Aircraft accidents occur daily. Some are caused by mechanical malfunctions, but most accidents are caused by human error. Since the dawn of flight, technology has been consistently advancing, making flights safer and the aircraft more mechanically sound. From the mid 1970s, the rate of aviation accidents per flight hour have steadily decreased due to the high mechanical standards and inspections aircraft must pass. Unfortunately, aircraft accidents are still occurring and nearly 80% of them are because of human error. Human error can be the result of a variety of packages including fatigue, complacency, and different medical factors.
One of the major contributors to pilot error is fatigue. According to the Federal Aviation Administration, fatigue is defined as a condition characterized by increased discomfort with lessened capacity for work, reduced efficiency of accomplishment, loss of power or capacity to respond to stimulation, and is usually accompanied by a feeling of weariness or tiredness (G.J. Salazar). Pilot fatigue is the leading cause of pilot error in aviation and its consequences can often be disastrous for the crew and passengers onboard.
There are two main types of fatigue: peripheral (muscle) and central (mental) (Latman). Fatigue has many different symptoms that can endanger any flight. It decreases the pilot’s ability to carry out tasks. According to the FAA, studies have shown that there is a significant impairment in a person’s ability to carry out simple and complex tasks that require manual dexterity, concentration, and a high amount of intellectual processing (G.J. Salazar). Other symptoms of fatigue include sleepiness, apathy, the feeling of isolation, annoyance, slower reaction time decreased vigilance, memory problems, task fixation, and increased errors. Fatigue can develop over a short period of time or over a long period of time. Fatigue can occur in little time due to a large amount of physical assertion or concentration over a few minutes or hours. It can also occur due to continuous work over a period of days or weeks with very little rest.
The effects of pilot fatigue can result in pilots not taking proper precautions and not performing all necessary tasks to keep the flight safe. In 2007 there were two regional jet accidents that occurred due to fatigue. On April 12, 2007 a CRJ operated by Pinnacle ran off the departure end of Runway 28 at Cherry Capital Airport in Michigan. There were no injuries in this accident, but it could have been disastrous if there were obstacles at the end of the runway. According to the NTSB, the probable cause of the crash was determined to be the pilots’ decision to land without performing a landing distance assessment, which is a requirement of company policy because of the ground contamination reported by the ground crews. The poor decision making was a result of crew fatigue caused by a long work day with demanding duties, including duties associated with check airman functions (FAA, 2008). If the pilot were not fatigued, he most likely would have made the required calculations and determined that there was inadequate runway land with the current weather conditions. As shown in this example, the fatigue resulted in the pilot not following proper company procedures and an accident that could have been prevented.
Fatigue isn’t just limited to a physical condition; it can also be mental. Its causes can range from boredom to heavy physical exertion. For an average individual, fatigue is a minor inconvenience which can be fixed by taking a nap or relaxing from the person’s current activity. However, in aviation, fatigue can result in a disastrous accident involving the loss of life. One of the most recent accidents that occurred due to pilot fatigue was the Continental Connection accident that occurred outside of Buffalo in 2009.
In 2009, Continental Connection flight 3407 crashed in Buffalo, killing 50 people in the process. (Zremski, 2011) The crash occurred while the flight was on the approach to the Buffalo airport. The main cause of this deadly crash was pilot error due to pilot fatigue resulting in complacency and confusion (Stark, 2010). The crash occurred in wintery conditions at night. The aircraft lost lift due to icing, resulting in the stick-shaker activating and eventually the plane stalling and crashing to the ground short of the runway. The pilots of the flight were well trained and rehearsed install recovery procedures. The crew was also on the third flight of the day and had very little sleep the night before. This caused both peripheral and central fatigue which directly contributed to their slow reaction to the airplane’s stalling conditions (Zremski, 2011).
The crash of the Continental Connection flight renewed the push to create new regulations in the aviation industry to reduce fatigue and increase the safety of airlines. The new rules to reduce pilot fatigue are aimed to reduce human error involved in aviation accidents. The belief is that a well rested pilot will be able to function more efficiently in normal conditions as well as in an emergency situation. Analysts believe that they will be able to make better decisions in a more timely manner and that this will be able to save lives when an emergency occurs.
As shown in the previous examples, fatigue is a major issue in the aviation industry. It has been directly related to many accidents in the past. It is one of the biggest contributors to flight related accidents and the Federal Aviation Administration is looking to change this. In 2008, pilots were allowed to have a 14-hour workday, with 8 hours of logged flight time. With new regulations being placed, the FAA is looking to limit the workdays and reduce fatigue in pilots. (Association, Airline Pilots, 2008)
In 2011, the FAA issued a new rule on pilot fatigue, which would help limit pilot fatigue in the cockpit. The new rule is comprised of seven key parts including varying the flight and duty requirements based on the time the pilot’s day starts, flight duty lengths, flight time limits, rest periods, cumulative flight duty and time limits, fitness for duty, and fatigue risk management systems.
The new fatigue regulation will vary the flight and duty requirements based on what time the pilot’s day begins. The new rule takes into consideration scientific studies to set different requirements for flight time, duty period, and rest based on the time of day the pilots begin their first flight. It also includes the number of scheduled flight segments, and the number of time zones they cross. (FAA, 2011).
The new rules also alter the time that a pilot is considered “on-duty”. The time allowed for a flight duty period will depend on the time of day the pilot starts and the number of flight segments the pilot is expected to fly. The time ranges from 9-14 hours for single crew operations and begins when a flight crew member is required to report for duty until the aircraft is parked after the last flight. The duty period includes the time before a flight or between flights that a pilot is working without a rest period and includes the deadhead transportation, training in an aircraft, and acting as standby or reserve duty (FAA, 2011).
The new regulation limits a pilot’s flight time and creates a minimum rest period between shifts. The rule limits flight time to eight or nine hours depending on the pilot’s flight duty start time. Flight time is considered the time that the plane is moving under its own power before, during, or after a flight. The new regulation also sets a 10-hour minimum rest period prior to the flight duty period, which is an additional 2 hours more than the previous rules. The new regulation also includes a statement that a pilot must be able to get eight hours of uninterrupted sleep within that period (FAA, 2011).
The new rule also limits fatigue by placing weekly and 28-day limits on the amount of time a pilot may be assigned any type of flight duty. It places a 28-day and annual limits on flight time. The rule also requires that pilots have at least 30 hours of consecutive hours free from duty on a weekly basis.
The new regulation also requires pilots to report if they feel that they are not fit for duty. This includes pilot fatigue or illness. Before each flight segment, the new regulation also requires that a pilot to affirmatively state that he or she is fit for duty and if they report that they are not fit for duty, the airline must remove that pilot from duty immediately with no consequences to the pilot.
Automation complacency in the cockpit has become an ever-growing issue amongst pilots. With the constant development of new technology, it is no wonder that pilots have began to sit back, relax, and allow the computer fly the airplane while they simply observe. This results in the pilots losing the sharpness of their piloting skills, and sometimes even forgetting how to recover from simple abnormalities in flight. The result can often be fatal, as this section will demonstrate.
One of the most famous crashes occurred on August 31, 1983 over the former Soviet Union. Korean Airlines Flight 007 had departed Anchorage, Alaska and was enroute to Seoul, China. While the Boeing 747 was enroute, the airplane strayed several hundred miles into Soviet territory. Being as this was a very tense time in the Cold War, the soviets shot the plane out of the sky with a heat-seeking missile (NASA).
Upon departure from Anchorage, the flight crew received air traffic control instruction to follow the transoceanic route “R-20” from Anchorage to Seoul. The crew programmed the autopilot to follow the assigned route, and was on their way to Seoul. Or so they thought. When the crew initially engaged the autopilot he placed it in “heading” mode. This mode causes the airplane to fly towards a particular magnetic heading, as selected by the pilot. “Heading” mode is quite useful when initially setting up for an instruction or clearance, but rarely should be used for an entire flight. After the crew received their clearance to follow R-20 they programmed the waypoints along the route into the 747’s Inertial Navigation System (INS). The INS system analyzes the aircraft’s latitude and longitude in relation to the latitude and longitude of selected waypoints in order to navigate to them. When the autopilot is activated in “INS” mode and certain other criteria are met, the computer will guide the airplane along the correct route. The issue with this particular flight was that “INS” mode was not activated, and the airplane stayed in “heading” mode. While the airplane was in heading mode it followed a route that somewhat paralleled R-20, but slowly and steadily deviated from the actual desired route. The result was a fully loaded, civilian Boeing 747 operating some 200 miles inside Soviet Russia’s airspace. The Soviet’s believed that the airplane was actually an American spy plane and shot it down, killing all on board (NASA).
This accident is a clear example of automation complacency. The pilots had the resources available to them in the cockpit to clearly identify that they were not on their assigned route, yet they chose to trust the computer to lead them to their ultimate death. Had the crew been less reliant on the autopilot, they most likely would have noticed that they were not on the right route. Furthermore, if the pilots had been paying attention to their geographic location utilizing their INS, they would have realized that they were not actually flying over the waypoints that they entered, and were nearing dangerous territory.
A second example of automation complacency involves a Turkish Airlines flight in 2009. Flight TK-1951 involved a Boeing 737 that crash-landed over a mile short of runway 18R in Amsterdam (Dutch Safety Board). During approach, one of the aircraft’s onboard radio altimeters malfunctioned, causing it to read eight feet below the surface. The published approach procedure for the runway was to intercept the ILS eight miles from the runway. TK-1951, however, was being vectored to intercept the ILS closer to five and a half miles from the runway. Controllers never instructed the crew to descend, so this put them above the glide-slope upon interception. When the localizer was intercepted, the 737’s autothrottles automatically retarded. The crew assumed that this response was in order to intercept the glideslope that was currently below them. The aircraft was actually retarding the throttles as part of an automatic landing sequence due to the faulty radio altimeter, however (Hradecky, 2009). Once the airplane finally intercepted the glideslope, the throttles remained retarded, causing the airspeed to drop dangerously low. The aircraft ultimately stalled and crashed a mile short of the runway. The result was nine fatalities, 86 injuries, and a complete hull loss (Dutch Safety Board).
This crash could have been avoided had the flight crew recognized a variety of factors. First off, if the crew had been paying attention to their radio altimeter, they should have noticed that it was faulty and realized that the auto throttles were responding to an auto-land sequence rather than the glideslope. They also should have noticed their airspeed decreasing once they intercepted the glide slope and should have corrected accordingly. The airspeed indicator is one of the primary instruments that an instrument pilot is taught to include in their scan, and therefore, had the pilots not been complacent on the autopilot, they would have realized that they were rapidly approaching stall speed.
In each of these accidents it is clear that the crews became complacent with the automation capabilities of their aircraft. Furthermore, in each of these instances lives could have been saved if the pilots simply would have used their training instead of relying on the computers to make the correct move. To avoid future accidents related to automation complacency it is crucial that pilots are trained in the subject area and taught to always cross check their computers.
Medical factors in regard to the Aeromedical Perspective is the belief that they are simply the symptoms of a underlying physiological or mental condition such as fatigue, stress, or an illness. These few factors then our triggered by environmental conditions (Such as flying in an unpressurized aircraft at 12,000 feet). According to Reinhart, physiology affects nearly all areas of safe behavior. Thus determining whether or not the aircrew is medically airworthy. Ensuring that the aircrew is medically airworthy plays one of the most crucial roles in aviation safety, as well as performance. Checklists such as the I.M.S.A.F.E. (illness, medicine, stress, attitude, fatigue, eating) are precautions that must be taken to ensure safe air transportation. The pilot highlights a crucial role in safe performance as it allows for mistakes to be made, hazardous environment, risk-taking, and increased margin for human error. Along with common illnesses that we suffer on the ground other medical phenomenon’s such as hypoxia, hyperventilation, middle ear and sinus problems, spatial disorientation, motion sickness, carbon monoxide poisoning, and dehydration are all common once flying in the air. By learning about the symptoms and effects of these illnesses we can minimize the risk associated with these Aeromedical Factors.
One of the most common in-flight medical conditions is hypoxia, which in general terms means reduced oxygen to the brain. The four types of hypoxia are based on their respective causes. Hypoxic hypoxia is the result of insufficient oxygen available to the body as a whole. The most common cause for hypoxic hypoxia is flying too high without supplemental oxygen. Hypemic hypoxia occurs when the blood is not able to transport a sufficient amount of oxygen to the cell within the body. Two common cause of hypemic hypoxia would be carbon monoxide poisoning, and anemia. The third form of hypoxia is stagnant hypoxia, which means not flowing and is the result of an oxygen rich blood in the lungs not moving to the tissues that need it. A few causes of stagnant hypoxia would be shock, cold temperatures, and excessive g-forces. The fourth and final form of hypoxia is histotoxic hypoxia, which is the inability to distribute oxygen due to alcohol and drugs. When dealing with hypoxia it is important to understand that everyone has different symptoms and impaired judgment is inevitable with severe forms of hypoxia. Pilots should recognize the symptoms and descend to a lower altitude and use supplemental oxygen if available. The many symptoms of hypoxia include cyanosis, headache, decreased reaction time, impaired judgment, euphoria, visual impairment, drowsiness, tingling, and numbness.
Hyperventilation can be defined as the excessive rate and depth of respiration leading to abnormal loss of carbon dioxide from the blood. Understanding that symptoms are so similar to hypoxia, it is important to properly identify the correct medical condition. Any pilot who encounters an unexpected situation may increase their breathing rate without even realizing it. If flying at higher altitudes this will only add to the problem as it make pilots breathe more rapidly that normal. Some of the symptoms caused by hyperventilation include visual impairment, unconsciousness, dizziness, tingling, hot and cold sensations, and muscle spasms. A pilot must restore proper carbon dioxide level by breathing normally, breathing into a paper bag, and talking aloud. These techniques allow for higher levels of carbon dioxide to build up in the body.
A common medical factor associated with flying into IMC conditions is spatial disorientation, which specifically refers to the lack of orientation with regard to position, attitude, or movement of the airplane in space. Conflicting messages sent to the brain cause confusion, and the end result is spatial disorientation. Some symptoms of spatial disorientation include the leans, graveyard spiral, inverse illusion, false horizon, and autokinesis. In order to mitigate these symptoms rely on aircraft instruments, leave IMC as soon as possible, and do not make sudden head movements.
The last and final of the major Aeromedical Factors is fatigue. Fatigue could be the number one cause of mistakes made by pilots and aircrews around the world. No one other than yourself can decide if you are safe to fly or not, and fatigue could be the deciding factor whether or not your flight is made safely or not. Symptoms of fatigue include impaired judgment, forgetfulness, and stress. Corrective actions should be adequate rest, workload management, relaxation techniques, and relieve stressors.
In conclusion to aeromedical factors we as pilots must understand while most of our flight training is based on flying and operating the aircraft in different situations, we must not neglect the importance of aeromedical factors and how the safety of flight is directly related. For example, what should you do if you become lightheaded or dizzy at altitude? What do you do if you enter clouds and become disoriented? Or, you have had a stressful week at work and lack of sleep at night. Should you fly? Answering questions such as these are what keep us as pilot alive every time we decide to fly. Thus, Aeromedical factors should be the upmost importance to any pilot.
Training and Prevention
When it comes to human factors in aircraft accident analysis, pilot training and prevention are of the utmost important aspects. Training is the most efficient hands on way to get a pilot comfortable and proficient behind the flight controls. Also, practicing accident prevention significantly helps pilots and crewmembers become aware of the dangers involved with every flight. The area in which flight training and prevention are most critical would be in an emergency or unusual situation. Two particular accidents that have had a direct correlation with pilot training were the Air France 447 and the Colgan Air flight 3407 crashes. As we look into the training issues of these accidents, we can also evaluate how proper prevention practices could have saved the lives of many.
As we all know, pilot training requires many hours of studying and practice in order to become a well rounded and experienced pilot, but the main concern that has been evolving is if there is more that can be done in order to help keep the skies safe? Well according to Air France flight 447, the answer is yes. The catastrophic accident that killed 228 people on the way from Brazil to France on June 1, 2009 is considered one of the biggest killers in the aviation industry. The aircrafts speed sensors/pitot tubes froze up and caused the airspeed instruments to read incorrectly. Instead of flying straight and level, one pilot made an abrupt change in pitch attitude resulting in a climb. This was a critical error as the aircraft then entered an aerodynamic stall. Rather then executing a proper stall recovery, the pilots held back on the yoke, which kept them in a 7-mile stall all the way into the Atlantic Ocean (Learmount 2011). The pilots were simply not prepared, as they did not know how to react in the outcome of an emergency situation. Some may say pilot error is the concluding cause of the accident, but the investigation goes beyond that. The pilots are to do what they have been trained, and if the training in instrument failure or incorrect readings are weak, their reactions are going to be weak as well. As the USA Today report states, “stall training has been lacking for decades. Newer flight simulators can better teach airline pilots how planes respond in stalls, and their use should be dramatically increased.” Although this training is very costly to airlines, just as everything else is, the cost of putting pilots through better training will never surpass the cost of crashing numerous multi-million dollar jets. Cutting corners in flight training will only hurt the industry in the long run (Levin, 2011).
In a very similar occurrence, the crash of Colgan Air flight 3407 killed 50 people near Buffalo on February 12, 2009. The aircraft was on an ILS approach when the aircraft became slow. The pilots disregarded the stall warning systems and put the aircraft into a nose up attitude causing them to lose more airspeed and lift; in other words, an aerodynamic stall just as the Air France accident. Had the pilot pushed the nose down, as stall recovery requires, they may have been able to save the aircraft and the lives of many. This accident also raised many questions and concerns with pilot training and resilience. In the Flight Global article, a consultant states that the problem with loss of control accidents is caused by the training system. The consultant states, “the standard training template is set by pilot licensing and training regulations, which have not changed in their fundamentals since the 1950’s. In addition, pilot attitudes to their employment are conditioned by a relatively new phenomenon, a broad based Western airline withdrawal from accepting any part of the financial responsibility for the provision of a sustainable supply of quality pilots to fly their aircraft.” Anthony Petteford, from Oxford Aviation Academy states, ” this as a major influence both on the kind of applicants for pilot training, those with access to funds, and the output from the training industry, pilots saddled with stressful levels of debt (Learmount, 2011).
Seeing that clearly there are issues revolving around the training aspect of pilot’s and crewmembers on board airline flights, one can only wonder what preventative measures have been take or will be taken in order to reduce the number or training related accidents. Some solutions have come from ICAO and the International Air Transport Association, which are the next-generation aviation professionals (NGAP) and IATA’s training and qualification initiative (ITQI). These programs have been established to modernize pilot and maintenance training in order to improve effectiveness of qualification schemes and identify the means to improve industry attractiveness. Under these new training programs, their philosophy is to issue a license to “sufficiently competent,” individuals and base their skills from actual performance opposed to completion of exercises in an approved syllabus without actual mishaps (Learmount, 2011). Another solution has come from the FAA. A bill, which has been approved, will require 1,500 hours and an Air Transport Pilot certificate for all pilots flying for a passenger-carrying airline. By this bill going into effect, pilots are going to have a significantly higher amount of flight experience and training. The more comfortable pilots are before they hop in the right seat of a regional or major passenger air carrier, then the safer each flight is going to be. Preventing accidents is always going to be the number one priority from aviation authorities such as the FAA and ICAO. By moving in the right direction with safety training and prevention, the skies are going to be notably safer (Associated Press, 2009).
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