Human Factors in Aircraft Accidents and Incidents


It is in acceding to mistakes that another human factor surfaces. Like most concepts in psychology, conformity is difficult to define. The first is:

  • obedience to a possibly mistaken authority
  • the second is going along with other people’s views rather than one’s own
  • the third is the excessive desire to please.

All these are gradations of the same human factor of conformity. 

It is, of course, essential for our own group’s survival that we are obedient. Chaos will result if we refuse and there are other multifarious benefits from group obedience. There are also, of course, as in almost all human concepts, dangers. Blind obedience has killed many people–on and off the battlefield.  At the same time, we each believe that we would not carry obedience beyond our moral limits, as happened in Nazi Germany. But so ingrained is obedience in us that we very well might do so.

The second head of conformity is when someone goes along with another’s views although they are not in accord with his own. Krech, Crutchfield and Ballanchey in Individuals in Society state:

“The essence of conformity, in distinction to uniformity or conventionality, is yielding to group pressures. For there to be conformity, there must be conflict – conflict between those forces in the individual which tend him to act, value and believe in one way and those pressures emanating from the society or group which tend to lead him another way.”

The psychologist Harvey found that the second highest member of a group was the most conforming. The first officer is the second-in-command of an aircraft. The status of the captain in the small group community of the cockpit may exert pressure on the rest of the crew to conform to his way of thinking. this may hinder intelligent interaction and good monitoring. 

Norms have refined the respective roles on the flight deck and regulated the overall hierarchy of behaviour within the group. One of the forms of conformity is that it may inhibit action, making a person yield his right to express an opinion. 

The first officer of KLM 747 in the Tenerife disaster had only ninety-five hours flying experience in a B-747. His captain was the Chief Flying Instructor of the KLM B-747 fleet. The higher the status of the authoritarian figure, the more chance of conformity in his second-in-command.

The problem of the subordinate conforming to the ideas and wishes of his superior and being too scared or too wary to risk his job and promotion, is not confined to aviation. It is just more dangerous. Surgeons have been known to remove the wrong limb or eye while the nurses looked on. It is not unusual, according to one authority on accidents, for “a deck officer to remain aghast and silent while his captain grounds the ship or collides with another“. Very few of us will, in fact contradict authority. The usual excuses are that we can’t be bothered or that it will simply cause a row.

The first officer’s main responsibility is to monitor the captain. He provides a feedback for the captain. If the captain infers from the first officer’s actions or inactions that his judgment is correct, the captain could receive reinforcement for an error or poor judgment.

The third head of conformity – the desire to please – is more of a menace than the other because it wears such a benign and lovable face. All of us want to please. Most of us are members of many different-sized groups – family, office, societies, organizations and friends. Unless there is a high degree of conformity, it is impossible to have a group. And the strength of the conformity pressure varies with the common interest of the group and the relevance of a issue to a group.
The group inside an aircraft – captain, crew, passengers – is a particularly cohesive one. The passengers need to believe implicitly in the crew. They want to please the father figure at the controls and the mother/mistress who comes around with food and drinks and soothing words. On their part, the crew want to please the passengers. On board, then, there is a high degree of group conformity and a strong reciprocal and interacting desire to please.


“Here lie the bones of Emily Bright
Who put out her left hand
And turned right”.

If conformity, with all its dangers, is still waiting to be recognized as a cause of accidents, even more hidden lies laterality, the pattern of hand preferences, the mixing of left and right. Yet most of us have a laterality pattern and some of us have a laterality problem.

Rolf Gerhardt, chief psychologist to the Norwegian Forces, who studied pilots in the Norwegian Air Force for many years, stressed the “laterality personality” – pilots with varying degrees of hand preference. He found (1959) connections between laterality and maladjustment in military pilots. He quoted many cases– one fighter pilot feared close-formation flying because in that situation he was uncertain which way to turn. “We found this pilot to be ambivalent about hand preferences. In the aeroplane he had to look for his wedding ring to identify left and right.”

He cites expectancy in such pilots as omitting parts of a chain of actions, wrong instrument reading, reversing numbers, uncertainty of direction in thought and space. He believes such a laterality pattern may be present in considerable numbers of people with no overt left-handedness. Over learning has made them carry out such actions “normally”. Only when surprised and under stress will they revert to their laterality pattern in certain behaviour situations. He thinks the laterality pattern is basic, and if it involves a tendency to reverse, this is inevitable, saying: A person may learn to write g and d, but when he, in fluent use of the two letters, has a marked tendency to use them in the opposite manner, he is also due to make other movements in an opposite manner. He may learn to use the right letter in the right place, if he can hesitate a little before forming the letter. But when he is in a hurry, he will inevitably make the wrong movement at one time or another.

Similar behaviour is often shown by dyslexics. The condition of “word blindness” was first recognized in 1895 by James Kinshelwood, an eye surgeon, who published an article in the Lancet. Even now the condition is widely ignored and there are many conflicting views on its origins and causes.
Clinical data supports the conclusion that in right-handed people it is the right hemisphere that decides how we feel. And it is the left hand (which is said to be controlled by the right hemisphere) that is called “the thinking, feeling hand”.

Human Factor Education
IFALPA also endorses the emphasis on all aspects of human performance relating to safe and efficient operation of the aviation system, and considers that suitable training in relevant aspects of human performance, human limitations, aviation psychology and crew co-ordination should be given to all flight crew members and trainee pilots.
All this is a beginning. The main thing is to get pilots to look at themselves and the environment in which they function. They should learn to recognize that a danger as great as clear-air-turbulence, thunderstorms, icing or microbursts may be within the cockpit in the crew situation. The aviation world had to learn to cope with these meteorological hazards. Now it must come to grips with the hazard of human factors.

Whether or not examinations on human factors are going to be effective or desirable remains to be seen. Examination devoted to the reduction of human factor errors (especially conformity) are something of a paradox. It is a subject for “hanging loose”, for coming clean, for admitting and examining one’s mistakes for discussion and argument rather than for marks in an examination. After all, in an exam you must conform to what the examiner reckons is the right answer.
In reality, the right aim and the right answer are self-knowledge and self-recognition. And the worst would be if human factors were made into undigested pellets to be regurgitated for the examiner. So, if it is difficult to examine on human factors, how can they be taught?

Fairly naturally, there is still some suspicion of human factor study. There are questions such as: will psychological investigation damage the pilot’s ego? Will the management find out things which might lower him in their estimation, might lead to his demotion or even dismissal? Isn’t this a further disguised medical examination? There is so much that a pilot must absorb, isn’t this added subject a bit much? Won’t the study of all too simple slips that are the main cause of aircraft accidents reduce confidence? And why, if the pilots have their errors put under the microscope, shouldn’t other people, particularly the management, have the same treatment?

There is also, despite the advertising industry’s very profitable love affair with psychology, a natural antipathy in most industries to the subject. None of us likes the idea of the darker corners of our psyches being too brilliantly illuminated. And, for most of us, self-knowledge comes later in life: the study of ourselves is not yet taught in schools. As a result, there is for most people no groundwork on which to add the study of human factors and human errors.

Then too we dislike the whole concept of mistakes. We are the products of our culture and our early teaching. That teaching has made us regard mistakes with guilt and shame – school exercise books full of black crosses, like so many little deaths. Early on we learn to give the “right” answer expected by the authority figure over us, rather than to think for ourselves, though some improvement in this area seems at last to be appearing. And it is just this expected, pleasing answer which pilots must learn now to reject.

So, the teacher/learner concept has to be stood on its head. At best, pilots who do the job don’t particularly like to be taught by laymen who don’t. Besides, human factor study is no black and white exercise. In its own way it should be a vast research project. There should be no platform, just everyone arguing on the floor in an exercise of two-way learning. Everyone has some valuable experience and insight to offer; it is just the interpretation that can be guided. Real accidents can re-enact, real mistakes on video studied in real situations; those mistakes can then be interpreted and the commonality of them recognized.

Personal awareness is the theme. For pilots are as other people, but functioning in a more unforgiving environment, wherein they may be exposed to making simple human slips which on the ground might be no ore than the breaking of a tumbler, but which in the air might produce a catastrophe.
It is also important that the course should not become a let-out for management in case of accident: “You’ve had your course. Why did you make the mistake about which you were adequately warned”? Nor should be quick-fix courses, which don’t examine the real problems, and which look good only on paper.

The standard of airline flying– thanks to the billions of dollars spent on flying training – is excellent. A far smaller amount is at last being spent on human factor training, which airlines try to augment by selling their training products. How is it progressing?
Deregulation in America has increased the competition between airlines and enables all sorts of companies to start operating. The inflation rate is rising and there is a relation between a carrier’s financial position and its safety record. Two-man crews, twin-engine ocean flying and fatigue on the long range B747/200 three- crew and the two-crew and 747/400 are problems related to economics and still unresolved.

Big companies are merging and creating monopolies. At the same time, 50 % of the world’s jet fleet is nearly twenty years old. What the engineers call BFO’s – Bits Falling Off – are now more frequent than ever. There has been a pilot shortage – like bull and bear on the stock market, there is always either a glut or a famine – as many experienced pilots retire. But with the recession and Gulf Crisis putting enormous financial pressures on airlines, many which have closed down, this may no longer be the case. Pilots in the past have played “company hopping” for more pay, while managements hopefully dredged an already swept-clean pilot market – all in an era of aviation expanding world wide at 10% per annum.

In such a climate, aircraft accidents are likely to increase unless the nettle of the human factor problem throughout the industry is much more firmly grasped. Automation, supposedly the pilot’s helpmate, has been shown to be two-faced. In most airlines, captains are allocated crew members whom they haven’t even met, let alone those whose expertise and experience they are acquainted with. It has been shown by many experiments that a crew who have flown together for three days or so communicate far more and are more willing to express their opinions.

Excerpts from “The Naked Pilot” by David Beaty

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