"My mind clicks on and off. I try letting one eyelid close at a time while I prop the other with my will. But the effect is too much, sleep is winning, my whole body argues dully that nothing, nothing life can attain is quite so desirable as sleep. My mind is losing resolution and control."
Charles Lindbergh about his 1927 transatlantic flight
In mid-November 1998, I found myself trying to fly a Boeing 727 on an NDB approach to Category I ILS minimums at Sea-Tac International with one of its three engines inoperative. My previous flying experience had mostly been flying single-engine Cessnas and Piper Chieftains, yet here I was in a 180,000-pound 727 flying in conditions worse than I had ever seen. I was battling to keep up with the airplane for quite a while and was not being very successful. I landed a half-mile short of the runway and to the right of the centerline. Fortunately, no one was hurt and there was no damage -- except to my pride.
We were in a simulator, of course, and the lesson of the day was about how, in an emergency, a mathematical glideslope may quickly be calculated to turn an NDB approach into a precision approach. It's a lesson that I have quickly erased from the cerebral database; however, I learned a more important lesson that day which has stayed with me ever since: I learned that I am not immune to fatigue.
I had not eaten since noon the day before or slept well that night. I was pretty exhausted just going into the simulator, but after four hours, I was wiped out. I was in no condition to fly in those conditions and my performance proved it.
The next day was checkride day. I made sure that I was well-rested and well-fed. This time I was ready, and this time I did a fantastic job. I kept the needles centered as if they were glued in place. I performed the same approach as the day before and broke out of the clouds right over the approach lights and landed well within the touchdown zone. Without a doubt, being well-rested made all of the difference.
The Accident Record
After that experience, I have been much more aware of my state of alertness and the things that might diminish it. However, many people and organizations either don't seem to take the issue seriously enough or place their own agendas ahead of safety. For example, in order to save the reputations of some airlines and pilots, company doctors often disguise symptoms of fatigue as other illnesses.
Also, in 1996, the U.S. Air Transport Association (ATA) voiced
opposition to an FAA proposal to set new limits on flight and duty time,
reserve duties and crew rest. They said there is no scientific evidence to
show fatigue is a factor in safety. This kind of thinking
is not only irrational but also dangerous. Only recent events are bringing the
importance of recognizing fatigue to the fore.
Many pilots have heard the story of the pilot who fell asleep with his
autopilot on and woke up two hours from the nearest land with only one hour of
fuel remaining. The story may be just an "airborne legend," dreamed
up by a group of hangar-flying buddies after a long day of towing gliders.
True or not, no pilot with a modicum of experience can deny having
occasionally had to battle a bout of fatigue or that it somehow affected their
many documented accidents that can been attributed to pilot fatigue. Most
recently would be the June 1999 fatal runway accident of American Airlines
Flight 1420 in which a McDonnell Douglas MD-82 overran the end of the runway,
went down an embankment, and impacted approach light structures after landing
at the Adams Field Airport in Little Rock, Ark. Thunderstorms and heavy
rain were reported in the area at the time of the accident. There were 11
fatalities, including the aircraft captain, and numerous injuries among the
145 passengers and crew aboard the flight. While the final report has not been
released, it is expected that fatigue will be listed as a contributing cause.
Although Korean Airline's (KAL) management emphatically denies it, the
crash of KAL Flight 801 in Guam on August 6, 1997, was the result of several
errors by the crew, most notably a lack of situational awareness resulting in
"controlled flight into terrain (CFIT)." However, the pilot in
command of the flight, Captain Park Yong-chul, was a senior and experienced
pilot in the company. While Captain Park was not familiar with the terrain,
and visibility at the time was reduced due to rain, the approach into Guam
should not have been difficult. So what caused Captain Park to lose
concentration and situational awareness, and thereby fly a perfectly good 747
into a hilltop, killing 227 people? Could it be that prior to flying to Guam
he had flown from Seoul to Australia, back to Seoul, to Hong Kong, and then
back to Seoul again before his fateful trip to Guam, all with only a few hours
of rest? The answer should seem pretty obvious.
NTSB said that Joe Reid, pilot-in-command of the Cessna 177B Cardinal in which
he, seven-year-old Jessica Dubroff and her father were killed, suffered
fatigue from the first day's flight. That fatigue seems to have impaired his
judgment, allowing him to depart into weather that a United Express Beech 1900
Captain deemed worth a delay.
On August 18, 1993, a Connie Kalitta DC-8 crashed on a 1/4-mile base leg to
final. The flight crew had been on duty for 18 hours and flown nine, thereby
experiencing sleep loss and a disruption of their circadian rhythms. In his
introductory speech at the November 1995 Fatigue Symposium near Washington,
D.C., Jim Danaher, chief of the NTSB's Operational Factors Division, commented
on the accident by stating, "The company had intended for the crew to
ferry the airplane back to Atlanta after the airplane was offloaded in
Guantanamo Bay. This would have resulted in a total duty time of 24 hours and
12 hours of flight time ."
Was the crew legal to fly? Unfortunately yes, but doing so proved to be
nearly fatal. The NTSB accident report states, "Probable Cause: The
impaired judgment, decision-making, and flying abilities of the captain and
flightcrew due to the affects of fatigue." While the report goes on to
list other causes, it is rare to find fatigue as the primary cause as it does
here. Usually, pilot fatigue is relegated to the Additional Factors section of
a report. As for the Additional Factors section, the NTSB lays some blame on
the FAA for inadequate flight and duty time regulations.
One must wonder how a person may be legally rested if they are flying under
one part of the Federal Aviation Regulations (FARs), but not legally rested if
they are flying under another part. Does it not make sense that if a person is
too tired to fly, then the part of the regulations that they are operating
under is irrelevant?
2, 1989, the captain of a 707 tried to maneuver his plane to land in Salt Lake
City after breaking out of the clouds at 200 feet. He dragged his left,
outboard engine on the runway, leaving a 60-foot-long gouge. Within the
preceding 30 hours, he had been on duty for 19 hours, and flown 13 hours. He
had been off duty for almost 12 hours, but was only able to get one hour of
sleep in that time. Pilot fatigue due to disrupted circadian rhythm was cited
as a contributing factor.
In August 1985, the crew of a Learjet killed themselves and their passenger
in a botched approach to Gulkana, Alaska. One of the contributing factors was
that the company would shift the crew's duty/rest requirements from FAR Part
135 to those of FAR Part 121, thereby disrupting their sleep patterns and
The problem is not limited to aviation either. In maritime events, fatigue
has been cited as contributing to the Exxon Valdez and
World Prodigy disasters. It was a factor in the nuclear
accidents at Three Mile Island and Bhopal and affected the decision-making
process of the doomed space shuttle Challenger mission.
The list goes on and on. So how do we address the issue? What can be done
to rectify the problem? Before we can offer any solutions, we have to identify
the problem. Fatigue is closely interrelated to other problems in that it can
be a symptom of them, or it can be the cause. The most obvious cause of
fatigue would be a lack of sleep, but other factors would include stress,
anxiety and poor health. It can also be a cause of these problems.
Furthermore, fatigue can be the symptom of other problems such as hypoxia and
Symptoms of fatigue include a feeling of indifference to one's performance,
increased reaction time, a decreased ability to concentrate on multiple tasks,
fixation, short-term memory loss, impaired judgment, impaired decision-making
ability, distractibility, sloppy flying skills, reduced visual perception,
loss of initiative, personality changes and depression.
understand the problem of inadequate sleep, we should understand what sleep
is. There are four stages of sleep starting with about 10 minutes of REM
(rapid eye movement) sleep where the mind is active (dreaming) and the smaller
muscles twitch. During the next three stages the mind and body slow down.
After 45-70 minutes, we return to REM. People go through this cycle several
times through the night and an interruption of any stage (i.e., the hotel maid
waking you up to see if you need the room cleaned, or a phone call from
dispatch to tell you that they have received your fax) will render that whole
One major cause of sleep deprivation is a disruption of our internal
light/dark cycle, called circadian rhythms. Circadian rhythms are the
biological clock existing in our brains since prehistoric times, which tell us
that we should work when it is light (day) and sleep when it is dark (night).
The word comes from the Latin "circa" (about), and "dies"
(day). Circadian changes make a person try to sleep
when their mind is wide-awake, and they force them to remain awake when their
mind is screaming to go to bed. Long schedules and changes in circadian
rhythms are among the most common causes of fatigue faced by pilots, mainly
because there is little that can be done to change them. We are all subject to
these factors and the best defense is to limit their effects by controlling
the fatiguing factors that we can.
Diet And Nutrition
example, any pilot from a brand-new student to the about-to-retire captain
will tell you that the beverage of choice among pilots is coffee. However,
while coffee is a stimulant and causes a temporarily increased level of
alertness, fatigue is symptomatic of its withdrawal. Furthermore, coffee is a
diuretic, which causes the body to discharge more fluid than it is taking in,
resulting in dehydration, which in turn can cause fatigue.
While there can be no argument against being in good physical shape, a
strenuous workout can also cause dehydration and should be completed with
ample time for rehydration. Also, environmental conditions can cause
dehydration. Obviously, the 130-degree ramp at Phoenix is a place where
dehydration is of concern, but what about the 72-degree cockpit in which we
work? Worry about it, too. The average humidity there is low and can cause a
dramatic increase in fluid loss.
Another factor is nutritional intake. The diet of a pilot can at times be
horrendous. What can you do when you are sitting in an FBO, ten miles from the
nearest restaurant, and have not eaten since 5:00 a.m.? You may have slept
well the night before and the flight may have been easy and relaxing; but you
are tired and weak and do not know why. You pull out a few bucks and feed them
to the vending machine, hoping that it might relinquish its firm grasp on that
bag of Ruffles and the Snickers bar. Then you buy a Coke with the change. Very
quickly you notice that your energy is returning. Even your mood improves. It
turns out that you may have been hypoglycemic; your blood sugar was too low.
While the nutritional value of that kind of food is objectionable, it does
have a redeeming quality in that it can stave off or reverse the effects of
hypoglycemia, which can be a cause of fatigue. It should be noted that a
healthy diet is much better in the long term and may be had by packing your
own meal, receiving catered meals from the company, or getting a healthy meal
at the airport diner.
Illness And Environment
If you're sick, don't fly. It is an obvious statement, but many people fly
when they are sick anyway. Many companies make it financially disadvantageous
for crew members to report their malady. Some pilots think that they are
invincible and that they perform better than most even when afflicted with a
cold or flu. Others know that they are impaired by an illness so they
compensate with antihistamines. Antihistamines help by alleviating the
symptoms of illness but by their nature they also increase fatigue.
Regardless, these people are doing their fellow crew members a disfavor by
exposing them to their illness and further increasing the possibility of an
operational error due to fatigue. They may be involved
in an accident, or maybe not, but they can unwittingly be a contributing cause
Other environmental concerns include noise and vibration, hypoxia, extreme
temperatures, and flickering light (as in helicopters). Many less-experienced
pilots will go out and enjoy an exciting layover at the cost of their vitally
required rest. Some companies stretch their employees' rest requirements to
the legal limit of flight and duty time restrictions to maximize productivity.
Long international flights and automation cause a reduction of mental stimulus
and an increase in boredom.
in pilots can be reduced or eliminated with simple and practical steps on the
part of the FAA, the airlines and the individual crew members. The FAA's role
is to make and enforce laws concerning the conduct of airlines and pilots.
These laws should be rewritten to be simple and straightforward, and should
not vary by type of operation. The FARs already regulate certain activities
which may affect fatigue, such as alcohol and drug use, medical certification
requirements, and requirements for the use of oxygen. Why does the FAA not
consider circadian rhythm changes in their law making? Why is it that one type
of operation has different flight and duty time restrictions than another?
Does the type of operation have any bearing on the level of fatigue that crew
members experience? Why does the FAA mandate that simple duct tape requires
their testing and approval (thus quadrupling the cost) yet companies are
allowed to put a flight crew in the noisiest hotels just to save a dime? Why
is it not allowed for flight crews to alternate taking controlled, planned
naps while en route? The rules are changing, but not fast enough.
The airlines need to recognize that the cost of fatigue and the errors that
result are many times higher than the cost of ensuring adequate rest for their
crews. Seventy percent of the accidents in aviation are due to pilot error,
and fatigue is a major cause of those errors. If the airlines took measures to
reduce fatigue, they would reduce the chances of errors due to fatigue. Many
airlines have seen their total demise due to a single accident (i.e., Valujet
Flight 592). It is obvious that preventing fatigue would have a major cost
and arguably most importantly, fatigue can be prevented by individuals taking
preemptive measures. Pilots take great pride in their skills and abilities,
yet they let their performance degrade needlessly due to fatigue. It is in
their hands to take the necessary steps to remain safe and alert, even when
the government and their employers are allowing them to work irrational and
dangerous schedules. Planning to get enough sleep before a trip is the most
obvious step. Using earplugs and eye masks can help in this endeavor. Another
step would be to eat properly. Everyone should exercise often, but remember to
do so well before the start of a trip. This will make the pilot healthier and
more alert. Pilots can stay hydrated by drinking plenty of water, especially
during a flight, and avoid coffee, sodas and alcohol. They can wear
noise-reducing headsets if the cockpit is loud. Finally, they must stay home
when they are ill, for their own sake and for their fellow crew members.
Fatigue is often the cause of pilot error and it is therefore often the
vital link in the chain of events leading to an accident. It is often the
reason that pilots don't make the right decisions or fly as well as they can.
If a reduction in fatigue yielded an increase in pilots' decision-making
abilities and performance, then there would obviously be a decrease in pilot
error and the accidents that sometimes ensue. Not all errors result in
accidents, but if everyone in the airline industry took the appropriate steps
to combat fatigue, it is likely that pilot error due to fatigue, therefore
accidents due to pilot error, would drop significantly.
-- Mark Brandon Printup
1. Daniel Waddell, Doctors 'help to disguise pilot
fatigue', The Daily Telegraph, 17 Sep 1998.
2. Steve Holland, Independent pilots back new FAA
fatigue rules, Reuters, 17 Jun 1996.
3. Don Phillips/Washington Post, Crew reportedly didn't
know crash imminent: Plane's wheels were in place for Guam Landing, The
Dallas Morning News, 8 Aug 1997.
9. Marine Accident Report-Grounding of the US. Tankship
Exxon Valdez on Bligh Reef, Prince William Sound, Near Valdez, Alaska, 24
Mar 1989. Washington, DC: National Transportation Safety Board (NTSB/Mar-90/04);
10. Marine Accident Report-Grounding of the Greek
Tankship World Prodigy off the Coast of Rhode Island, 23 Jun 1989.
Washington, DC: National Transportation Safety Board (NTSB/Mar-90/04);
11. Biological Rhythms: Implications for the Worker.
Washington, DC: US Congress, Office of Technology Assessment. US Government
Printing Office; 1992: 1-249.
12. Reinhart, Richard O. "Basic Flight
Physiology." (Blue Ridge Summit: TAB Books, 1992), pp. 177-182.
13. "Learning to Live with Light-Dark
Cycles," Vol. 124, USA Today Magazine, 1 Feb 1996.
Tom, Duke "Battling Fatigue-The Challenge is to Manage It."
Editorial. NATCA Voice, February 1997.
Steve Holland, "Independent Pilots Back New FAA Fatigue
Rules." Reuters, June 17, 1996.
Don Phillips/Washington Post, "Crew Reportedly Didn't Know Crash
Imminent: Plane's Wheels Were in Place for Guam Landing." The Dallas
Morning News, August 8, 1997.
Reinhart, Richard O. Basic Flight Physiology. Blue Ridge Summit:
TAB Books, 1992.
Daniel Waddell, "Doctors Help to Disguise Pilot Fatigue." The
Daily Telegraph, September 17 1998.
"Learning to Live with Light-Dark Cycles." Vol. 124, USA
Today Magazine, 1 Feb 1996.
Biological Rhythms: Implications for the Worker. Washington, DC:
US Congress, Office of Technology Assessment. US Government Printing Office;
Marine Accident Report-Grounding of the Greek Tankship World Prodigy off
the Coast of Rhode Island, 23 Jun 1989. Washington, DC: National
Transportation Safety Board (NTSB/Mar-90/04); 1990:1-47.
Marine Accident Report-Grounding of the US Tankship Exxon Valdez on
Bligh Reef, Prince William Sound, Near Valdez, Alaska, 24 Mar 1989.
Washington, DC: National Transportation Safety Board (NTSB/Mar-90/04);