Dana Air - Human Factor As Cause of Mishap

The final report on the Dana Air accident of June 3, last year, has indicated human factor as the probable cause of the crash. This, in effect, has vindicated the regulatory agency, the aircraft in question, and the airline's maintenance capability.

The people who operate and support the Nigerian aviation system are crucial to its safety; the resourcefulness and skills of crew members, air traffic controllers, and mechanics help prevent countless mishaps each day. However, despite the excellent safety record, many studies consider human error as a factor in at least two-thirds of commercial aviation accidents.

The leading human-factor theorists and modern researchers believe that between 70 and 80 per cent of all aviation accidents are attributable to human error somewhere in the chain of causation.

Safety attention at present is, therefore, heavily focused on trying to understand the human decision-making process and how humans react to operational situations and interact with new technology and improvements in aviation safety systems.

According to Rodrigues & Cusick (2012), the way in which human beings are managed affects their attitudes, which affect their performance of critical tasks. Their performance affects the efficiency and, therefore, the economic results of the operation.

It is important to understand how people can be managed to yield the highest levels of error-free judgement and performance in critical situations, while at the same time providing them with a satisfactory work environment. A review of accident cockpit voice recording clearly indicates that distractions must be minimised, and strict compliance with the sterile cockpit rule must be maintained during the critical phases of flight (taxi, takeoff, approach, and landing).

While the emphasis often focuses on the pilots, they are not the lone threat. They are, however, the last link in the chain and are usually in a position to identify and correct errors that result in accidents and incidents.

Basically, the problem is one of poor human decision making. Essentially, three reasons explain why people make poor decisions: they have incomplete information; they use inaccurate or irrelevant information; or they process the information poorly. Psychologists have traditionally explained the limited information-processing capabilities of humans.

Miller's Law states that the number of objects an average human can hold in working memory is 7 (plus or minus 2). This magic number of 7 is improved when a pilot uses both his visual and auditory channels because the information is processed differently in the brain. Modern research has shown that accidents are more likely to occur during high workload, task saturation periods, when there is an overload of one or more of the pilot's processing channels.

In order to reduce the workload during critical task saturation situations, new pilots are taught a task-shedding strategy to focus on the most important task in the cockpit -- flying the plane.

In other words, in an emergency, fly the plane first; then, if circumstances permit, navigate; and, finally, if the other two tasks are in hand, communicate with air traffic control.

Post-accident investigations usually uncover the details of what happened. With mechanical failures, accident data analysis often leads logically to why the accident occurred. Determining the precise reason for human errors is much more difficult. Without an understanding of human behaviour factors in the operation of a system, preventive or corrective actions are impossible.

Understanding human factors is especially important to systems where humans interact regularly with sophisticated machinery and in industries where human-error-induced accidents can have catastrophic consequences. However, human factors are not treated as a technology in commercial aviation. Technical decisions for aircraft design, regulation, production and operation are based on "hard" sciences such as aerodynamics, propulsion, and structures.

Human capabilities do not lend themselves readily to consistent, precise measurements. And human factors research requires much more time and cooperation than most other aeronautics research. Data on human performance and reliability are regarded by many technical experts as "soft" and receive little attention in some aviation system designs, testing, and certification. Data used in designs are often after the fact.

Human factor is a multidisciplinary science that attempts to optimise the interaction among people, machines, methods, and procedures that interface with one another within an environment in a defined system to achieve a set of systems goals. Human factors encompass fields of study that include but are not limited to engineering, psychology, physiology, anthropometry, biomechanics, biology, and certain fields of medicine.

Human-factor science concentrates on studying the capabilities and limitations of the human in a system with the intent of using this knowledge to design systems that reduce the mismatch between what is required of the human and what the human is capable of doing. If this mismatch is minimised, errors (that could lead to accidents) will be minimised and human performance will be minimised. Human performance is a measure of human activity that expresses how well a human has carried out an assigned, well-defined task or a portion of a task (task element), and it is a function of speed and accuracy.

If a task is not performed "accurately" in accordance with its requirements, an error has occurred. Accidents rarely involve a deliberate disregard of procedures. They are generally caused by situations in which a person's capabilities are inadequate or are overwhelmed in an adverse situation. Humans are subject to such a wide range of varying situations and circumstances that not all can be easily foreseen.

Careful attention should therefore be given to all the factors that may have influenced the person involved. In other words, consideration must be given not only to the human error (failure to perform as required) but also to why the error occurred.

It is senseless to constantly blame the regulatory agency, the Nigerian Civil Aviation Authority (NCAA), for the cause of an aircraft accident in our airspace. Let's allow proper, professional investigation to deduce the probable cause(s) of an air crash before we deliver hasty judgement.