Human Performance – Cognitive Capacity

This graph is representational only. At different times and in different circumstances, the different types of workload will be different, and so will the Total workload which will lead to variations in spare capacity thus affecting crew abilities to adjust and cope with changing environments/situations.

Your total workload is a combination of the physical and cognitive tasks required of flying and procedures.

If we don’t manage workload effectively i.e. prioritising and doing tasks at appropriate times, the combination of the two will reduce our spare capacity or maybe result in overload.

The relationship between stress levels and Workload has been long established.

There is an optimum level of stress (or Arousal which was the original term used, Tee hee) to ensure maximum performance. Stress below or above this level, leads to a degradation of performance and ultimately either boredom or Burnout.

The sharp drop that occurs with overload reflect Catastrophe theory. The degradation in performance due to overload is sudden and significant.

Note: Errors can occur due to both overload and low workload (under engagement with the task) (FAA AC23.1523)

How can you detect workload overload in your team?

Your short term memory has a finite number of items that it can recall. (7 +/- 2) As workload increases, how does this affect our ability to recall all 7 of these items?

What are some of the signs/symptoms of overload?

• Distress or Discomfort;
• Indecision or Distraction;
• Lack of Response;
• Fixation;
• Errors;
• Falling behind the Aeroplane;
• Missing SOP’s / Checks;
• Change in vocal tone.