Causal Factors and Adverse Events of Aviation Accidents and Incidents Related to Integrated Vehicle Health Management

Causal factors in aviation accidents and incidents related to system/component failure/malfunction (SCFM) were examined for Federal Aviation Regulation Parts 121 and 135 operations to establish future requirements for the NASA Aviation Safety Program s Integrated Vehicle Health Management (IVHM) Project. Data analyzed includes National Transportation Safety Board (NSTB) accident data (1988 to 2003), Federal Aviation Administration (FAA) incident data (1988 to 2003), and Aviation Safety Reporting System (ASRS) incident data (1993 to 2008). Failure modes and effects analyses were examined to identify possible modes of SCFM. A table of potential adverse conditions was developed to help evaluate IVHM research technologies. Tables present details of specific SCFM for the incidents and accidents. Of the 370 NTSB accidents affected by SCFM, 48 percent involved the engine or fuel system, and 31 percent involved landing gear or hydraulic failure and malfunctions. A total of 35 percent of all SCFM accidents were caused by improper maintenance. Of the 7732 FAA database incidents affected by SCFM, 33 percent involved landing gear or hydraulics, and 33 percent involved the engine and fuel system. The most frequent SCFM found in ASRS were turbine engine, pressurization system, hydraulic main system, flight management system/flight management computer, and engine. Because the IVHM Project does not address maintenance issues, and landing gear and hydraulic systems accidents are usually not fatal, the focus of research should be those SCFMs that occur in the engine/fuel and flight control/structures systems as well as power systems

The organisational precursors to human automation interaction issues in safety-critical domains: the case of an automated alarm system from the air traffic management domain

Much has been written about the side effects of automation in complex safety-critical domains, such as air traffic management, aviation, nuclear power generation, and healthcare. Here, human factors and safety researchers have long acknowledged that the potential of automation to increase cost-effectiveness, quality of service and safety, is accompanied by undesired side effects or issues in human automation interaction (HAI). Such HAI issues may introduce the potential for increased confusion, uncertainty, and frustration amongst sharp end operators, i.e. the users of automation. These conditions may result in operators to refuse to use the automation, in impaired ability of operators to control the hazardous processes for which they are responsible, and in new, unintended paths to safety failure. The present thesis develops a qualitative framework of the organisational precursors to HAI issues (OPHAII) that can be found in safety-critical domains. Organisational precursors denote those organisational and managerial conditions that, although distant in time and space from the operational environment, may actually influence the quality of HAI found there. Such precursors have been extensively investigated by organisational safety (OS) scholars in relation to the occurrence of accidents and disasters—although not HAI issues. Thus, the framework’s development is motivated by the intent to explore the theoretical gap lying at the intersection between the OS area and the current perspectives on the problem—the human computer interaction (HCI) and the system lifecycle ones. While considering HAI issues as a design problem or a failure in human factors integration and/or safety assurance respectively, both perspectives, in fact, ignore, the organisational roots of the problem. The OPHAII framework was incrementally developed based on three qualitative studies: two successive, historical, case studies coupled with a third corroboratory expert study. The first two studies explored the organisational precursors to a known HAI issue: the nuisance alert problem relative to an automated alarm system from the air traffic management domain. In particular, the first case study investigated retrospectively the organisational response to the nuisance alert problem in the context of the alarm’s implementation and improvement in the US between 1977 and 2006. The second case study has a more contemporary focus, and examined at the organisational response to the same problem within two European Air Navigation Service Providers between 1990 and 2010. The first two studies produced a preliminary version of the framework. The third study corroborated and refined this version by subjecting it to the criticism from a panel of 11 subject matter experts. The resulting framework identifies three classes of organisational precursors: (i) the organisational assumptions driving automation adoption and improvement; (2) the availability of specific organisational capabilities for handling HAI issues; and (3) the control of implementation quality at the boundary between the service provider and the software manufacturer. These precursors advance current understanding of the organisational factors involved in the (successful and problematic) handling of HAI issues within safety-critical service provider organisations. Its dimensions support the view that HAI issues can be seen as and organisational phenomenon—an organisational problem that can be the target of analysis and improvements complementary to those identified by the HCI and the system lifecycle perspectives

Evaluation of software dependability

It has been said that the term software engineering is an aspiration not a description. We would like to be able to claim that we engineer software, in the same sense that we engineer an aero-engine, but most of us would agree that this is not currently an accurate description of our activities. My suspicion is that it never will be. From the point of view of this essay – i.e. dependability evaluation – a major difference between software and other engineering artefacts is that the former is pure design. Its unreliability is always the result of design faults, which in turn arise as a result of human intellectual failures. The unreliability of hardware systems, on the other hand, has tended until recently to be dominated by random physical failures of components – the consequences of the ‘perversity of nature’. Reliability theories have been developed over the years which have successfully allowed systems to be built to high reliability requirements, and the final system reliability to be evaluated accurately. Even for pure hardware systems, without software, however, the very success of these theories has more recently highlighted the importance of design faults in determining the overall reliability of the final product. The conventional hardware reliability theory does not address this problem at all. In the case of software, there is no physical source of failures, and so none of the reliability theory developed for hardware is relevant. We need new theories that will allow us to achieve required dependability levels, and to evaluate the actual dependability that has been achieved, when the sources of the faults that ultimately result in failure are human intellectual failures

The Law Commission presumption concerning the dependability of computer evidence

We consider the condition set out in section 69(1)(b) of the Police and Criminal Evidence Act 1984 (PACE 1984) that reliance on computer evidence should be subject to proof of its correctness, and compare it to the 1997 Law Commission recommendation that acommon law presumption be used that a computer operated correctly unless there is explicit evidence to the contrary (LC Presumption). We understand the LC Presumption prevails in current legal proceedings. We demonstrate that neither section 69(1)(b) of PACE 1984 nor the LC presumption reflects the reality of general software-based system behaviour

Software reliability and dependability: a roadmap

Shifting the focus from software reliability to user-centred measures of dependability in complete software-based systems. Influencing design practice to facilitate dependability assessment. Propagating awareness of dependability issues and the use of existing, useful methods. Injecting some rigour in the use of process-related evidence for dependability assessment. Better understanding issues of diversity and variation as drivers of dependability. Bev Littlewood is founder-Director of the Centre for Software Reliability, and Professor of Software Engineering at City University, London. Prof Littlewood has worked for many years on problems associated with the modelling and evaluation of the dependability of software-based systems; he has published many papers in international journals and conference proceedings and has edited several books. Much of this work has been carried out in collaborative projects, including the successful EC-funded projects SHIP, PDCS, PDCS2, DeVa. He has been employed as a consultant t

Alternative sweetener from curculigo fruits

This study gives an overview on the advantages of Curculigo Latifolia as an alternative sweetener and a health product. The purpose of this research is to provide another option to the people who suffer from diabetes. In this research, Curculigo Latifolia was chosen, due to its unique properties and widely known species in Malaysia. In order to obtain the sweet protein from the fruit, it must go through a couple of procedures. First we harvested the fruits from the Curculigo trees that grow wildly in the garden. Next, the Curculigo fruits were dried in the oven at 50 0C for 3 days. Finally, the dried fruits were blended in order to get a fine powder. Curculin is a sweet protein with a taste-modifying activity of converting sourness to sweetness. The curculin content from the sample shown are directly proportional to the mass of the Curculigo fine powder. While the FTIR result shows that the sample spectrum at peak 1634 cm–1 contains secondary amines. At peak 3307 cm–1 contains alkynes

A safety analysis approach to clinical workflows : application and evaluation

Clinical workflows are safety critical workflows as they have the potential to cause harm or death to patients. Their safety needs to be considered as early as possible in the development process. Effective safety analysis methods are required to ensure the safety of these high-risk workflows, because errors that may happen through routine workflow could propagate within the workflow to result in harmful failures of the system’s output. This paper shows how to apply an approach for safety analysis of clinic al workflows to analyse the safety of the workflow within a radiology department and evaluates the approach in terms of usability and benefits. The outcomes of using this approach include identification of the root causes of hazardous workflow failures that may put patients’ lives at risk. We show that the approach is applicable to this area of healthcare and is able to present added value through the detailed information on possible failures, of both their causes and effects; therefore, it has the potential to improve the safety of radiology and other clinical workflows