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11.13.2 Human Factor Considerations


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Decision Making

"Stay ahead of the Aircraft". How many flight instructors have used this term to tell a student to think about his flying? Does he mean that the student's Situational Awareness is lacking?

When we look at aircraft accidents we have to ask ourselves this question:

Why does a well motivated crew, in an aircraft fitted with all the latest equipment, fail to perform at a critical point during a flight?

Decision Making Process

Decision Making can be broken down into a series of steps or actions that the pilot follows:

  • The recognition that there is a problem. Note that no action is taken at this stage.
  • The gathering of information in order to assess the situation. This is undertaken by all crewmembers.
  • The information required and where that information can be located needs to be established. How this information can be verified is set at this stage.
  • The options that are identified and the alternative solutions are now risk evaluated. Advantages and disadvantages are weighed to give the best solution.
  • Decision implementation and any actions are executed. Remember, doing nothing can be an action.
  • Review the consequences by use of feedback. Evaluation and revision may be necessary.
Reaction to Decision Making

The following actions are not a comprehensive list of addressing the decision making problem. The intent is to give a logical safe progression to a problem:

  • Fly the aircraft.
  • Never assume that you do not have the time.
  • Identify the problem.
  • Assess the situation using all resources.
  • Select and carry out the correct procedure.
  • Continue evaluating the situation.
  • Inform the cabin crew.
  • Inform the passengers? Good idea or bad - will it cause panic.
Making and Taking Decisions

There are very few situations in an aircraft that require an immediate decision. There is not an infinite time period in which a problem can be solved; the aircraft will eventually run out of fuel. Therefore, certain principles need to be applied to decision making. They can be described as below:

  • Inquiry: What is wanted. Priorities and timescale need to be defined.
  • Advocacy: Consultation of all participants.
  • Conflict Resolution: Commitment to a plan of action and being able to resolve this with other members of the crew.
  • Decision Making: All decisions must be explained. At this stage, why there was rejection of any plans must also be explained.
  • Critique: A review of the situation is needed to ensure that the plan is working. At this stage checks for Confirmation Bias should be made.
Decision Making

Models Most airlines use simple acronyms to ensure that a logical process, like the above, is followed. British Airways use DODAR.

  • Diagnosis
  • Options
  • Decide
  • Assign
  • Review

It does not matter what model is used, all have the same intent and format. All are closed loop situations which allow a continuous evaluation of the problem and its consequences.

Atlantic Airlines use DECIDE:

The emergency occurs...

    • Detect: The pilot detects the fact that a change has occurred that requires attention.

    What is the problem?

    • Estimate: The decision making team have to estimate the significance of the change to the flight.

    What are the options?

    • Choose: The team now choose a safe outcome.

    What is the best course of action?

    • Identify: The team identifies actions that will control the change.

    Carry out the action!

    • Do: The team do action on the best option.

    Review of the situation.

    • Evaluate: Evaluation of the effect of the change is monitored continuously.
Group Versus Individual Decision Making

A crew as opposed to an individual will usually make a better decision. It is one reason why committees are formed. A crew working as a team, where knowledge and experience are combined, can be very effective. To be effective all must be confident and comfortable in raising doubts or opinions. Each crewmember must be confident that their opinion is a valued one.

In team decision making the following guidelines can be used:

  • Use all the available resources.
  • Differences of opinion can be expected. This must be regarded as helpful not a hindrance.
  • Avoid arguing. All problems must be approached logically.
  • Majority voting is acceptable in committees. In the aircraft there is one Captain. The final decision must rest with him.
  • All inputs have to considered as important.
  • Why a solution has been taken has to be explained to all.
Influences on Decision Making

Certain factors have to be taken into account where group or individual pressure can influence pre-decision thinking. These factors are listed below.


Most people will tend to comply with decisions rather than question them.This is true when the decision is made by someone of a perceived higher status. Compliance can also occur when a person has disagreed with a previous decision and does not wish to seem obstructive.


Peer pressure. A person will tend to conform with the group's decision because they wish to be the same as the rest of the team. If 2 or more people have given an answer to a problem then it is likely that a third will give the same answer. Status affects conformity. Differences must be voiced at this time.

Confirmation Bias

Confirmation Bias is the natural tendency for a person to accept information which agrees with their ideas about what is happening and to reject that information which does not agree, as spurious.

Group Polarisation (Risky Shift)

The tendency for a particular attitude to prevail within a group. A group decision reflects an extreme rather than a norm. The problem is worst when a pilot who likes taking risks flies with a pilot who is similar in attitude. The tendency for the pair is to take greater risks. A phenomenon known as "Risky Shift". Conversely, cautious pilots would make a more cautious decision.

Other factors affect the decision making processes of a pilot. These are more social influences than the effects of the above:

  • Vigilance: With a normal person as workload increases so does vigilance. Vigilance is a degree of activation of the body. It is different from attention which depends upon the capacity of the brain to deal with problems. Where boredom or monotony occur, hypovigilance can lead to a state of near sleep where decision making is difficult.
  • Judgement: Where a pilot is vigilant then judgement is usually sound. Good judgement is learnt through the flying processes and can be said to be based upon experience. What matters with judgement is the outcome. Judgement depends upon the decision to act and the response given. Judgement in a pilot is the recognition of all the variables that effect decision making and their outcome.
  • Attitude: What does the term "Safe Pilot" mean. Is it someone who is over autious or someone who weighs up all eventualities and their outcome. Attitude is a part of the mind you as a pilot put to all processes of flying. Hence its affect on decision making. A good attitude does not necessarily mean good decision making but it does help.

Summary Decision making depends upon evidence given to us by certain senses, it is based upon:

  • Our expectations and desires which can distort the perceived information.
  • Any erroneous mental modelling in building our situational awareness.

No matter how we perceive a problem it is essential that in the decision making process we always hold an open mind. We must:

Hope for the best; but plan for the worst.