DE · FR

Answer

D)

Explanation

The correct answer is D because blood platelets (thrombocytes) are cell fragments that aggregate at injury sites and activate the clotting cascade to form a fibrin clot, stopping bleeding.

Q16: Which is the function of the white blood cells (leucocytes)? ^t40q16

DE · FR

Answer

A)

Explanation

The correct answer is A because white blood cells (leucocytes) are the cellular components of the immune system, responsible for identifying and destroying pathogens, foreign substances, and abnormal cells.

Q17: Which is the function of the blood platelets (thrombocytes)? ^t40q17

DE · FR

Answer

C)

Explanation

The correct answer is C because thrombocytes (platelets) are the primary agents of haemostasis — they rapidly aggregate at vascular injury sites and release chemicals that trigger the coagulation cascade, forming a stable clot.

Q18: Which of these is NOT a risk factor for hypoxia? ^t40q18

DE · FR

Answer

B)

Explanation

The correct answer is B because scuba diving is a risk factor for decompression sickness (nitrogen bubbles forming in tissues), not hypoxia — diving itself does not reduce the blood's oxygen-carrying capacity.

Q19: What is an appropriate reaction when a passenger during cruise flight suddenly feels uncomfortable? ^t40q19

DE · FR

Answer

A)

Explanation

The correct answer is A because adjusting the cabin temperature to a comfortable level and reducing bank angle minimises the most common causes of passenger discomfort — thermal discomfort and vestibular stimulation that can trigger motion sickness.

Q20: What ist the correct term for an involuntary and stereotypical reaction of an organism to the stimulation of a receptor? ^t40q20

DE · FR

Answer

A)

Explanation

The correct answer is A because a reflex is defined as an involuntary, rapid, and stereotyped neural response to a specific stimulus, mediated through a reflex arc without requiring conscious thought.

Q21: Which is the correct term for the system which, among others, controls breathing, digestion, and heart frequency? ^t40q21

DE · FR

Answer

C)

Explanation

The correct answer is C because the autonomic nervous system (ANS) regulates involuntary body functions including heart rate, breathing, digestion, and glandular activity through its sympathetic and parasympathetic branches.

Q22: Which is the parallax error? ^t40q22

DE · FR

Answer

A)

Explanation

The correct answer is A because parallax error occurs when an instrument is read from an oblique viewing angle rather than straight on, causing the pointer to appear displaced against the scale and producing a false reading.

Q23: Which characteristic is important when choosing sunglasses used by pilots? ^t40q23

DE · FR

Answer

D)

Explanation

The correct answer is D because polarised lenses can render LCD displays and glass cockpit instruments unreadable by blocking the plane of light they emit, and they may also mask glare reflections from other aircraft or water surfaces that serve as important visual cues.

Q24: The connection between middle ear and nose and throat region is called ^t40q24

DE · FR

Answer

C)

Explanation

The correct answer is C because the Eustachian tube (auditory tube) is the anatomical passage connecting the middle ear to the nasopharynx, allowing pressure equalisation during altitude changes by opening when you swallow or yawn.

Q25: In which situation is it NOT possible to achieve a pressure compensation between the middle ear and the environment? ^t40q25

DE · FR

Answer

B)

Explanation

The correct answer is B because when the Eustachian tube is blocked — typically due to a cold, sinus infection, or allergic swelling — air cannot flow between the middle ear and the throat, making pressure equalisation impossible and causing severe ear pain during altitude changes.

Q26: Wings level after a longer period of turning can lead to the impression of ^t40q26

DE · FR

Answer

B)

Explanation

The correct answer is B because during a prolonged coordinated turn, the semicircular canal fluid adapts and stops signalling the turn; when the pilot levels the wings, the fluid movement creates a false signal interpreted as rotation in the opposite direction — this is the "leans" illusion.

Q27: Which of these options does NOT stimulate motion sickness (disorientation)? ^t40q27

DE · FR

Answer

B)

Explanation

The correct answer is B because non-accelerated straight-and-level flight produces no vestibular stimulation and no conflict between the visual and balance systems, so it cannot trigger motion sickness.

Key Terms

D — Drag ### Q28: Which optical illusion might be caused by a runway with an upslope during the approach? ^t40q28

DE · FR

Answer

D)

Explanation

The correct answer is D because an upsloping runway appears shorter and steeper than a flat runway, tricking the pilot's visual system into perceiving a higher-than-actual approach angle, which leads to an instinctive descent below the correct glide slope — creating a dangerous undershoot risk.

Q29: What impression may be caused when approaching a runway with an upslope? ^t40q29

DE · FR

Answer

B)

Explanation

The correct answer is B because this question asks about the impression (what the pilot perceives), not the actual outcome. An upsloping runway gives the visual illusion of being too high, so the pilot perceives an overshoot situation.

Q30: The occurence of a vertigo is most probable when moving the head ^t40q30

DE · FR

Answer

D)

Explanation

The correct answer is D because moving the head during a turn creates the Coriolis illusion — the semicircular canals are already stimulated by the turn, and adding a head rotation in a different plane simultaneously stimulates additional canals, producing an overwhelming and disorienting sensation of tumbling.

Q31: A Grey-out is the result of ^t40q31

DE · FR

Answer

B)

Explanation

The correct answer is B because grey-out occurs when positive g-forces pull blood away from the head toward the lower body, reducing blood pressure in the retinal arteries and causing progressive loss of colour vision and peripheral vision before full blackout.

Key Terms

D — Drag ### Q32: Visual illusions are mostly caused by ^t40q32

DE · FR

Answer

B)

Explanation

The correct answer is B because the brain actively constructs perception by interpreting sensory input based on prior experience and expectations, and when environmental cues are ambiguous or unusual — as is common in aviation — the brain's "best guess" can be dangerously wrong.

Q33: The average decrease of blood alcohol level for an adult in one hour is approximately ^t40q33

DE · FR

Answer

D)

Explanation

The correct answer is D because the liver metabolises alcohol at a roughly constant rate of approximately 0.01% (0.1 per mille or 0.1 g/L) blood alcohol concentration per hour, regardless of body weight, food intake, or the type of drink consumed.

Q34: Which answer states a risk factor for diabetes? ^t40q34

DE · FR

Answer

B)

Explanation

The correct answer is B because overweight and obesity — particularly excess visceral fat — are the strongest modifiable risk factors for type 2 diabetes due to the insulin resistance they cause, and diabetes is a significant concern in aviation medicine because of the risk of hypoglycaemic episodes impairing pilot performance.

Q35: A risk factor for decompression sickness is ^t40q35

DE · FR

Answer

C)

Explanation

The correct answer is C because scuba diving causes nitrogen to dissolve into body tissues under high ambient pressure, and if the diver flies before adequate off-gassing time (typically 12-24 hours), the reduced cabin pressure causes dissolved nitrogen to form painful and dangerous bubbles in tissues and blood.

Q36: Which statement is correct with regard to the short-term memory? ^t40q36

DE · FR

Answer

C)

Explanation

The correct answer is C because George Miller's classic research established that short-term (working) memory can hold approximately 7 plus or minus 2 chunks of information for about 10-20 seconds without active rehearsal, which is why pilots must write down ATC clearances and frequencies immediately.

Key Terms

ATC = Air Traffic Control ### Q37: For what approximate time period can the short-time memory store information? ^t40q37

DE · FR

Answer

C)

Explanation

The correct answer is C because unrehearsed information in short-term memory decays within approximately 10-20 seconds, which is why aviation procedures emphasise immediate read-back of clearances and writing down critical information.

Q38: What is a latent error? ^t40q38

DE · FR

Answer

D)

Explanation

The correct answer is D because in James Reason's error model, latent errors are hidden failures embedded in the system — such as poor design, inadequate procedures, or organisational shortcuts — that remain dormant and undetected until they combine with an active error to cause an incident or accident.

Q39: The ongoing process to monitor the current flight situation is called ^t40q39

DE · FR

Answer

C)

Explanation

The correct answer is C because situational awareness (SA), as defined by Mica Endsley, is the continuous process of perceiving elements in the environment, comprehending their meaning, and projecting their future state — it is the foundation of sound aeronautical decision-making.

Q40: Regarding the communication model, how can the use of the same code during radio communication be ensured? ^t40q40

DE · FR

Answer

B)

Explanation

The correct answer is B because standardised ICAO radiotelephony phraseology ensures that both sender and receiver share the same unambiguous "code" with pre-defined meanings, minimising the risk of miscommunication in the communication model.

Key Terms

ICAO = International Civil Aviation Organization ### Q41: In what different ways can a risk be handled appropriately? ^t40q41

DE · FR

Answer

A)

Explanation

The correct answer is A because the four standard risk management strategies are: Avoid (eliminate the hazard entirely), Reduce (implement controls to lower probability or severity), Transfer (shift the risk to another party such as through insurance), and Accept (consciously acknowledge residual risk when it falls within acceptable limits).

Q42: Under which circumstances is it more likely to accept higher risks? ^t40q42

DE · FR

Answer

C)

Explanation

The correct answer is C because group dynamics can cause "risky shift" — a well-documented phenomenon where groups tend to accept bolder, riskier decisions than individuals would alone, driven by social pressure, conformity, and diffusion of responsibility.

Q43: Which dangerous attitudes are often combined? ^t40q43

DE · FR

Answer

C)

Explanation

The correct answer is C because the macho attitude ("I can handle anything") and invulnerability ("it won't happen to me") frequently occur together, as both stem from overconfidence and underestimation of personal risk.

Q44: What is an indication for a macho attitude? ^t40q44

DE · FR

Answer

C)

Explanation

The correct answer is C because the macho attitude is defined by the need to demonstrate daring and skill, often to an audience, and performing risky manoeuvres to impress spectators is a textbook example — the pilot prioritises ego over safety.

Q45: Which factor can lead to human error? ^t40q45

DE · FR

Answer

C)

Explanation

The correct answer is C because confirmation bias — the tendency to perceive and interpret information in a way that confirms pre-existing expectations — is a major source of human error, leading pilots to misread instruments, overlook abnormalities, or misidentify visual references.

Q46: Which is the best combination of traits with respect to the individual attitude and behaviour for a pilot? ^t40q46

DE · FR

Answer

B)

Explanation

The correct answer is B because extroversion supports effective communication, assertiveness, and crew coordination essential for CRM, while emotional stability ensures the pilot remains calm, consistent, and rational under pressure.

Q47: Complacency is a risk due to ^t40q47

DE · FR

Answer

D)

Explanation

The correct answer is D because as cockpit automation becomes more sophisticated and reliable, pilots tend to reduce their active monitoring, lose vigilance, and allow their manual flying skills to degrade — this is automation complacency, and it becomes critically dangerous when the automation fails unexpectedly.

Q48: The ideal level of arousal is at which point in the diagram? ^t40q48

DE · FR

Yerkes-Dodson Curve

Answer

C)

Explanation

The correct answer is C (Point B) because on the Yerkes-Dodson inverted-U curve, Point B sits at the peak where moderate arousal produces maximum performance.

Q49: At which point in the diagram will a pilot find himself to be overstrained? ^t40q49

DE · FR

![](figures/t40_q49.png)

Answer

B)

Explanation

The correct answer is B (Point D) because it lies at the far right of the Yerkes-Dodson curve where excessive arousal causes performance to collapse — the pilot is overstrained, experiencing cognitive overload, tunnel vision, and potentially panic.

Q50: Which of these qualities are influenced by stress? 1. Attention 2. Concentration 3. Responsiveness 4. Memory ^t40q50

DE · FR

Answer

C)

Explanation

The correct answer is C because stress affects all four cognitive functions: attention narrows (tunnel vision), concentration becomes fragmented, responsiveness changes (initially faster then degraded under extreme stress), and memory — especially working memory encoding and retrieval — is impaired by elevated cortisol.

Q51: The proportion of oxygen in the air at sea level is 21%. What is this percentage at an altitude of 5 km (16,400 ft)? ^t40q51

DE · FR

Answer

D)

Explanation

The correct answer is D because the proportion of oxygen in the atmosphere remains constant at approximately 21% regardless of altitude — what decreases with altitude is the total atmospheric pressure, and therefore the partial pressure of oxygen available for breathing. A, B, and C are all wrong because they suggest the percentage of oxygen itself changes with altitude, which is incorrect; the atmosphere maintains a homogeneous composition up to approximately 80 km.

Q52: The signs of oxygen deficiency ^t40q52

DE · FR

Answer

C)

Explanation

The correct answer is C because smokers already have elevated carboxyhaemoglobin levels from carbon monoxide binding to their red blood cells, effectively reducing their oxygen-carrying capacity even before flight, so hypoxic symptoms manifest at lower altitudes compared to non-smokers.

Q53: Carbon monoxide ^t40q53

DE · FR

Answer

C)

Explanation

The correct answer is C because carbon monoxide (CO) is a highly toxic gas produced by incomplete combustion of carbon-based fuels, and in aviation it can enter the cabin through leaking exhaust systems; it binds to haemoglobin with approximately 200 times the affinity of oxygen.

Q54: How long does it generally take for the human eye to fully adapt to darkness? ^t40q54

DE · FR

Answer

A)

Explanation

The correct answer is A because full dark adaptation requires approximately 30 minutes for the rod cells in the retina to reach maximum sensitivity through the regeneration of rhodopsin (visual purple), which is why pilots should avoid bright lights before night flying.

Q55: Low blood pressure ^t40q55

DE · FR

Answer

B)

Explanation

The correct answer is B because hypotension (low blood pressure) can cause dizziness, lightheadedness, and even fainting, particularly when changing posture (orthostatic hypotension), which poses a flight safety risk.

Q56: What symptom will most probably occur at 20,000 ft (6100 m) altitude without a pressurised cabin or oxygen equipment? ^t40q56

DE · FR

Answer

A)

Explanation

The correct answer is A because at 20,000 ft without supplemental oxygen, the time of useful consciousness (TUC) is very short — typically only a few minutes — and rapid loss of consciousness follows due to severe hypoxia as the partial pressure of oxygen is far below what the body requires.

Q57: When flying with a severe head cold, sharp pain can affect the sinuses. This pain occurs ^t40q57

DE · FR

Answer

A)

Explanation

The correct answer is A because during descent, external atmospheric pressure increases and trapped air within congested sinuses cannot equalise, creating a painful pressure differential — this is known as barosinusitis.

Q58: Which are the symptoms of motion sickness (kinetosis)? ^t40q58

DE · FR

Answer

C)

Explanation

The correct answer is C because the classic symptoms of motion sickness (kinetosis) are dizziness, sweating, pallor, and nausea, which may progress to vomiting — all caused by a conflict between visual and vestibular sensory inputs.

Q59: During a normal approach to an unusually wide runway, one may have the impression that the approach is being made ^t40q59

DE · FR

Answer

C)

Explanation

The correct answer is C because a runway wider than the pilot is accustomed to makes the visual perspective appear as though the aircraft is lower and closer than it actually is, creating the impression of being at too low a speed and too low a height — the pilot may then tend to fly the approach too high.

Q60: Under positive g-forces, a greyout can occur which precedes blackout. Which organ is primarily affected by greyout? ^t40q60

DE · FR

Answer

B)

Explanation

The correct answer is B because the eyes (specifically the retina) are the first organ to be affected by positive g-forces because retinal blood vessels are extremely sensitive to reduced blood pressure — the retina has the highest oxygen demand of any tissue, so when blood drains away under g-loading, vision degrades before consciousness is affected.

Q61: When a pilot scans the sky to detect the presence of other aircraft, he should ^t40q61

DE · FR

Answer

C)

Explanation

Effective visual scanning requires dividing the sky into sectors and pausing briefly on each one, allowing the eyes to focus and detect movement or contrast changes that indicate other aircraft.

Q62: Alcohol is eliminated at a rate of: ^t40q62

DE · FR

Answer

C)

Explanation

The human liver metabolises alcohol at a relatively constant rate of approximately 0.1 per mille per hour, regardless of the type of drink consumed or any attempted countermeasures such as coffee or exercise.

Key Terms

SPL = Sailplane Pilot Licence ### Q63: From the following factors, identify the one that increases the risk of heart attack: ^t40q63

DE · FR

Answer

A)

Explanation

A sedentary lifestyle with insufficient physical activity is a well-established cardiovascular risk factor that increases the likelihood of heart attack.

Q64: Amphetamine is a stimulant which in Switzerland can be obtained on prescription from pharmacies ^t40q64

DE · FR

Answer

D)

Explanation

Amphetamines are strictly prohibited for pilots on duty because their adverse effects — including impaired judgment, overconfidence, risk-taking behaviour, and a crash of fatigue after the drug wears off — directly compromise flight safety.

Q65: What is meant by "risk area awareness" in aviation? ^t40q65

DE · FR

Answer

C)

Explanation

Risk area awareness refers to the pilot's conscious understanding that different phases of flight — takeoff, climb, cruise, descent, approach, and landing — each carry distinct hazards requiring specific vigilance.

Q66: Several decision-making models are applied in aviation. A widely used model goes by the acronym "DECIDE". Which of the following statements is correct? ^t40q66

DE · FR

Answer

B)

Explanation

The DECIDE model follows the sequence: Detect, Estimate, Choose, Identify, Do, Evaluate. The first letter D stands for "Detect," meaning the pilot recognises that a change in the situation has occurred requiring a decision.

Q67: Regarding typical hazardous attitudes, which of the following statements is correct? ^t40q67

DE · FR

Answer

A)

Explanation

Human factors research identifies five hazardous attitudes — anti-authority, macho, invulnerability, resignation, and impulsivity — and demonstrates that pilots can learn to recognise these tendencies in themselves and apply corrective antidotes.

Q68: Which of these statements correctly describes "selective attention"? ^t40q68

DE · FR

Answer

B)

Explanation

Selective attention is a cognitive phenomenon where concentrating intensely on one task causes the brain to filter out other stimuli, even obvious ones like a loud alarm. This is sometimes called "inattentional blindness" or "tunnel hearing.

Q69: Regarding stress, which of the following statements is correct? ^t40q69

DE · FR

Answer

A)

Explanation

The Yerkes-Dodson law demonstrates that moderate stress (eustress) enhances alertness, focus, and performance, while too little or too much stress degrades it — forming an inverted-U curve.

Q70: The human internal clock ^t40q70

DE · FR

Answer

A)

Explanation

Research on circadian rhythms shows that the human endogenous biological clock runs on a cycle of approximately 25 hours when isolated from external time cues such as daylight and social schedules. Daily exposure to light resets (entrains) this internal clock to the 24-hour day-night cycle.

Q71: Which of the following measures is suitable for relieving the onset of motion sickness (kinetosis) in passengers? ^t40q71

DE · FR

Answer

C)

Explanation

Breathing fresh, cool air helps stabilise the autonomic nervous system and is one of the most effective immediate remedies for the onset of motion sickness.

Q72: During training, a pilot has mainly used narrow runways. What illusion will this pilot experience during a correct final approach to a flat, very wide runway? ^t40q72

DE · FR

Answer

C)

Explanation

A pilot accustomed to narrow runways perceives a wide runway as being closer (lower) than it actually is because the wider visual angle tricks the brain into interpreting the scene as a nearer surface. This creates the dangerous illusion of being too low, which may cause the pilot to fly a higher approach than necessary and flare too high.

Q73: When are middle ear pressure equalization problems most probable to occur? ^t40q73

DE · FR

Answer

B)

Explanation

Middle ear pressure equalisation problems are most likely during rapid descent because the Eustachian tube must open to allow higher-pressure air from the throat into the middle ear cavity, which is physiologically more difficult than the reverse. During ascent, expanding air in the middle ear vents outward relatively easily.

Q74: The proportion of oxygen in the atmosphere is 21% at sea level. How does it change at 5500 m? ^t40q74

DE · FR

Answer

D)

Explanation

The composition of the atmosphere remains constant at approximately 21% oxygen and 78% nitrogen from sea level up to about 80 km altitude. What decreases with altitude is not the percentage of oxygen but the total atmospheric pressure, and therefore the partial pressure of oxygen available to the lungs.

Q75: Which are the effects of inhaling carbon monoxide (from a defective exhaust system)? ^t40q75

DE · FR

Answer

A)

Explanation

Carbon monoxide (CO) binds to haemoglobin approximately 200 times more readily than oxygen, forming carboxyhaemoglobin and drastically reducing the blood's oxygen-carrying capacity. Even very low concentrations can cause headaches, impaired judgment, and eventually total incapacitation or death.

Q76: Which is the most effective hearing protection in the cabin of a powered aircraft or hot air balloon? ^t40q76

DE · FR

Answer

B)

Explanation

A helmet with integrated earphones provides the highest level of hearing protection by covering the entire ear with a rigid shell that attenuates both direct sound and vibration-transmitted noise, while simultaneously enabling clear radio communication.

Q77: Gas-forming foods that cause flatulence ought to be avoided before a high-altitude flight. Which of these foods must therefore be avoided? ^t40q77

DE · FR

Answer

A)

Explanation

Legumes such as beans, peas, and lentils are well known to produce significant intestinal gas during digestion. At altitude, ambient pressure decreases and any trapped gas in the body expands according to Boyle's law, potentially causing severe abdominal pain and distraction in flight.

Q78: The respiratory process enables gas exchange in somatic cells (metabolism). These cells ^t40q78

DE · FR

Answer

B)

Explanation

In cellular respiration, somatic cells take in oxygen and use it to metabolise glucose and other nutrients, producing energy (ATP) and releasing carbon dioxide (CO2) as a waste product.

Q79: A regular smoker pilot smokes a few cigarettes shortly before an alpine flight. What effects might this have on their flight fitness? ^t40q79

DE · FR

Answer

B)

Explanation

Cigarette smoke contains carbon monoxide (CO), which binds to haemoglobin and reduces the blood's oxygen-carrying capacity. A pilot who smokes before an alpine flight effectively raises their "physiological altitude" — they will experience symptoms of oxygen deficiency (hypoxia) at a lower altitude than a non-smoking pilot would.

Q80: When is the risk of vestibular disturbance causing dizziness greatest? ^t40q80

DE · FR

Answer

D)

Explanation

Rotating the head during a coordinated turn creates the Coriolis illusion — the semicircular canals are already stimulated by the angular acceleration of the turn, and a head rotation in a different plane stimulates additional canals simultaneously, producing a powerful and disorienting sensation of tumbling or spinning.

Q81: How can a pilot better withstand positive g-forces in flight? ^t40q81

DE · FR

Answer

C)

Explanation

Contracting the abdominal and leg muscles (the anti-G straining manoeuvre or L-1 technique) increases intra-abdominal pressure and impedes blood from pooling in the lower body, maintaining blood flow to the brain and delaying the onset of grey-out and G-LOC. Forced, cyclical breathing maintains thoracic pressure.

Q82: Which are the most dangerous effects of oxygen deficiency? ^t40q82

DE · FR

Answer

C)

Explanation

Impairment of judgment and concentration is the most dangerous effect of hypoxia because the pilot loses the very cognitive abilities needed to recognise the problem and take corrective action — a phenomenon known as "insidious hypoxia.

Q83: What can be said about the rate of blood alcohol elimination in humans? ^t40q83

DE · FR

Answer

B)

Explanation

Alcohol is eliminated from the blood by the liver at a nearly constant rate of approximately 0.1 per mille per hour, determined solely by time and the liver's enzyme capacity.

Q84: What impact does proprioception (deep sensitivity) have on position perception? ^t40q84

DE · FR

Answer

B)

Explanation

Proprioception — the sense of body position derived from receptors in muscles, joints, and tendons — can provide misleading information about the aircraft's attitude when visual references are absent. Without visual confirmation, the proprioceptive system cannot reliably distinguish between gravitational forces and centripetal forces in a turn.

Q85: Which of these factors has no direct effect on visual acuity? ^t40q85

DE · FR

Answer

A)

Explanation

High blood pressure (hypertension) does not directly impair visual acuity during normal flight operations, although severe chronic hypertension may eventually damage the retina over time.

Q86: Up to what maximum altitude can a healthy human body compensate for oxygen deficiency by increasing heart rate and breathing rate? ^t40q86

DE · FR

Answer

D)

Explanation

The human body can compensate for the reduced partial pressure of oxygen up to approximately 10,000-12,000 ft by increasing heart rate, respiratory rate, and cardiac output. Above this altitude, these compensatory mechanisms become insufficient and supplemental oxygen is required to prevent significant performance degradation.

Q87: What has to be observed when taking over-the-counter medications? ^t40q87

DE · FR

Answer

A)

Explanation

Many over-the-counter medications — including antihistamines, cold remedies, pain relievers, and decongestants — can cause drowsiness, dizziness, impaired reaction time, or blurred vision, all of which compromise flight safety.

Q88: What sensory illusion can a linear acceleration produce in horizontal flight when visual references are lost? ^t40q88

DE · FR

Answer

D)

Explanation

A forward linear acceleration in horizontal flight pushes the pilot back into the seat, and the otolith organs in the inner ear interpret the combined acceleration vector as a backward tilt — creating the somatogravic illusion of a climb. Without visual references, the pilot may instinctively push the nose down to "correct" the perceived climb, risking a dive into terrain.

Q89: How long does the human eye take to fully adapt to darkness? ^t40q89

DE · FR

Answer

D)

Explanation

Full dark adaptation of the human eye takes approximately 30 minutes as the rod photoreceptors in the retinal periphery gradually increase their sensitivity through biochemical changes in rhodopsin.

Q90: Which of these statements about hyperventilation is correct? ^t40q90

DE · FR

Answer

C)

Explanation

Hyperventilation — excessively rapid or deep breathing — is frequently triggered by stress, anxiety, or fear, which causes the pilot to unconsciously breathe faster than metabolically necessary. This excessive ventilation blows off too much CO2, causing hypocapnia (low blood CO2), not an excess.

Q91: Vestibular disturbances during a turn can cause dizziness. What measure is most effective in preventing them? ^t40q91

DE · FR

Answer

B)

Explanation

Keeping the head still during a turn prevents the Coriolis illusion, which occurs when head movement in one plane is combined with the angular rotation of the turn, stimulating multiple semicircular canals simultaneously and producing intense vertigo.

Q92: Which is the immediate effect of inhaling cigarette smoke on a regular smoker? ^t40q92

DE · FR

Answer

C)

Explanation

The carbon monoxide (CO) in cigarette smoke binds to haemoglobin far more readily than oxygen, forming carboxyhaemoglobin and immediately reducing the blood's capacity to transport oxygen to tissues and organs.

Q93: What is the relationship between oxygen deficiency and visual acuity? ^t40q93

DE · FR

Answer

A)

Explanation

The retina is one of the most metabolically active tissues in the body and is highly sensitive to oxygen deprivation. Even mild hypoxia can reduce visual acuity, diminish contrast sensitivity, and narrow the visual field, with night vision being affected first since rod cells are particularly oxygen-demanding.

Q94: Oxygen deficiency and hyperventilation share some similar symptoms. Which of these symptoms always indicates oxygen deficiency? ^t40q94

DE · FR

Answer

A)

Explanation

Cyanosis — a bluish discolouration of the lips and fingernails caused by deoxygenated haemoglobin — is a reliable and specific sign of oxygen deficiency that cannot be produced by hyperventilation alone.

Q95: What is the proportion of oxygen (in %) in the air at an altitude of approximately 34,000 feet? ^t40q95

DE · FR

Answer

B)

Explanation

The atmosphere maintains a constant composition of approximately 21% oxygen from sea level through the troposphere and well into the stratosphere. At 34,000 ft, while the total atmospheric pressure is only about one quarter of sea-level pressure, the proportion of oxygen remains 21%.

Q96: During a visual flight, you suddenly lose all external visual references. Spatial orientation using only cutaneous senses and proprioception is ^t40q96

DE · FR

Answer

A)

Explanation

Without external visual references, maintaining spatial orientation using only cutaneous senses (pressure on the skin) and proprioception (body position sense) is physiologically impossible because these senses cannot distinguish between gravitational forces and the centripetal or inertial forces experienced in flight.

Q97: Which is the most probable and most dangerous poisoning that can occur on board a piston-engine aircraft? ^t40q97

DE · FR

Answer

B)

Explanation

Carbon monoxide (CO) poisoning from a defective or leaking exhaust system is the most likely and most dangerous in-flight poisoning in piston-engine aircraft. CO is colourless and odourless, making it undetectable without a dedicated CO detector, and it binds to haemoglobin 200 times more strongly than oxygen, rapidly incapacitating the pilot.

Q98: What impression results from a correct final approach to a runway with a strong upslope in the landing direction? ^t40q98

DE · FR

Answer

C)

Explanation

When approaching a runway that slopes upward in the landing direction, the pilot perceives the runway surface at an unusual angle that creates the visual illusion of being too high on approach. The upsloping surface compresses the visual perspective, making the runway appear closer and the approach steeper than it actually is.

Q99: Why should gas-forming foods be avoided before undertaking a high-altitude flight? ^t40q99

DE · FR

Answer

B)

Explanation

As altitude increases, ambient pressure decreases and trapped gases in the body expand according to Boyle's law. Intestinal gas produced by gas-forming foods such as beans and lentils expands significantly at altitude, causing abdominal distension, pain, and distraction from flying tasks.

Q100: Which blood component primarily transports oxygen? ^t40q100

DE · FR

Answer

A)

Explanation

Red blood cells (erythrocytes) contain haemoglobin, the iron-containing protein that binds oxygen in the lungs and releases it to tissues throughout the body. Each red blood cell carries approximately 270 million haemoglobin molecules, making erythrocytes the primary oxygen transport system.

Q101: What illusion can occur when visual references are lost during a prolonged coordinated turn? ^t40q101

DE · FR

Answer

A)

Explanation

During a prolonged coordinated turn at constant rate, the fluid in the semicircular canals gradually matches the rotation speed and stops deflecting the sensory hairs, causing the vestibular system to signal "no turn" even though the aircraft remains banked. The pilot perceives wings-level flight. If the pilot then levels the wings, they experience the sensation of turning in the opposite direction and may re-enter the original turn — this is the mechanism behind the deadly graveyard spiral.

Q102: Your passenger wishes to ease their fear of flying by drinking a strong alcoholic drink just before departure. What effect has to be expected at high altitude? ^t40q102

DE · FR

Answer

D)

Explanation

At altitude, the reduced partial pressure of oxygen (hypoxia) acts synergistically with alcohol to amplify its impairing effects on the central nervous system. Both hypoxia and alcohol independently degrade cognitive function, and together they produce a combined impairment far greater than either alone — sometimes described as a multiplier effect.

Q103: Which is the correct technique for seeing at night? ^t40q103

DE · FR

Answer

B)

Explanation

At night, the central fovea of the retina — used for direct vision — contains only cone cells, which require more light to function effectively. The rod cells responsible for low-light sensitivity are concentrated in the retinal periphery. Looking slightly to the side of an object (off-centre viewing) places its image on the rod-rich area, making it visible in dim conditions.

Q104: Your passenger complains of middle ear pressure equalization problems. How can you help them? ^t40q104

DE · FR

Answer

B)

Explanation

Middle ear pressure equalisation problems occur most commonly during descent, when increasing external pressure cannot enter the middle ear cavity fast enough through the Eustachian tube. The correct remedy is to stop the descent, climb slightly if possible to reduce the pressure differential and allow the pain to subside, then resume the descent at a slower rate to give the Eustachian tube time to equalise.

Q105: Which of the following symptoms may indicate oxygen deficiency? ^t40q105

DE · FR

Answer

D)

Explanation

Difficulty concentrating is one of the earliest and most characteristic symptoms of hypoxia (oxygen deficiency), reflecting the brain's high sensitivity to reduced oxygen supply. As altitude increases and oxygen partial pressure drops, cognitive functions deteriorate before physical symptoms become apparent.

Q106: What causes motion sickness (kinetosis)? ^t40q106

DE · FR

Answer

B)

Explanation

Motion sickness is caused by irritation of the vestibular system (balance organ) in the inner ear when it receives conflicting signals from the eyes, the vestibular apparatus, and proprioceptors. This sensory mismatch — for example, the inner ear detecting motion while the eyes see a stationary cockpit interior — triggers the autonomic nervous system response that produces nausea and vomiting.

Q107: Which are the side effects of anti-motion-sickness medications? ^t40q107

DE · FR

Answer

A)

Explanation

Anti-motion-sickness medications — primarily antihistamines (such as dimenhydrinate) and anticholinergics (such as scopolamine) — commonly cause drowsiness and significantly slowed reaction times as their primary side effects. These effects directly compromise the alertness and rapid decision-making required for safe flying.

Q108: What is decisive for the onset of noise-induced hearing loss? ^t40q108

DE · FR

Answer

B)

Explanation

Noise-induced hearing loss depends on the total sound energy dose received by the ear, which is a function of both the intensity (measured in decibels) and the duration of exposure. A very loud noise over a short period or a moderately loud noise sustained over many hours can both cause permanent damage.

Q109: Increasing and sustained positive g-loads can produce symptoms that appear in the following order: ^t40q109

DE · FR

Answer

A)

Explanation

As positive g-forces increase, blood drains from the head toward the lower body in a predictable sequence of visual and neurological symptoms: first grey-out (loss of colour vision as the retina receives less oxygenated blood), then tunnel vision (reduction of peripheral vision as the outer retina fails first), then complete blackout (total loss of vision), and finally G-LOC (loss of consciousness).

Q110: From what altitude does the body of a healthy person begin to compensate for oxygen deficiency by accelerating breathing rate? ^t40q110

DE · FR

Answer

A)

Explanation

At approximately 6,000-7,000 ft, the reduced partial pressure of oxygen becomes sufficient to trigger the body's chemoreceptors, which detect the drop in blood oxygen and stimulate an increase in respiratory rate as a compensatory mechanism.

Q111: The ideal level of arousal is at which point in the diagram? ^t40q111

DE · FR

![](figures/t40_q111.png)

Answer

C)

Explanation

The Yerkes-Dodson law, illustrated by the inverted-U curve in figure, shows that performance peaks at a moderate, optimal level of arousal — represented by Point B at the top of the curve.

Q112: Which answer is correct concerning stress? ^t40q112

DE · FR

Answer

C)

Explanation

Stress commonly arises when a person perceives a threatening or problematic situation for which no adequate solution appears available — the feeling of being trapped or overwhelmed triggers the physiological stress response.

Q113: During flight you have to solve a problem, how to you proceed? ^t40q113

DE · FR

Answer

C)

Explanation

The fundamental principle of airmanship is "aviate, navigate, communicate" — in that order. The pilot's primary duty is always to fly the aircraft and maintain stable flight before addressing any secondary problem.

Q114: At which point in the diagram will a pilot find himself to be overstrained? ^t40q114

DE · FR

![](figures/t40_q114.png)

Answer

A)

Explanation

On the Yerkes-Dodson inverted-U curve, Point D represents the extreme right of the arousal axis where stress levels are very high and performance has collapsed — the pilot is overstrained. At this level of arousal, cognitive function breaks down, decision-making becomes erratic, and the risk of critical errors increases dramatically.

Q115: The swiss cheese model is used to explain the ^t40q115

DE · FR

Answer

C)

Explanation

James Reason's Swiss Cheese Model is a foundational concept in aviation safety that illustrates how accidents result from an error chain — a series of individual failures in successive defensive barriers that happen to align, allowing a hazard to penetrate all layers simultaneously. Each "slice of cheese" represents a safety barrier with inherent "holes" (latent conditions and active failures).

Key Terms

D — Drag ### Q116: What does the term Red-out mean? ^t40q116

DE · FR

Answer

C)

Explanation

Red-out occurs during sustained negative g-forces (such as during a bunt or inverted flight manoeuvre), when blood is forced upward into the head and eyes. The excess blood pressure in the ocular capillaries produces a characteristic red tinge across the visual field. This is the negative-g counterpart to grey-out and blackout, which occur under positive g-forces when blood drains away from the head.

Q117: What does presbyopia mean? ^t40q117

DE · FR

Answer

D)

Explanation

Presbyopia is an age-related condition in which the lens of the eye loses its flexibility and can no longer accommodate for near vision, making reading or checking cockpit instruments difficult without reading glasses.

Q118: The inner ear consists of ^t40q118

DE · FR

Answer

A)

Explanation

The inner ear contains three functional components: the three semicircular canals (which detect rotational accelerations), the two otolith organs - utricle and saccule - (which detect linear accelerations and static position relative to gravity), and the cochlea (which converts sound waves into nerve signals). These seven structures are essential for balance and hearing respectively.

Q119: What is the normal weight of a person? ^t40q119

DE · FR

Answer

A)

Explanation

The classical "normal weight" formula (also known as the Broca index) is simply height in centimetres minus 100, giving weight in kilograms. Thus a person 170 cm tall has a normal weight of 70 kg. Although this formula is simplistic and largely replaced by BMI in modern medicine, it remains used in aeronautical references.

Q120: Which profession carries a higher risk of contracting AIDS? ^t40q120

DE · FR

Answer

B)

Explanation

Doctors, nurses, and other healthcare professionals face an elevated risk of HIV exposure through accidental needle-stick injuries, blood splashes, or contact with infected bodily fluids during medical procedures. This occupational risk is specific to working with medical equipment and potentially infected patients.

Q121: How is the AIDS virus transmitted? ^t40q121

DE · FR

Answer

A)

Explanation

HIV is transmitted by direct contact with certain infected bodily fluids: blood, semen, vaginal secretions, and breast milk. Sharing used syringes is one of the primary transmission routes because it directly introduces infected blood into another person's bloodstream.

Q122: What can be said about vaccinations? ^t40q122

DE · FR

Answer

C)

Explanation

Basic vaccinations - such as those against tetanus, diphtheria, and poliomyelitis - provide immunity that wanes over time and requires regular booster doses to maintain effective protection. For example, the tetanus booster is generally recommended every ten years.

Q123: Which product carries the least risk of contact with an infectious disease? ^t40q123

DE · FR

Answer

D)

Explanation

Bottled mineral water is packaged in a controlled, sterile environment, and its sealed container protects it from subsequent contamination. It therefore carries the least risk of transmitting food- or water-borne infectious diseases, particularly when travelling in regions with uncertain hygiene standards.

Q124: What is the effect of taking a medication and alcohol simultaneously? ^t40q124

DE · FR

Answer

B)

Explanation

Alcohol interacts with many medications and potentiates (amplifies) their effect, particularly sedatives, antihistamines, sleeping pills, and anxiolytics. This interaction is especially dangerous for pilots because it can cause drowsiness, slowed reflexes, and impaired judgement far greater than those produced by either alcohol or the medication alone.

Q125: What is the sleep cycle for an adult? ^t40q125

DE · FR

Answer

C)

Explanation

For most adults, sleep requirement is approximately 8 hours per night, leaving approximately 16 hours of wakefulness. This 8/16 balance allows sufficient physical and mental recovery to maintain the cognitive and physical performance needed for daily activities, including flying. Chronic sleep deprivation degrades alertness, reaction time, and decision-making.

Q126: How is the AIDS virus transmitted? ^t40q126

DE · FR

Answer

B)

Explanation

HIV is transmitted primarily through unprotected sexual intercourse, through sharing contaminated syringes, and from mother to child during pregnancy or breastfeeding. Unprotected sexual intercourse is the most common route of transmission worldwide.

Q127: Which substance in cigarette smoke increases the probability of lung cancer? ^t40q127

DE · FR

Answer

B)

Explanation

Tar is a mixture of carcinogenic chemicals contained in cigarette smoke. When inhaled, it deposits in the lungs and irritates pulmonary tissue, causing cellular damage, genetic mutations, and ultimately lung cancer. It is tar, not nicotine, that is directly responsible for the carcinogenic effect of tobacco.

Q128: You must not fly with tonsillitis because ^t40q128

DE · FR

Answer

D)

Explanation

Tonsillitis (throat infection) causes swelling of the mucous membranes of the throat and nasopharynx, which can block the Eustachian tube. In flight, during altitude changes, this prevents pressure equalisation in the middle ear and can lead to barotraumatic otitis media (middle ear inflammation) that is particularly painful and potentially dangerous.

Q129: What physical training is recommended to prevent heart disease? ^t40q129

DE · FR

Answer

A)

Explanation

Standard cardiology guidelines for the prevention of cardiovascular disease recommend moderate-intensity aerobic exercise (heart rate approximately double the resting rate) for at least 20 minutes, repeated a minimum of three times per week. This regular training strengthens the heart muscle, improves circulation, and reduces cardiovascular risk factors.