The theory subject "Human Performance" is about understanding processes in the pilot's body and what effects these can have on flight. Physiological principles are described, human perception and its effects on flight. This is followed by psychological aspects, information processing and stress management and finally various behavioural strategies.
Physiological principles and perception
Flight physiology deals with the effects of flying on the human body, particularly with regard to oxygen supply and blood circulation. Breathing plays a central role, as it is responsible for the intake of oxygen from the ambient air and the release of carbon dioxide. At high altitudes, the partial pressure of oxygen in the air decreases, which can lead to hypoxia, a lack of oxygen in the blood. This impairs performance and, in extreme cases, can lead to unconsciousness and death. An adequate oxygen supply is therefore essential in aeroplanes.
The blood transports oxygen to the body's cells and carbon dioxide back to the lungs. The heart and blood circulation are central elements in this process. Different types of hypoxia can be caused by a lack of blood, circulatory disorders, inability of the cells to utilise oxygen or low oxygen partial pressure. Symptoms of hypoxia include fatigue, headaches, difficulty concentrating, euphoria and, in cases of severe oxygen deficiency, unconsciousness.
Hyperventilation, often psychologically induced, can also be problematic as it can lead to an excessive exhalation of carbon dioxide and thus to an oxygen deficiency situation. A controlled reduction in the breathing rate or breathing 100 % oxygen can provide relief.
Flight physiology emphasises the need for an adequate oxygen supply and the importance of pressurised cabins in aircraft, especially when flying at high altitudes. The ability to recognise hypoxia symptoms at an early stage and act accordingly is crucial for flight safety.
Furthermore, it is generally about the human sensory system. This consists of five senses (sight, hearing, smell, taste and touch) and is not primarily designed for flying. While some senses such as taste and touch are secondary in the context of flight, sight and the sense of balance in the ear can lead to critical situations. On the ground, the position is determined via the balance apparatus in the inner ear, visual perception and the sense of touch and position. In flight, however, external aids such as instruments are essential for assessing the flight attitude.
The nervous system, consisting of the central and peripheral nervous system, functions as the body's information and reaction system. It is susceptible to the stresses and strains of flying. Certain substances can impair the function of synapses and affect the nervous system.
Visual perception is crucial for flying, as the eye is an important sensory organ. Malfunctions of the eye can cause significant limitations when flying.
Acoustic perception, made possible by the ear, includes the hearing and balance organs. Disorders of the vestibular system can lead to dizziness, nausea and other symptoms.
Acceleration during flight can cause various physiological effects and perceptual illusions. Positive and negative accelerations have different effects on the body.
Kinetosis, also known as motion sickness or air sickness, results from a conflict between the movements perceived via the sense of balance in the inner ear and the impressions of other sensory organs. Measures to prevent and alleviate the symptoms include avoiding turbulence, a good supply of fresh air and, in some cases, medication.
Finally, it is emphasised that the "seat-of-the-pants" feeling for orientation in space is not reliable when flying and that various factors such as fog, darkness and poor visibility can lead to estimation errors in distance, size and speed. When scanning the surroundings, the pilot should proceed systematically in order to recognise potential dangers in good time.
Psychological aspects
This theory chapter deals with various psychological aspects that are important for pilots in aviation. Firstly, psychology is described as a science that studies human behaviour and its development. Particular emphasis is placed on the importance for pilots of understanding decision-making processes in the brain in order to minimise wrong decisions and emotional influences and thus increase safety in flight operations.
In the section on information processing, the brain is emphasised as the central location for managing and storing information. Different types of memory, such as sensory, short-term and long-term memory, are explained, as well as the importance of learning for the development of flying skills.
The section on stress addresses how stress can trigger both physical and psychological reactions due to external factors (stressors). Stress can be positive in some cases (eustress), but usually leads to a high level of strain. The workload in the cockpit and its subjective perception, stressors and stress symptoms as well as strategies for coping with stress are discussed in detail.
Finally, the importance of personality for safe flight operations is emphasised. A sense of responsibility, compliance with rules, self-confidence and the ability to work in a team are emphasised as important characteristics for pilots. In addition, various forms of misconduct and their psychological backgrounds are discussed in order to show how important mental attitude and behavioural changes are for flight safety.
Behavioural strategies
Humans remain a decisive factor in aviation, both as operators of complex technology and as a potential source of errors. The human body is often unprepared for the stresses and strains of flight operations, and health restrictions or the use of performance-inhibiting drugs can interfere with piloting an aircraft. It is important to prepare the body and behaviour for unaccustomed stresses through training and protective measures, whereby physical and psychological factors must be taken into account equally. Physical impairments can also reduce mental performance, which can be particularly critical in stressful situations. In order to deal with such situations, standard procedures and behavioural strategies have been developed to support safe flight operations.
Humans are central to the aircraft system: they make decisions, assess situations and bear responsibility. In the context of aircraft accidents, it becomes clear that human error is not limited to the cockpit, but can also occur in aircraft construction, maintenance and other areas.
Human error is cited as a major cause of over 80% of aviation accidents, with several factors usually leading to an accident. The most common causes include a lack of flying skills, breaking the rules, incorrect decisions and errors in perception.
Alcohol and drugs also play a role in aviation accidents. Even small amounts of alcohol can significantly impair performance, with the effect increasing with altitude. Medication can also impair fitness to fly, which is why pilots should consult an aviation physician before taking medication.
The SHEL(L) concept and the Swiss cheese model offer approaches for understanding and managing the interaction of various factors during a flight. The FORDEC principle serves as a decision-making aid in unusual situations and is based on analysing facts, options and risks, followed by a decision, its execution and continuous review.
The cockpit management chapters emphasise that not only the condition of the aircraft, but also the mental and physical condition of the pilot are crucial for a safe flight. Decision-making, standard procedures and conflict management are important aspects for the safe conduct of a flight. Analysing and dealing with misconduct and attending flight safety briefings are essential for preventing accidents.