Institutionalisation, Capability and Effectiveness of Aviation Safety Management Systems

In the frame of an on-going 4-years research project, the Aviation Academy Safety Management Systems (AVAC-SMS) metric for the self-assessment of aviation Safety Management Systems (SMS) was designed based on the Safety Management Manual of the International Civil Aviation Organization and in cooperation with knowledge experts and aviation companies. The particular metric evaluates three areas, namely (1) the degree of institutionalisation of SMS (design and implementation of processes), (2) the extent of managers' capability to deliver the SMS processes, and (3) the employees' perceived effectiveness of the SMS-related deliverables. The metric concludes with a score per area and per SMS component/element assessed, and it is scalable to the size and complexity of each organisation. Results of a survey at 18 aviation companies did not show statistically significant differences in their SMS scores across all three assessment areas but revealed a distance between the area of Institutionalization and the areas of Capability and Effectiveness. Also, differences were detected regarding the scores per SMS component and element within and across companies and assessment areas. The various assessment options offered for the AVAC-SMS metric accommodates the resources each SME and large company can invest in the application of the metric. Even the lowest level of resolution of the SMS metric can trigger companies to investigate further their weaker areas and foster their SMS-related activities. Therefore, the AVAC-SMS metric is deemed useful to organisations that want to self-assess their SMS and proceed to comparisons amongst various functions and levels and/or over time

Acute paretic syndrome in juvenile White Leghorn chickens resembles late stages of acute inflammatory demyelinating polyneuropathies in humans

Background: Sudden limb paresis is a common problem in White Leghorn flocks, affecting about 1% of the chicken population before achievement of sexual maturity. Previously, a similar clinical syndrome has been reported as being caused by inflammatory demyelination of peripheral nerve fibres. Here, we investigated in detail the immunopathology of this paretic syndrome and its possible resemblance to human neuropathies. Methods: Neurologically affected chickens and control animals from one single flock underwent clinical and neuropathological examination. Peripheral nervous system (PNS) alterations were characterised using standard morphological techniques, including nerve fibre teasing and transmission electron microscopy. Infiltrating cells were phenotyped immunohistologically and quantified by flow cytometry. The cytokine expression pattern was assessed by quantitative real-time PCR (qRT-PCR). These investigations were accomplished by MHC genotyping and a PCR screen for Marek’s disease virus (MDV). Results: Spontaneous paresis of White Leghorns is caused by cell-mediated, inflammatory demyelination affecting multiple cranial and spinal nerves and nerve roots with a proximodistal tapering. Clinical manifestation coincides with the employment of humoral immune mechanisms, enrolling plasma cell recruitment, deposition of myelinbound IgG and antibody-dependent macrophageal myelin-stripping. Disease development was significantly linked to a 539 bp microsatellite in MHC locus LEI0258. An aetiological role for MDV was excluded. Conclusions: The paretic phase of avian inflammatory demyelinating polyradiculoneuritis immunobiologically resembles the late-acute disease stages of human acute inflammatory demyelinating polyneuropathy, and is characterised by a Th1-to-Th2 shift

Frequency and variance of communication characteristics in aviation safety events

In the aviation sector communications plays a critical role, and training and education include communication theory and practice. Studies suggest that communication problems contribute into 70% to 80% of safety occurrences, but literature does not provide further information about the types and frequencies of the corresponding communication variables. Our objective was to develop a relevant tool to be used for post analyses of safety (investigation) reports. This way, the efforts of practitioners and scholars could be targeted to the weakest areas

Do experts agree when assessing risks? An empirical study

Risk matrices have been widely used in the industry under the notion that risk is a product of likelihood by severity of the hazard or safety case under consideration. When reliable raw data are not available to feed mathematical models, experts are asked to state their estimations. This paper presents two studies conducted in a large European airline and partially regarded the weighting of 14 experienced pilots’ judgment though software, and the calculation of agreement amongst 10 accident investigators when asked to assess the worst outcome, most credible outcome and risk level for 12 real events. According to the results, only 4 out of the 14 pilots could be reliably used as experts, and low to moderate agreement amongst the accident investigators was observed. Although quite alarming results, this paper does not aim at raising concerns about the skills of experienced employees; rather, we urge organizations to comprehend the distinction between experience and expertise, and focus on training their staff in published expert judgment methods

Frequency and Variance of Communication Characteristics in Aviation Safety Events

In the aviation sector, communication problems have contributed into 70% to 80% of safety occurrences. However, to date we haven’t depicted which communication aspects have affected aviation safety most frequently. Based on literature, we developed a tool which includes communication characteristics related to actors, signal, coder, channel, decoder, direction, timing, distance, predictability and interference. After achieving inter-rater reliability, the tool was used to analyse 103 safety investigation reports that correspond to events occurred in various regions and which included in total 256 communication problems. The results suggest that communication between humans and representation media, visual and audio signalling and decoding, air-transmitted messages, and verbal, unidirectional, local and synchronous communication contributed most frequently into safety events. Statistical tests showed that the frequencies of most of those characteristics were significantly different across regions, time periods, types of operations and event severity. The tool developed can be used by different organizations and industry sectors to distil and analyse data from mandatory and voluntary reports and identify weak communication areas. Depending on the findings, analysts might need to alert designers of technical systems, inform management of organizations, warn end-users about most frequent pitfalls, modify/enrich communication training and steer research efforts

Do experts agree when assessing risks?: an empirical study

Risk matrices have been widely used in the industry under the notion that risk is a product of likelihood by severity of the hazard or safety case under consideration. When reliable raw data are not available to feed mathematical models, experts are asked to state their estimations. This paper presents two studies conducted in a large European airline and partially regarded the weighting of 14 experienced pilots’ judgment though software, and the calculation of agreement amongst 10 accident investigators when asked to assess the worst outcome, most credible outcome and risk level for 12 real events. According to the results, only 4 out of the 14 pilots could be reliably used as experts, and low to moderate agreement amongst the accident investigators was observed

Institutionalisation, capability and effectiveness of aviation safety management systems

In the frame of an on-going 4-years research project, the Aviation Academy Safety Management Systems (AVAC-SMS) metric for the self-assessment of aviation Safety Management Systems (SMS) was designed based on the Safety Management Manual of the International Civil Aviation Organization and in cooperation with knowledge experts and aviation companies. The particular metric evaluates three areas, namely (1) the degree of institutionalisation of SMS (design and implementation of processes), (2) the extent of managers’ capability to deliver the SMS processes, and (3) the employees’ perceived effectiveness of the SMS-related deliverables. The metric concludes with a score per area and per SMS component/element assessed, and it is scalable to the size and complexity of each organisation. Results of a survey at 18 aviation companies did not show statistically significant differences in their SMS scores across all three assessment areas but revealed a distance between the area of Institutionalization and the areas of Capability and Effectiveness. Also, differences were detected regarding the scores per SMS component and element within and across companies and assessment areas. The various assessment options offered for the AVAC-SMS metric accommodates the resources each SME and large company can invest in the application of the metric. Even the lowest level of resolution of the SMS metric can trigger companies to investigate further their weaker areas and foster their SMS-related activities. Therefore, the AVAC-SMS metric is deemed useful to organisations that want to self-assess their SMS and proceed to comparisons amongst various functions and levels and/or over time

Finalisation and application of new safety management metrics

Following the completion of the 2nd research phase regarding the design of new safety metrics thatcould be used in Safety Management Systems (SMS), Section 2 of this report explains the methodology of designing the five new metrics: the AVAC-SMS for the self-assessment of Safety Management Systems, the AVAC-SCP for the assessment of Safety Culture Prerequisites (SCP) that companies could plan and implement to foster a positive safety culture, three indicators for assessing the effectiveness of risk controls, five indicators reflecting the utilization of organisational resources, and a metric for the complexity of socio-technical systems. Section 3 presents briefly the particular metrics which have been published as part of the proceedings of the 2nd International Cross-industry Safety Conference (Amsterdam, 1-3 November 2017). Section 4 of the report discusses the application of two of the metrics by companies (i.e. AVAC-SMS and AVAC-SCP), and section 5 presents the respective results. The report concludes with a discussion of the results and suggestions for the next project steps..

Measuring safety in aviation: Empirical results about the relation between safety outcomes and safety management system processes, operational activities and demographic data

A literature review conducted as part of a research project named “Measuring Safety in Aviation – Developing Metrics for Safety Management Systems” revealed several challenges regarding the safety metrics used in aviation. One of the conclusions was that there is limited empirical evidence about the relationship between Safety Management System (SMS) processes and safety outcomes. In order to explore such a relationship, respective data from 7 European airlines was analyzed to explore whether there is a monotonic relation between safety outcome metrics and SMS processes, operational activity and demographic data widely used by the industry. Few, diverse, and occasionally contradictory associations were found, indicating that (1) there is a limited value of linear thinking followed by the industry, i.e., “the more you do with an SMS the higher the safety performance”, (2) the diversity in SMS implementation across companies renders the sole use of output metrics not sufficient for assessing the impact of SMS processes on safety levels, and (3) only flight hours seem as a valid denominator in safety performance indicators. At the next phase of the research project, we are going to explore what alternative metrics can reflect SMS/safety processes and safety performance in a more valid manner