Association of Medical Certification Factors with All-Cause Mortality in U.S. Aviators

INTRODUCTION: The value of aeromedical certification in reducing adverse medical outcomes is an especially important question for this era of increasing flight operations that do not require an FAA medical certificate. The study of this question has previously been thwarted by a lack of information about pilots when their medical certificates are not renewed.METHODS: We matched airmen in the FAA medical certification database to the U.S. Social Security Death Index to identify date of death for deceased pilots. Logistic regression models were used to explore associations of certification data with odds of death while holding a medical certificate and within 4 yr of expiration of a medical certificate.RESULTS: FAA aeromedical waivers were associated with 33% lower odds of death while holding a medical certificate and 35% increased odds of death within 4 yr after expiration of a medical certificate. Denial was associated with 21% increased odds of death in the next 4 yr. Only 13 of 47 medical conditions having significant associations were associated with increased odds of death during certification.DISCUSSION: We found that FAA aeromedical certification reduces the odds of death while holding a medical certificate compared to the 4 yr after certificate expiration. We believe this helps provide a positive answer to the question of whether medical certification reduces medically related events.Mills WD, Greenhaw RM. Association of medical certification factors with all-cause mortality in U.S. aviators. Aerosp Med Hum Perform. 2019; 90(11):938-944.

A Medical Review of Fatal High-G U.S. Aerobatic Accidents

INTRODUCTION: Exposure to high G force is a known safety hazard in military aviation as well as civilian aerobatic flight. Tolerance to high G forces has been well studied in military pilots, but there is little research directed at civilian pilots who may have medications or medical conditions not permitted in military pilots.METHODS: In this case-control study, we identified 89 fatal high-G aerobatic accidents and 4000 fatal control accidents from 1995 through 2018 from the NTSB accident database and the FAA autopsy database. We retrieved medications and medical conditions from the FAA's pilot medical databases. Logistic regression models were used to explore the associations of drugs, medical conditions, height, and medical waivers with high-G accidents.RESULTS: Seven drugs (alprazolam, clonidine, ethanol, meclizine, phentermine, triamterene, and zolpidem) reached statistical significance in our models, but had such small case counts that we consider these findings to be uncertain, except for ethanol, which was found in seven cases. Of these, only triamterene was known to the FAA. Statistically significant medical predictors included only alcohol abuse (seven cases) and liver disease (only two cases).DISCUSSION: Our analysis found that the drug ethanol and the condition alcohol abuse are significantly associated with high-G accidents. Seven other factors were statistically significant, but should only be considered as hypothesis generating due to very low case counts. Our study does not suggest that restricting pilots with otherwise permissible medications or medical conditions from aerobatics is warranted.Mills WD, Greenhaw RM, Wang JMP. A medical review of fatal high-G U.S. aerobatic accidents. Aerosp Med Hum Perform. 2019; 90(11):959-965.

Aviation Safety vs. Medical Confidentiality: Disclosure of Health Information for Accident Prevention and Investigation

INTRODUCTION: In this article an analysis is made of existing legal provisions and policies regarding medical confidentiality and the use of medical information on pilots, for the reporting of unfit pilots and for accident and incident investigation. An overview is given of the applicable international, European and several national legal frameworks in relation to this question. The applicable national legislation and relating policies of the Netherlands, the U.S., and Canada are compared on this subject. These three States (countries) are selected because of the differences between them in legal provisions when it comes to medical confidentiality of pilots' health information. The article will conclude with tools derived from this analysis, which can be used to find a balance between medical confidentiality vs. aviation safety.Schuite JM. Aviation safety vs. medical confidentiality: disclosure of health information for accident prevention and investigation. Aerosp Med Hum Perform. 2019; 90(10):872-881.

Integration of a Vestibular Model for the Disorientation Research Device Motion Algorithm Application

INTRODUCTION: Spatial disorientation (SD) remains a leading cause of Class A mishaps and fatalities in aviation. Motion-based flight simulators and other research devices provide the capacity to rigorously study SD in order to develop effective countermeasures. By applying mathematical models of human orientation perception, we propose an approach to improve control algorithms for motion-based flight simulators to study SD.METHODS: The Disorientation Research Device (DRD), or the Kraken™, is the Department of Defense's newest and most capable aerospace medicine motion-based research device. We implemented an "Observer" model for predicting aircrew spatial orientation perception within the DRD, and perceptions experienced in flight. Further, we propose a framework that uses the model output, in addition to pilot control inputs, to optimize multiaxis motion control including human-in-the-loop control capability.RESULTS: A case study was performed to demonstrate the functionality of the framework. Additionally, the case study highlights both how limitations of human perception are crucial to consider when designing motion algorithms, and the challenges of effective flight simulation with multiple motion axes.DISCUSSION: We implemented a mathematical model for spatial orientation perception to improve the design of control algorithms for motion-based flight simulators, using the DRD as an example application. We provide an example of predicting perceptions, producing quantitative information on the efficacy of motion control algorithms. This mathematical model based approach to validating motion control algorithms aims to improve the fidelity of ground-based SD research.Dixon JB, Etgan CA, Horning DS, Clark TK, Folga RV. Integration of a vestibular model for the Disorientation Research Device motion algorithm application. Aerosp Med Hum Perform. 2019; 90(10):901-907.

Anticipated Negative Emotions Effect on Incident Involvement Among Civil Pilots

INTRODUCTION: Human factors have contributed to a constant increase in the level and numbers of aviation incident involvement. The primary objective of this study is to investigate the relationships between anticipated negative emotions (ANEs) and incident involvement among Chinese civil pilots. Furthermore, this paper examines the role of risk perception and proactive coping within the relationships in order to understand the mechanisms underlying pilots' involvement in air transport incidents.METHODS: A cross-sectional regression design was used to measure ANEs (Anticipated Negative Emotions Scale), proactive coping (Proactive Coping Scale), risk perception (Pilot Risk Perception Scale), and incident involvement (Hazardous Events Scale) among 295 Chinese civil pilots from China Southern Airlines. Mediation and moderating effects were explored using regression analyses and were confirmed by the bootstrapping approach.RESULTS: The results show that ANEs are significantly correlated with risk perception (r = -0.55) and incident involvement (r = 0.28). ANEs have a direct effect on pilot involvement in incidents and have an indirect effect on pilot incident involvement through the influencing of risk perception. Proactive coping was also found to weaken the direct effect of anticipated negative emotions on incident involvement.DISCUSSION: The safety benefits of proactive coping are more pronounced among pilots with high levels of ANEs. The practical implications of the study include recommendations relating to injury prevention efforts in incident involvement. Future research directions are also discussed.Wang H, Xu Q, Yang C, You X, Ji M. Anticipated negative emotions effect on incident involvement among civil pilots. Aerosp Med Hum Perform. 2019; 90(9):774-781.

Self-Assessed Preferred Retraining Intervals of Helicopter Underwater Egress Training (HUET)

BACKGROUND: Royal Netherlands Air Force (RNLAF) helicopter aircrew get Helicopter Underwater Egress Training (HUET) using a Modular Egress Training Simulator (METS™) in order to be prepared for escaping the aircraft when ditching into water. In the current situation the retraining intervals are only chosen on an arbitrary basis for different backgrounds of the crew (maritime and regular flight crew). The frequency of refresher training depends on the expected degree of retention, but evidence-based research on required intervals between refresher courses is scarce. Ideally, training should be based on the amount of retention of acquired competencies.METHODS: Retrospective questionnaires were filled in by 132 helicopter aircrew who followed the HUET course(s) at the Survival Evasion Resistance and Escape (SERE) school in Gilze-Rijen (Netherlands). They assessed themselves on competencies and gave their opinion on the preferred interval.RESULTS: Maritime crew report increasing competence levels with the number of refresher courses followed. According to the opinion of all aircrew, retraining intervals may take longer than 18 (first refresher) to 30 mo (fourth refresher). Maritime and regular flight crew differ in preferred retraining intervals (up to 22 mo and up to 33 mo, respectively).DISCUSSION: This study provides indications to reconsider the retraining interval and to differentiate between maritime and regular flight crew based on aircrew's opinions and self-assessments. As competence levels still increase with the number of courses followed, it is recommended to reconsider the current fixed intervals of once a year or once every 3 yr for maritime and regular flight crew, respectively.Bottenheft C, Oprins EAPB, Houben MMJ, Meeuwsen T, Valk PJL. Self-assessed preferred retraining intervals of Helicopter Underwater Egress Training (HUET). Aerosp Med Hum Perform. 2019; 90(9):800-806.

Preflight Risk Assessment for Improved Safety in Helicopter Emergency Medical Service Operations

INTRODUCTION: Adverse weather and poor visual cues are common elements in night-time Helicopter Emergency Medical Service (HEMS) operations contributing to spatial disorientation and fatal accidents. Pilots are required to make weather-related preflight risk assessments to accept or reject a flight. This study's aim was to develop predictive risk assessment tools based on historical accident data to assist the decision-making process.METHODS: We analyzed 32 single-pilot HEMS night-time visual flight rules fatal accidents to identify contributory risk factors. Logistic regression analysis was used to develop prediction nomograms for nonvisual meteorological conditions (non-VMC), cause and nonsurvivable accidents as dependent variables. Risk factors such as temperature dew point spread, elevation difference, and years of HEMS pilot experience, were entered as continuous variables. Flight crew composition, pilot DTE (domain task experience) and flight rule capability, primary missions, and temperature dew point spread were entered as categorical variables. A point scoring matrix transposed model probability to likelihood and consequence severity.RESULTS: The nomograms correctly predicted the likelihood of entering non-VMC, accident cause, and sustaining a nonsurvivable accident in 75%, 55%, and 94% of cases, respectively. Using data from a recent nonsurvivable HEMS accident, the nomogram estimated a 92% probability (Very Likely) of nonsurvivable accident if visual cues were lost.CONCLUSION: These nomograms can provide preflight information to predict the likelihood of adverse safety outcomes occurring during a planned HEMS mission. While further development work is needed, this approach has the potential to improve HEMS operational safety.Aherne BB, Zhang C, Chen WS, Newman DG. Preflight risk assessment for improved safety in Helicopter Emergency Medical Service operations. Aerosp Med Hum Perform. 2019; 90(9):792-799.

U.S. Army Parachute Mishap Fatalities: 2010-2015

INTRODUCTION: Despite the large number of U.S. military members who conduct parachuting operations, its inherent safety risks, and the introduction of a new military parachute in 2010, little has been published in the last decade on U.S. military parachute fatalities.METHODS: Parachute fatality investigative records maintained by the U.S. Army Combat Readiness Center were reviewed for U.S. Army fatalities resulting from military parachuting operations from January 1, 2010, through December 31, 2015. De-identified data on cases were collected, including causes, lethal injuries, and demographic, environmental, and missional factors. A descriptive analysis was performed.RESULTS: There were 13 cases which met study inclusion criteria. Most occurred during static-line operations and were jumps from a C-17 aircraft using a T-11 parachute. The two most common assigned accident codes were "improper or abnormal exit" and "unstable or improper body position," which combined accounted for 33% of cases. Also noteworthy at 11% each were "entanglement," "parachute malfunction," and "dragged on the drop zone," and at 6% each were "static line injury," "lost or stolen air," and "drop zone hazard." In 69% of cases blunt force trauma was the cause of death.DISCUSSION: Incident factors included human actions, equipment failure, and the environment. Death from blunt force trauma upon impact with the ground as the most frequent lethal injury was expected for parachute operations. This descriptive study provides awareness to military leaders of circumstances in which fatalities occur. Future investigations should include data on the total number of jumps to provide a more comprehensive analysis of risk.Johnson ES, Gaydos SJ, Pavelites JJ, Kotwal RS, Houk JE. U.S. Army parachute mishap fatalities: 2010-2015. Aerosp Med Hum Perform. 2019; 90(7):637-642.

An analysis of human factors in fifty controlled flight into terrain aviation accidents from 2007 to 2017

INTRODUCTION

Controlled Flight Into Terrain (CFIT) account for a considerable amount of fatalities when compared to other accident categories. Human factors are deemed significant contributory causes in these accidents. This paper aims to identify the human factors involved with aviation accidents that resulted in CFIT.

METHOD

The study used the Human Factors Analysis and Classification System (HFACS) framework to determine the factors involved in 50 CFIT accidents from 24 counties over a 10 year period, i.e. 2007-2017. Interviews with five senior aviation safety experts were used to provide a better comprehension of the human factors affecting the flight safety.

RESULTS

The study identified 1289 individual causal and contributory human factors with unsafe actions and preconditions for unsafe actions being the main subcategories of the accidents. The study found that CFIT occur across a range of pilot experience and 44% of accidents occurred in cruise flight. Distraction, complacency and fatigue are all elements that flight crews may experience as contributors to CFIT during cruising.

CONCLUSIONS

Human factors represent a major component of CFIT accidents. The analysis revealed a similar pattern of contributory and causal human factors across the various flight categories, with some noteworthy isolated variations. The prevalent factors were decision and skill-based errors along with communication, coordination and planning issues. Practical applications: Provision of specific CFIT awareness, pilot training focusing on improved decision-making and revision of basic flight skills, development of specific Global Positioning System routes for transiting high terrain areas are necessary to prevent CFIT accidents. Installation of Terrain Avoidance and Warning System and Ground Proximity Warning System and appropriate equipment training, specific CFIT Crew Resource Management training and improvement of organizational knowledge on the elements involved in CFIT are also recommended.

Modafinil as a Stimulant for Military Aviators

INTRODUCTION: Modafinil is a wakefulness-promoting stimulant that has been approved by the Republic of Singapore Air Force (RSAF) as a fatigue countermeasure medication since 2011. Each RSAF aircrew member must undergo a ground test to exclude operationally relevant adverse drug effects prior to consuming the medication for operational reasons. This study describes the RSAF's modafinil ground testing outcomes over a 7-yr period.METHODS: This is a retrospective case series of 243 RSAF aircrew members who underwent modafinil 100-mg test dosing over the 7-yr period from September 2011 to September 2018.RESULTS: The median age was 31 yr (range, 21-53 yr) and mean age was 31.7 yr ± 6.19 yr. Of the aircrew members, 234 (96.3%) were men and all were of Asian ethnicity. Of the subjects, 237 (97.5%) were medically cleared for the operational use of modafinil. Among the six (2.47%) who failed modafinil ground testing, headache (cumulative incidence, 1.65%), anxiety (cumulative incidence, 0.41%), diarrhea (cumulative incidence, 0.41%), and insomnia (cumulative incidence, 0.41%) were reported as the side effects experienced. None of the aircrew members experienced major adverse drug events.DISCUSSION: Our findings suggest a low occurrence of adverse drug effects among military aircrew members who undergo modafinil test dosing prior to using the drug operationally. To our knowledge, this is the single largest published case series of modafinil ground testing outcomes among Asian military aviators.Ooi T, Wong SH, See B. Modafinil as a stimulant for military aviators. Aerosp Med Hum Perform. 2019; 90(5):480-483.

Safety Implications of 6-Month vs. 1-Year First-Class Aeromedical Certificates

INTRODUCTION: This study explores the safety risk due to delayed detection of hazardous health conditions that would result from increasing the duration of U.S. first-class aeromedical certificates from 6 mo to 12 mo for pilots ages 40 yr old through 60 yr old.METHODS: All pilots who submitted a U.S. first-class application in 2014 with no electrocardiogram and with the previous exams 4.5 to 7.5 mo prior were selected from the FAA pilot medical database. Proportions of Federal Aviation Administration (FAA) denial pathology codes and Aviation Medical Examiner (AME) deferrals were compared for these exams within and between age groups from 40 yr old through 75 yr old. The absolute incidence rates for delayed detection were calculated and relative incidence of these proportions was compared graphically.RESULTS: The relative risk between age groups for delayed identification of disqualifying medical conditions showed that the 56-60-yr-old group would be at about twice the risk as the 40-45-yr-old group. The absolute incidence for the 56-60-yr-old group was 0.46% for denial conditions and 0.60% for AME deferrals over 6 mo.DISCUSSION: Increasing FAA first-class medical certificate duration from 6 mo to 12 mo would put 56-60-yr-old pilots at double the currently accepted risk for delayed detection of significant medical conditions. The absolute risk for this 6-mo delayed identification for the 56-60-yr-old group would average 0.53%.Mills WD, DeJohn CA. Safety implications of 6-month vs. 1-year first-class aeromedical certificates. Aerosp Med Hum Perform. 2019; 90(5):484-487.

Systems Safety Risk Analysis of Fatal Night Helicopter Emergency Medical Service Accidents

INTRODUCTION: In the United States, the proportion of Helicopter Emergency Medical Service (HEMS) fatal accidents remained unchanged despite an overall decreasing accident rate. Previous research showed night HEMS operations influenced fatal outcomes. Pilots with <6 yr of HEMS domain task experience (low-DTE) had a higher likelihood of a night operational accident in conditions associated with adverse weather. This study sought to determine whether a difference existed between day and night fatal accident rates and identify influences contributing to night fatal HEMS accidents. Any risk factors identified will be used for a risk analysis to inform future operational safety of the night visual flight rule (VFR) HEMS transport system.METHODS: Historical accident data and industry hours were obtained. Both pilot DTE groups (low and high) and mission VFR and instrument flight rule (IFR) capability were identified using data from 32 night VFR operational fatal HEMS accidents. Accidents were stratified by loss of control and controlled flight into terrain, pilot DTE, and flight rule capability. The effectiveness of both DTE groups and both flight rule capabilities were measured using system safety risk analysis techniques.RESULTS: Night fatal accident rates were statistically different from daytime. Low-DTE pilots and the VFR capability combination had the highest likelihood of night operational nonsurvivable accident.CONCLUSION: Low-DTE pilots and the VFR capability were the least effective mission combination to avoid hazardous conditions at night and maintain spatial orientation, respectively. The analysis identified measures to reduce likelihood of night fatal operational accidents.Aherne BB, Zhang C, Chen WS, Newman DG. Systems safety risk analysis of fatal night Helicopter Emergency Medical Service accidents. Aerosp Med Hum Perform. 2019; 90(4):396-404.

Speech Analysis for Fatigue and Sleepiness Detection of a Pilot

BACKGROUND: Mental fatigue and sleepiness are well recognized determinants of human-error related accidents and incidents in aviation. In Brazil, according to the Center for Investigation and Prevention of Aeronautical Accidents (CENIPA), the rate of accidents in the aerial modal is 1 per 2 d. Human factors are present in 90% of these accidents.CASE REPORT: This paper describes a retrospective study of the communication between a pilot and an air traffic control tower just before a fatal accident. The objective was the detection of fatigue and sleepiness of a pilot, who complained of these signs and symptoms before the flight, by means of voice and speech analysis. The in-depth accident analysis performed by CENIPA indicated that sleepiness and fatigue most likely contributed to the accident. Speech samples were analyzed for two conditions: 1) nonsleepy data recorded 35 h before the air crash (control condition), which were compared with 2) data from samples collected about 1 h before the accident and also during the disaster (sleepy condition). Audio recording analyses provided objective measures of the temporal organization of speech, such as hesitations, silent pauses, prolongation of final syllables, and syllable articulation rate.DISCUSSION: The results showed that speech during the day of the accident had significantly low elocution and articulation rates compared to the preceding day, also indicating that the methodology adopted in this study is feasible for detection of fatigue and sleepiness through speech analysis.de Vasconcelos CA, Vieira MN, Kecklund G, Yehia HC. Speech analysis for fatigue and sleepiness detection of a pilot. Aerosp Med Hum Perform. 2019; 90(4):415-418.

What went right? An analysis of the protective factors in aviation near misses

Learning from successful safety outcomes, or what went right, is an important emerging component of maintaining safe systems. Accordingly, there are increasing calls to study normal performance in near misses as a part of safety management activities. Despite this, there is limited guidance on how to accomplish this in practice. This article presents a study in which using Rasmussen's risk management framework to analyse 16 serious incidents from the aviation domain. The findings show that a network of protective factors prevents accidents with factors identified across the sociotechnical system. These protective networks share many properties with those identified in accidents. The article demonstrates that is possible to identify these networks of protective factors from incident investigation reports. The theoretical implications of these results and future research opportunities are discussed. Practitioner Statement: The analysis of near misses is an important part of safety management activities. This article demonstrates that Rasmussen?s risk management framework can be used to identify networks of protective factors which prevent accidents. Safety practitioners can use the framework described to discover and support the system-wide networks of protective factors.

Maintenance and inspection as risk factors in helicopter accidents: Analysis and recommendations

In this work, we establish that maintenance and inspection are a risk factor in helicopter accidents. Between 2005 and 2015, flawed maintenance and inspection were causal factors in 14% to 21% of helicopter accidents in the U.S. civil fleet. For these maintenance-related accidents, we examined the incubation time from when the maintenance error was committed to the time when it resulted in an accident. We found a significant clustering of maintenance accidents within a short number of flight-hours after maintenance was performed. Of these accidents, 31% of these accidents occurred within the first 10 flight-hours. This is reminiscent of infant mortality in reliability engineering, and we characterized it as maintenance error infant mortality. The last quartile of maintenance-related accidents occurred after 60 flight-hours following maintenance and inspection. We then examined the "physics of failures" underlying maintenance-related accidents and analyzed the prevalence of different types of maintenance errors in helicopter accidents. We found, for instance, that the improper or incomplete (re)assembly or installation of a part category accounted for the majority of maintenance errors with 57% of such cases, and within this category, the incorrect torquing of the B-nut and incomplete assembly of critical linkages were the most prevalent maintenance errors. We also found that within the failure to perform a required preventive maintenance and inspection task category, the majority of the maintenance programs were not executed in compliance with federal regulations, nor with the manufacturer maintenance plan. Maintenance-related accidents are particularly hurtful for the rotorcraft community, and they can be eliminated. This is a reachable objective when technical competence meets organizational proficiency and the collective will of all the stakeholders in this community. We conclude with a set of recommendations based on our findings, which borrow from the ideas underlying the defense-in-depth safety principle to address this disquieting problem.

Using Neural Networks to predict HFACS unsafe acts from the pre-conditions of unsafe acts

Human Factors Analysis and Classification System (HFACS) is based upon Reason's organizational model of human error which suggests that there is a 'one to many' mapping of condition tokens (HFACS level 2 psychological precursors) to unsafe act tokens (HFACS level 1 error and violations). Using accident data derived from 523 military aircraft accidents, the relationship between HFACS level 2 preconditions and level 1 unsafe acts was modelled using an artificial neural network (NN). This allowed an empirical model to be developed congruent with the underlying theory of HFACS. The NN solution produced an average overall classification rate of ca. 74% for all unsafe acts from information derived from their level 2 preconditions. However, the correct classification rate was superior for decision- and skill-based errors, than for perceptual errors and violations. Practitioner Summary: A model to predict unsafe acts (HFACS level 1) from their preconditions (HFACS level 2) was developed from the analysis of 523 military aircraft accidents using an artificial NN. The results could correctly predict approximately 74% of errors.

Eye tracking as a debriefing tool in upset prevention and recovery training (UPRT) for general aviation pilots

Upset prevention and recovery training (UPRT) is intended to improve the ability of pilots to recognize and avoid situations that can lead to airplane upsets and to improve their ability to recover control of an airplane that has exceeded the normal flight envelope. To this end, a set of different training contents - from theoretical knowledge of aerodynamics and human factors to practice-based flight training - is necessary. In order to support the debriefing with an objective feedback, and because visual scanning is a core competence, two studies on subjective evaluation of aviation pilots - one conducted in a flight simulator and the other one in-flight - focussed on the practical application of eye tracking as a debriefing tool in UPRT. From a practitioner's perspective, eye tracking appeared to be a useful method in terms of visualising instrument scanning techniques, supporting the instructor with objective debriefing material and fostering self-awareness in human processes. The discussion recommends adjusted UPRT instructor training and further improvements to eye tracking hardware and software. Practitioner Summary: The article focuses on pilot evaluations of eye tracking as a debriefing tool in UPRT and the identification of critical elements in its use. Eye tracking is a promising debriefing tool for UPRT. The discussion points to desirable improvements of eye tracking hardware and software as well as adjustments to instructor training that are pertinent.

Modelling distributed crewing in commercial aircraft with STAMP for a rapid decompression hazard

Changes to crewing configurations in commercial airlines are likely as a means of reducing operating costs. To consider the safety implications for a distributed crewing configuration, system theoretic accident model and processes (STAMP) was applied to a rapid decompression hazard. High level control structures for current operations and distributed crewing are presented. The CONOPS generated by STAMP-STPA for distributed crewing, and design constraints associated with unsafe control actions (UCAs) are offered to progress in the route to certification for distributed crewing, and improve safety in current operations. Control loops between stakeholders were created using system-theoretic process analysis (STPA). The factors leading to the Helios 255 incident demonstrated the redundancy that a ground station could offer without the risk of hypoxia, during a decompression incident. STPA analysis also highlighted initial UCAs that could occur within the hypothetical distributed crewing configuration, prompting consideration of design constraints and new CONOPS for ground station design. Practitioner Summary: SPO in commercial aircraft is likely as a means to reduce costs. This paper makes a case for distributed crewing using STAMP-STPA. Comparing current operations with a distributed crewing configuration, the redundancy offered by a ground station is demonstrated. Design constraints and new CONOPs for distributed crewing, and current operations are proposed.

Parachute use to prevent death and major trauma when jumping from aircraft: randomized controlled trial

OBJECTIVE

To determine if using a parachute prevents death or major traumatic injury when jumping from an aircraft.

DESIGN

Randomized controlled trial.

SETTING

Private or commercial aircraft between September 2017 and August 2018.

PARTICIPANTS

92 aircraft passengers aged 18 and over were screened for participation. 23 agreed to be enrolled and were randomized.

INTERVENTION

Jumping from an aircraft (airplane or helicopter) with a parachute versus an empty backpack (unblinded).

MAIN OUTCOME MEASURES

Composite of death or major traumatic injury (defined by an Injury Severity Score over 15) upon impact with the ground measured immediately after landing.

RESULTS

Parachute use did not significantly reduce death or major injury (0% for parachute v 0% for control; P>0.9). This finding was consistent across multiple subgroups. Compared with individuals screened but not enrolled, participants included in the study were on aircraft at significantly lower altitude (mean of 0.6 m for participants v mean of 9146 m for non-participants; P<0.001) and lower velocity (mean of 0 km/h v mean of 800 km/h; P<0.001).

CONCLUSIONS

Parachute use did not reduce death or major traumatic injury when jumping from aircraft in the first randomized evaluation of this intervention. However, the trial was only able to enroll participants on small stationary aircraft on the ground, suggesting cautious extrapolation to high altitude jumps. When beliefs regarding the effectiveness of an intervention exist in the community, randomized trials might selectively enroll individuals with a lower perceived likelihood of benefit, thus diminishing the applicability of the results to clinical practice.

A modified accident analysis and investigation model for the general aviation industry: Emphasizing on human and organizational factors

INTRODUCTION

Currently, there is a lack of specific analytical tools for general aviation accidents (GAAs). This has led to loopholes in the prevention of GAAs.

METHODS

A Swiss Cheese model for general aviation (SCM-GA) is proposed to identify the human and organizational factors involved in GAAs. In the proposed SCM-GA, 5 categories, 45 subcategories, a general aviation safety management system (GA-SMS) and safety culture were developed based on the classic accident causation models combined with the laws and regulations and safety management practices in the general aviation industry.

RESULTS

One GAA was analyzed using SCM-GA. The human and organizational causes revealed by SCM-GA were more complete than the causes revealed through the accident report. The identification results of the deficiencies in the subcategories of GA-SMS and the safety culture were more consistent with the requirements in the general aviation laws and regulations than the organizational factors in the accident report. Based on the subcategories of SCM-GA, 41 GAAs that occurred between 1996 and 2010 in China were statistically analyzed and χ² test analyses were performed to estimate the statistical strength of the association between two adjacent subcategories of SCM-GA. The results showed that two adjacent subcategories of SCM-GA were significantly associated. They helped to determine the hidden problems in the accident report based on the path of accident.

CONCLUSIONS

SCM-GA is an accident analysis tool that can comprehensively analyze the human and organizational deficiencies involved in GAAs. The accident causes revealed by SCM-GA were more consistent with the general aviation safety management practices.

PRACTICAL APPLICATIONS

General aviation companies should establish their own GA-SMS and safety culture based on the subcategories developed herein. Using SCM-GA for routine safety inspection and accident investigation will help the management and the staff make effective safety decisions to effectively prevent GAAs.

Parallels in safety between aviation and healthcare

Aviation and healthcare are complex industries and share many similarities: the cockpit and the operating theater, the captain and the surgeon. While North American commercial aviation currently enjoys a tremendous safety record, it was not always this way. A spike of accidents in 1973 caused 3214 aviation-related fatalities. Over the past 20years, the rate of fatal accidents per million flights fell by a factor of five, while air traffic increased by more than 86%. There have been no fatalities on a U.S. carrier for over 12years. Last year, there were 251,454 deaths in the United States owing to medical error. Pilots pioneered ways to address risks through crew resource management (CRM), and threat and error management (TEM). Both strategies, which are aimed at minimizing risk and optimizing safety, are applicable to surgery and the healthcare industry. These strategies as well as the Swiss Cheese Model, Checklists and the Normalization of Deviance will be reviewed in this article.

Concurrent Pilot Instrument Monitoring in the Automated Multi-Crew Airline Cockpit

INTRODUCTION

Pilot instrument monitoring has been described as "inadequate," "ineffective," and "insufficient" after multicrew aircraft accidents. Regulators have called for improved instrument monitoring by flight crews, but scientific knowledge in the area is scarce. Research has tended to investigate the monitoring of individual pilots when in the pilot-flying role; very little research has looked at crew monitoring, or that of the "monitoring-pilot" role despite it being half of the apparent problem.

METHODS

Eye-tracking data were collected from 17 properly constituted and current Boeing 737 crews operating in a full motion simulator. Each crew flew four realistic flight segments, with pilots swapping between the pilot-flying and pilot-monitoring roles, with and without the autopilot engaged. Analysis was performed on the 375 maneuvering-segments prior to localizer intercept.

RESULTS

Autopilot engagement led to significantly less visual dwell time on the attitude director indicator (mean 212.8-47.8 s for the flying pilot and 58.5-39.8 s for the monitoring-pilot) and an associated increase on the horizontal situation indicator (18-52.5 s and 36.4-50.5 s).

DISCUSSION

The flying-pilots' withdrawal of attention from the primary flight reference and increased attention to the primary navigational reference was paralleled rather than complemented by the monitoring-pilot, suggesting that monitoring vulnerabilities can be duplicated in the flight deck. Therefore it is possible that accident causes identified as "inadequate" or "insufficient" monitoring, are in fact a result of parallel monitoring.Jarvis SR. Concurrent pilot instrument monitoring in the automated multi-crew airline cockpit. Aerosp Med Hum Perform. 2017; 88(12):1100-1106.

Debiasing visual pilots' weather-related decision making

Pilots who decide to continue a flight into deteriorating weather conditions, rather than turn back or divert, are a significant cause of fatal crashes in general aviation. Earlier research has suggested that cognitive biases such as the anchoring effect and confirmation bias are implicated in many decisions to continue into worsening weather. In this study, we explored whether a simple debiasing technique, 'considering the alternative', reduced the effect of these two potentially fatal biases. Despite the study being adequately powered, our attempts to reduce the effects of biases were both unsuccessful. Negative findings such as these are particularly useful in aviation, as they can provide information on what does not work in this high stakes industry, even though such strategies may work elsewhere.

Rates and causes of accidents for general aviation aircraft operating in a mountainous and high elevation terrain environment

BACKGROUND

Flying over mountainous and/or high elevation terrain is challenging due to rapidly changeable visibility, gusty/rotor winds and downdrafts and the necessity of terrain avoidance. Herein, general aviation accident rates and mishap cause/factors were determined (2001-2014) for a geographical region characterized by such terrain.

METHODS

Accidents in single piston engine-powered aircraft for states west of the US continental divide characterized by mountainous terrain and/or high elevation (MEHET) were identified from the NTSB database. MEHET-related-mishaps were defined as satisfying any one, or more, criteria (controlled flight into terrain/obstacles (CFIT), downdrafts, mountain obscuration, wind-shear, gusting winds, whiteout, instrument meteorological conditions; density altitude, dust-devil) cited as factors/causal in the NTSB report. Statistics employed Poisson distribution and contingency tables.

RESULTS

Although the MEHET-related accident rate declined (p<0.001) 57% across the study period, the high proportion of fatal accidents showed little (40-43%) diminution (χ²=0.935). CFIT and wind gusts/shear were the most frequent accident cause/factor categories. For CFIT accidents, half occurred in degraded visibility with only 9% operating under instrument flight rules (IFR) and the majority (85%) involving non-turbo-charged engine-powered aircraft. For wind-gust/shear-related accidents, 44% occurred with a cross-wind exceeding the maximum demonstrated aircraft component. Accidents which should have been survivable but which nevertheless resulted in a fatal outcome were characterized by poor accessibility (60%) and shoulder harness under-utilization (41%).

CONCLUSION

Despite a declining MEHET-related accident rate, these mishaps still carry an elevated risk of a fatal outcome. Airmen should be encouraged to operate in this environment utilizing turbo-charged-powered airplanes and flying under IFR to assure terrain clearance.