Instrument failure in civil aircraft is potentially very dangerous. It is therefore imperative to understand where breakdowns in the distributed cognitive process of understanding occur in the cockpit. In this paper I present a model of distributed situational understanding using eye-point-ofgaze equipment. The model includes a range of constructs, from perceivablestimuli in the cockpit, to eye-point-of-gaze data, to situational awareness, and finally understanding and action. To test the model, in series of simulated flights, conducted in the VINTHEC project, experienced pilots were presented with situations of instrument failure. In the experimentalsetting, the pilot’s understanding was found to be adequate to deal with an altitude bust event, but not with a map shift event. It is concluded that the complicated situational awareness construct does not contribute to the model, whereas pilot actions and eye-point-of-gaze data are importantmeasuring points for understanding the pilots process of understanding.
2002. 569-574 p.