Fatigue proofing: The role of protective behaviours in mediating fatigue-related risk in a defence aviation environment

In the military or emergency services, operational requirements and/or community expectations often preclude formal prescriptive working time arrangements as a practical means of reducing fatigue-related risk. In these environments, workers sometimes employ adaptive or protective behaviours informally to reduce the risk (i.e. likelihood or consequence) associated with a fatigue-related error. These informal behaviours enable employees to reduce risk while continuing to work while fatigued. In this study, we documented the use of informal protective behaviours in a group of defence aviation personnel including flight crews. Semi-structured interviews were conducted to determine whether and which protective behaviours were used to mitigate fatigue-related error. The 18 participants were from aviation-specific trades and included aircrew (pilots and air-crewman) and aviation maintenance personnel (aeronautical engineers and maintenance personnel). Participants identified 147 ways in which they and/or others act to reduce the likelihood or consequence of a fatigue-related error. These formed seven categories of fatigue-reduction strategies. The two most novel categories are discussed in this paper: task-related and behaviour-based strategies. Broadly speaking, these results indicate that fatigued military flight and maintenance crews use protective 'fatigue-proofing' behaviours to reduce the likelihood and/or consequence of fatigue-related error and were aware of the potential benefits. It is also important to note that these behaviours are not typically part of the formal safety management system. Rather, they have evolved spontaneously as part of the culture around protecting team performance under adverse operating conditions. When compared with previous similar studies, aviation personnel were more readily able to understand the idea of fatigue proofing than those from a fire-fighting background. These differences were thought to reflect different cultural attitudes toward error and formal training using principles of Crew Resource Management and Threat and Error Management.

Human risk factors associated with pilots in runway excursions

A breakdown analysis of civil aviation accidents worldwide indicates that the occurrence of runway excursions represents the largest portion among all aviation occurrence categories. This study examines the human risk factors associated with pilots in runway excursions, by applying a SHELLO model to categorize the human risk factors and to evaluate the importance based on the opinions of 145 airline pilots. This study integrates aviation management level expert opinions on relative weighting and improvement-achievability in order to develop four kinds of priority risk management strategies for airline pilots to reduce runway excursions. The empirical study based on experts' evaluation suggests that the most important dimension is the liveware/pilot's core ability. From the perspective of front-line pilots, the most important risk factors are the environment, wet/containment runways, and weather issues like rain/thunderstorms. Finally, this study develops practical strategies for helping management authorities to improve major operational and managerial weaknesses so as to reduce the human risks related to runway excursions.

Injury and fatality risks in aeromedical transport: focus on prevention

BACKGROUND

Aeromedical transport (AMT) is a reliable and well-established life-saving option for rapid patient transfers to health care delivery hubs. However, owing to the very nature of AMT, fatal and nonfatal events may occur. This study reviews aeromedical incidents reported since the publication of the last definitive review in 2003, aiming to provide additional insight into a wide range of factors potentially associated with fatal and nonfatal AMT incidents (AMTIs). We hypothesized that weather and/or visual conditions, postcrash fire, aircraft make and/or type, and time of day all correlate with the risk of AMTI with injury or fatality.

METHODS

Specialty databases were queried for AMTI between January 1, 2003 and July 31, 2015. Additional Internet-based resources were also used to find any additional AMTI (including non-US occurrences) to augment the event sample size available for analysis. Univariate analyses of the collected sample were then performed for association between "fatal crash or injury" (FCOI) and weather/visual conditions, aircraft type and/or make, pilot error, equipment failure, post-incident fire, time of day (6 am-7 pm versus 7 pm-6 am), weekend (Friday-Sunday) versus weekday (Monday-Thursday), season of the year, and presence of patient on board. Variables reaching significance level of P < 0.20 were included in multivariate analysis.

RESULTS

A total of 59 AMTIs were identified. Helicopters were involved in 52 of 59 AMTIs, with 7 of 59 fixed-wing incidents. Comparing pre-2003 data with post-2003 data, we noted a significant decrease in AMTIs per month (0.70 versus 0.39, respectively, P = 0.048), whereas the number of fatalities per year increased slightly (7.20 versus 8.26, p = n/s). In univariate analyses, abnormal weather conditions, impaired visibility, time of incident (7 pm-6 am), aircraft model/make, and post-incident fire all reached statistical significance sufficient for inclusion in multivariate analysis (P < 0.20). Factors independently associated with FCOI included post-incident fire (odds ratio, 19.0; 95% confidence interval, 1.41-255.5) and time of incident between 7 pm and 6 am (odds ratio, 11.2; 95% confidence interval, 1.29-97.2). Weather conditions, impaired visibility, and aircraft model/make were not independently associated with FCOI.

CONCLUSIONS

The present study supports previous observation that post-crash fire is independently associated with FCOI. However, our data do not support previous observations that weather conditions, impaired visibility, or aircraft model/make are independently predictive of fatal AMTI. In addition, this report demonstrates that flights between the hours of 7 pm-6 am may be associated with greater odds of FCOI. Efforts directed at identification, remediation, and active prevention of factors associated with AMTI and FCOI are warranted given the global increase in aeromedical transport.

Hot Air Balloon: An Unusual Cause of Multicasualty Trauma Incident

Hot air balloon incidents are few and far between compared with the total number of flights. Nevertheless, hot air balloon incidents may produce severe trauma involving several patients and are linked to significant mortality. The prehospital management of injured patients starts after having secured potential surrounding dangers, such as fire or explosion. In the context of a rescue by helicopter, close attention must be paid to potential obstacles, like trees or electrical wires, and the risk of aspiration of the balloon envelope into the rotor. Patients involved in such incidents are often split up in a closed perimeter around the crash point. The severity of the trauma depends essentially on the height of the fall. The most frequent traumatic lesions involve fractures of the lower limbs, the spine, and the pelvis as well as severe burns caused by the balloon fire. Because of the number of patients present, an initial triage is usually required at the site. The use of rescue helicopters can be helpful. They can perform aerial reconnaissance, provide on-site high-level resources, enable access to the patients even in hostile environments, and quickly transport them to trauma center hospitals.

Airline Safety Improvement Through Experience with Near-Misses: A Cautionary Tale

In recent years, the U.S. commercial airline industry has achieved unprecedented levels of safety, with the statistical risk associated with U.S. commercial aviation falling to 0.003 fatalities per 100 million passengers. But decades of research on organizational learning show that success often breeds complacency and failure inspires improvement. With accidents as rare events, can the airline industry continue safety advancements? This question is complicated by the complex system in which the industry operates where chance combinations of multiple factors contribute to what are largely probabilistic (rather than deterministic) outcomes. Thus, some apparent successes are realized because of good fortune rather than good processes, and this research intends to bring attention to these events, the near-misses. The processes that create these near-misses could pose a threat if multiple contributing factors combine in adverse ways without the intervention of good fortune. Yet, near-misses (if recognized as such) can, theoretically, offer a mechanism for continuing safety improvements, above and beyond learning gleaned from observable failure. We test whether or not this learning is apparent in the airline industry. Using data from 1990 to 2007, fixed effects Poisson regressions show that airlines learn from accidents (their own and others), and from one category of near-misses-those where the possible dangers are salient. Unfortunately, airlines do not improve following near-miss incidents when the focal event has no clear warnings of significant danger. Therefore, while airlines need to and can learn from certain near-misses, we conclude with recommendations for improving airline learning from all near-misses.

A sonic net excludes birds from an airfield: implications for reducing bird strike and crop losses

Collisions between birds and aircraft cause billions of dollars of damages annually to civil, commercial, and military aviation. Yet technology to reduce bird strike is not generally effective, especially over longer time periods. Previous information from our lab indicated that filling an area with acoustic noise, which masks important communication channels for birds, can displace European Starlings (Sturnus vulgaris) from food sources. Here we deployed a spatially controlled noise (termed a "sonic net"), designed to overlap with the frequency range of bird vocalizations, at an airfield. By conducting point counts, we monitored the presence of birds for four weeks before deployment of our sonic net, and for four weeks during deployment. We found an 82% reduction in bird presence in the sonic net area compared with change in the reference areas. This effect was as strong in the fourth week of exposure as in the first week. We also calculated the potential costs avoided resulting from this exclusion. We propose that spatially controlled acoustic manipulations that mask auditory communication for birds may be an effective long term and fairly benign way of excluding problem birds from areas of socioeconomic importance, such as airfields, agricultural sites, and commercial properties.

Accident-precipitating factors for crashes in turbine-powered general aviation aircraft

General aviation (14CFR Part 91) accounts for 83% of civil aviation fatalities. While much research has focused on accident causes/pilot demographics in this aviation sector, studies to identify factors leading up to the crash (accident-precipitating factors) are few. Such information could inform on pre-emptive remedial action. With this in mind and considering the paucity of research on turbine-powered aircraft accidents the study objectives were to identify accident-precipitating factors and determine if the accident rate has changed over time for such aircraft operating under 14CFR Part 91. The NTSB Access database was queried for accidents in airplanes (<12,501lb) powered by 1-2 turbine engines and occurring between 1989 and 2013. We developed and utilized an accident-precipitating factor taxonomy. Statistical analyses employed logistic regression, contingency tables and a generalized linear model with Poisson distribution. The "Checklist/Flight Manual Not Followed" was the most frequent accident-precipitating factor category and carried an excess risk (OR 2.34) for an accident with a fatal and/or serious occupant injury. This elevated risk reflected an over-representation of accidents with fatal and/or serious injury outcomes (p<0.001) in the "non-adherence to V Speeds" sub-category. For accidents grouped in the "Inadequate Pre-Flight Planning/Inspection/Procedure" the "inadequate weather planning" sub-category accounted (p=0.036) for the elevated risk (OR 2.22) of an accident involving fatal and/or serious injuries. The "Violation FARs/AIM Deviation" category was also associated with a greater risk for fatal and/or serious injury (OR 2.59) with "Descent below the MDA/failure to execute the missed approach" representing the largest sub-category. Accidents in multi-engine aircraft are more frequent than their single engine counterparts and the decline (50%) in the turbine aircraft accident rate over the study period was likely due, in part, to a 6-fold increased representation of single engine airplanes. In conclusion, our study is the first to identify novel precursive factors for accidents involving turbine aircraft operating under 14CFR Part 91. This research highlights areas that should receive further emphasis in training/recurrency in a pre-emptive attempt to nullify candidate accident-precipitating factor(s).

Training General Aviation Pilots for Convective Weather Situations

BACKGROUND

Over the past 10-15 yr, considerable research has occurred for the development, testing, and fielding of real-time Datalink weather products for general aviation (GA) pilots to use before and during flight. As is the case with the implementation of most new technologies, work is needed to ensure that the users (in this case, the pilots) understand both the capabilities and limitations of the new technologies as well as how to use the new systems to improve their task performance. The purpose of this study was to replicate and extend a previous study on training pilots how and when to use these new weather technologies.

METHOD

This field study used a quasi-experimental design (pre- vs. post-test with a control group). There were 91 GA pilots from the Midwest, Northeastern, and Southeastern United States who participated in a 2-h short course or a control activity. The lecture-based short course covered radar basics, Next Generation Weather Radar (NEXRAD), NEXRAD specifics/limitations, thunderstorm basics, radar products, and decision making.

RESULTS

The pilots who participated in the course earned higher knowledge test scores, improved at applying the concepts in paper-based flight scenarios, had higher self-efficacy in post-training assessments as compared to pre-training assessments, and also performed better than did control subjects on post-test knowledge and skills assessments.

DISCUSSION

GA pilots lack knowledge about real-time Datalink weather technology. This study indicates that a relatively short training program was effective for fostering Datalink weather-related knowledge and skills in GA pilots.

Risk Analysis for Unintentional Slide Deployment During Airline Operations

We present a risk analysis undertaken to mitigate problems in relation to the unintended deployment of slides under normal operations within a commercial airline. This type of incident entails relevant costs for the airline industry. After assessing the likelihood and severity of its consequences, we conclude that such risks need to be managed. We then evaluate the effectiveness of various countermeasures, describing and justifying the chosen ones. We also discuss several issues faced when implementing and communicating the proposed measures, thus fully illustrating the risk analysis process.

The Pilot-Patient and Mental Health

The recent crash of an airliner in the French Alps drew attention to the critical importance of the mental health of pilots and the key role physicians play in determining whether a pilot is fit to fly. This article reviews Federal Aviation Administration regulations and guidelines for making that determination and discusses the role of both the aviation medical examiner and the community physician in caring for pilots. It also offers community physicians tips for building solid relationships with pilot-patients so as to ensure they receive the best care possible.

Modelling runway incursion severity

Analysis of the causes underlying runway incursions is fundamental for the development of effective mitigation measures. However, there are significant weaknesses in the current methods to model these factors. This paper proposes a structured framework for modelling causal factors and their relationship to severity, which includes a description of the airport surface system architecture, establishment of terminological definitions, the determination and collection of appropriate data, the analysis of occurrences for severity and causes, and the execution of a statistical analysis framework. It is implemented in the context of U.S. airports, enabling the identification of a number of priority interventions, including the need for better investigation and causal factor capture, recommendations for airfield design, operating scenarios and technologies, and better training for human operators in the system. The framework is recommended for the analysis of runway incursions to support safety improvements and the methodology is transferable to other areas of aviation safety risk analysis.

The impact of airport characteristics on airport surface accidents and incidents

INTRODUCTION

Airport surface safety and in particular runway and taxiway safety is acknowledged globally as one of aviation's greatest challenges. To improve this key area of aviation safety, it is necessary to identify and understand the causal and contributing factors on safety occurrences. While the contribution of human factors, operations, and procedures has been researched extensively, the impact of the airport and its associated characteristics itself has received little or no attention.

METHOD

This paper introduces a novel methodology for risk and hazard assessment of airport surface operations, and models the relationships between airport characteristics, and (a) the rate of occurrences, (b) the severity of occurrences, and (c) the causal factors underlying occurrences.

RESULTS

The results show for the first time how the characteristics of airports, and in particular its infrastructure and operations, influence the safety of surface operations.

Assessing Knowledge Retention of an Immersive Serious Game vs. a Traditional Education Method in Aviation Safety

Thanks to the increasing availability of consumer head-mounted displays, educational applications of immersive VR could now reach to the general public, especially if they include gaming elements (immersive serious games). Safety education of citizens could be a particularly promising domain for immersive serious games, because people tend not to pay attention to and benefit from current safety materials. In this paper, we propose an HMD-based immersive game for educating passengers about aviation safety that allows players to experience a serious aircraft emergency with the goal of surviving it. We compare the proposed approach to a traditional aviation safety education method (the safety card) used by airlines. Unlike most studies of VR for safety knowledge acquisition, we do not focus only on assessing learning immediately after the experience but we extend our attention to knowledge retention over a longer time span. This is a fundamental requirement, because people need to retain safety procedures in order to apply them when faced with danger. A knowledge test administered before, immediately after and one week after the experimental condition showed that the immersive serious game was superior to the safety card. Moreover, subjective as well as physiological measurements employed in the study showed that the immersive serious game was more engaging and fear-arousing than the safety card, a factor that can contribute to explain the obtained superior retention, as we discuss in the paper.

[Shuttle Challenger disaster: what lessons can be learned for management of patients in the operating room?]

For many years hospitals have been implementing crew resource management (CRM) programs, inspired by the aviation industry, in order to improve patient safety. However, while contributing to improved patient care, CRM programs are controversial because of their limited impact, a decrease in effectiveness over time, and the underinvestment by some caregivers. By analyzing the space shuttle Challenger accident, the objective of this article is to show the potential impact of the professional culture in decision-making processes. In addition, to present an approach by cultural factors which are an essential complement to current CRM programs in order to enhance the safety of care.

The sustained attention to response task (SART) does not promote mindlessness during vigilance performance

OBJECTIVE

In this study, we evaluated the validity of the Sustained Attention to Response Task (SART) as a means for promoting mindlessness in vigilance performance.

BACKGROUND

Vigilance tasks typically require observers to respond to critical signals and to withhold responding to neutral events. The SART features the opposite response requirements, which supposedly leads it to promote a mindless, non-thoughtful approach to the vigilance task To test that notion, we compared the SART to the traditional vigilance format (TVF) in terms of diagnostic accuracy assessed through decision theory measures of positive and negative predictive power (PPP and NPP), perceived mental workload indexed by the Multiple Resource Questionnaire, and oculomotor activity reflected in the Nearest Neighbor Index and fixation dwell times.

METHOD

Observers in TVF and SART conditions monitored a video display for collision flight paths in a simulated air traffic control task.

RESULTS

Diagnostic accuracy in terms of NPP was high in both format conditions. While PPP was poorer in the SART than in the TVF, that result could be accounted for by a loss of motor control rather than a lack of mindfulness. Identical high levels of workload were generated by the TVF and SART tasks, and observers in both conditions showed similar dynamic scanning of the visual scene.

CONCLUSION

The data indicate that the SART is not an engine of mindlessness.

APPLICATION

The results challenge the widespread use of the SART to support a model in which mindlessness is considered to be the principal root of detection failures in vigilance.

Higher landing accuracy in expert pilots is associated with lower activity in the caudate nucleus

The most common lethal accidents in General Aviation are caused by improperly executed landing approaches in which a pilot descends below the minimum safe altitude without proper visual references. To understand how expertise might reduce such erroneous decision-making, we examined relevant neural processes in pilots performing a simulated landing approach inside a functional MRI scanner. Pilots (aged 20-66) were asked to "fly" a series of simulated "cockpit view" instrument landing scenarios in an MRI scanner. The scenarios were either high risk (heavy fog-legally unsafe to land) or low risk (medium fog-legally safe to land). Pilots with one of two levels of expertise participated: Moderate Expertise (Instrument Flight Rules pilots, n = 8) or High Expertise (Certified Instrument Flight Instructors or Air-Transport Pilots, n = 12). High Expertise pilots were more accurate than Moderate Expertise pilots in making a "land" versus "do not land" decision (CFII: d' = 3.62 ± 2.52; IFR: d' = 0.98 ± 1.04; p<.01). Brain activity in bilateral caudate nucleus was examined for main effects of expertise during a "land" versus "do not land" decision with the no-decision control condition modeled as baseline. In making landing decisions, High Expertise pilots showed lower activation in the bilateral caudate nucleus (0.97 ± 0.80) compared to Moderate Expertise pilots (1.91 ± 1.16) (p<.05). These findings provide evidence for increased "neural efficiency" in High Expertise pilots relative to Moderate Expertise pilots. During an instrument approach the pilot is engaged in detailed examination of flight instruments while monitoring certain visual references for making landing decisions. The caudate nucleus regulates saccade eye control of gaze, the brain area where the "expertise" effect was observed. These data provide evidence that performing "real world" aviation tasks in an fMRI provide objective data regarding the relative expertise of pilots and brain regions involved in it.

In-flight automatic detection of vigilance states using a single EEG channel

Sleepiness and fatigue can reach particularly high levels during long-haul overnight flights. Under these conditions, voluntary or even involuntary sleep periods may occur, increasing the risk of accidents. The aim of this study was to assess the performance of an in-flight automatic detection system of low-vigilance states using a single electroencephalogram channel. Fourteen healthy pilots voluntarily wore a miniaturized brain electrical activity recording device during long-haul flights ( 10 ±2.0 h, Atlantic 2 and Falcon 50 M, French naval aviation). No subject was disturbed by the equipment. Seven pilots experienced at least a period of voluntary ( 26.8 ±8.0 min, n = 4) or involuntary sleep (N1 sleep stage, 26.6 ±18.7 s, n = 7) during the flight. Automatic classification (wake/sleep) by the algorithm was made for 10-s epochs (O1-M2 or C3-M2 channel), based on comparison of means to detect changes in α, β, and θ relative power, or ratio [( α+θ)/β], or fuzzy logic fusion (α, β). Pertinence and prognostic of the algorithm were determined using epoch-by-epoch comparison with visual-scoring (two blinded readers, AASM rules). The best concordance between automatic detection and visual-scoring was observed within the O1-M2 channel, using the ratio [( α+θ )/β] ( 98.3 ±4.1% of good detection, K = 0.94 ±0.07, with a 0.04 ±0.04 false positive rate and a 0.87 ±0.10 true positive rate). Our results confirm the efficiency of a miniaturized single electroencephalographic channel recording device, associated with an automatic detection algorithm, in order to detect low-vigilance states during real flights.