Safety System in Aviation

Air travel has evolved to become one of the most commonly used modes of transport in the world. Different people have had different experiences; some positive others unpleasant, even fatal. Although still regarded, albeit statistically, as the safest mode of transport, several aviation accidents some with very high levels of fatalities have been witnessed. It has been a norm to rigorously analyse any airline accident so as to understand its potential cause and to prevent future similar occurrences. As noted by Taneja, (2002), the Boeing company reports that, with a statistic of 56%, the most common cause of air travel accidents involving commercial jet fleet is flight crew related, seconded by mechanical faults of the airplane at 17%, weather 13%, undetermined 6%, maintenance 4% and faults of the airport or air traffic controls 4%. At around 9. 16 Eastern American Standard Time on the 12th, November 2001 an American Airlines flight 587 Airbus A300-600 crashed into a residential area of Belle Harbour in New York City. This occurred minutes after takeoff from the John F. Kennedy (JFK) International Airport. The aircraft had left for Santo Domingo’s Las Americas International Airport. The accident killed all the 251 passengers, the 2 crew members and the 7 flight attendants on board and an additional five people on the ground. The plane was also badly damaged as a result of post crash fire. This aircraft crash occurred just two months after the New York City’s terror ist attacks, in which coincidentally, two American Airline planes had been involved and only 12 miles from the location of the New York terrorist attack site. The impact of the crash particularly elicited fear and suspicion from the American people who suspected potential terrorists attack. Aircraft details To better apply an analysis, it is imperative to understand the aircraft specifications. As released by the American Airline, the plane was an Airbus Industry, A300-600R manufactured in France with the registration (Tail number) N14053. The plane had a capacity of 251 seats all of which were occupied at the time of crash with a crew of 2 pilots and 9 flight attendants. The plane was powered by General Electronic Turbofan Engines (Two in number) and had had the latest maintenance check on the day preceding the crash (on the 11th, November, 2001. ) The flight also operated under the provisions of code 14 part 121 of the American Federal Government’s regulations and had an instrument flight rules fight plans, Air Safe, (2008). The Accident The National Transport Safety Board, (NTSB), the official investigators into the crash estimates that the time between the flight’s liftoff from the runaway in JFK international airport and ground impact was 103 seconds. National Transport Safety Board’s investigations indicate that, the aircraft crashed as a result of its rudder and vertical stabilizer separation from the airframe during flight. It asserts that following the departure of a Japanese Airline’s Boeing 747 just minutes ahead of the Airbus (the Flight Data Recorder indicated that the flight was about 105 seconds from the Japanese Airlines 747, NTSB, 2008), the plane experienced two instances of turbulence due to vortex encounter. The two planes had a separation of five miles at the time of the encounter. The vertical fin and one of the two engines of the aircraft had broken up landing away from the main impact site. The rudder and the vertical stabilizer were recovered at the Jamaican Bay, approximately one kilometre from the location of the main plane wreckage, while one of the plane’s engines, which also separated was recovered at a distance, several blocks from the main wreckage. Reports by NSTB indicates that following the effects of the larger aircraft’s (Japanese Airlines Boeing 747) motion, the area in which the Airbus took off was of very turbulent air. As the first officer tried to maintain the plane in an upright position by implementing aggressive rudder inputs, the turbulent air compromised the craft’s vertical stability making it to entirely snap. This made the aircraft to loose control and subsequently crash. The official cause of the accident as reported by the NTSB, therefore, was the excessive use of rudder to counter wake turbulence by the first officer, Condit, (2003). With the official cause of the accident established, the aircraft manufacturer, air control pilots and the airline had a share of shortcomings that resulted into the crash. The American authorities through the NTSB have stated that the Airbus model that crashed had an oversensitive rudder control system. The amount of ruder control witnessed from the data retrieved from the Flight Data recorder had resulted from increased pressure on the rudder pedals of the aircraft which were hazardous owing to the speed of the aircraft at that time. The plane manufacturer, Airbus however, blamed the Airline citing inadequacy in pilot training based on the fact that the pilots lacked adequate information on the characteristics of the rudder and assumed that the aircraft tail could withstand rudder deflections in either direction at high maneuvering speed, CNN, (2002). Other investigators suspected the accident as having occurred as a result of engine failure. The NSTB conclusion was based on the retrievals of the flight data recorder FDR from the ill fated plane. The FDR had recorded large ruder multidirectional movements signifying intense turbulence. According to Air Safe, (2008), there were two probable causes of the air crash; the flight crew inappropriate action on the rudder and the rudder system malfunctioning. During the investigation, the NTSB started by evaluating the accelerations preceding the crash, angular motions, cockpit displays, visual cues and flight control motions based on simulations of what could have occurred during the accident. This was followed by the evaluation of the probable flight control characteristics as certain inherent factors such as pilot perception and performance could have contributed to the crash. Tran,& Hernandez (2004) further ascertain that as part of the investigation undertaken by the National Transport Safety board (NSTB) in collaboration with NASA Ames Research Centre, onto the American Airlines Flight 587 crash, Vertical Motion Stimulators were used to in creating simulations of the original accident. The process involved evaluation of the possible acceleration experiences during the accident by; back-driving the retrieved cockpit control displays, out of the window scene, cockpit communications and both the Flight Data Recorder and Cockpit Voice recorder retrievals. System Safety From the synopsis, it is imperative to note that there were full rudder deflections on both sides which made the plane to loose its balance leading to the crash. Although most transport airplanes are equipped with rudder limiter systems to limit deflections at high airspeed and the possibilities of structural overloads, the limiters should be a safety concern as they limit the pilot’s perception especially when the structural capabilities of an aircraft are constrained. A full deflection on one side followed by a similar deflection on the other side on an aircraft with rudder limiter systems may be an indication of structural loads far exceeding the capability of the aircraft Air Safe, (2008). Noteworthy, all systems have documented problem areas which often leads to severe malfunctioning, some of which are fatal. Some of the system safety problem areas include Standardization, risk assessment codes, software in use, human factors, the life cycle of a system, communication between stakeholders and the availability of data. Lack of Standardization could have been a potential cause of the Flight 578 crash. Lacking safety standard regulations could have led to the overlook of certain critical safety issues leading to the crash. The Airbus rudder was also not standardized. Standardization in the aeroplane part manufacture is lacking as different aircraft manufactures design the rudders for specific aeroplanes. The Planes rudders were oversensitive, making the first attendant to apply unnecessary pressure on the control leading to the crash. Had the rudders been standardized, the pilots even with minimal training could have known the appropriate measures to counter the turbulence, Tran, & Hernandez, (2004). Undoubtedly, the turbulence resulting from the preceding Japanese Airlines flight contributed to the fatal crash. This implies that probably the severity of such effects had not been correctly analysed during risk assessment. If they had been, then its effects had not been properly estimated. To avoid future accidents, stakeholders in the aviation industry should develop effective time separation between flights taking off and those leaving the airport. This can be made possible via the implementation of valid and reliable Risk Assessment Codes built upon valid data with the involvement of all the major stakeholders so as to minimize errors. Reports by the American Airlines indicate that the plane had been maintained a day prior to the crash. All airplanes should be properly checked using the MIL STD Standard 882 before being operational and using MORT to investigate, the operational cycle of the system. The complexity of an aviation system may make determination of errors elusive. Proper and consistent maintenance are a key to ensuring aviation safety and minimization of aviation accidents. The plane could have as well crashed as a result of engine failure or electric fault, an indication that proper maintenance was not undertaken prior to the flight. Human factors are the largest contributor to civil aviation accidents. It is reported that human error are the cause of 70-80% of all aviation accidents, (Taneja, 2002), 56% Boeing (2000). These factors include; inadequate crew resource management, distraction of the cockpit, cockpit indiscipline, fatigue and communication errors. The American Airlines Flight 587, primarily crashed as a result of misjudgement of the first attendant. It is therefore important to understand human factors in aircraft accidents for effective accident prevention, Taneja, (2002). Noteworthy, the extent to which human error leads to aviation accidents is still not properly understood. Proper understanding of human factors would enable safety investigators and implementers to offer recommendations and intervening strategies that could prevent future accidents. Some of the important errors resulting from human failure include; poor distance estimation, non adherence to instructions and perfunctory manner of operation. Flight 587 crashed mainly due to the first assistant’s overestimation of turbulence and the subsequent improper use of the rudders, Tran, & Hernandez, (2004). As a safety precaution, airline designers and manufactures should ensure that critical aspects such as effects of turbulence, critical distances, clearances and speeds are properly indicated on the system so as not to leave such important aspects to human intuition or guess. Instructions on the use of various components of an aircraft should also be short, clear and to the point as most people rarely read labels or instructions, critical to both the system’s and their personal safety. Furthermore, most technical personnel such as Flight engineers, aeronautical engineers, the flight control personnel and even system safety engineers and managers are lacking in system safety education and training. Proper education and training should be given to these personnel to minimize the possibilities of any future accidents. Although the crash of flight 587 is primarily attributable to human error, other factors owing to improperly managed systems could have been the cause of the accident. Consistent and well formulated system identification and analysis would certainly lead to improved aeroplane safety thereby minimizing aviation accidents. Ignoring accidents and aviation strategies would lead to accidents with repeated faults as commonly experienced, Condit, (2003). Ensuring safety of any airplane should be a step by step undertaking. Safety requirements should be adhered to from the time of conception until disposal. The life cycle of an airplane like any other system can be divided into five phases; the concept design, production, operations and the disposal phase. Safety precautions are critical in every stage to ensure safety and minimize financial losses. At the concept phase; a critical phase in the life cycle of an airplane, guided by the general and the specific objectives, a detailed description of the product detailing all the necessary requirements should be documented. Preliminary Hazard List (PHL) which assists in the assessment of possible hazards, time needed to develop the plane and all the necessary requirements for the success of the project should be applied during this stage. The design phase is key to the success of any airplane in terms of security and safety. All safety requirements and the governmental regulations should be adhered to. The design should be logical leading to the development of specific plans, drawings and specifications. At this stage, the Preliminary Hazard Analysis (PHA), Subsystem Hazard Analysis PHA, System Hazard Analysis (SHA) and Operational Hazard Analysis (OHA) should all be undertaken to ensure the implementation of proper designs. All these analysis would ensure proper identification of hazards not detected at the conception phase and additionally offer recommendations on possible control mechanisms of these hazards. All safety regulation pertaining to proper development of the end product should be adhered to minimize aviation accidents in the production phase. During this stage both the Operating System Analysis (OHA) and the Change Analysis are initiated. These serve to analyze potential threats during the operation of the system. At the operations phase; critical safety requirements such as regular mainten ance and checkups should be adhered to. This is to determine and correct any faults that would compromise the operation of an aircraft. Accident Analysis and change analysis should all be considered to minimize the possibilities of any aeroplane system malfunctioning. The disposal phase is an equally important phase. GAO, (2007), notes that most aeroplane owners, both individuals and companies, fail to know when to dispose of worn out or malfunctioned aircraft. This has led to an increment in aeroplane disasters; especially in the developing world, as worn out aeroplanes are still in use. OHA would aid in the determination of proper life cycle of the aircraft thereby assisting in the determination of when to properly dispose off the aircraft. To reduce the number of aviation accidents experienced, hazards must be identified and level of safety improved. Governments and airline industry officials must be proactive by anticipating possible accident causes rather than react to aviation accidents which are in most cases, quite devastating. Proper guidance coupled with research and instructional materials on cases of aviation accidents should be provided to the pilots and aviation professionals so as to minimize the possibilities of recurrence of such incidents. Proper and continued maintenance of the aircraft by the use of system safety products; the SSPP, PHL, PHA, HTL, SSHA, SHA, OHA and CAR through all the five stages of its life cycle could have possibly prevented the occurrence of this particular accident. Furthermore, adoption of risk assessment methodologies into the operations of the airline could have set standards that would have limited the possibility of the accident occurring. Furthermore, the data problem can be overcome via the consultations of and access to information in aviation data banks where past aviation accidents records can be accessed. Though speculative, Flight 587 accident could also be attributed to ignorance of similar prior experiences. A critical study and implementation of accident analysis reports of similar occurrences would have been handy in preventing the accident. The implementation of the recommendations of accident's Analysis reports could further offer insight into the real cause of the accident causing the prevention of any future accidents. The execution of fault tree analysis during the maintenance of the American Airline involved in the accident could have possibly reduced the chances of the accident occurring. This is because Fault tree analysis; through the application of deductive logic, analyses possible system faults starting from the major ones down to the minor ones. , Its prediction of occurrence of basic. Conditional, undeveloped, external and intermediate events are very important as it identifies fault causes, evaluates effects, evaluates further threats, assists in decision making Aviation accidents are inherently dangerous and unforgiving. Well balanced safety systems, prevention programs and intervention strategies should be implemented to prevent further aviation accidents. All airlines should adopt a System safety program by planning to initiate the program, establishing primary system safety tasks to conduct the program and initiating support tasks to maintain the program. Those who have initiated and conducted the program should seek to maintain the program to ensure that airplanes system safety is not compromised. These programs seek to protect airplanes from accidents as they ensure potential threats or hazards identification, leading to an in-depth analysis of such threats and further development of hazard control.