Attentional Tunneling in Flight: When Pilots Stop Scanning

What is attentional tunneling?

Attention is a limited resource. When a situation becomes demanding, the pilot has to choose where to direct it. Attentional tunneling, also called attentional focusing, describes the point at which that selection becomes excessive: all attention converges on one problem, one instrument or one flight path, and nothing else is being monitored.

It can affect hearing as much as vision. A tunneled pilot may stop cross-checking the instruments, stop looking outside, or fail to perceive an aural alarm that is perfectly audible. In that last case, researchers speak of inattentional deafness ^[1].

What simulator studies show

In 2014, a research team put pilots in a simulator facing a wind shear, a situation that places heavy demands on attention. A critical alarm sounded during the manoeuvre. 11 out of 28 pilots, or 39.3%, failed to report it or to respond to it correctly, even though the same alarm was detected outside that situation ^[1].

Other work seeks to track what the pilot actually perceived. In 24 crew members in a simulator, a model incorporating EEG predicted which alerts had been processed with 87% accuracy, against 72% for the same model without EEG ^[3]. Brain activity therefore adds information that behaviour alone does not provide.

Visual scan and general aviation accidents

A report from the US Federal Aviation Administration analysed 14,436 general aviation accidents that occurred between 1990 and 2000. Skill-based errors were associated with 79.2% of them, and decision errors with 29.7% ^[2]. These percentages do not add up: a single accident can involve several types of error.

Among skill-based errors, the report notably cites a breakdown in visual scan ^[2]. These figures relate to general aviation in the United States over that period: they should not be generalised to aviation as a whole, nor read as the sole cause of accidents.

How to detect a loss of scan

An instructor sitting behind the student sees some of the signs, but not all of them, and cannot note everything while teaching at the same time. The debrief then rests on what the instructor saw and what the pilot remembers.

Several signals can help. Eye tracking measures where the gaze is directed. Head movements reveal whether the pilot is still scanning the environment or has frozen, without measuring gaze itself. EEG provides information on the workload that triggers the tunneling.

That is the SPARK AERO approach: combining the workload read from the brain signal with the scanning movements of the head and the flight events. When workload rises and the scan stops at the same moment, two independent signals describe the same phenomenon. The available studies concern the simulator, which is also where SPARK AERO starts.

Preventing attentional tunneling

• Understand the phenomenon: a pilot who knows that attention closes in under workload is better at watching for their own warning signs.
• Share tasks within the crew, so that one person keeps the big picture while the other deals with the problem.
• Train in the simulator for the situations that trigger tunneling, such as failures and alarms during a high-workload phase.
• Debrief on objective evidence, to link the exact moment workload peaked with what went unseen or unheard.