Aviation & Fatigue Essay
Human factors in aviation are a relatively new discipline. It has progressed through three broadly-defined eras since its early foundations in the mid-1940s. From mid-1960s, human factors began to make increasingly large contributions in the areas of training and simulation with further contributions in the design and layout of flight decks. However, the discipline really began to come of age with the CRM (cockpit – later crew – resource management) revolution, which brought applied social psychology and management science onto the flight deck to promote better teamwork.
However, the major emphasis of the work in these formative years of the discipline (particularly in commercial aviation) was safety related. Human factors were seen as a discipline necessary to help in avoiding accidents. Poor human factors increased the likelihood of poor performance.
This paper proposes a number of connections between administratively controllable causes of fatigue and problems associated with pilot performance, health, and safety – problems that have long been overlooked. The effects of fatigue on human behavior, performance, and physiology are well understood, and widely known.
Excess fatigue arising from sleep loss, circadian disruption, and other factors tends to decrease alertness, impair performance, and worsen mood. It therefore may be expected to influence the performance, health, and safety of the captain and also their first officers. The argument is made that much of the fatigue experienced by pilots could be controlled administratively, just as we control the working hours of many other occupational groups.
Fatigue- Definition & Symptoms
Caldwell (1997) has described fatigue is defined as a non-pathologic state resulting in a decreased ability to maintain function or workload due to mental or physical stress. This is also the term medically used to illustrate an assortment of experiences from being sleepy, to lethargic to drained, to exhausted.
“There are two major physiological phenomena that have been demonstrated to create fatigue: sleep loss and circadian rhythm disruption. Fatigue is a normal response to many conditions common to flight operations because of sleep loss, shift work, and long duty cycles. It has significant physiological and performance consequences because it is essential that all flight crewmembers remain alert and contribute to flight safety by their actions, observations and communications. The only effective treatment for fatigue is adequate sleep.”
Fatigue is widespread in the job of a pilot. Psychologists, health care professionals, researchers, and practitioners all acknowledge fatigue as a fundamental source of stress in the aviation environment (e.g. Strauss, 2004; Caldwell, 1997). Patrol officers often have to resolve complicated, emotionally-charged, and threatening situations; to fly the plane while subdividing their attention between sending and receiving communications, and also, ironically, stay alert during long periods of crushing boredom. There often are times when they perform their duties while exhausted from job-related activities that result in chronic lack of sleep and irregular sleep patterns shift changes.
The National Transportation Safety Board (NTSB) had conducted a safety study of all the primary major aircraft accidents from 1978 to 1990. Their findings revealed that one of the investigations relates directly to fatigue and its repercussions. It had stated that “Half the captains for whom data were available had been awake for more than 12 hours prior to their accidents. Half the first officers had been awake for more than 11 hours. Crews comprising captains and first officers whose time since awake was above the median for their crew position made more errors overall and significantly more procedural and tactical decision errors.” (cited in NTSB, 1994)
The main symptoms of this killer medical condition includes a sensation of unresponsiveness to their tasks, additional time to react to situations, a reduced capability to focus on multi-tasking, short-term memory loss, changes in personality, impaired judgment, sloppy flying skills, reduced visual perception and depression (Reinhart, 1992).
Diet & Circadian Rhythm
It is common knowledge that most pilots drink a lot of coffee, just like most of us to increase alertness due to the stimulant component in caffeine. However, what most people do not realize is that coffee tends to cause the body to release more liquid than it takes, and this eventually leads to dehydration, which subsequently then becomes fatigue. During long flights, food sometimes becomes an issue with pilots. Even with a nice 8-hour uninterrupted sleep, pilots may tend to find themselves tired and lethargic and may not even know why.
After a quick fix with a carbonated drink, for example, they might then notice their energy quickly improving, and all of a sudden, they might even start feeling better too. This situation is so most likely as they might have been hypoglycemic, with very low sugar levels running through the blood stream (Reinhart, 1992).This is another situation which causes fatigue, hence a healthy diet, just as recommended for everyone else is very advisable for all pilots, and they should be taking it more seriously considering the impact their jobs have on the lives of hundreds of people traveling on board with them.
In addition to this, the direction of the flight also makes a difference to the pilot and the fatigue level he experiences. In most cases, heading west is a simpler task and less strenuous than flying to the east, as you are traveling with the sun. It is also important to realize that a change in one’s circadian rhythm is the main reason for pilot error between 4:00am-6:00am on the pilot’s home rhythm (Bryman, 2000).
Preventions Against Fatigue
Of course one of the most important players in the airline industry is Federal Aviation Administration (FAA), and they should also shoulder some responsibility in enforcing the laws with regards to the code of conduct of airlines and their crew. Most importantly, law reinforcements needs to be in place for substances and activities that might lead to fatigue such as the use of alcohol, drugs and nicotine. Apart from the authorities, the persons involved themselves need to ensure that in most cases, common sense should prevail. They need to ensure that precautionary measures are taken to prevent fatigue, such as planning enough sleep, watching their diet and so on.
Although the aircraft itself might fail on us occasionally, it is more often that not the human component that is the cause of aviation accident. Medical conditions such as strokes, heart-attacks and seizures only account to 3% of such failures. Fatigue in pilots can be abridged or eradicated with easy and sensible measures on the part of the FAA, airlines and aircraft crew, especially the pilots. Carriers sometimes tend to get a little carried away with the scheduling for sufficient work force and more often than not fail to realize that the errors made by pilots as a result of fatigue is costlier than the cost of ensuring that their crew has enough rest before each flight. Studies by the FAA show that 70% of airplane accidents are caused by errors made by pilots.
Fatigue is often the grounds of pilot blunders and it is consequently the crucial link in the events leading to an mishap. 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. It is indeed common sense that preventing fatigue will be a cost advantage.
1. Bryman, D. (2000). The Human Component in General Aviation Accidents.
Retrieved November 17, 2007 from http://www.pilotfriend.com/safe/safety/human_and_accidents.htm
2. Caldwell, J.A. (1997). Fatigue in the Aviation Environment: An Overview of
the Causes and Effects As Well As Recommended Countermeasures, Aviat Space and Environ Med, 68, 932-8.
3. NTSB (1994). Safety Study: A Review of Flight Crew Involved, Major
Accidents of U.S. Air Carriers, Washington, D.C: NTSB
4. Reinhart, O. (1992). Basic Flight Physiology, Blue Ridge Summit: TAB
5. Strauss, S. Pilot Fatigue, Retrieved November 17, 2007 from