Nowadays there are a lot of international airline companies that provide intercontinental air transport services. Often, the duration of such intercontinental flights may be as long as 12 hours or more, such as international ultra long-haul flights. Therefore, many aviation experts as well as airline customers are concerned whether these flights are simple to handle, and whether flight crews take effective measures to handle them. There are long flights in every airline company nowadays. Therefore, the subject was selected to have a better knowledge and understanding for investigation purpose. Thus, writing a report and researching will be valuable especially involving aircrafts and long flights. This project will have a lot of benefits such as increasing the knowledge and helping to understand the topic, the aspects of long flights and their effects on the flight crew. In addition, this project will help teachers, students, pilots, aircraft institutes and everyone who has interest in the subject. The main argument for this research is that long hour flights produce negative and cumulative effects on the flight crew, such as stress, fatigue, problems with sleeping, hearing and decision-making, which are believed to be the leading causes of airplane crashes.
Most of airline transportations cover short or medium distances that last up to 3 hours and up to 6 hours respectively and usually provide services for domestic flights. However, international flights that get to other continents are mostly long hour flights, also known as long-haul flights, and they last for 7 hours and more. For instance, flights from Americas to Asia are always long hour flights because of the long travel distance. During long hour flights, planes, especially smaller airplanes, might make stops to refuel (McMahon 2015). Flights that take more than 12 hours to reach their destination are called ultra long-haul flights. The longest ultra long flights are always between continents. For example, the flight from New York to Singapore took 19 hours long. However, it was terminated because airplanes needed too much fuel to make such trip. When more fuel is on board, the plane gets heavier, and consumes even more fuel per kilometre. Currently, the longest flight is Dallas to Sydney, which is 17 hours (Richard 2014).
For travellers and the flight crew, a long hour flight can be exhausting, and most airlines recognize that fact. For passengers, there are a lot of things for entertainment so that they would not feel bored. They can watch movies, listen to music, as well as take different things with them, such as books, newspapers, computers or a sleep mask. Sitting for a time during a long hour flight may cause discomfort, so passengers should also stretch their legs from time to time. Another problem for passengers is a change in the state of organism due to changes of time zones. This effect is called jet lag.
For flight crew, there are also difficulties and stresses in a long hour flight. They also experience the same troubles as untrained people, and, in addition, they have to handle passengers. The flight crew has a space where they can rest, and there are different shifts, so the members of the crew can change one another and get less tired. However, there are still various physiological and psychological effects on the personnel during long-haul flights.
Even though the human organism is able to adjust to various strong external changes, during flights, such compensatory mechanisms are exposed to a great deal of stress. The strongest physiological effects on human body during flights include changes in barometric pressure, changes of temperature, and fast movement in three dimensions. Additional challenges to the organism may be adjusting to the effects of acceleration on the body, poor visibility, and as a result, possible disorientation. People are not able to fly airplanes at their full capacity, so they have to use different physical support systems. These include, for instance, an additional supply of oxygen and pressurized cabins to be used at heights of 3 km (Federal Aviation Administration n.d.).
Flying in different divisions of atmosphere can have significant effects on human physiology. Flying at altitudes below 3.8 km is not dangerous in general. However, during long hour flights, the flight crew can experience minor trapped gas problems (ears, sinus, and GI tract) while flying in the lower region of this zone or being short of breath, dizziness, headaches and fatigue while flying in the upper region of this zone (Federal Aviation Administration n.d.). Another physiological problem related to the decreasing atmospheric pressure is a decompression sickness (DCS). It can result in nitrogen bubbles inside the body at high altitudes. The risk of DCS becomes significantly greater during long hour flights at altitude above 5.5 km (Federal Aviation Administration n.d.).
Another serious problem for the flight crew is the noise in a cockpit during the flight. Aircrafts that make long hour flights are generally big and create a high level of noise from carburettors or turbulence. A prolonged exposure to such noises can cause hearing problems. Most of pilots who make regular long hour flights have a moderate loss of hearing. Many of the flight personnel say that they feel an increased level of fatigue after making a particularly noisy trip. Some even may lose hearing for a short period after such flights. While being in the air, high level of noise may create problems for pilots to understand commands from flight operations officers. This problem is serious because loud noises are very harmful when they affect the flight crew during a long period. According to the Occupational Safety and Health Act, workers must not work in harmful and noisy conditions more than 8 hours a day. However, during a long hour flight, especially during an ultra long-haul flight, there is not much the flight crew can do to avoid the effects of loud damaging noises in such aircrafts as “all propeller driven, fixed-wing aircraft and all helicopters” (Federal Aviation Administration n.d.). Of course, aviation engineers design different protection systems for the crew, but it is not enough to keep pilots from being affected. One of the reasons for it is that the harmful effects of loud noise are greater for pilots than for other crew members or passengers because the pilots are more mentally active. Passengers are relaxing during the flight, and even the crew can have some short periods of rest, whereas pilots in command cannot relax during the flight. For this reason the noise has more serious effects on them, both physiologically and psychologically (Federal Aviation Administration n.d.).
During long hour flights, the flight crew, especially pilots, spend most of their time sitting in one position. They do not have many opportunities to move around. Such state of immobility may result in a deep vein thrombosis (DVT), which creates blood clots in veins in legs and other body parts. Clots can move to the lungs and create breathing problems or even a heart attack. There is a higher chance of DVT when the crew members do not drink enough water or there is a lack of oxygen in the cockpit. According to aviation studies, people are more likely to have a DVT on a long hour flight than anywhere else. The risk becomes much higher when the duration of the flight is more than four hours, and it becomes extremely high on flights longer than eight hours (Lavelle 2009). Due to this condition, the flight crew has to go through regular medical check-ups because DVT is dangerous for people with blood disorders and for obese people.
Hypoxia. Hypoxia is one of the most severe physiological problems that may happen to the flight crew during a long hour flight. It is characterized by the lack of oxygen in the organism that may lead to problems in different organs of the human body, including the brain. There are reasons that may cause hypoxia and prevent the organism from getting the amount of oxygen needed for its proper functioning. The danger of hypoxia is that only an observer can properly identify it in another person. People suffering from this condition often cannot identify it in themselves. In addition, its symptoms are individual and can vary from person to person. In general, people who experience hypoxia will show such signs as fast breathing, cyanosis (a state when the skin turns blue), bad coordination and lethargy. It may cause air hunger, fatigue, nausea, pain in the head and the body, dizziness, feelings hot and cold, itchiness, visual problems, poor judgment and euphoria. However, every person experiences these symptoms in a different way, and in every other person they may be less or more severe. The positive side is that hypoxia symptoms remain the same for an individual over the years. This is very helpful for experienced pilots as they would always know if they have hypoxia (Federal Aviation Administration n.d.).
The risk of hypoxia changes with altitude and duration of a flight. The aviation health experts state that the effects of hypoxia are cumulative. This means that this condition becomes more intense on high altitudes and during long hour flights (Av Med 2011). Therefore, the flight crew that travels on intercontinental flights takes different preventive measures that help them avoid hypoxia. These measures include flying at altitudes where oxygen is not required, flying in pressurized cabins, and following the rules of Federal Aviation Regulations (flying at 3.8 – 4.2 km for no more than 30 minutes) (Federal Aviation Administration n.d.).
Long hour flights have different effects on mental health of the flight crew. The major reason for psychological difficulties during such flights is the growing level of fatigue. Psychological health of the flight crew is influences by such aspects as physiological sleepiness, reduced sleep, irregular working hours and flying through many time zones. Fatigue or exhaustion is characterized by both physical and psychological state of being tired and weak. While physiological fatigue is well-understood, psychological fatigue is a little difficult to define. Although fatigue can be measured through various tests, it does not necessarily result from long hour flights, lack of rest and poor sleep. For instance, pilots that do the same task in the same circumstances may not suffer from fatigue. According to the study on long-haul flights made by Airbus Industrie, differences in fatigue levels depend on “day-night, daylight-darkness, heat-cold and work-rest cycles” (Sparaco 1996).
Don't waste your time on boring tasks!
Save your time for something pleasant!
Another significant factor is human psychological stress, which is considered the main problem of aviation safety. High levels of flight crew stress reduce job performance and increase the risk of “pilot error” (Chong 2001). Work stress is a serious problem in long hour flights because its effects are cumulative. For example, if the pilot cannot cope with stress appropriately during a long flight, its effects reach an extreme level. High level of stress does not let pilots make effective decisions during the flight (Federal Aviation Administration 2009). Many other types of stress influence crew members and pilots in particular in the air. They include the effects of hunger and thirst, lack of sleep and discomfort from sitting still for many hours in a row (Burrows 1957).
Pilot’s health can be characterized as not only an absence of disease, but also a complete physical and mental fitness, which includes absence of stress and fatigue. For a common person, fatigue may seem a minor inconvenience, but for pilots who work on long hour flights, the results of fatigue can lead to disasters. Aviation safety experts state that sleep loss and tiredness have a direct effect on the crew members’ general performance. Fatigue can lead to the lack of concentration, slow reactions, disorientation, illusions and confusion of information on the flying equipment. Pilots who have fatigue may not complete all needed procedures and routines and have problems with decision-making. Pilots and other flight crew members can suffer from the lack of attention at the same time. For example, two pilots who do similar or synchronized tasks may become less attentive because of the monotony of work (Sparaco 1996).
A usual working day of a flight attendant starts with a 15-minute briefing at the airport, where they and other members determine their working positions and tasks. They also pass tests on actions in case of emergency and on medicine knowledge. They also receive specific information about the flight and its security. Due to the regularly changing crews, it is hard to create stable and long working relations (Partridge & Goodman 2007). Such relations are very important for crew members during long hour flights. However, modern flight attendants have high quality training for their job duties. The main task of flight attendants is the safety of passengers during the flight. It is the most important thing for them, and passenger service comes second (Baron 2014). For this reason, flight attendants have to be fit for their work, free of stress and fatigue.
However, monotony of the work of flight attendants can reduce their attentiveness, which is directly influenced by repetitive sensory stimulation, a limited visual field and body movements, rare social communication, temperature in the aircraft, and lack of lighting. As studies show, the level of wakefulness and the heart rate of flight attendants decrease and the blood pressure drops due to their monotonous routine life. During long hour flights, such monotony becomes extreme, causing stress and severe fatigue (Sparaco 1996).
During long hour flights, people travel through several time zones, and for many of them such changes have negative effects on their organisms. Different statistical studies in long hour flights have discovered that the majority of people who travel through several time zones experience a ‘jet lag’ effect. It is a condition that results from a phase shift of their ‘head clock’ or ‘stomach clock’ and makes the body confused. People suffering from jet lag experience various types of discomfort for a few days, up to 10-12 days after transatlantic flights. They may feel hungry and sleepy, or wake up at the wrong time regarding the new local time. These effects become stronger when the number of time zones people cross into increases. When a person flies through 12 time zones, his or her usual cycle of day and night changes, which leads to a complete reversal of the day-night cycle, which disorients the person, causes severe fatigue and even some health problems. Some passengers adapt easier when traveling east and others when traveling west. Some people cannot adapt completely until they return home, but there is a small share of people whom jet lag does not affect at all.
Difficulties in adapting to the changes of time zones are particularly hard for the airline crew members that make long hour flights. Flight crews fly through a number of time zones many times back and forth. They often have several flights a month, and frequent shifts in their day-night cycle are reported to cause fatigue (Federal Aviation Administration n.d.). In addition, according to the research by psychologists of University of California, chronic jet lag changes the brain, causing memory and learning problems even long after return to a regular cycle (Sanders 2010). This problem is recognized by pilot associations and medical experts. Therefore, airlines try to limit the amount of such long hour flight for their personnel.
There is no single treatment to reduce fatigue. Every measure should focus on reducing its particular causes. Methods that aim at reducing fatigue include measuring the flight crew’s workload, attentiveness, amount of sleep and sleeping habits, jet lag effects as well lifestyle when not in flight. Based on these aspects, the recommendations that can help reduce fatigue include avoiding adapting to local time and keeping the home time instead. Additionally, the flight crew should follow their usual day cycle routine, such as sleep and meals (Sparaco 1996).
Fatigue can be reduced by taking different medication or other stimulants. It is common for flight crew members to drink coffee or tea as they have caffeine that helps them remain active and does not have side effects. Some pilots take caffeine pills to increase attention, especially if a long hour flight occurs at night. In order to help with sleeping problems resulting from jet lags, flight staff may take sleeping pills, which are effective and not harmful for the organism. However, as with any drug, they should not abuse these medications. Another useful way of coping with jet lag is to take medications that include melatonin. It is a hormone that the body produces at night, and its intake can help to adapt the crew members’ biological clock to a new sleeping schedule (Sparaco 1996).
One of the major concerns of flight safety experts is to find out how fatigue of the flight crew caused incidents and accidents. Most airlines, aviation experts, human resource management teams, universities, research agencies, aviation engineers and manufacturers are becoming more interested in reducing all the factors that cause fatigue so that they can improve aviation safety (Sparaco 1996).
According to David F. Dinges, the director and professor of psychology at the Psychiatry University of Pennsylvania, “Inattention and fatigue are major causes for catastrophes” (Sparaco 1996). Since modern airplanes are equipped with complex automated systems, the flight crew should only monitor the equipment, detect any potential dangers and solve them when needed. However, lack of attentiveness still is the leading cause of accidents and incidents (Sparaco 1996). Fatigue greatly decreases the flight crew’s performance, and the condition of fatigue can be compared to the influence of alcohol. Studies show that the amount of aircraft crashes increases when pilots make frequent long hour flights. The threat of crash increases in many times when a pilot makes a flight of 12 hours or more. According to the US National Transportation Safety Board (NTSB), which studied the aircraft crashes between 1978 and 1990, a half of the crew captains had been working for over 12 hours (Accident cause: pilot fatigue n.d.).
Stress is another leading cause of aircraft accidents. Pilots under stress become more distracted from their routine tasks and less attentive to details, such as information on flight machines. They think about problems that are not important or not related to their work, make poor decisions and technical errors more often, and lack situational awareness. Numerous aircraft crashes occurred due to pilots’ inability to cope with stress. For instance, the 1972 crash of Eastern 401 occurred because the flight crew got distracted by a minor problem with the landing equipment. The crew became inattentive and upset because the landing gear was not functioning properly, although it turned out to be a not working landing gear indicator. As a result, they failed to pay attention to a more important task while actually flying the airplane, and 99 people died in this preventable crash (Homan 2002).
Another example is the accident of two B-747s in 1977. The pilot, who was under great stress, thought he was allowed to take off and thus crashed into another airplane at the runway. Due to his error, which resulted from the effects of stress, 583 people died. This case proves that even the most experienced flight crew members may make bad decision when they are not absolutely mentally and physically healthy and fit (Homan 2002).
There are a lot of objectives that should be reached from this project. One of them is that it will increase general knowledge and thus help a lot of people who are involved in this field. The aviation field is concerned with different aspects of safety, especially those relating to well-being of the flight crew. Therefore, the objective of this research is to provide answers to the questions about human resources’ health and its effect on flight performance and routine tasks. The report focuses on the disadvantages of flying for long hours and analyses its pros and cons. The results of this project will help to improve aviation safety and increase awareness of the threats of long-haul flights. These results can be of use for various groups of people related to the aviation industry, such as pilots, flight attendants, aircraft technicians, and aviation students.
Long hour flights, also known as long-haul flights, last for 7 hours and more. Some of them may even take from 12 hours and to 19 hours. During all that time, the flight crew needs to always stay focused and attentive when handling with aircraft controls. However, human organism is not adapted to long-distance air travels and prolonged work at the peak of its activity. Therefore, the crew members of long hour flights experience a wide range of harmful effects. These negative effects are the major causes of aircraft incidents and accidents. These effects can result from the flight crew’s exhaustion and inability to move a lot, from changes of time zones, or the ‘jet lag.’ These and other factors lead to various physiological and psychological problems in the aircraft personnel during the long-haul flights.
The physiological effects of flights include changes in barometric pressure, changes of temperature, fast movement in three dimensions, effects of acceleration on the body, poor visibility, and as a result, possible disorientation. One of the strongest problems is the lack of oxygen supply to the body, or hypoxia. It can cause shortness of breath, dizziness, and headaches. Another serious problem is deep vein thrombosis, which results from immobility of the flight crew members. DVT creates blood clots, which can cause breathing problems or even a heart attack. In addition, high levels of noise on the aircraft can also have negative effects during long hour flights.
The two most dangerous psychological effects are fatigue and stress. Fatigue is the leading reason of performance problems in pilots and flight attendants. It becomes more severe if the crew lacks sleep, has irregular working hours and flies through many time zones. Fatigue is one of the leading causes of aircraft crashes as about half of all accidents occur in cases when the crew captains work for over 12 hours. Stress is also a very dangerous factor, which increases over time during long hour flights, reduces job performance and increases the risk of “pilot errors.”
Measures for combating stress and fatigue include methods to reduce the flight crew’s workload and jet lag effect, increase attentiveness and amount of sleep, and improve sleeping habits. Additionally, such negative effects as fatigue and stress can be decreased by using different medication or other stimulants, such as coffee, tea, caffeine pills and others.