The current schedule selected for MQ-1B Medium Altitude, Long Endurance (MALE) UAS squadron
tasks the crews with six continuous days of operation. This requires the crew to work for 48 hours
and, at a minimum, spend roughly 60 hours in work related activities. This includes a minimum 30-minute commute,
plus 1 hour of prep time before the shift.
The decision to expose the crews to this schedule is questionable as
there are already reports of fatigue and inadequate sleep from the crew. An initial recommendation to combat
fatigue would be to decrease the shift frequency from 6 to 5 days, while maintaining
two days off’ this is shown in Figure 1. This decreases the total continuous operating
time and provides for more frequent rest for the crews. A crew that is not
experiencing fatigue can maintain the “operator involved in the crucial tasks
to the extent that any task emergencies are recognized and acted on within a
critical time envelope” (Barnes & Matz, 1998) . Reducing the total continuous days of work
also reduces the level of social and water isolation experienced by the crews.
The cognitive load associated with
operating an UAS, along with the level of stress from performing military
operations, can be compared to stressors experienced by Air Traffic Controllers
(ATC). Both career fields expose the
operators to long missions, high level of stress, and a high cognitive
demand. The FAA has commissioned studies
on the effectiveness and effect of multiple shifts on stress and fatigue. A commonly used shift is called the
counterclockwise shift, which progressively moves the shift start date earlier
with every shift. This was ultimately
found to be counterproductive as it reduced the hours and quality of sleep on
the ATCs (Signal & Gander, 2007) . Applying this research to UAS crews provides
insight on what can be recommended from a human factors perspective. This first improvement would be the
incorporation of short duration naps within the schedule. “A daytime nap as short as 10-min can improve
alertness and performance for about 2.5 h in the face of prior sleep loss, and
for almost 4 h if preceded by normal sleep” (Ficca, Axelsson, Mollicone, Muto, & Vitiello, 2010) .
A subsequent improvement to the UAS crew
schedule would result in the implementation of a rotating clockwise
schedule. This type of schedule moves
the start date to the right, later each shift, to provide additional
opportunities for sleep. The shifts
would start one hour later each day for all teams; the progressive nature of
the change provides more time to sleep in order for the crew to recover from
compounded fatigue. In addition to the
progressive schedule, the crews would be required to participate in periodic stress
and fatigue assessments for further adjustments. Waiting for a crewmember to report symptoms
is not conducive to safe operations. The
evaluations would include the requirement for all crewmembers to wear a sleep
monitoring device to ensure accurate sleep tracking.
The quality of sleep is a critical
component of the health assessment of the crew.
Lack of sleep is a direct contributor to reduced cognitive function and
poor performance from the crew. A progressive shift, naps, and sleep monitoring
provide the best way to ensure proper crew rest and optimum operational
capabilities from the crew. In the same
manner that an air vehicle undergoes preventive maintenance, the crew and
operators require monitoring for optimum performance.
Figure 1.
Existing and Proposed shift scheduled for UAS operators.
References
Barnes, M. J., & Matz, M. F. (1998). Crew
simulations for Unmanned Aerial Vehicle (UAV) applications: Sustained
effects, shift factors, interface issues, and crew size. Proceedings of
the Human Factors and Ergonomics Society 42nd Annual Meeting (pp.
143-147). Ft. Huachuca: ProQuest Central.
Ficca, G., Axelsson, J., Mollicone, D.
J., Muto, V., & Vitiello, M. V. (2010). Naps, cognition and performance. Sleep
Medicine Reviews, 14, 249-258.
Signal, T. L., & Gander, P. H.
(2007, September). Rapid Counterclockwise Shift Rotation in Air Traffic
Control: Effects on Sleep and Night Work. Aviation, Space, and
Environmental Medicine, 78(9), 878-885.
