Human Factors and Ergonomics in the Cockpit

Based on a book by Green, Muir, James, Gradwell and Green, 1996

Intro :

Since the early days of aviation, pilots faced a lot of challenges in the air. It took hundreds of accidents and incidents before the aviation community realised the facts of human errors and why pilots do sometimes make vital mistakes. Flight crew’s Human Factors (HF) represents an ongoing challenge to the aviation industry and a vocal point to many scholars. This page will briefly highlight some of the basic issues contributing to HF in the cockpit that been affecting flight crews at work all over the globe.

1-The Flight Dynamics and HF:

Flying is something unique. Pilots can experience many sorts of effects depending on the individual himself and the condition of his immediate environment. The effects of flight on pilots can be physiological as well as psychological. Green, Muir, James, Gradwell and Green, 1996 have noted that Among the things that can affect the physiology of the flight crew are the composition of the outside atmosphere, the human need for oxygen, the effects of reduced ambient pressure, the entrapped gas and barotraumas, and the physiology of the air. Pilots can also suffer from vision illusions, effects of acceleration, decompression sickness, hyperventilation, and Hypoxia.

2- Health issues as a HF :

Flight crews need to be in a sound health before they can fly. This is what is called a Class 1 medical certificate. HF can arise as a result of a poor health and unhealthy practices. Some of the health issues that can affect flying are : hearing loss, visual defects, obesity, coronary artery disease, psychiatric disease, tropical diseases, incapacitation during flight, the effects of alcohol and drugs use, the effects of bad diet and fitness, and some other common ailments that can affect flying (Green et al, 1996).Crews also need to be aware of inhalation of dangerous substances, for instance toxic fumes in an engine could contain:

  • Exhaust gases
  • Vapours from fuels
  • Lubricants
  • Hydraulic fluids

The air frame could contain:

  • Anti-icing agents
  • Fire extinguishing agents

Other toxic fumes include:

  • Ozone
  • Dangerous cargo

Of these dangerous fumes the most important is carbon monoxide. This is an odourless gas that is highly toxic,
for more information on carbon monoxide follow the link to another wiki dot page:
Fuels and lubricants are also dangerous as they produce a irritant vapour that eventually leads to drowsiness.
Fire extinguishing agents can be toxic through suffocation, lung irritation and effects of the brain.
Ozone is also Irritant to the lungs but is only present at altitudes above 40000 feet

3- HF and the Human Information Processing Dynamics :

Humans are able to process info through a unique mechanism as the receptors and sensory stores such as eyes and ears starts to receive physical stimuli such as sounds or visual patterns. These stimuli inputs then briefly stored in the short memory before the human brain has a sufficient processing capacity to deal with them and make a decision upon them. The implication of such unique mechanism, especially in regard to workload, is that flight crews are in constant need for attention and management in order to accomplish the task of flying. This involve various sub-tasks of sensing, observing, acting, and reacting to events throughout the flight, and the ability to make sound decision-making upon these events. Accordingly, flight crews should develop an awareness of the human processing system, so they are able to understand how it works and how to manage such system in a safe manner. Including in such system is a number of other factors such as perception, mental models, central decision making, response selection or execution, working memory, long term memory, motor memory or the skills that been accumulated over time, feedback, and mental workload (Green et al, 1996).

4- Cognition in Flying and HF :

When humans try to deal with various elements of information processing, they sometimes encounter some unexpected problems as a result of different situations. Some of these problems can be related to situational awareness, visual cues, spatial disorientation, erroneous mental models, and crew behaviours setup such as skill-based, rule based, or knowledge based behaviour. All these elements can be a contributing HF that have a decisive outcome on the task of flying an aircraft safely (Green et al, 1996).

5- Stress and HF :

This is a problem that is affecting modern-day human beings. Today, life can be very demanding, and as a result, people tend to get stressed beyond their limits. Flying is not for stressed crew, as it can lead to devastating consequences. Stress can negatively affect attention, motivation, and performance. It can also affect arousal and can lead to either over or under arousal. HF related to stress can be caused by many different situations, such as human relationships, bereavements, financial problems, time commitments, work load and work relations, life and health issues, and domestic and environmental stressors. Within the context of managing HF in aviation, stress can be a serious problem that should be identified and managed in order to insure safety (Green et al, 1996).

6- Sleep, and Fatigue as HF :

Today, work commitments could stretch beyond employees’ control. Accordingly, many employees find themselves working when they should be resting. In aviation, this is even more true when flight crews cross several time zones during long-haul flights. The risk of sleep loss or deprivation can be devastating as it can leads to fatigue while on the job. Generally, humans have a biological rhythms that control the sleep – wakefulness cycles. When this system disturbed or badly managed, flight crews put themselves, others and the flight safety at risk. HF in aviation related to this problem can also happen because of shift work or sleeping at abnormal times of the day in order to get ready for the next shift. This could mean sleeping when the mind and body are not ready to accept such sleep. A good and helpful practice to achieve sleep outside sleep times or when sleep is still in credit is to use the guidelines of what is called in the literature “sleep hygiene”. Time zone crossing is a major factor in sleep and fatigue problems faced by flight crews nowadays, and many programmes have been developed to manage fatigue through different techniques ranging from a simple naps to a more comprehensive sleep management programmes. On the other hand, there are other sleep factors that can affect the safety of the flight. Among these are sleep disorders such as sleep apnoeas and insomnia, and consuming sleeping drugs (Green et al, 1996).

7- Flight Crew Individual Differences and the Social Psychology HF :

This is related to the personality and intelligence of each flight crew dealing with both the aircraft equipments and technology at hand and with other crew members. Every human being is unique in the way he handles these interfaces. Accordingly, there are few different personality-related issues that can come to the fore in the flight deck, which could affect the safety of flight and become a contributing HF. Moreover, the social skills and interactive styles attained by individuals can also play a role in that regard. Flight crews need to safely manage the systems of the aircraft as well as interacting with other crew, cabin crew, passengers, and Air Traffic Control (ATC). Within this social psychology context, individuals’ ability, status, role, position, rank, and even sometimes their culture can in part play a role in shaping the task and safety of the flight (Green et al, 1996).

8- Flight Deck Ergonomics as HF in Flying :

This is to do with the design of the aircraft’s cockpit and its interface systems, the design of documentations used in flying, and the design of procedures needed to achieve safe operations. For flight crews, the cockpit is their immediate workplace, and therefore, it is important to achieve a design that supports the principles of comfort, ease of operation, convenience, and safety. Mostly, this means designing better displays, controls, and warnings systems, to elevate situational awareness and alertness, and to eliminate boredom. Intelligent flight decks and Glass Cockpits are both recent examples of good flight deck ergonomics. Furthermore, the design of documentation, checklists, and manuals used in the cockpit, and the design of aviation operational procedures should also follow the same principles in order to minimise the risk of HF in the flight deck (Green et al, 1996).

References :

Green, R. G., Muir, H., James, M., Gradwell, D. & Green, R. L. ( 1996 ). Human Factors for Pilots. (2nd ed.).Hants, England: Ashgate.

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