Just as the aviation industry, including the NTSB, has addressed alcohol use and adherence to SOPs, it
must also address the issue of fatigue. Unlike many of our complex, technical or cutting edge findings
that require further explanation to the public to show why we made the finding, I believe this situation is
one that requires an explanation of why we did not reach a conclusion – that is, why we did not identify
fatigue in the probable cause determination. Anyone who has attempted to overnight in a crew lounge, an
office or an airport waiting room, or has tried to get a night’s sleep on a red-eye flight from Seattle to
Newark will tell you, this type of sleep in not recuperative, and the data and science support this. Anyone
who has a new baby at home or is caring for an ill relative can tell you that interrupted sleep is not
restorative sleep, and studies support this. Any employee who is asked to remain awake throughout the
day and be prepared for the most demanding portion of their workday at 10pm after they have been awake
for at least 15 consecutive hours would likely acknowledge that they are not at peak performance, and
research supports this. Safety Board studies indicate that the duration of the most recent sleep period, the
amount of sleep during the previous 24 hours, and split or fragmented sleep patterns are among the most
critical factors leading to fatigue-related accidents.
13
The failure of the Safety Board to include fatigue as one of the contributing factors in this accident is
symptomatic of the Board’s inconsistent approach to addressing fatigue in transportation accidents. We
have developed a methodology to be used by our investigators in our on-going efforts to address fatigue
in accident investigations through a fatigue checklist.
14
It is not necessary for fatigue to be the sole cause
of an accident, but it should be included as a factor when it is present and performance deficiencies
consistent with fatigue are identified. In 1999 the NTSB recognized that, “[a]lthough generally accepted
as a factor in transportation accidents, the exact number of accidents due to fatigue is difficult to
determine and likely to be underestimated. The difficulty in determining the incidence of fatigue-related
accidents is due, at least in part, to the difficulty in identifying fatigue as a causal or contributing factor in
accidents. There is no comparable chemical test for identifying the presence of fatigue as there is for
identifying the presence of drugs or alcohol; hence, it is often difficult to conclude unequivocally that
fatigue was a causal or contributing factor in an accident. In most instances, one or more indirect or
circumstantial pieces of evidence are used to make the case that fatigue was a factor in the accidents.”
15
There is consensus at the Safety Board that the flight crew in this accident was likely fatigued, and our
accident report makes this conclusion. The factual information in the docket establishes the presence of
fatigue for both of these crew members.
16
The captain spent the night before the accident sleeping in the
company crew room, where he obtained, at best, 8 hours of interrupted sleep as evidenced by multiple
log-ins to the CrewTrac system at 2151, then 0310 and again at 0726. At worst, it was poor-quality,
interrupted sleep of a shorter duration. NASA and other studies show that even in an onboard rest facility
with beds available for long haul flight crews, pilots might get three hours of sleep and the quality does
not approach 'home' sleep.
17
So, conservatively, the captain in this accident obtained 2 fewer hours sleep
than his usual sleep and perhaps, significantly less based on the quality of sleep. In addition to this acute
13
National Transportation Safety Board, Factors That Affect Fatigue in Heavy Truck Accidents, Highway Safety
Study NTSB/SS-95/01 (Washington, D.C.: NTSB, 1995).
14
http://www.ntsb.gov/info/fatigue_checklist_V%202_0.pdf.
15
SR99-01 - Evaluation of U.S. Department of Transportation Efforts in the 1990s to Address Operator Fatigue
16
National Transportation Safety Board, Aircraft Accident Report: Crash on Approach to Airport Colgan Air, Inc.
Operating as Continental Connection Flight 3407 Bombardier DHC-8-400, N200WQ Clarence Center, New York,
Feb. 12, 2009, Human Performance Group Chairman Factual Report, Docket No. SA-531, and Addendum 1
DCA09MA027.
17
Rosekind, M.R., Gregory, K.B., Miller, D.L., Co, E.L. (2000). Crew factors in flight operations XII: A survey of
sleep quantity and quality in on-board crew rest facilities. (Technical Memorandum 2000-20961). Moffett Field,
CA: NASA and Rosekind, M. R., Gregory, K. B., Miller, D. L., Oyung, R. L., Neri, D. F., & Dinges, D. F. Sleep
quantity and quality of augmented long-haul flight crews in on-board crew rest facilities. Sleep Research, 1997,
26:41.
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