Aircraft Fuel Quantity Gauging Sub-system Safety (original) (raw)
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Scientific Research Journal
Hazard in technological development can occur anywhere, anytime, and caused by various factors. Every technology product has the possibility to failed or error in its operation. This failure can endanger the product itself, its users or the environment around it. The purpose of this research is to design mitigation for failure conditions at the system level in order to minimize and avoid the impact of failure conditions on an unmanned aircraft named PTTA MALE .The method used is descriptive qualitative method including architecture observation, discussion and interviews with experts. Research was also conducted using quantitative methods based on international standard documents (ARP 4761 & STANAG 4671) to improve the analysis of failure conditions. Mitigation design with a System Functional Hazard Assessment (SFHA) is carried out for each system level failure condition. Failure conditions are generally categorized into detected, undetected, announced and unannounced failures. When a failure condition occurs, the pilot can take action according to the best mitigation that has been designed, for example by turning off the automatic power control, or continuing the operation in manual mode. The results of this research can serve as a guide for pilots in operating PTTA MALE.
Fault Tree Analysis of LPG refuelling station
2014
Fault tree analysis (FTA) is a top-down approach for analysis of the reliability and safety of technical systems. It starts with a possible failure event, called a TOP event, and then determining the ways it can happen. The analysis proceeds by determining how the TOP event is caused by lower level failure events. The primitive or basic failure events that ultimately cause the TOP event are connected through logical AND-gates and OR-gates. As an example of the practical application of methods, the lpg release accident of a LPG refueling station is analyzed, the estimation of the significance of certain events is done that have a greater or less influence on its reliability, and it is considered to be able to eliminate causes of failure or to minimize the consequences of failure.)
In the presented work the idea of improvement the state space method for building safety models of complex technical systems for critical application is proposed. Result of the this improvement one single model is developed on which due to the split state of critical failure state quantitative reliability and safety quantitative indicators of the system can be obtained. Unlike traditional models as in a fault trees, dynamic tree failures and FMEA /FMECA-models the proposed model to allow to take into account independencies between accidental situations. This model allows to investigate the trend of risk indicators accidental situations variance from increasing system reliability through the use of fault-tolerant configurations and maintenance usage.
A Model Based Approach to Design for Reliability and Safety of Critical Aeronautic Systems
2016
This paper explores how the safety engineering practices applied to the aircraft design can be effectively associated to the MBSE. Requirements and procedures of the ARP4754/ED-79 and ARP4761 were considered. As an example the fuel system of a civil aircraft was used. Some key issues were found relevant, whilst modeling the system through the MBSE tools. The management of both the functional and dysfunctional analysis, leading to the Functional Hazard Analysis (FHA) of the whole aircraft, within the same modeling environment was tested. The elicitation of safety requirements with a direct link to the FTA and FMEA used to quantify the risk of failure was performed. The software tools which can be interoperated for those tasks were tested. As a result, the integration between the two above mentioned analyses looks fairly easy. In fact, further efforts are required to make fully interoperable the tools currently available to perform this activity and to include the human interaction wi...
A Method of Aircraft Reliability Assessment as Referred to the Operational-Use Safety
Journal of Konbin, 2010
A Method of Aircraft Reliability Assessment as Referred to the Operational-Use Safety Throughout the operational phase of aviation objects, the safety and reliability thereof are characterised with a set of a dozen or so, or even tens of indices correlated with each other. Hence, any analytical and assessment-oriented efforts as well as comparisons - for any specific feature - between both the objects themselves and the systems of manufacturing, operating, and maintaining them are usually hindered. The intended aim of this paper is to suggest some solution to this problem, one that consists in reducing the number of operational indices of safety down to several indices of significance which contain most information on the object under assessment or on a system of operating this object
Fault Tree Analysis in the Reliability of Heavy Fuel Oil Supply
Transactions on Maritime Science, 2014
Marine systems are complex and through the analysis of their reliability it is necessary to observe the reliability of their subsystems and components. With regard to the fact that the reliability is functionally dependent on faults, for the purpose of this study special attention has been given to possible faults on the heavy fuel oil supply pump of a two-stroke marine diesel engine MAN B&W 5L90MC. A deductive approach to reliability analysis, i.e. fault tree analysis method (FTA), has been used. By the use of this method it is simpler to identify the system’s weak link and it is shown that the method gives the basis for the ship’s system reliability analysis. Based on FTA analysis this paper suggests system parameters that require continuous monitoring in order to achieve reliability. The results show the behavior of the components in case of faults and this approach can help to create a plan of action in order to enforce timely corrective and preventive action and, accordingly, i...
IJERT-Fault Tree Analysis of LPG refuelling station
International Journal of Engineering Research and Technology (IJERT), 2014
https://www.ijert.org/fault-tree-analysis-of-lpg-refuelling-station https://www.ijert.org/research/fault-tree-analysis-of-lpg-refuelling-station-IJERTV3IS051486.pdf Fault tree analysis (FTA) is a top-down approach for analysis of the reliability and safety of technical systems. It starts with a possible failure event, called a TOP event, and then determining the ways it can happen. The analysis proceeds by determining how the TOP event is caused by lower level failure events. The primitive or basic failure events that ultimately cause the TOP event are connected through logical AND-gates and OR-gates. As an example of the practical application of methods, the lpg release accident of a LPG refueling station is analyzed, the estimation of the significance of certain events is done that have a greater or less influence on its reliability, and it is considered to be able to eliminate causes of failure or to minimize the consequences of failure.)
Journal of Occupational Health and Epidemiology, 2021
Article Info Background: Risk assessment is an important tool for reducing casualties and financial damage in the oil and gas industry. This research aimed to identify and evaluate process hazards in the petrochemical industry in 2016. Material and Methods: In this case study, a team was organized and briefed on the process. Besides, hazard identification was performed using the Hazard and Operability Study. Next, causes were analyzed using the Fault Tree Analysis and occurrence probability of top events. Finally, events and subevents were ranked. The minimum cut sets were determined using Boolean algebra. Results: A total of 77 events were identified. Accordingly, unacceptable, tolerable, and acceptable risk levels were 41, 31, and 5 events, respectively. Fire was the most unacceptable risk level, with the final events of "human errors in correct gasket installation on the flange surface" and "flange defects" having had the shares of 51.2 and 21.55%, respectively. Conclusion: The combination of the two HAZOP and FTA techniques is useful in process industries in which incomplete performance of the system and control systems is the most effective factor in the potential occurrence of fire. Human errors and flange defects are the two main factors in this event, so occupational safety and health must be improved in this system. Thus, due to complex interactions between humans, machines, materials, and the environment in systems, such as the petrochemical industry, which lead to uncertainties in safety results of the process, risk assessment is recommended to be performed periodically using different techniques.
Analysis of the Aircraft Operation in the Context of Safety and Effectiveness
2015
The paper presents a method for evaluating the technical object submerged in a logistical system from the point of view of sustainability, availability and utilization. These factors determine the effectiveness of the object. The probabilistic models of reliability theory and semi-Markov process were used to the evaluation. An example of a technical object in the paper is the airplane. The operation of the aircraft consists in usage of its functioning resource accumulated during the manufacturing process and periodic reproduction of this resource. The decisive factor of the effectiveness of the aircraft operation process is the readiness to perform its airborne tasks and the extent usage of aircraft during their implementation. An important parameter is the damage stream parameter for serviceable components. The basic information is the answer, whether it falls within the tolerance lane. To calculate the limit values of the damage stream parameter, the relationship between the uptim...
— this article presents an algorithm, which allows to automate the developing of fault trees for the safety exploitation assessment of complex technical systems. As result, this algorithm produces logical and graphical representations of fault tree. Obtained fault tree can be used for the exploitation safety assessment. Presented algorithm is a further step in the development of the technology of modeling the discrete-continuous stochastic systems, based on so-called structural-automaton models. I. INTRODUCTION For the effective functioning of the complex technical system (henceforth named CTS), it's extremely important to provide the required levels of reliability and safety. The failure of CTS can have devastating consequences that can lead to significant damage, including the loss of lives. Therefore, problems of safety, reliability and failure consequences assessment, during the design stage, are very important. The assessment of the reliability and exploitation safety of CTS is carried out by modeling, which is used for determining reliability and exploitation safety indicators. There are several approaches for reliability and exploitation safety assessment, namely: simulation modeling (hereafter SM), stochastic simulation and state space modeling. Stochastic simulation has been indicated as being the most commonly used approach [1]. Important feature of stochastic simulation is that algorithms for developing models are well-formalized, so they are simple to program, and there are quite a lot of software based on that algorithms. The most commonly used method of stochastic simulation of CTS involves the fault tree (henceforth named FT) development [2]. FT is a type of structure flowchart, which is used for graphical representation of events (determined with deductive method) that can lead to catastrophic system failure [3]. FT analysis can be used to obtain minimal cut sets (hereafter MCS). MCS is a minimal combination of events that leads to system failure. If any event is removed from the MCS, the remaining events collectively are not able to cause the system failure. MCS, obtained via FT analysis, can also include the probability of MCS (probability of all the events from the cut set occur in the same time).