Written for Global Aerospace by Matthew van Wollen, Pulsar Informatics

It may be November, but the clouds are clearing for air operators. People are flying again. Business meetings are being scheduled live. And the busy holiday season is coming up soon. Is your flight department ready?

Turbulent Times Lead to Increased Fatigue
The pandemic-related downturn and subsequent (and ongoing) recovery have traced a dramatic yo-yo pattern that is unprecedented in modern times. Some operators have faced a rapid acceleration of activity while at the same time being forced to make do with limited staffing, as some existing crew members are at home with COVID-19 while new recruits take time to hire and train. It all boils down to a high-intensity work environment for those who are on duty, with little schedule flexibility or downtime.

Fatigue is normal with long duty days and round-the-clock operations. But how do you know when crew fatigue is too much? Where do you draw the limit to ensure safety and reliability?

Subjective and Objective Measures of Fatigue
The traditional approach has been to rely on self-reported measures such as sleepiness or perceived fatigue. For example, on the popular Karolinska Sleepiness Scale, there are nine possible responses ranging from 1 (extremely alert) to 9 (fighting sleep). One problem with self-reported measures is that they are subjective—one crew member’s 7 may be another’s 4—and this means that setting a standard risk threshold across the operation is hard.

There is a simple test that provides an objective measure of fatigue and alertness. It’s called the Psychomotor Vigilance Test, and it is used by astronauts, special forces, and professional athletes to optimize performance. It is also used by commercial airlines to help validate the safety case for ultra-long-haul routes.

Unlike self-reported measures, the PVT doesn’t depend on a person’s opinion. It simply measures the speed of responses to visual stimuli on a screen. A high score on the PVT suggests an alertness impairment. And because it is an objective test, PVT scores can be compared between different flight crew members.

Taking the PVT is easy and requires just three minutes or less. A flight crew member can consider a PVT assessment as part of check-in procedures, especially at the beginning of a long day, or when preparing to operate through the night. Augmented crews can use the PVT at top of descent to determine which crew member is best placed from a fatigue perspective to land the aircraft. Even non-flying personnel can benefit from the evidence-based decision support that the PVT offers.

For example, when a maintenance technician that has just returned home after a full day’s work is called back to the hangar at 10 p.m. to perform urgent repairs to an aircraft scheduled for imminent departure, a quick PVT can show whether the individual is in fact sufficiently alert for duty.

Using PVT Technology Effectively
When considering using PVT data as part of the overall safety assurance posture, air operators should note that the PVT is unlike other tests in that focus and effort are essential to good data quality. Picture a sprinter competing in the 100m dash—it wouldn’t make sense for the athlete to check their phone or eat an apple during the race. In the same way, the PVT requires discipline and full cooperation from crew members.

Pulsar Informatics has been deploying PVT technology in commercial settings for over 10 years. We are experts in interpreting PVT data and using it as part of a proactive fatigue hazard identification workflow. For more information about the PVT or to find out how it can benefit your organization, drop us an email at info@pulsarinformatics.com.