Page 169 - PPL-engelsk 2025

Human Performance

As shown in the figure, our senses are stimulated by one or more types of

physical stimuli.

These can be changes in the environment: changes in sound, light or pressure,

someone asking a question that is expected to be answered, or changes in the
instruments in the cockpit.

These stimuli affect our senses. Each sense has its own “storage” where the

information is stored for a short time.

The perception process itself involves converting physical stimuli into

meaningful information.

How meaningful the information becomes depends on what information we

have previously stored about the subject. If it is a subject that we have a lot of

experience with, it is a simple matter for the system to find information. It does

not place great demands on our mental capacity, and so we are quickly ready

with a solution.

On the other hand, if the stimuli occur within an area that we have no or little

experience with, the process itself will take longer and use up more capacity

than in the case mentioned above.

The system is not perfect. It happens that we receive a stimulus that we think

we have experienced many times before and about which we have already

formed an opinion. This means that we can extract information from the

stimulus that confirms what we expect, and the result is that we overlook small

changes in the stimulus.

This tendency to see or hear what we expect has contributed to many airplane

accidents where the human factor has been the cause.

Flight Theory PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 169