By Steven Green, FRAeS, Principal at Flight Operations Research in Underhill, Vermont.

During the final few years of my career, my employer developed a threat-and-error management (TEM) model that utilized three concentric circles, green in the center, then yellow and red. The green zone was associated with ability of the crew to effectively manage threats and errors at the highest level, which was the target, while the outer red ring was associated with a significantly diminished ability to manage threats. The idea was to evaluate and locate where the cognitive capacity of any individual, or the crew collectively, was on this envisioned target; as that cognitive capacity drifted outward, through the yellow and into the red, actions needed to be taken to return it to the green zone.

This was quite a useful tool in some respects, and potentially misleading in others. The very last thing I did before entering a runway for departure was ask the First Officer, “Are you in the green?”. Everyone knew what that meant, and it was a way of opening the door for evaluation and discussion of any concerns. It was also a great reminder that, in the end, we needed to be “in the green”.

On the other hand, as I tried explaining to nearly every instructor who taught TEM in recurrent training, many accidents have occurred without the crew having the slightest perception that their cognitive state had departed the green zone until it is too late. While we might attribute this to poor situational awareness or the challenges of cognitive dissonance, those aspects are only part of the problem. The elephant in the room is how we, as humans, think, and how our modes of thought influence the ability to differentiate between specific risk and probabilistic risk.

 To read the entire paper, click here.