ICAO: fundamental human factors concepts

< [PEREZGONZALEZ Jose D [ed] (2009). ICAO: fundamental human factors concepts. AviationKnowledge, 2009, page 2. ISSN 1179-6685.] >

ICAO addressed the systemic nature of human error and the management of Human Factors in the 1989 circular Human Factors Digest no 11. Although the publication itself is relatively old, the ideas it describes are generic enough to remain valid today. The circular is a rather brief but good introduction to Human Factors for operational personnel. What follows is a synopsis of the contents in that circular, focusing more on the circular's introductory value than on its practical value.

Chapter 1. The meaning of human factors

2.32. The concept of Human Factors is so widely used that it has become difficult to define with accuracy. In brief, however, it is an applied multi-disciplinary approach mostly concerned with the interaction of humans with their working (and living) environments (i.e. with providing solutions for a "good fit" of humans to their environments).
2.2. As a multi-disciplinary approach, Human Factors draws knowledge from a broad range of academic disciplines, such as psychology, physiology, anthropometry, biomechanics, biology and chronobiology, design, statistics etc. Ergonomics, for example, is a concept often used in lieu of Human Factors, although its concern is more specific to the human-technical interface, and thus to technical design. Work psychology is another concept related to Human Factors although it is more concerned with the psychological and social aspects of humans at work.
2.1. Human Factors is normally thought of as the re-engineering of physical and social environments to better fit the capabilities and limitations of the human operator. However, it also considers the alternative option: when the environment cannot be made to fit the operator, then the operator can be made to fit the environment (e.g. through selection or training).
3.2. "Human Factors is about people in their living and working situations; about their relationship with machines, with procedures and with the environment about them; and also about their relationships with other people (at work). In aviation, Human Factors involves a set of personal, medical and biological considerations for optimal aircraft and air traffic control operations (ICAO, 1989, ch.1, p.2)."
4.1. A good model for understanding Human Factors is the SHELL model, as it puts the person in the centre of the model and focuses on the interactions (or fit) of this operator with the remaining components that surrounds him/her: software, hardware, environment, and liveware.

Chapter 2. The industry need for human factors

1.3. The industry need for Human Factors relates to two broad areas:

  • System effectiveness, namely in regards to safety and efficiency
  • Well-being of crew members

2.1. The safety output is best illustrated by past accidents where Human Factors have been either the cause of the accident or a contributory element to it (e.g. poor crew resource management, visual illusions, misinformation, lack of awareness, miscommunication, lack of assertiveness, over-reliance on automation, violation of standard operating procedures, vague legislation, etc.)
2.2. The efficiency output can be affected by levels of motivation, flight deck design, crew training, supervision, adherence to standard operating procedures, crew resource management, etc.
3. The well-being of crew members is also affected by variables that can be managed by a Human Factors approach. Variables of relevance are both human related (such as fatigue, body rhythm disturbance, sleep, health and fitness levels, stress, etc.) and environment related (such as temperature, noise, humidity, light, vibration, workstation design and seat comfort).

Chapter 3. Human factors in flight operations

Human capabilities and limitations are always present in flight operations. Thus, the knowledge that Human Factors provides has applications to the management of different issues, such as:

  1. Human error
  2. Operational training and evaluation
  3. Extra-curriculum training on Human Factors issues (e.g. leadership, personality, attitudes, communication, crew coordination, etc.)
  4. Motivation
  5. Flight documentation
  6. Flight deck design
  7. Cabin design
  8. Visual performance and collision avoidance

Chapter 4. Education and expertise

2.1. All staff in any civil aviation organization should have, at least, a general knowledge of Human Factors so that they are more aware of humans' performance, capabilities and limitations. This level of knowledge also helps employees understand any bulletins on Human Factors issues distributed by the organization.
2.2. Supervisory staff should have basic formal education on Human Factors so that they are able to assist their employees and because of their role in decision-making.
2.3. In-house specialists are recommended for large aviation companies as they provide in-house expertise and capability to recognise Human Factors issues adequately.
2.4. Human Factors consultants are handy resources when they are highly knowledgeable on Human Factors through education and experience. Consultants also provide advice free from internal organizational pressure and can provide solutions to specific problems that may have already been encountered elsewhere.

1. ICAO - INTERNATIONAL CIVIL AVIATION ORGANIZATION (1989). Human factors digest no 1. Fundamental human factors concepts. Circular 216-AN/131. ICAO (Montreal, Canada), 1989.
+++ Footnotes +++
2. This number corresponds to the paragraph number in the ICAO circular. Missing paragraphs deal with examples and other information deemed not too important for a synopsis.

Want to know more?

AviationKnowledge - ICAO: Ergonomics
Human Factors and Ergonomics are related concepts but are not necessarily the same. This AviationKnowledge page provides a synopsis of ICAO's Digest number 6 on Ergonomics.
ICAO's Human Factors Digest No 1
You can access the whole document online as "CAP 719, Fundamental Human Factors Concepts. CAA (UK), 2002".


Jose D PEREZGONZALEZ (2009). School of Aviation, Massey University, New Zealand (JDPerezgonzalezJDPerezgonzalez).


Melissa J PERRY (2009). School of Aviation, Massey University, New Zealand (MJPerryMJPerry).
Rachel PATTENDEN (2009). School of Aviation, Massey University, New Zealand (R_PattendenR_Pattenden).
David RAE (2009). School of Aviation, Massey University, New Zealand (DJ-RaeDJ-Rae).

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