The tendency of operators to deal with disturbances sequentially [Moray and Rotenberg (1989)]
As a result of cognitive lockup, pilots are inclined to focus on the current task and are reluctant to switch to another task, even if that task has a higher priority.
Eastern Airlines Flight 401
The potential consequences of cognitive lockup are illustrated by the 29th December 1972 accident involving an Eastern Airlines aircraft which crashed northwest of Miami.
Following a missed approach, because of a suspected nose gear malfunction, the aircraft climbed to 2,000ft MSL and proceeded on a westerly heading. The three flight crew members and a jump seat occupant became engrossed in the malfunction.
In its aircraft accident report (NTSB-AAR-73-14), the NTSB determined that the probable cause of the accident was "the failure of the flight crew to monitor the flight instruments during the final four minutes of flight, and to detect an unexpected descent soon enough to prevent impact with the ground. Preoccupation with a malfunction of the nose landing gear position indicating system distracted the crew's attention from the instruments and allowed the descent to go unnoticed."
Task Switching Costs as an Explanation for Cognitive Lockup
When people switch between tasks, the mental reconfiguration to another task takes time (called the switching cost) and thus the most efficient way of working is to complete one task before moving on to the next. Cognitive lockup is reduced when it is obvious that the benefits of a switch exceed the switching cost.
Decision Making Bias
The decision to switch or not to switch tasks may be influenced by a misperception of the expected benefits. This decision-making bias may mean that the benefits of switching have to be significant before the decision to switch is made. Furthermore, if an individual feels that the ongoing task is almost complete, they are more likely to stick to the ongoing task even if the new task is more urgent.
- Decision Support Tools: Tools that assist pilots in recognising the relative priorities of tasks, allowing them to focus on the more urgent task and so reduce the likelihood of cognitive lockup.
- Training: Simulator exercise scenarios that expose pilots to situations where new, more urgent, tasks arise when they are dealing with an existing task reinforce awareness of the need to continuously assess and prioritise tasks. Greater understanding of aircraft systems may also reduce the likelihood of cognitive lockup.
- Crew Resource Management: Separation of tasks and roles between pilots, for example, by the captain passing control of the aircraft to the first officer while the captain deals with the malfunction, reduces the risk of both pilots fixating on the malfunction.