Air Legislation - the Shell Model in Analyzing Human Factors in the Aviation System - Assignment Example

Air legislation INTRODUCTION The management in institutions is liable for the effective control and administration of all units to ensure that proper control is achieved and organizational goals are met. Civil aviation management encompasses the use of the SHELL model to ensure that control and maintenance and thus prevent failure in the system. The model which was first advanced by Edwards in 1972 and later modified by Hawkins in 1984 clarifies the scope of human factors in aviation and helps understand the role or the interrelations between the aviation system resources and the human components. The model is derived from the initial letters of its components which are: software, hardware, environment and liveware. It places great emphasis on the human element and the role they play in the execution of duties and the interaction with other interfaces. Since, the human being is mainly the cause of most accidents within the aviation system, the model looks at several factors that interact with the operators to cause system failure and affect performance (Cacciabue, 2004). The SHELL model elements and interfaces The major elements in the model relate to hardware, software, the environment and liveware. There are four forms of interfaces. The L-H interface is the interaction between the human operator and the machines in the aviation system. It relates to the match of human characteristics with the equipment and tools such as designing controls to correspond to sensory or designing seats to match the human bodies of passengers. The design of displays and controls should indicate proper information that can be easily understood by people so as to reduce the occurrence of errors. Secondly is the L-S interface whose main role is to provide a link between the liveware and the software. It involves the formulation of software that matches the human users and ensuring that it is possible to implement it. Thirdly is the L-E interface which forms the link between the liveware and the environment. Human operators interact with both internal and external environment and therefore are able to adapt to various situations. Lastly is the L-L interface which relates to links between the central human operator and any other person in the system for execution of activities (HELMREICH, 1991). G-OBMM- Boeing 737-400, 23 February 1995 The aircraft in this incident was on route to Lanzarote airport in the Canary Islands from East Midlands the plane which had beeen subjected to Boroscope Inspections the previous night had not been refitted which resulted to losss of almost all the oil on flight and the cosequential shutdown of both engines during landing. The crew had to divert to Luton airport due to loss of oil and oil pressure on both engines . On analysis of the components, its noted that the Boroscope inspections did not correspont to laid down procedures. The two rotor drive covers had not been refitted after inspection and inpections on ground tests afterwards had not been conducted as required in the maintenance manual. The entry in the log relating to the inspections was not correct because then proper procedures were not adhered to. This is in relation to the liveware element in the model where the workers are responsible in the execution of their duties. Secondly, the software component is depicted in that the night base maintenace controller did not obtain the necessary task cards that were relevant to the job even though they were readily available. Instead, he used his own set of training notes which was not approved in carring ou the inspections without obtainid task cards that contained the work sequence (Wiegmann, & Shappell, 2003). Following the absence of the paperwork, verbal handover were given by the engineer to the base controller who failed to approve of them. Due to the inadequate handover and the lack of reference materail by the controller, the rotor drives covers were not refitted and system reinstatements were not followed. This is a direct software issuie where the procedures laid down in the acviation system are not observered ar are irrelevant and unclear. The third element relates to this incident is the environment component of the Shell modfel. For instance, the inspections were done when the ability of the controller to concentrate on the task and to reason were low. The last inspection in restoring the plane was conducted when the ability to inspect by the controller was low. Most of the supewrvisors were absent due to sick leaves and the base controller was aware of this. This environment was therefore not fit and the inspections were likely to fail (Hawkins, & Orlady,1993). Lastly, the hardware component is depicted in that the qiuck reference handbook failed to provide a drill needed for emegency situations. The plane was adequately loaded and had proper certificates of maintenance. this hardware element did not fully contribute to the incident. G-KMAM- Airbus A320-212, 26 August 1993 This case relates to an airplane A320 which was operated by Excalibur Airways limited and had developed maintenance problems resulting to the incapability of the pilot to take a left turn and thus was forced to return to Gatwick. Investigations leading to this defined other causes of the incidence such as computer and airborne system failures (EARL, 2006). The causes of this incident relate to the analysis and matching of the features that led to the accident and therefore follow the SHELL model. An example in relation to the software element shows that the aircraft maintenance crew was in a lot of pressure and was observing unrealistic procedures and documentation that was confusing. Important practices relating to after maintenance of the plane were not present in the manual which was necessary to reset the spoilers to operational mode (Johnston, McDonald, & Fuller, 2001). Another software issue related to the fact that the flight control system was not equipped with designs of coping with flight failure situations. For instance, the spoiler was in maintenance mode instead of operational mode and the warning systems gave inappropriate responses. Maintenance manuals were in the computer database system and were not available to the engineers who had worked on the plane the previous night. The engineers used worksheets printed from a copy on microfilm which was not readable and the cross-references were difficult to follow so as to obtain proper procedures. This is a failure in the software element of the SHELL model which should ensure that information is clear, user-friendly and accurate (REINHART, 1996). Besides this the pressure on the teams carrying out the maintenance was interfered with. There were missing tools from the maintenance kit and the breaking of the flap sling only added to the frustration. The previous night engineers had used the wrong forms in the preparation of the stage sheets. He had handed correct and incorrect stage sheets and so instruction for refitting were altered. The failure of the maintenance manual was a common occurrence but neither the engineers nor the local line managers seemed to deem this lack of tools and irrelevant manuals as important. The engineers failed to follow the set procedures and focused more on the delivery of the plane to service. These are examples of the failures of the hardware component of the SHELL model. Warning systems failure and the failure of the flaps to operate relates to the hardware components (Warnock, & Papadakis, 2011). The flight crew did not notice the delay in the response given by on- board warning systems. Their check procedures before flight were therefore ineffective. The advice that was given to the flight crew by the ECAM was inappropriate and failed to show the crew the real cause of the issue. In referring to the manuals, wrong elements were used to correct the landing distance. These two examples are a clear indication of the role of the liveware in the SHELL model. Proper interactions and communications are necessary in the flight system. Another example relates to the failure of the DFDR which had problems like random track change, data corruption and incorrect indications. Data corruption was as a result of vibrations and the DFDR which is important in recording the history of the flight was not functional. This is an internal environmental issue which led to the panic of the pilots (Wiener, & Nagel, 1988). CONCLUSION In conclusion, the shell model is very useful and important in analyzing human factors in the aviation system. It gives a clear approach towards factors that are to be considered when ensuring the system runs appropriately. The model helps to determine the underlying factors in management and the role of the components in achieving organizational goals. Human factors such as size and shape, information processing, input and output traits, fuel requirements and environmental tolerance in the system can be measures effectively to determine capacity to meet goals in the organization (Campbell, & Bagshaw, 2002). REFERENCE Cacciabue, P.C. 2004. Guide to applying human factors methods: Human error and accident management in safety critical systems. London: Springer-Verlag London Ltd. Campbell, R.D., & Bagshaw, M. 2002. Human performance and limitations in aviation United Kingdom: Blackwell Science Ltd. EARL, L. 2006.190.216 Aviation Human Factors Study Guide NZ: Massey University. Hawkins, F.H., & Orlady, H.W. 1993. Human factors in flight England: Avebury Technical. HELMREICH, R. L. 1991. Strategies of Study of Flight Crew Behaviour. In International Civil Aviation Organisation, Report of the Flight Safety and Human Factors Regional Seminar. Bangkok, Thailand. Johnston, N., McDonald, N., & Fuller, R. 2001. Aviation psychology in practice. England: Ashgate Publishing Ltd. REINHART, R.O. 1996. Basic flight physiology.New York, USA: McGraw-Hill. Warnock, B. & Papadakis, M. P. 2011. Aircraft accident reconstruction and litigation. Lawyers & Judges Pub. Co. Wiegmann, D.A., & Shappell, S.A. 2003. A human error approach to aviation accident analysis: The human factors analysis and classification system. England: Ashgate Publishing Ltd. Wiener, E.L., & Nagel, D.C. 1988. Human factors in aviation. California: Academic Press Inc Read More