An Analysis of the Role of Safety Nets in the National Airspace System

Safe operations of aircraft in the National Airspace System (NAS) may be attributed to many factors, including the application of a variety of safety nets (SNs) as a last line of defense. In preparation for the Next Generation Air Transportation System (NextGen), a review of Aviation Safety Reporting System (ASRS) reports for incidents with positive outcomes was conducted to investigate the importance of current safety nets. The examination of positive outcomes not only shows what went wrong, but also what went right to prevent accidents and save the day. More than 400 incident reports for 2015 from the voluntary ASRS reporting database were studied in detail to create event sequence diagrams (ESDs), illustrating the effectiveness of SNs. The developed ESDs are considered top-level, representative models and are limited with respect to being reliably quantitative because they are based on only reports from a single year. The ESDs could offer insights into human systems integration research, such as strategically using technologies as SNs without human interface or alleviating human workload with new technologies to provide resilient recovery from off-nominal conditions ensuring flight safety

Air Traffic Management Safety Challenges

The primary goal of the Air Traffic Management (ATM) system is to control accident risk. ATM safety has improved over the decades for many reasons, from better equipment to additional safety defences. But ATM safety targets, improving on current performance, are now extremely demanding. Safety analysts and aviation decision-makers have to make safety assessments based on statistically incomplete evidence. If future risks cannot be estimated with precision, then how is safety to be assured with traffic growth and operational/technical changes? What are the design implications for the USA’s ‘Next Generation Air Transportation System’ (NextGen) and Europe’s Single European Sky ATM Research Programme (SESAR)? ATM accident precursors arise from (eg) pilot/controller workload, miscommunication, and lack of upto- date information. Can these accident precursors confidently be ‘designed out’ by (eg) better system knowledge across ATM participants, automatic safety checks, and machine rather than voice communication? Future potentially hazardous situations could be as ‘messy’ in system terms as the Überlingen mid-air collision. Are ATM safety regulation policies fit for purpose: is it more and more difficult to innovate, to introduce new technologies and novel operational concepts? Must regulators be more active, eg more inspections and monitoring of real operational and organisational practices

Assessment of the State-of-the-Art of System-Wide Safety and Assurance Technologies

Since its initiation, the System-wide Safety Assurance Technologies (SSAT) Project has been focused on developing multidisciplinary tools and techniques that are verified and validated to ensure prevention of loss of property and life in NextGen and enable proactive risk management through predictive methods. To this end, four technical challenges have been listed to help realize the goals of SSAT, namely (i) assurance of flight critical systems, (ii) discovery of precursors to safety incidents, (iii) assuring safe human-systems integration, and (iv) prognostic algorithm design for safety assurance. The objective of this report is to provide an extensive survey of SSAT-related research accomplishments by researchers within and outside NASA to get an understanding of what the state-of-the-art is for technologies enabling each of the four technical challenges. We hope that this report will serve as a good resource for anyone interested in gaining an understanding of the SSAT technical challenges, and also be useful in the future for project planning and resource allocation for related research

Occupational injuries among construction workers at the Chep Lap Kok Airport construction site, Hong Kong : analysis of accident rates, and the association between injuries, error types and their contributing factors : a thesis presented in partial fulfilment of the requirements for the degree of Master of Aviation at Massey University, Palmerston North, New Zealand

Accidents on construction sites are a major cause of morbidity and mortality in Hong Kong. This study investigated the likely causes of occupational injuries that were present among the construction workers during the construction of the new Chep Lap Kok (CLK) Airport in Hong Kong. In order to accumulate the requisite information, 1648 accident investigation reports in a four-year period (1993-1996) were reviewed. The first part of the study described the pattern and magnitude of occupational injuries among the CLK construction workers and compared the accident rates of the CLK workers with those of the construction industry as a whole in Hong Kong. The study examined the effects of the workplace infrastructure at CLK in order to explain why this site presented fewer work place injuries and accidents than other workplaces. The second part of the research used these injury and accident occurrences as the basis to construct the causes of accidents and injuries within an error causation classification system. The results showed that at CLK, the commonest workplace injury was contusion & crushing which appeared to be due to mistakes made through lapses in memory often caused by pressure of work being imposed on the employee. This section also indicated what types of errors were most closely associated with what kinds of injuries and what conditions were most likely to trigger these types of events. Among the major associations were links between contusion and crushing and violation error, perceptual error; between memory lapse and work pressure, equipment deficiencies, poor working environment, fatigue, and between violation error and work pressure. The research suggested that work pressure was an important contributing factor to construction injury and it increased the prevalence of a human error type namely, memory lapse many fold. The outcomes from this study provide important new information on the causes and types of errors which have led to occupational injuries among construction workers in Hong Kong. A better understanding of the human factors-based causes of accidents and injuries in the construction industry and an inculcation of a safety culture on construction sites are critically important in the reduction of the rate of construction accidents and improvement of workers' human performance. The results should assist the construction industry in the designing accident prevention training and education strategies, estimating human error probabilities, and the monitoring organizational safety performance

Engineering psychology: Contribution to system safety

There has been a growing interest in the area of engineering psychology. This article considers some of the major accidents which have occurred in recent years, and the contribution which engineering psychology makes to designing systems and enhancing safety. Accidents are usually multi-causal, and the resident pathogens in the design and operation of human-machine systems can lead to devastating consequences not only for the workers themselves but also for people in the surrounding communities. Specifically, in each of the accidents discussed, operators were unaware of the seriousness of the system malfunctions because warning displays were poorly designed or located, and operators had not been sufficiently trained in dealing with these emergency situations. Since the 1940s machines and equipment have become more complex in nearly every industry. This, coupled with the continuing need to produce effective and safe systems, has resulted in psychology professionals being called to assist in designing even more efficient operating systems. In earlier times, a worker who made a mistake might spoil a piece of work or waste some time. Today, however, a worker's erroneous action can lead to dire consequences

Air Traffic Safety: continued evolution or a new Paradigm.

The context here is Transport Risk Management. Is the philosophy of Air Traffic Safety different from other modes of transport? – yes, in many ways, it is. The focus is on Air Traffic Management (ATM), covering (eg) air traffic control and airspace structures, which is the part of the aviation system that is most likely to be developed through new paradigms. The primary goal of the ATM system is to control accident risk. ATM safety has improved over the decades for many reasons, from better equipment to additional safety defences. But ATM safety targets, improving on current performance, are now extremely demanding. What are the past and current methodologies for ATM risk assessment; and will they work effectively for the kinds of future systems that people are now imagining and planning? The title contrasts ‘Continued Evolution’ and a ‘New Paradigm’. How will system designers/operators assure safety with traffic growth and operational/technical changes that are more than continued evolution from the current system? What are the design implications for ‘new paradigms’, such as the USA’s ‘Next Generation Air Transportation System’ (NextGen) and Europe’s Single European Sky ATM Research Programme (SESAR)? Achieving and proving safety for NextGen and SESAR is an enormously tough challenge. For example, it will need to cover system resilience, human/automation issues, software/hardware performance/ground/air protection systems. There will be a need for confidence building programmes regarding system design/resilience, eg Human-in-the-Loop simulations with ‘seeded errors’

Human Performance Contributions to Safety in Commercial Aviation

In the commercial aviation domain, large volumes of data are collected and analyzed on the failures and errors that result in infrequent incidents and accidents, but in the absence of data on behaviors that contribute to routine successful outcomes, safety management and system design decisions are based on a small sample of non- representative safety data. Analysis of aviation accident data suggests that human error is implicated in up to 80% of accidents, which has been used to justify future visions for aviation in which the roles of human operators are greatly diminished or eliminated in the interest of creating a safer aviation system. However, failure to fully consider the human contributions to successful system performance in civil aviation represents a significant and largely unrecognized risk when making policy decisions about human roles and responsibilities. Opportunities exist to leverage the vast amount of data that has already been collected, or could be easily obtained, to increase our understanding of human contributions to things going right in commercial aviation. The principal focus of this assessment was to identify current gaps and explore methods for identifying human success data generated by the aviation system, from personnel and within the supporting infrastructure

Managing Environmental, Health, and Safety Risks: A Comparative Assessment of the Minerals Management Service and Other Agencies

This study compares and contrasts regulatory and related practices—in particular, regulatory decisionmaking, risk assessment and planning processes, inspection and compliance, and organization structure, budgets, and training—of the Minerals Management Service (MMS, now the Bureau of Ocean Energy Management, Regulation, and Enforcement, or BOEMRE) with those of the Federal Aviation Administration (FAA) and the Environmental Protection Agency (EPA). Comparing MMS practices with those of other federal agencies that also manage low-probability but high-consequence environmental risks provides a basis for identifying opportunities for enhancing regulatory capacity and safety performance in managing deepwater energy exploration and production. Our research finds important differences in processes for setting standards; peer review contribution to the rulemaking process; establishment of tolerable risk thresholds; and training of key staff. The paper concludes with several recommendations for how various EPA and FAA practices might be modified and used at BOEMRE to strengthen its regulatory and risk management processes.Minerals Management Service, Federal Aviation Administration, Environmental Protection Agency, risk management

Aircraft Loss of Control: Problem Analysis for the Development and Validation of Technology Solutions

Aircraft loss of control (LOC) is a leading cause of fatal accidents across all transport airplane and operational classes. LOC can result from a wide spectrum of precursors (or hazards), often occurring in combination. Technologies developed for LOC prevention and recovery must therefore be effective under a wide variety of conditions and uncertainties, including multiple hazards, and the validation process must provide a means of assessing system effectiveness and coverage of these hazards. This paper provides a detailed description of a methodology for analyzing LOC as a dynamics and control problem for the purpose of developing effective technology solutions. The paper includes a definition of LOC based on several recent publications, a detailed description of a refined LOC accident analysis process that is illustrated via selected example cases, and a description of planned follow-on activities for identifying future potential LOC risks and the development of LOC test scenarios. Some preliminary considerations for LOC of Unmanned Aircraft Systems (UAS) and for their safe integration into the National Airspace System (NAS) are also discussed