ABSTRACT

The aim of this paper is to observe the growing concern of pilot fatigue and the role it plays in aviation safety. A brief assessment of the effects and possible solution to this problem will be carried out. A mention of some of the incidents from the past will also find its place in this paper.

Introduction

                   Aviation industry is on a growing spree and in the times to come there are going to be more and more airlines filling the sky.

As we move steps further towards globalization we are going to need this service more frequently which further increases the pressure on our airlines. To tackle with this situation, especially when the availability of trained pilots is less than required, the pilots are forced to fly more frequently and for longer hours. This causes physical as well as mental stress to buildup as a result of which the efficiency of pilots decreases. This non-pathologic state resulting in physical and mental stress is known as ‘Fatigue’.

Human body is always in need of rest, especially in the form of sleep, after regular intervals of time. Any lack in the required rest causes fatigue to be developed in one’s body. Due to fatigue there can be a feeling of sleeplessness, tiredness or exhaustion in a person. This feeling if effective during flight hours can be really dangerous not only for the pilot but also for the lives of the passengers traveling with him and can cause accidents. The only solution to this problem that has been known so far and will ever be known in the times to come is sufficient amount of sleep. This unfortunately is what the pilots are not getting these days and are not expected to get at least in the near future.

                   The findings from the past have shown that fatigue was responsible for a large number of aviation accidents. According to a study carried out by the National Transportation Safety Board (NTSB) of flight accidents related to flight crew in US from 1978 to 1990, one of the findings related the accidents to fatigue by stating 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.” (Strauss, n.d.).

Sleep and Sleep Loss

                  It is essential for a human body to get the required amount of sleep. Sleep is considered to be an essential ingredient of our life without which it is not possible to survive. Whenever a person does not get enough sleep a signal is sent by brain to the body which results in Sleepiness. Eyelids start to get heavier and there is fatigue in the whole body. A person starts to loose concentration and may even go to sleep while he is on a job. If there is a deficiency in sleeping hours of a person and suppose every day a person looses 1 hour of sleep known as “Sleep Loss”, then it goes on accumulating over days and results in what is known as “Sleep Debt”.

This debt if not cleared can cause serious problems ultimately resulting in fatigue. It has been found in researches that before flying a plane it is necessary to have sufficient amount of sleep (about 8 hours) for the pilots. If they are allowed to fly continuously without getting the required amount of rest (or sleeping hours) in between their flying schedules, then fatigue is most likely to develop in them resulting in, loss of concentration, memory  and  alertness, slow reaction time, reduced decision power, and bad mood. All these factors are basic ingredients of making mistakes and thus causing accidents.

Crew rest

                   Fatigue starts to build up from the time one gets out of sleep. Development of fatigue also depends on the amount of time a person was awake before the actual flight operation. Some times there are delays in flight timings due to several reasons ranging from weather conditions to mechanical problems. This means that a pilot has been “on duty” for a long time before boarding in the plane.

Although he may be flying the plane for the normal length of time but delay in flight timing has resulted in him being involved in the activities for much longer, which also results in the pilot being fatigued. Similarly there may be a case of airport congestion as a result of which a pilot cannot land and has to hover in the air for a long time or due to bad whether the plane needs to be redirected to some other destination causing him to fly for longer duration than normal. These instances also cause fatigue to be developed. Overall the fact is that ample amount of rest is essentially required by the human body to keep it fit and fatigue free.

                    “A brief review of US Federal Aviation Administration (FAA) flight time and rest rules for scheduled domestic commercial carriers (US Code Title 14, part 121.471) are as follows” (Strauss, n.d.).:
Crewmember total flying time maximum of:

• 1000 hours in any calendar year.
• 100 hours in any calendar month.
• 30 hours in any 7 consecutive days.
• 8 hours between required rest periods.

Rest for scheduled flight during the 24 hours preceding the completion of any flight segment:

• 9 consecutive of hours rest for less than 8 hours scheduled flight time.
• 10 hours rest for 8 hours or more, but less than 9 hours scheduled flight time.
• 11 hours rest for 9 hours or more scheduled flight time.

Diet and nutrition

                   People all over the world use coffee as a stimulant to remain awake for longer periods of time. Same is the case with pilots. To remain alert they normally consume coffee. The problem with coffee is that although it keeps a person alert, it cannot prevent body from getting tired and thus fatigued. The body still is in working condition for all these hours and hence the effect of coffee is temporary alertness and not a solution to fatigue. Also coffee is diuretic which means that it discharges more fluids than what it takes in and hence results in dehydration which is a cause of fatigue. It is always good to keep your body fit by exercising but there should be a sufficient amount of rest and consumption of water followed by it as exercises cause a lot of dehydration.

However dehydration can also be caused by the fact that inside the cockpit humidity is very. There is always a balanced diet recommended for not only pilots but everyone. A pilot should always ensure a healthy diet which provides sufficient energy as well as nutrients for his body. Hypoglycemia, which is caused by low blood sugar levels, is a major cause of feeling sleepiness. A healthy diet ensures sufficient levels of blood sugar and thus energy, preventing hypoglycemia.

                   ‘Finally, alcohol is known to disrupt sleep dramatically and therefore contributes to the poor quantity and quality of sleep obtained on trip nights. Alternative approaches to the use of alcohol to unwind after duty and promote sleep should be identified and offered (e.g., relaxation skills)’ (Rosekind, 1994).

Other causes of fatigue

                One of the most important factors of causing fatigue, other than sleep debt, is the flight deck environment. Inside the deck there are a lot of factors contributing to fatigue such as lesser availability of space, variation in air flow, low atmospheric pressure, low humidity and presence of a lot of noise and vibration. Also in modern aircrafts a number of additional features and systems have been incorporated which means that the pilots have to handle multiple systems resulting in more stress.

History of incidents

There have been incidents in the past where fatigue has proved to not only be dangerous but also fatal. A legend in aviation refers to an incident when a pilot went to sleep with his autopilot on and found on waking up that the plane was 2 hours from the nearest destination with only one hour of fuel left. This may just be a story but in many cases researches have proved fatigue to be a cause of dangerous and fatal accidents. Some of the cases have been listed below:-

• In June 1999 there was a runway accident of American Airlines Flight 1420 in which 11 people died, including the aircraft captain, and many injuries among the 145 passengers and crew aboard the flight
• KAL Flight 801 crashed in Guam on August 6, 1997, was mainly due to a lack of situational awareness resulting in “controlled flight into terrain (CFIT).” The captain prior to flying to Guam had flown from Seoul to Australia, back to Seoul, to Hong Kong, and then back to Seoul again before his fateful trip to Guam, including only a few hours of rest in between.
• Cessna 177B Cardinal was flown by Joe Reid, pilot-in-command in which he, seven-year-old Jessica Dubroff and her father were killed. He suffered fatigue from the first day’s flight.
• 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.
• ‘On January 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 groove. 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’ (Printup, 2000).
• In August 1985, the crew of a Learjet killed themselves and their passenger in a failed 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 inducing fatigue (Printup, 2000).

Countermeasures

Based on several reports a number of countermeasures have been devised to improve alertness to counter fatigue. Preventive measures like 3-4 hours of sleep can restore alertness for 12-15 hours and 10-30 minutes of sleep can do it for about 3-4 hours. Similarly it is advised to rest for 15-20 minutes after awakening and before flying.

Some of other means to restore alertness are:-

• Consumption of high protein diet and less intake of fat and high carbohydrate food.
• Consumption of large quantities of fluids.
• Use of caffeine to work against fatigue symptoms if awake for 18 hours or less.
• Due rotation of flight tasks and frequent conversation with other crewmembers
• Maintenance of temperature inside the deck to lower levels.
• Frequent movement of body parts and a possible walk in the cabin.
• Gradually shift times for sleep, meals, and exercise to adjust to a new time zone (Strauss, n.d.).

Conclusion

For the safety of pilots as well as passengers the issue of pilot fatigue is of major concern. Growing number of aircrafts in the sky also means longer durations of flight for the pilots, which is a major cause of this problem. History bears the testimony to the fact that fatigue has resulted in numerous aviation accidents resulting in the loss of thousand of lives. To save more lives from getting lost there is a need to solve this problem. Allowing flexible schedules for the pilots is the only viable solution in sight at the moment. Our lives are getting busier and it would be wonderful if they become safer as well.

References

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Dr Samuel Strauss. (n.d.). Pilot Fatigue. Retrieved December 1, 2007, from http://aeromedical.org/Articles/Pilot_Fatigue.html

Goode, Jeffrey H. (27 March 2003). Are pilots at risk of accidents due to fatigue?. Retrieved December 1, 2007, from https://monkessays.com/write-my-essay/eurocockpit.be/media/Goode-2003.pdf

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Rosekind, Mark R. (November 1994). Fatigue in Aviation. Retrieved December 1, 2007, from http://cf.alpa.org/internet/projects/ftdt/alpmag/FATIGUE.html

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