BACKGROUND: The aim of the study was to determine the characteristics of cervical muscle activity in different head postures when using helmet-mounted display in one fighter vs. two aircraft air combat within visual range (WVR).METHODS: Cervical EMG was measured with eight F/A-18 pilots using the Joint Helmet Mounted Cueing System (JHMCS) during air combat maneuvering. In-flight G_z acceleration and continuous head position were recorded. EMG activity is divided and presented in a matrix with three-class rotation and five-class flexion-extension postures.RESULTS: The mean muscle activity in sternocleidomastoids and cervical extensors was 28.9% of maximal voluntary contraction (MVC) and 44.8% MVC, respectively. Cervical flexor and extensor muscles are subjected to loading over MVC during high G_z sorties. Cervical rotation combined with extension exceeded muscle force-producing capacity during high G_z, resulting in a decline in muscle activity.DISCUSSION: Awkward postures, especially rotational ones, are more prone to increase loading over muscles’ capacity. Overloading of muscles increases the risk of muscular and ligamentous injury. In addition, the lack of muscular support potentially leads to the G_z loading being transferred to spinal structures via intervertebral discs and the vertebral column. The JHMCS helmet seems to change the pattern of most loading muscles toward the extensor (posterior) neck muscles.Sovelius R, Mäntylä M, Heini H, Oksa J, Valtonen R, Tiitola L, Leino T. Joint helmet-mounted cueing system and neck muscle activity during air combat maneuvering. Aerosp Med Hum Perform. 2019; 90(10):834–840.

INTRODUCTION: In the present study, an Adaptive Ground Control System for Multiple-UAV Operator Workload Decrement (AGCS) has been developed and the effectiveness of the system has been analyzed using eye-tracking and task performance data. The AGCS contained four more functions than the conventional GCS (CGCS) functions. The functions were based on real-time operator gaze information, multiple UAV operational state, and mission state information to help safe and efficient multiple UAV operation.METHODS: A total of 30 volunteers participated in the human-in-the-loop experiment to compare the performances of the newly developed AGCS and CGCS while executing reconnaissance and strike missions by operating multiple UAVs.RESULTS: According to the results, the AGCS demonstrates a statistically significant increase in mission performance, such as the mission completion rate (M = 97.3 vs. M = 95.4; SD = 3.1 vs. SD = 4.9) and mission success rate (M = 90.4 vs. M = 88.4; SD = 5.7 vs. SD = 5.6). In addition, the subjects’ pupil diameter and gaze indicator show significant differences in the direction of workload reduction (α = 0.05). The subjects expressed positive opinions about using the AGCS.DISCUSSION: The originally developed AGCS showed a promising future extension based on the experimental data. After completion of the experiment, domain experts were interviewed and the next version will reflect their opinion.Lim H-J, Choi S-H, Oh J, Kim BS, Kim S, Yang JH. Adaptive ground control system of muliple-UAV operators in a simulated environment. Aerosp Med Hum Perform. 2019; 90(10):841–850.

INTRODUCTION: Paragliding is an emerging discipline of aviation, with recreational pilots flying distances over 100 km. It remains risky. Accidents typically relate to pilot error rather than equipment failure. We measured cognition and physiological responses during simulated flight, to investigate whether errors might be due to pilot impairment, rather than misjudgment.METHODS: There were 10 male paraglider pilots (aged 19–58 yr) who undertook a simulated flight in an environmental chamber from sea level (0.209 F_Io₂) to 1524 m (0.174 F_Io₂), 2438 m (0.156 F_Io₂), and 3658 m (0.133 F_Io₂), over approximately 2 h. They experienced normobaric hypoxia, environmental cooling and headwind, completing logical reasoning, mannikin, mathematical processing, Stroop Color-Word and Tower Puzzle tasks; as well as measures of risk-taking (BART), mood (POMS), and subjective experience.RESULTS: Results were compared to ten controls, matched by age, sex, and flying experience. Physiological measures were oxygen consumption, carbon dioxide production, ventilation, heart rate, oxygen saturation, rectal and skin temperatures, blood glucose, blood lactate, and urine production. There were no significant differences between pilots and controls at any altitude. Results were heterogenous within and between individuals. As altitude increased, oxygen consumption and minute volume increased significantly, while oxygen saturations fell (98.3% [baseline] to 88.5% [peak]). Rectal temperatures fell by a statistically (but not clinically) significant amount (37.6°C to 37.3°C), while finger skin temperatures dropped steeply (32.2°C to 13.9°C).DISCUSSION: Results suggest cognitive impairment is unlikely to be a primary cause of pilot error during paragliding flights (of less than 2 h, below 3658 m), though hand protection requires improvement.Wilkes M, Long G, Massey H, Eglin C, Tipton MJ. Cognitive function in simulated paragliding flight. Aerosp Med Hum Perform. 2019; 90(10):851–859.

BACKGROUND: The study aimed to identify factors associated with an increased likelihood of aircraft maintenance personnel reporting a fatigue-related error.METHODS: There were 966 maintenance engineering personnel (mean age = 42 yr, 98% male) who completed a survey with items on personal factors, work factors and a question asking whether during the last month they had made an error in their work due to tiredness. Logistic regression analyses were used to determine factors independently associated with making an error at work due to tiredness.RESULTS: Respondents obtained on average 7.0 h sleep and nearly half (45%) reported that they had felt close to falling asleep while driving home from work in the past 12 mo. Most respondents (70%) had received no education on strategies for coping with shift work. Among respondents, 22% agreed/strongly agreed with the statement “During the last month, I have made an error in my work due to tiredness.” Unexpected roster changes independently predicted the likelihood of reporting an error in work due to tiredness and for certain groups of aircraft maintenance personnel, < 6.5 h sleep increased the odds of an error in work due to tiredness fivefold, whereas > 7.5 h sleep almost halved the odds of reporting such an error.DISCUSSION: These findings indicate the importance of stable and predictable work patterns to minimize the risk of fatigue-related errors in this safety critical environment, and also the need for education on coping with shift work to ensure the workforce are best placed to manage their sleep away from work.Signal TL, van den Berg MJ, Mulrine HM. Personal and work factors that predict fatigue-related errors in aircraft maintenance engineering. Aerosp Med Hum Perform. 2019; 90(10):860–866.

BACKGROUND: Preventive treatment for incidentally detected blebs or bullae is required for fast jet pilots, but their aeromedical risk is not clearly proven.METHODS: This is a retrospective study and includes 46 pilots 40 yr and older with incidentally detected emphysema-like changes (ELCs) comprising blebs or bullae in low-dose chest CT (LDCT) during health screening. Two radiologists retrospectively reviewed imaging features. Statistical analysis was done using independent t-tests and bivariate analysis.RESULTS: Among 46 pilots, 39 pilots flew fast jet aircraft and 7 pilots flew nonfast jet aircraft. The mean follow-up period was 1531 d and the LDCT follow-up interval mean period was 424.4 d. There was no evidence of rupture in incidentally detected ELCs during the follow-up period. The mean size of the ELCs was 19.15 mm. There were five cases showing changes in size. There was a statistically significant correlation between the size of ELCs and height. There were no statistically significant differences in the size or number of ELCs relating to smoking status or aircraft type, and there were no statistically significant correlations between the size or number of ELCs and multiple factors, including smoking quantity, flight time, age, BMI, and weight.CONCLUSION: This study demonstrates the aeromedical safety of incidentally detected ELCs in pilots 40 yr and older without underlying lung disease. The results indicate no need for recommending preventive treatment for ELCs in pilots 40 yr and older, even those flying fast jet aircraft, as a requisite to continue their flight duties. KEYWORDS: bleb, bulla, pilot, CT.Bang S, Yang S, Cho SW, Kim DH, Kang H. Follow-up of blebs and bullae in pilots 40 years and older using CT. Aerosp Med Hum Perform. 2019; 90(10):867–871.

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.

BACKGROUND: During flight, fast jet pilots frequently move their heads into extreme positions while withstanding large amounts of stress on their cervical spines. These factors are thought to contribute to episodes of neck pain.METHODS: We conducted a systematic review and meta-analysis of previous neck pain prevalence data in fast jet pilots to determine an overall pooled prevalence. Subgroup analyses were performed according to when pilots complained about their neck pain, whether these same pilots sought treatment, and if they lost time from flying. Four research databases were searched. Studies were eligible for inclusion if they were written in English, involved a group of fast jet pilots who were actively flying high performance aircraft, and reported quantitative prevalence data about neck pain in these pilots. These eligibility criteria were independently applied by two reviewers and risk of bias was evaluated. MetaXL software was used to conduct the meta-analysis.RESULTS: In total, 8003 fast jet pilots across 18 eligible studies were included in the review. The overall pooled prevalence of neck pain in fast jet pilots was 51%. It was found that 39% of subjects lost time from flying, while only 32% sought medical treatment.DISCUSSION: Neck pain in fast jet pilots adversely affects operational capabilities of defense forces. The prevalence of neck pain varies according to the definitions or thresholds of complaints used across the literature. Further research is required to standardize the definition of neck pain.Riches A, Spratford W, Witchalls J, Newman P. A systemic review and meta-analysis about the prevalence of neck pain in fast jet pilots. Aerosp Med Hum Perform. 2019; 90(10):882–890.

BACKGROUND: The stroboscopic effect made by helicopter blades passing through rays of sunlight is known as a factor that can induce an epileptic seizure.CASE REPORT: We report a case of inaugural tonic-clonic generalized seizure while refueling an NH 90 helicopter by an aeronautical technician standing under the rotating main rotor on a sunny day at a South of France naval air station. The stroboscopic effect of the helicopter blades was identified as one of the factors involved in the induction of this seizure.DISCUSSION: This aeronautical factor identified here during ground hot refueling must be considered for patients predisposed to epileptic seizures who are being evacuated by helicopter, but also for the medical screening of flight members. This is even more important within the military aeronautical environment, justifying electroencephalogram testing implementation on initial aeronautical medical evaluation in France.Corgie L, Huiban N, Quesnel L, Brocq F-X, Boulard J-F, Monteil M. Generalized epileptic seizure induced by the stroboscopic effect of helicopter blades. Aerosp Med Hum Perform. 2019; 90(10):891–895.

BACKGROUND: A fundamental responsibility of aerospace medicine is the analysis and mitigation of the human component’s risk to the aviation system. Medications are part of this risk mitigation process and are present within a multitude of work environments, including aviation. For example, during fiscal year (FY) 2013–2015, the Army Aeromedical Activity (AAMA) received 8596 medication waiver requests. During this same time period the U.S. Army Medical Department’s Patient Administration Systems and Biostatistics Activity reported the organization prescribed over 187,668 prescriptions for opioids, 133,475 prescriptions for SSRIs, 116,649 prescriptions for muscle relaxants, and 71,723 prescriptions for hypnotics to its active duty soldiers in the outpatient setting.METHODS: A conceptual model to mitigate the risk of adverse reactions to medications by severity score was developed based off the methodology published by Prudhomme et al.RESULTS: The mean severity score of the 50 historically safe medications in the Army aviation community is 7346. The standard deviation of the population is 7300. The difference between safe and unsafe drugs determined by subject matter experts (SME) is highly significant when tested with the nonparametric Wilcoxon rank sum test.CONCLUSION: The visual representation of the data from this conceptual model clearly demonstrates room for improvement from current methods. Historically, utilizing SME opinion has created a system with deficiencies related to high variance, inconsistencies, and perceived ambiguity. There is need for a model addressing adverse drug reactions that has concrete strengths of transparency, simplicity, and speed of use.Cronrath CM, Klick MP, Merfeld CM, Gaydos SJ. Medication Adverse Reaction, Risk Stratification (MAR²S) model. Aerosp Med Hum Perform. 2019; 90(10):896–900.

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.

Leary DB. You’re the flight surgeon: measles. Aerosp Med Hum Perform. 2019; 90(10):908–910.

McAviney HD. You’re the flight surgeon: papillary thyroid carcinoma. Aerosp Med Hum Perform. 2019; 90(10):910–913.