The assessment of nonroutine situations by pilots: a two-part process

A pilot encountering a nonroutine event must make a decision based on what may often result from a two-part process. The first is the diagnosis of the nature of the nonroutine event (Assessment A), followed by a determination of the potential consequences of that event (Assessment B). Analyses of aircraft accidents and incidents show that overestimation or underestimation in Assessment B can be a serious determinant of pilot misjudgment, even though Assessment A was entirely accurate.