Thursday, 23 March 2017


Acknowledgements: FAA Advisory Circular 60-22

The Circular explains that ADM is a systematic approach to the mental process used by all involved in aviation to consistently determine the best course of action for a given set of circumstances. It has the following elements:
· Perceive: Information affecting the outcome of a flight is all around you. How you perceive and manage that flow of information will have an effect on each and every flight.
· Process: The second step is to process the information that you perceived.
· Perform: How you perform will be based on the perceiving and processing you did. At the most basic level, you perform in one of two ways: action or inaction. In the perform step, you need to eliminate or at least mitigate any hazard and risk that you perceived and processed.
· Evaluate: The relative success or failure of the flight may hinge on how well you have perceived, processed, and performed in the ADM process. Question your judgment and your action (or inaction) at every step, and then start the 3-P process all over again. The ADM process should not stop until your airplane is parked, shut down, and securely tied down.

Experience, education, and intuition enable us to fill in “gaps” in information received through our five senses. You may not have heard exactly every single word of the ground controller’s taxi instructions, but your expectation helps you fill in the missing words. The problem, of course, is that you might fill in the gaps incorrectly.

Suppose you are in a rented airplane with a scratchy radio, and you have passengers on board who are chatting among themselves. You are tired, but the airport is your home base, so you know exactly what that taxi clearance from your parking spot to the active runway is likely to be. The bad radios and the noise from your passengers cause you to miss a few words of the ground controller’s instructions. Your brain is expecting a certain sequence, so it automatically fills in the missing words. Today, however, the ground controller gave you different instructions, which you “heard” as the normal taxi clearance.

The problem is clear, and it escalates at each step of the ADM process: because you perceived incorrectly, you process & evaluate the taxi clearance and judge it to be “routine,” even though it is not. The mistake becomes greater, and possibly more dangerous, when you perform on the basis of the incorrect information.

The example above begins with a perceptual error in which you simply do not see, hear, or notice a particular piece of information. Human beings are also vulnerable to procedural errors, such as when you correctly perceive and mentally process the controller’s instruction to change to a new radio frequency, but you enter it incorrectly in the radio itself. Forgetting to lower the landing gear is another example of a procedural error.

There are also decisional errors, such as when a pilot elects to continue VFR flight into IMC when neither pilot nor aircraft are equipped for it. Errors in how you perceive and process information can also lead to decisional errors, which in turn affect your performance. Other factors that play a part in decisional error include:
• Framing the alternatives: alternatives can be “framed” in positive terms to support a higher risk decision; e.g. “I know that the weather at my destination is marginal, but I can get there so much faster in the airplane than I can in the car.” But framing in negative terms can help bring a much-needed touch of reality into the ADM process; e.g. “If I find that I cannot land at my destination, I will be stuck at another airport, which would make me late for this appointment.”
• Judgmental heuristics: This term simply means that we sometimes jump to a conclusion too quickly without considering all available or relevant) input.
• Bias: There are several types of bias at play in human decision-making processes. One is confirmation bias, which is the human tendency to look for information to confirm a decision already made, perhaps erroneously as in the taxi clearance example above.
• Expertise, training, experience: Two pilots faced with the same situation will very likely make different decisions, based on past experience and training. In the taxi clearance example, a pilot who is new to a particular airport has no experience with local procedures and, thus, has no preconceived ideas about what the clearance “should” be. That pilot’s lack of experience with the airport can lead to a very different perception of the situation than that of the pilot whose aircraft is based there.

A realistic evaluation of each situation on the basis of ADM should result in a simple “go or no-go” decision, or if already in flight, a “continue or discontinue” decision.


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