Unmanned
Aircraft System (UAS) Rotating Shift Work Schedule
Circadian rhythms are a human’s physiological processes that
follow a roughly twenty-four hour cycle, and are regulated by external sources,
or zeitgebers (Orlady & Orlady, 2014).
The most influential of these is the earth’s day (light) / night
(darkness) (Orlady & Orlady, 2014). The
issues with rotating shift work “…stem mainly from working in opposition to the
body’s normal circadian rhythms” (American College of Emergency Physicians
[ACEP], 2003, para. 1). Adaptation to
shift work can be very difficult because an
individual’s “…internal circadian clock adapts slowly, if at all, to rapid
transitions between different shift schedules” (Arendt, 2010, p. 10). This disruption can lead to issues with
fatigue, alertness, efficiency, job performance, and, most importantly, health (Arendt, 2010).
When
addressing the issue of employee adaptation to shift work, scheduling is a
primary consideration (ACEP, 2003). Unfortunately, there is no one “correct”
schedule or shift/team composition
(ACEP, 2003). In fact, “from a
circadian perspective, the gold standard is never to rotate shifts” (ACEP,
2003, para. 13). Unfortunately, however,
shift work is a requirement in numerous industries and organizations. In these cases, a “best fit” schedule must be
developed that takes into consideration an organization’s unique aspects and
requirements. According to the Handbook of Occupational Safety and Health
(2010):
…solutions
for work schedules should be based on the following suggestions:
- The number of consecutive night shifts should not exceed four (Knauth 1993).
- Shift rotation should always be in agreement with the normal course of a day (morning, afternoon, night; Barton and Folkard 1993).
- A system with quick shift rotation is more favourable than a system including several consecutive days of working the same shift.
- A five-crew system is more favourable for shift work and work constantly on the move, compared to a four-crew system (Lillqvist et al. 1997).
- Each shift should begin at a time that does not result in forced sleep shortening (e.g. morning shifts should not begin earlier than 6 am; Knauth 1993).
- Shift and night workers should work no longer than 8 hours, particularly while working night shifts. … (pp. 510-511)
And as Burgess
(2007) notes, “optimal scheduling would use a
clockwise (morning-afternoon-night) rotational schedule: limiting night shifts
to blocks of 3, limiting shift duration to 8 hours, and allowing 3 days of
recuperation after night shifts” (p. S88).
Discussion
The
current shift work schedule for the United States Air Force (USAF) MQ-1B Medium Altitude, Long Endurance
(MALE) unmanned aircraft system (UAS) squadron for conducting round-the-clock
missions, shown in Figure A1, utilizes four teams in a continuous shift work
schedule of six days on and two days off.
When applying the work schedule suggestions discussed previously, it can
be seen how this “6-on-2-off” plan could result in the extreme fatigue being reported
by the UAS crews. Specifically, it keeps
the crews’ circadian rhythms in a constant state of disruption due to
longer/slower rotations and longer consecutive night shifts. This schedule does not provide adequate time
for personnel’s circadian rhythms to adapt to, or recover from, each shift
before starting their next scheduled rotation.
The proposed
plan, shown in Figure A2, is the Metropolitan rota, or “2-2-2”, plan (Miller, 2012). This plan consists of rapidly rotating eight
hour shifts that result in “…six consecutive work shifts in an 8-day cycle”
(Miller, 2012, p. 2). While this
schedule maintains the “6-on-2-off” format, specifically the six-day work week,
it’s benefits include quicker shift rotations, which helps to reduce the
disruptions in circadian rhythms; a reduction in the number of consecutive
night shifts, which will help to reduce sleep deprivation, time provided each
week for regular social contact (Circadian, 2014).
References
American
College of Emergency Physicians. (2003, September). Circadian rhythms and shift
work. Retrieved from http://www.acep.org/Clinical---Practice-Management/Circadian-Rhythms-and-Shift-Work/
Arendt, J. (2010, January). Shift work:
Coping with the biological clock. Journal
of the Society of Occupational Medicine, 60(1), 10-20. Retrieved from
http://occmed.oxfordjournals.org/content/60/1/10.full
Burgess, P. (2007, April). Optimal shift
duration and sequence: Recommended approach for short-term emergency response
activations for public health emergency management. American Journal of Public Health, 97(Suppl 1), S88-S92. doi:
10.2105/AJPH.2005.078782
Circadian. (2014). Managing 24/7
enewsletter: Shiftwork trends, best practices, research. Retrieved from http://www.circadian.com/solutions-services/publications-a-reports/newsletters/managing-247-enewsletter.html
Miller, J. (2012, April). White paper:
Shift plans with seven consecutive shifts. Retrieved from
http://primis.phmsa.dot.gov/crm/docs/shift_plans_with_seven.pdf
Orlady, H., & Orlady, L. (2014). Human Factors in Multi-Crew Flight
Operations. Burlington, VT, USA: Ashgate Publishing Company.
Appendix A
Figure A1. Current USAF MQ-1B MALE UAS Squadron Shift
Rotation Schedule
Mon
|
Tue
|
Wed
|
Thu
|
Fri
|
Sat
|
Sun
|
|||||||
1
|
2
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3
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4
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5
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6
|
7
|
|||||||
Team 1
|
Day
|
Team 1
|
Day
|
Team 1
|
Day
|
Team 1
|
Day
|
Team 1
|
Day
|
Team 1
|
Day
|
Team 1
|
off
|
Team 2
|
off
|
Team 2
|
off
|
Team 2
|
Swing
|
Team 2
|
Swing
|
Team 2
|
Swing
|
Team 2
|
Swing
|
Team 2
|
Swing
|
Team 3
|
Night
|
Team 3
|
Night
|
Team 3
|
Night
|
Team 3
|
Night
|
Team 3
|
off
|
Team 3
|
off
|
Team 3
|
Day
|
Team 4
|
Swing
|
Team 4
|
Swing
|
Team 4
|
off
|
Team 4
|
off
|
Team 4
|
Night
|
Team 4
|
Night
|
Team 4
|
Night
|
8
|
9
|
10
|
11
|
12
|
13
|
14
|
|||||||
Team 1
|
off
|
Team 1
|
Swing
|
Team 1
|
Swing
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Team 1
|
Swing
|
Team 1
|
Swing
|
Team 1
|
Swing
|
Team 1
|
Swing
|
Team 2
|
Swing
|
Team 2
|
off
|
Team 2
|
off
|
Team 2
|
Night
|
Team 2
|
Night
|
Team 2
|
Night
|
Team 2
|
Night
|
Team 3
|
Day
|
Team 3
|
Day
|
Team 3
|
Day
|
Team 3
|
Day
|
Team 3
|
Day
|
Team 3
|
off
|
Team 3
|
off
|
Team 4
|
Night
|
Team 4
|
Night
|
Team 4
|
Night
|
Team 4
|
off
|
Team 4
|
off
|
Team 4
|
Day
|
Team 4
|
Day
|
15
|
16
|
17
|
18
|
19
|
20
|
21
|
|||||||
Team 1
|
off
|
Team 1
|
off
|
Team 1
|
Night
|
Team 1
|
Night
|
Team 1
|
Night
|
Team 1
|
Night
|
Team 1
|
Night
|
Team 2
|
Night
|
Team 2
|
Night
|
Team 2
|
off
|
Team 2
|
off
|
Team 2
|
Day
|
Team 2
|
Day
|
Team 2
|
Day
|
Team 3
|
Swing
|
Team 3
|
Swing
|
Team 3
|
Swing
|
Team 3
|
Swing
|
Team 3
|
Swing
|
Team 3
|
Swing
|
Team 3
|
off
|
Team 4
|
Day
|
Team 4
|
Day
|
Team 4
|
Day
|
Team 4
|
Day
|
Team 4
|
off
|
Team 4
|
off
|
Team 4
|
Swing
|
22
|
23
|
24
|
25
|
26
|
27
|
28
|
|||||||
Team 1
|
Night
|
Team 1
|
off
|
Team 1
|
off
|
Team 1
|
Day
|
Team 1
|
Day
|
Team 1
|
Day
|
Team 1
|
Day
|
Team 2
|
Day
|
Team 2
|
Day
|
Team 2
|
Day
|
Team 2
|
off
|
Team 2
|
off
|
Team 2
|
Swing
|
Team 2
|
Swing
|
Team 3
|
off
|
Team 3
|
Night
|
Team 3
|
Night
|
Team 3
|
Night
|
Team 3
|
Night
|
Team 3
|
Night
|
Team 3
|
Night
|
Team 4
|
Swing
|
Team 4
|
Swing
|
Team 4
|
Swing
|
Team 4
|
Swing
|
Team 4
|
Swing
|
Team 4
|
off
|
Team 4
|
off
|
Figure A1. Displays the current
“6-on-2-off” shift plan for the United
States Air Force (USAF) MQ-1B Medium Altitude, Long Endurance (MALE) unmanned
aircraft system (UAS) squadron for conducting round-the-clock missions.
Figure A2. Proposed USAF MQ-1B MALE UAS Squadron Shift
Rotation Schedule
Mon
|
Tue
|
Wed
|
Thu
|
Fri
|
Sat
|
Sun
|
|||||||
1
|
2
|
3
|
4
|
5
|
6
|
7
|
|||||||
Team 1
|
Day
|
Team 1
|
Day
|
Team 1
|
Swing
|
Team 1
|
Swing
|
Team 1
|
Night
|
Team 1
|
Night
|
Team 1
|
off
|
Team 2
|
off
|
Team 2
|
off
|
Team 2
|
Day
|
Team 2
|
Day
|
Team 2
|
Swing
|
Team 2
|
Swing
|
Team 2
|
Night
|
Team 3
|
Night
|
Team 3
|
Night
|
Team 3
|
off
|
Team 3
|
off
|
Team 3
|
Day
|
Team 3
|
Day
|
Team 3
|
Swing
|
Team 4
|
Swing
|
Team 4
|
Swing
|
Team 4
|
Night
|
Team 4
|
Night
|
Team 4
|
off
|
Team 4
|
off
|
Team 4
|
Day
|
8
|
9
|
10
|
11
|
12
|
13
|
14
|
|||||||
Team 1
|
off
|
Team 1
|
Day
|
Team 1
|
Day
|
Team 1
|
Swing
|
Team 1
|
Swing
|
Team 1
|
Night
|
Team 1
|
Night
|
Team 2
|
Night
|
Team 2
|
off
|
Team 2
|
off
|
Team 2
|
Day
|
Team 2
|
Day
|
Team 2
|
Swing
|
Team 2
|
Swing
|
Team 3
|
Swing
|
Team 3
|
Night
|
Team 3
|
Night
|
Team 3
|
off
|
Team 3
|
off
|
Team 3
|
Day
|
Team 3
|
Day
|
Team 4
|
Day
|
Team 4
|
Swing
|
Team 4
|
Swing
|
Team 4
|
Night
|
Team 4
|
Night
|
Team 4
|
off
|
Team 4
|
off
|
15
|
16
|
17
|
18
|
19
|
20
|
21
|
|||||||
Team 1
|
off
|
Team 1
|
off
|
Team 1
|
Day
|
Team 1
|
Day
|
Team 1
|
Swing
|
Team 1
|
Swing
|
Team 1
|
Night
|
Team 2
|
Night
|
Team 2
|
Night
|
Team 2
|
off
|
Team 2
|
off
|
Team 2
|
Day
|
Team 2
|
Day
|
Team 2
|
Swing
|
Team 3
|
Swing
|
Team 3
|
Swing
|
Team 3
|
Night
|
Team 3
|
Night
|
Team 3
|
off
|
Team 3
|
off
|
Team 3
|
Day
|
Team 4
|
Day
|
Team 4
|
Day
|
Team 4
|
Swing
|
Team 4
|
Swing
|
Team 4
|
Night
|
Team 4
|
Night
|
Team 4
|
off
|
22
|
23
|
24
|
25
|
26
|
27
|
28
|
|||||||
Team 1
|
Night
|
Team 1
|
off
|
Team 1
|
off
|
Team 1
|
Day
|
Team 1
|
Day
|
Team 1
|
Swing
|
Team 1
|
Swing
|
Team 2
|
Swing
|
Team 2
|
Night
|
Team 2
|
Night
|
Team 2
|
off
|
Team 2
|
off
|
Team 2
|
Day
|
Team 2
|
Day
|
Team 3
|
Day
|
Team 3
|
Swing
|
Team 3
|
Swing
|
Team 3
|
Night
|
Team 3
|
Night
|
Team 3
|
off
|
Team 3
|
off
|
Team 4
|
off
|
Team 4
|
Day
|
Team 4
|
Day
|
Team 4
|
Swing
|
Team 4
|
Swing
|
Team 4
|
Night
|
Team 4
|
Night
|
Figure A2. Displays the proposed Metropolitan rota, or “2-2-2”, shift plan for the United States Air Force (USAF) MQ-1B Medium Altitude,
Long Endurance (MALE) unmanned aircraft system (UAS) squadron for conducting
round-the-clock missions.
