Prevalence and network analysis of internet addiction, depression and their associations with sleep quality among commercial airline pilots: A national survey in China

OBJECTIVE

Airline pilots are members of a unique occupational group that is often confronted with sleep routine disruptions, yet relatively few studies have examined their mental health status. This study assessed the prevalence and network structure of internet addiction, depression and sleep quality problems in commercial airline pilots.

METHOD

A total of 7055 airline pilots were included in analyses. Internet addiction and depression were measured with the Internet Addiction Test (IAT) and 9-item Patient Health Questionnaire (PHQ-9), respectively. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI). The network model was constructed based on an Ising model and its association with sleep quality was evaluated using a flow procedure.

RESULTS

Internet addiction, depression and sleep quality were common among airline pilots. The prevalence of internet addiction was 8.0 % (95 % CI: 7.3-8.6 %), while the rates of depression and poor sleep quality were 23.3 % (95 % CI: 22.3-24.2 %) and 33.0 % (95 % CI: 31.9-34.1 %), respectively. In the depression and internet addiction network model, "Fatigue" (PHQ4; Expected Influence (EI): 2.04) and "Depressed/moody/nervous only while being offline" (IAT20; EI: 1.76) were most central symptoms while "Fatigue" (PHQ4; Bridge EI: 1.30) was also the most important bridge symptom. The flow network model of sleep quality with internet addiction and depression showed that "Appetite" (PHQ5) had the strongest positive association with poor sleep quality.

CONCLUSION

Internet addiction, depression and sleep quality were common among airline pilots and warrant regular screening and timely treatment. Strategies to improve sleep hygiene may be useful in preventing onsets or exacerbations in depression and internet addiction among airline pilots.

Senior Aviator Medical Qualification Status

INTRODUCTION

Aviation personnel are expensive to train and challenging for the services to retain because of lucrative opportunities in the civilian aviation sector and a desire among pilots for agency. The military services' retention efforts have typically utilized a combination of high continuation pays and longer service commitments of up to 10 years following initial training. One area that the services have overlooked in their attempts to retain senior aviators is quantifying and reducing medical disqualifications. Much as aging aircraft require increasing maintenance to retain full operational capability, so may pilots and other aircrew members.

MATERIALS AND METHODS

This article reports on a prospectively collected cross-sectional research study evaluating the medical status of senior aviation personnel who reported being considered or selected for command. The study was deemed exempt from human subjects research by the Institutional Review Board and a waiver of Health Insurance Portability and Accountability Act was granted. The study, which collected data at the Pentagon Flight Medical Clinic over 1 year, used a chart review of routine medical encounters and flight physicals to collect descriptive data. The goals of the study were to establish the prevalence of medically disqualifying conditions, assess the association between disqualifying conditions and age, and generate hypotheses for further research. Logistic regression of waiver need was performed for variables including prior waivers, waiver count, service, platform, age, and gender. ANOVA of readiness percentages vs. DoD targets were assessed between the services individually and in aggregate.

RESULTS

The study demonstrated medical readiness rates among command-eligible senior aviators ranging from 74% for the Air Force to 40% for the Army with the Navy and Marine Corps in the middle. The sample was insufficiently powered to demonstrate differences in readiness between the services; however, the population as a whole was significantly below the DoD's readiness target of >90% (P = .000).

CONCLUSIONS

None of the services met the DoD minimum readiness target of 90%. Markedly higher readiness was observed in the Air Force, the only service with a medical screening incorporated into its command selection process, but this difference was not statistically significant. Waivers increased with age and musculoskeletal concerns were common. A larger prospective cohort study should be considered to further elucidate and confirm the findings of this study. If further research confirms these findings, consideration should be made of screening command applicants for medical readiness.

Aeromedical Implications of Cerebral Cavernomas

BACKGROUND: Cavernomas, cavernous angiomas, or cerebral cavernous malformations are clusters of endothelium-lined blood vessels usually found in the brain. With the increasing use of radiological imaging, these are being detected incidentally in asymptomatic aircrew. The UK Civil Aviation Authority (CAA) experience of cavernomas is described and the aeromedical concerns, that is, the risk of epilepsy, hemorrhage, and the development of a neurological deficit, are considered.METHODS: A search of the CAA database between 1990 and 2020 was performed for the term cavernoma. The gender, age at diagnosis, class of certification held, clinical presentation, location, and size of the lesion were noted. A PubMed literature review for papers with complications of cavernoma was performed.RESULTS: Six cases of cavernoma have been declared to the CAA: five professional pilots and one private pilot. Five were men and one was a woman. The age range was between 38 and 60 yr, with a mean of 48 yr. Two cases presented with clinical symptoms and four were asymptomatic. Complication rates for seizure and hemorrhage were extracted from the published literature together with the significance of other factors such as cavernoma size, family history, multiplicity, and the development of new lesions.DISCUSSION: A policy for the medical certification of aircrew with cavernomas that have presented with clinical symptoms and those that are detected incidentally is proposed.Jagathesan T, OBrien M. Aeromedical implications of cerebral cavernomas. Aerosp Med Hum Perform. 2021; 92(2):120123.

Flight Crew Alertness and Sleep Relative to Timing of In-Flight Rest Periods in Long-Haul Flights

BACKGROUND: In-flight breaks are used during augmented long-haul flight operations, allowing pilots a sleep opportunity. The U.S. Federal Aviation Administration duty and rest regulations restrict the pilot flying the landing to using the third rest break. It is unclear how effective these restrictions are on pilots ability to obtain sleep. We hypothesized there would be no difference in self-reported sleep, alertness, and fatigue between pilots taking the second vs. third rest breaks.METHODS: Pilots flying augmented operations in two U.S.-based commercial airlines were eligible for the study. Volunteers completed a survey at top-of-descent (TOD), including self-reported in-flight sleep duration, and Samn-Perelli fatigue and Karolinska Sleepiness Scale ratings. We compared the second to third rest break using noninferiority analysis. The influence of time of day (home-base time; HBT) was evaluated in 4-h blocks using repeated measures ANOVA.RESULTS: From 787 flights 500 pilots provided complete data. The second rest break was noninferior to the third break for self-reported sleep duration (1.5 0.7 h vs. 1.4 0.7 h), fatigue (2.0 1.0 vs. 2.9 1.3), and sleepiness (2.6 1.4 vs. 3.8 1.8) at TOD for landing pilots. Measures of sleep duration, fatigue, and sleepiness were influenced by HBT circadian time of day.DISCUSSION: We conclude that self-reported in-flight sleep, fatigue, and sleepiness from landing pilots taking the second in-flight rest break are equivalent to or better than pilots taking the third break. Our findings support providing pilots with choice in taking the second or third in-flight rest break during augmented operations.Gregory KB, Soriano-Smith RN, Lamp ACM, Hilditch CJ, Rempe MJ, Flynn-Evans EE, Belenky GL. Flight crew alertness and sleep relative to timing of in-flight rest periods in long-haul flights. Aerosp Med Hum Perform. 2021; 92(2):8391.

Health-related quality of life in pilots of a Chinese commercial airline

Health-related quality of life (HRQOL) is currently an important issue in the medical industry. However, data on HRQOL in commercial airline pilots are lacking. This study aimed to investigate HRQOL and its related factors in a sample of commercial pilots. A purposive sample of 373 participants was recruited from a Chinese Commercial Airline. The median (IQR) score for physical health, psychological health and social relationship were 64.3 (75-53.6), 62.5 (70.8-54.2) and 75 (75-58.3), respectively. The mean (SD) score for Environment was 62.2 (16). After controlling for demographics, the multiple linear regression analyses showed that physical activity, fruit intake and vegetable intake were positively correlated with HRQOL score (p < .05), while time-zone flights, smoking, alcohol drinking and being dyslipidemic showed a negative correlation with HRQOL score (p < .05). Healthcare providers should consider time-zone flights, behavioral factors and dyslipidemia when planning related health promotion and disease prevention programs for commercial pilots in the future.

Pilots' Visual Scanning Behaviors During an Instrument Landing System Approach

BACKGROUND: Since eye movement can provide a reliable index of the attention allocation, which can assist in understanding pilots' cognitive state, this study investigated the effect of pilots' experience and the autopilot mode on their attention allocation on the Primary Flight Display (PFD) and Multi-Function Display (MFD) during an approach task.METHODS: There were 16 pilots who were classified into two levels of aviation expertise depending on the flight hours, and required to fly an Instrument Landing System approach. Their visual scanning behaviors were recorded through an eye tracker and analyzed based on fixation number and dwell time.RESULTS: The results revealed that the pilot experience level, instrument panel and autopilot mode all had significant impact on the fixation time ratio and dwell time. The pilots fixated most often on the PFD and had shorter dwell time. Furthermore, they had a lower fixation number and shorter dwell time on the PFD and MFD when the autopilot was off that they should allocate visual resources to the others (e.g., out-of-the-window) and obtain more information to maintain overall situation awareness under higher time pressure. Compared to pilots with more expertise, pilots with less expertise had an increased fixation number and decreased dwell time on the airspeed after turning off the autopilot.DISCUSSION: The present study indicated that the pilots had different visual scanning modes according to the flight mode and their experience. We expect that pilots' visual scanning behaviors during tasks will help the training and the design of the human-machine interaction.Lu Y, Zheng Y, Wang Z, Fu S. Pilots' visual scanning behaviors during an instrument landing system approach. Aerosp Med Hum Perform. 2020; 91(6):511-517.

Hypertension and Obesity Among Civil Aviation Pilots

BACKGROUND: Raised blood pressure (BP) is a risk factor for cardiovascular disease, which is a common cause of sudden in-flight incapacitation among pilots. Prevalence of hypertension (HT) among pilots as per new criteria is largely unknown. This study aims to understand the prevalence of hypertension and obesity in civil aviation pilots and their correlation.METHODS: Enrolled were 1185 civilian pilots reporting for medical evaluation to a regulatory medical establishment in India. Their height, weight, and blood pressure (BP) were measured. Pilots were categorized as hypertensive or normotensive as per JNC VIII criteria and hypertensive, having elevated BP, or normotensive as per new ACC/AHA criteria of 2017. Data were analyzed for prevalence of obesity and overweight as per both WHO and Asia Pacific criteria. Results were analyzed using SPSS version 17.RESULTS: Prevalence of hypertension was 4.1%. Maximum hypertensives were in the 26-35 yr age group. Under the new ACC/AHA guidelines, prevalence of HT was 18.7%. Prevalences of overweight and obesity as per WHO criteria were 39% and 7.3% and as per Asia Pacific guidelines were 23.3% and 46.3%, respectively. As BMI increased above 23, risk of developing hypertension or white coat hypertension as per JNC VIII criteria increased by 6.86 times (OR 6.86, 95% CI 0.9-52.58).CONCLUSIONS: Prevalence of HT rose from 4.1% to an alarmingly high 18.7% when new criteria were applied. Prevalence of obesity was 7.3% but increased to 46.3% when Asia Pacific guidelines were applied. Risk of hypertension increased as BMI increased above 23 kg · m^-2.Bhat KG, Verma N, Pant P, Marwaha MPS. Hypertension and obesity among civil aviation pilots. Aerosp Med Hum Perform. 2019; 90(8):703-708.

U.S. Statement of Demonstrated Ability Aeromedical Waivers

INTRODUCTION: The Statement of Demonstrated Ability (SODA) is a type of U.S. aeromedical waiver used for disqualifying conditions that are not expected to change. About 21,000 (2%) U.S. pilots possess a SODA waiver.METHODS: We matched all pilot medical exams from the FAA's medical certification database from 2002 through 2011 to their respective accidents in the National Transportation Safety Board accident database. The association of SODA waivers and SODA conditions with the odds of an accident were explored using logistic regression techniques.RESULTS: For 3^rd class flight exams, the presence of a SODA waiver was not associated with the odds of an accident. For the 1^st and 2^nd class exams, the accident odds ratio (OR = 1.45) was statistically significant. Crop dusting operations accounted for 17 of the 40 accidents where SODAs were present and returned a significant accident OR = 1.68. SODAs were not associated with the odds of accidents during other commercial operations. Six SODA conditions (amputation, internal eye, external eye, visual fields, bone and joint, and miscellaneous) were also found to have elevated ORs but were based on very small accident counts. NTSB investigators and the authors reviewed all accidents and none thought the SODA condition to be contributory.DISCUSSION: SODA waivers were not associated with increased accident odds except for crop dusting operations. Six specific SODA conditions also had elevated odds of an accident, but there was no evidence they contributed to the accidents. Overall, U.S. pilots with SODA waivers appear to have a satisfactory safety record.Mills WD, Davis JT. U.S. Statement of Demonstrated Ability aeromedical waivers. Aerosp Med Hum Perform. 2019; 90(12):1034-1040.

ACTN-3 Genotype, Body Composition, Fitness, and +Gz Tolerance in Senior Cadets

BACKGROUND: This study aimed to investigate the relationships among ACTN-3, body composition, fitness, and +G_z tolerance for senior cadet training development and their safe task performance.METHODS: The subjects were all senior cadets (N = 68) at the Korea Air Force Academy. All cadets are required to pass a physical fitness test (3-km running, sit-ups, push-ups) and body composition test on a semiannual basis. Isokinetic muscle function (strength and endurance), +G_z test (+6 G_z ⋅ 30 s^-1), and target gene (ACTN-3) were analyzed.RESULTS: The effects of body composition and physical fitness along with the relationship of the ACTN-3 genotype to the +6 G_z test results were determined. Consequently, no significant difference was found concerning the effect of ACTN-3 on the +6 G_z test result, body composition, and physical fitness; however, body fat (%) and isokinetic muscle strength (peak torque right leg extension and left leg flexion) showed significance between the pass and failure groups in the +G_z test.DISCUSSION: The cadets of the Korea Air Force Academy showed dominant fast genetic expression type based on their ACTN-3 genotype [RR and RX (N = 51, 75%) > XX (N = 17, 25%)]. Body fat (%) and isokinetic muscle strength (PT R EX, L FL) can be more effective predictors in the +6 G_z test for cadet training. Another speculation is that more RR- and RX-type-oriented training can promote cadets' G_z tolerance from the isokinetic factors such as high peak torque and low fatigue index.Shin S, Jee H. ACTN-3 genotype, body composition, fitness, and +G_z tolerance in senior cadets. Aerosp Med Hum Perform. 2019; 90(12):1055-1060.

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.

Cardiac Autonomic Activity in Commercial Aircrew During an Actual Flight Duty Period

BACKGROUND: The work schedules of airline crewmembers include extended workdays, compressed work periods, and limited time for recovery, which may lead to cardiovascular strain and fatigue. The aim of this study was to evaluate changes in heart rate variability (HRV) during work and sleep, and with respect to work characteristics and breaks.METHODS: We followed 49 airline crewmembers during four consecutive workdays of ≥39 h. Data included HRV measurements, a questionnaire, and sleep/work diaries. HRV parameters include root mean square of successive differences (RMSSD), standard deviation of the normal beat-to-beat differences (SDNN), and the low and high frequency ratio (LF/HF).RESULTS: The results indicate higher levels of cardiovascular strain on the 4th compared to the 1st workday, most prominent among cabin crewmembers. In this group, we observed indications of decreased cardiovascular strain by increasing duration of sleep, demonstrated by increased RMSSD (B = 2.7, 95% CI 1.6, 3.8) and SDNN (B = 4.4, 95% CI 3.0, 5.7), and decreased LF/HF (B = -0.2, 95% CI, -0.4,-0.01). Similarly, longer duration of breaks was associated with lower cardiovascular strain, indicated by increased RMSSD (B = 0.1, 95% CI 0.03, 0.1) and SDNN (B = 0.1, 95% CI 0.1, 0.1). Among pilots, increased LF/HF indicated higher cardiovascular strain in those who often or always reported of high workload (B = 4.3, 95% CI 2.3, 6.3; and B = 7.3, 95% CI 3.2, 11.4, respectively).DISCUSSION: The results support the contention that the studied work period increases cardiac strain among airline crew. Work characteristics, breaks, and sleep are associated with changes in HRV.Goffeng EM, Nordby K-C, Tarvainen M, Järvelin-Pasanen S, Wagstaff A, Skare Ø, Lie J-A. Cardiac autonomic activity in commercial aircrew during an actual flight duty period. Aerosp Med Hum Perform. 2019; 90(11):945-952.

Restless Legs Syndrome in Aircrew

INTRODUCTION: Restless legs syndrome (RLS) is characterized by an uncomfortable sensation on the legs, which causes the urge to move the legs. The main cause is unknown but there are many risk factors, including geographical properties and high altitude. Our objective was to explore the frequency of RLS in aircrew.METHODS: There were 301 Turkish aircrew who were admitted to Istanbul Medipol University Hospital Neurology Department for periodic examinations and 272 healthy (non-aircrew) subjects included in the study. The International RLS Study Group's Questionnaire and the International RLS Study Group Rating Scale (IRLSSGRS) were used to evaluate RLS. The participants filled the RLS questionnaire and then both groups were divided into two subgroups as having RLS or not. The subjects years in the profession, average flight duration in a month, daily sleep duration, smoking, and coffee consumption were recorded. None of the subjects had previously been diagnosed with RLS.RESULTS: The frequency of RLS was 6.7% in the aircrew group and 7.9% in the control group, and there was no significant difference between the two groups. Age, gender, daily duration of sleep, smoking, coffee consumption, family history of RLS, being a pilot or a flight attendant, years in profession, and monthly flight hours were similar in aircrew with and without RLS.DISCUSSION: The RLS frequency in aircrew was similar to that of the control group. We can conclude flying at high altitude wasnt a risk factor for RLS.Düz OA, Yilmaz NH, Olmuscelik O. Restless legs syndrome in aircrew. Aerosp Med Hum Perform. 2019; 90(11):934937.

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.

Follow-Up of Blebs and Bullae in Pilots 40 Years and Older Using CT

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.

A Systematic Review and Meta-Analysis About the Prevalence of Neck Pain in Fast Jet Pilots

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.

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.

Success Rates at an Air Force Pilot Academy and Its Relation to Methylphenidate Use

BACKGROUND: Attention deficit hyperactivity disorder (ADHD) is a chronic neurological disorder characterized by persistent patterns of inattention, impulsivity, and hyperactivity. The most common treatment for this disorder is methylphenidate, which is a disqualifying medication for flight. Candidates with previous use of methylphenidate are not necessarily disqualified from the Israeli Air Force (IAF) flight academy.METHODS: Flight cadets from 12 consecutive flight courses who have used methylphenidate at least once in the past were identified according to their medical records. The graduation ratio of cadets with previous use of methylphenidate was compared with that of the rest of the cadets. A comparison was also made with regard to the causes of disqualification from the flight course. Statistical significance was assessed using the Fischer Test.RESULTS: Among the 90 flight cadets who have used methylphenidate, only 2 (2.2%) successfully graduated from the IAF flight academy. Among the 2983 flight cadets who have no history of methylphenidate use, 461 (15.4%) successfully graduated. We found no significant differences in the disqualification causes between the two groups.CONCLUSION: The IAF flight academy graduation rate was meaningfully and significantly lower among cadets who reported previous use of methylphenidate. The study design, however, limits the inference of causal relationship.Sarfati S, Nakdimon I, Tsodyks J, Assa A, Gordon B. Success rates at an air force pilot academy and its relation to methylphenidate use. Aerosp Med Hum Perform. 2019; 90(9):788-791.

Noise Exposure and Hearing Impairment in Air Force Pilots

OBJECTIVE: The goal of this study was to estimate noise exposure and hearing impairments in Swedish military pilots. It also aimed to analyze possible relations between noise exposure and hearing impairments.METHODS: The study group was an open cohort of 337 male pilots. They were longitudinally followed with pure tone audiograms every fifth year from the beginning of flight service until discharge. Outcome measures were prevalence of thresholds >20 dB HL and >40 dB HL at different ages, and incidence of impairments >20 dB HL, 30 dB HL, and 40 dB HL. Exposure variables were individual flight data and noise dose measurements. The ISO 1999 Database A was used for reference data.RESULTS: At 50 yr of age, 41% of the pilots were exposed to an equivalent noise dose exceeding the EU action level of Leq 80 dB(A). We observed significant elevated prevalence values of thresholds >20 dB HL in all age classes compared to the ISO 1999 Database A. These elevations were most pronounced at ages 30 and 40 yr and at 4 and 6 kHz in the left ear. Significantly elevated prevalence values of thresholds >40 dB HL compared to the ISO 1999 Database A were observed at age 40 and 50 yr at 4 and 6 kHz. In a Cox analysis we observed elevated hazard ratios of deteriorating thresholds with longer flight time/year in fast jet pilots.DISCUSSION: Military pilots had elevated prevalence values of hearing impairment. Of the subjects, 41% had been exposed to noise exceeding the EU risk limit. Increased flight time/year and flying fast jets were associated with elevated risk of hearing deterioration.Muhr P, Johnson A-C, Selander J, Svensson E, Rosenhall U. Noise exposure and hearing impairment in air force pilots. Aerosp Med Hum Perform. 2019; 90(9):757-763.

Hypoxia Hangover and Flight Performance After Normobaric Hypoxia Exposure in a Hawk Simulator

INTRODUCTION: The incidence of hypoxia-like symptoms in military aviators is on the rise. Cases can be related to On-Board Oxygen Generating System (OBOGS) malfunction, air contamination, loss of cabin pressurization, hyperventilation, or a combination of these issues simultaneously. Normobaric hypoxia training in tactical fighter simulations has been conducted in the Finnish Air Force since 2008. This training helps aviators to recognize their individual hypoxia symptoms and refreshes hypoxia emergency procedures in a realistic cockpit.METHODS: A flight mission included three set-ups and a return to base (RTB) after the third set-up. In a tactical Hawk simulator, different concentrations of oxygen were used (8%, 7%, and 6% oxygen in nitrogen) to create normobaric hypoxia exposures. During the RTB, the flight instructor evaluated the subjects' flight performance (N = 16) in order to estimate cognitive functions after hypoxia. A control flight was evaluated before or after the flight with normobaric hypoxia exposure.RESULTS: Instrumental flight rule performance during RTB decreased significantly from 4.81 to 3.63 after normobaric hypoxia and emergency procedures. Some pilots reported fatigue, headache, memory problems, and cognitive impairment as adverse effects up to 12 h after normobaric hypoxia training.DISCUSSION: Hypoxia has a significant effect on flight performance during RTB, even 10 min after hypoxia emergency procedures. Since 100% oxygen was used as emergency oxygen, as in a real aircraft, the oxygen paradox may decrease flight performance. Hypoxia training in tactical fighter simulations provides an opportunity for pilots to also understand the effects of the "hypoxia hangover" on their flight performance.Varis N, Parkkola KI, Leino TK. Hypoxia hangover and flight performance after normobaric hypoxia exposure in a Hawk simulator. Aerosp Med Hum Perform. 2019; 90(8):720-724.

Risk of Fatigue Among Airline Crew During 4 Consecutive Days of Flight Duty

BACKGROUND: Airline crew are being exposed to extended workdays and compressed work periods, with quick returns between duties, implying a heightened physiological and psychological strain that may lead to sleep deprivation and fatigue. The aim of the study was assessment of the effect of an extended day of flight duty and a compressed work week with regard to recovery, cumulative fatigue, and neurobehavioral performance.METHODS: We followed 18 pilots and 41 cabin crewmembers during four consecutive days of flight duty, comprising a total of ≥ 39 h, where the first day was ≥ 10 h. Information on demographics, work characteristics, health status, and physical activity was collected at baseline. Subjects completed logs for the first and fourth workday, including the Samn-Perelli Fatigue Checklist at three time points during these workdays. Two computer-based neurobehavioral tests were completed the evening prior to the first shift, and after the first and the fourth day of the work period.RESULTS: Number of flight sectors during the work period was 10-20. Self-reported fatigue levels increased during the workdays. Neurobehavioral test-scores did not deteriorate. The effects of each additional flight sector during the work period was elevated reaction times (RT) both among cabin crewmembers (B = 5.05 ms, 95% CI 0.6, 9.5) and pilots (B = 4.95 ms, 95% CI 0.4, 9.5). Precision was unaffected.DISCUSSION: Airline pilots and cabin crewmembers seem to obtain satisfactory sleep before and during the period of 4 consecutive days. The association between multiple flight sectors and increased fatigue supports previous findings.Goffeng EM, Wagstaff A, Nordby K-C, Meland A, Goffeng LO, Skare Ø, Lilja D, Lie J-AS. Risk of fatigue among airline crew during 4 consecutive days of flight duty. Aerosp Med Hum Perform. 2019; 90(5):466-474.

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.

Occupant Injury Severity in General Aviation Accidents Involving Excessive Landing Airspeed

BACKGROUND: Of all phases of flight operations, accidents during landings are the most frequent. Of these, poor speed management during landing has ramifications for injury severity since: 1) impact forces increase as a square of forward velocity; and 2) an aerodynamic stall, associated with inadequate landing speed, imparts high vertical G forces. Herein, the proportion of landing accidents involving deficient airspeed control and occupant injury severity was determined.METHODS: General aviation landing accidents (1997-2016) were identified from the NTSB database. An accident involving high-airspeed (high-energy) was one for which the NTSB cited airplane porpoising, multiple bounces, or floating, whereas an inadequate airspeed related (low energy) mishap was one citing this term or in which an aerodynamic stall occurred. An anonymous online survey of certificated pilots was used to inform landing technique. Statistical analyses used Poisson distribution and Chi-squared tests.RESULTS: Relative to the earliest period (1997-2001), the landing accident rate was undiminished for more recent years (2007-2016). Of 235 accidents, 38% involved high-energy, whereas 4% were inadequate airspeed-related. For the former, 17% resulted in occupants with fatal-serious injuries, twofold higher than for mishaps with no evidence of mis-speed. Of 1392 survey respondents, 73% selected a landing airspeed higher than required for an under-maximum weight airplane.CONCLUSION: For landing accidents involving airspeed mismanagement, those related to excessive energy predominate and are associated with more severe injuries. Two mitigating strategies are advanced: 1) pilot training should discuss landing airspeed adjustment for aircraft weight; and 2) installation of inflatable restraints for reducing injury severity should be encouraged.Boyd DD. Occupant injury severity in general aviation accidents involving excessive landing airspeed. Aerosp Med Hum Perform. 2019; 90(4):355-361.

New ACC/AHA Blood Pressure Guidelines and the Operational Readiness of Naval Aviators and Aircrew

INTRODUCTION: Hypertension, also known as high blood pressure, is the "silent killer" and may lead to more severe conditions if left unmanaged. Hypertension in service members of the U.S. military has the potential to negatively impact readiness. The aim of this study was to assess the potential impact to readiness of active duty Naval aviators and aircrew under the new 2017 ACC/AHA blood pressure guidelines.METHODS: This cross-sectional study used the Military Health System Data Repository for 2015. The population included all active duty Naval aviators and aircrew. The absolute number and proportion of those with hypertension were compared based on previous Joint National Committee 7 and 2017 ACC/AHA guidelines. Impact to readiness was calculated based on lost work days and the number of individuals with hypertension that fit the criteria to be medically grounded according to the U.S Naval Aeromedical Reference and Waiver Guide.RESULTS: Hypertension diagnoses will increase by 2904 individuals (599%) in the 23,492 Naval aviators and aircrew included in the population. Impact to readiness will result in an estimate of 510 lost work days.CONCLUSION: The 2017 ACC/AHA hypertension guidelines will lead to a dramatic increase in hypertension diagnoses in this population. Depending on the U.S. Navy disposition on hypertension, the impact can be minor or substantial, but the early opportunity for care made available with the 2017 ACC/AHA guidelines may provide long-term benefits of a healthy fighting force worth the immediate impact to readiness.Johnson MC, Banaag AL, Condie KJ, Servies TE, Pérez Koehlmoos TL. New ACC/AHA blood pressure guidelines and the operational readiness of Naval aviators and aircrew. Aerosp Med Hum Perform. 2019; 90(4):409-414.

Flight Performance Aspects During Military Helicopter Flights

INTRODUCTION: A flight is composed of many flight performance aspects. However, not all of these aspects are equally important for the success and safety of a flight. When investigating the influence of a stressor on flight performance, it is important to understand not only which flight performance aspects are important for the success and the safety of the flight, but also which of these aspects will most likely be affected by reduced alertness.METHOD: A total of 136 helicopter pilots of the Royal Netherlands Air Force (RNLAF) of all qualification levels were invited to participate in a three-round ranking Delphi study.RESULTS: A total of 41 (30%) helicopter pilots completed the first questionnaire round and 20 (77%) flight instructors completed the ranking round. The top ten skills elements comprised seven nontechnical skills (NTS), namely, awareness of the environment, decision making, workload management, stress management, planning and coordinating, general knowledge, and basic fitness; and three technical skills (TS), that is, advanced aircraft handling, flight maneuvers and procedures, and abnormal and emergency procedures. The top three ranked skill elements (awareness of environment, decision making, and workload management) were considered by the flight instructors to be highly influenced by reduced pilot alertness.CONCLUSION: NTS are considered more important and more affected by reduced pilot alertness during operational helicopter flight compared to TS.Steinman Y, van den Oord MHAH, Frings-Dresen MHW, Sluiter JK. Flight performance aspects during military helicopter flights. Aerosp Med Hum Perform. 2019; 90(4):389-395.

Evaluating non-technical skills and mission essential competencies of pilots in military aviation environments

To develop and validate a classification of non-technical skills (NTS) in military aviation, a study was conducted, using data from real operations of F16 aircraft formations. Phase 1 developed a NTS classification based on the literature review (e.g. NOTECHS) and a workshop with pilots. The Non-TEChnical-MILitary-Skills (NOTEMILS) scheme was tested in Phase 2 in a series of Principal Component Analysis with data from After-Action-Review sessions (i.e. 900 records from a wide range of operations). The NTS were found to make a good prediction of Mission Essential Components (R² > 0.80) above the effect of experience. Phase 3 undertook a reliability analysis where three raters assessed the NOTEMILS scheme with good results (i.e. all r_wg > 0.80). To look into the consistency of classifications, another test indicated that, at least, two out of three raters were in agreement in over 70% of the assessed flight segments. Practitioner Summary: A classification scheme of Non-Technical Skills (NTS) was developed and tested for reliability in military aviation operations. The NTS scheme is a valuable tool for assessing individual and team skills of F-16 pilots in combat. It is noteworthy that the tool had a good capability of predicting Mission Essential Competencies.

A Method of Applying Flight Data to Evaluate Landing Operation Performance

Pilots' operation has an important effect on flight safety and performance, particularly in the final landing stage when pilots need to deal with complicated operations. This study aims to determine the potential value of flight data and develop a method of evaluating a pilot's performance during landing phase based on flight quick access recorder (QAR) data from the perspective of risk assessment. First, a Landing Operation Performance Evaluation Model was developed based on risk evaluation principles. Three landing parameters, which are touchdown distance, touchdown vertical acceleration and touchdown pitch angle, were selected as indicators to evaluate the pilots' landing operation performance in this model. Second, the flight landing operation performance evaluation system (FLOPES) was set up based on the evaluation model. Test results showed that FLOPES can accomplish all calculation flow of operation performance evaluation. Finally, it concluded that this method is a more accurate and effective way for evaluating the landing operation performance of a flight. It could be as a practical tool for airlines to manage landing risk quantitatively and to provide a more practical support for improving training and design in aviation.Practitioner summary: This study aims to determine the potential value of flight data and to develop a method of evaluating pilot's landing operation performance from the risk evaluation perspective. Test results showed that this method is effective and could be as a practical tool for airlines to manage landing risk and improve training.Abbreviations:QAR: Quick Access Recorder; FLOPES: Flight Landing Operation Performance Evaluation System; ICAO: International Civil Aviation Organization; IATA: International Air Transport Association; SMS: Safety Management System; CAAC: Civil Aviation Administration of China; FOQA: Flight Operations Quality Assurance; VBA: Visual Basic for Applications.

Aircraft-Assisted Pilot Suicides in the General Aviation Increased for One-Year Period after 11 September 2001 Attack in the United States

Pilot aircraft-assisted suicides (AAS) are rare, and there is limited understanding of copycat phenomenon among aviators. The aim of this study was to evaluate the possible effect the 11 September 2001, terrorist attacks had on pilot AASs in the U.S. Fatal aviation accidents in the National Transportation Safety Board (NTSB) database were searched using the following search words: “suicide”, “murder-suicide” and “homicide-suicide”. The timeline between 11 September 1996, and 11 September 2004, was analyzed. Only those accidents in which NTSB judged that the cause of the accident was suicide were included in the final analysis. The relative risk (RR) of the pilot AASs in all fatal accidents in the U.S. was calculated in order to compare the one, two, and three-year periods after the September 11 terrorist attacks with five years preceding the event. The RR of a fatal general aviation aircraft accident being due to pilot suicide was 3.68-fold (95% confidence interval 1.04–12.98) during the first year after 11 September 2001, but there was not a statistically significant increase in the later years. This study showed an association, albeit not determinate causal effect, of a very specific series of simultaneous terrorist murder-suicides with subsequent pilot AASs.

Aviation Accident Causes Among Sport Pilots as Compared to Class 3 Private Pilots from 2004-2017

BACKGROUND: In September 2004 a new pilot certificate, sport pilot, was established, which enabled pilots to fly with a valid driver's license in lieu of a valid third-class medical certificate. In 2016 Mills and DeJohn published a paper in which they demonstrated that sport pilots had a higher accident rate than private pilots with Class 3 medical certificates. They concluded that this privilege should not be extended to a broader range of pilots due to the higher accident rate. They failed to investigate why these pilots crashed. This short communication aims to fill that gap.METHODS: The NTSB database was reviewed for the entire period that sport pilot has been available, and reasons for the accidents were determined, both for sport pilots and private pilots with Class 3 medicals.RESULTS: Sport pilot accidents were caused by medical incapacitation 3.7% of the time. Private pilots with Class 3 medicals had accidents that cited medical incapacitation 2.5% of the time.DISCUSSION: Medical incapacitation represents either a probable cause or contributing factor in aviation accidents less than 5% of the time. There is a slightly higher rate of this incapacitation among pilots not receiving regular aeromedical evaluations, but the difference was not statistically significant.Mulvey JR. Aviation accident causes among sport pilots as compared to Class 3 private pilots from 2004-2017. Aerosp Med Hum Perform. 2018; 89(11):1002-1004.

The U.S. Experience with Special Issuance Waivers

INTRODUCTION

The special issuance (SI) waiver is the primary mechanism for U.S. pilots who do not meet FAA standards to obtain a medical certificate. About 34,000 pilots possess an SI waiver, but there is a large gap in knowledge of the relationship of SI waivers to aviation safety.

METHODS

All FAA pilot medical exams from 2002 through 2011 were matched to the National Transportation Safety Board accident database. The association of an SI waiver with accidents was explored using logistic regression models. Accident rates were also calculated using a novel technique based on pilots' reported flight times on their applications for medical certification.

RESULTS

For third-class flight exams overall, the presence of an SI waiver is associated with 8.7% lower odds of an accident than regular issuance exams. The calculated overall accident rate was 6.6 per 100,000 h. For the first and second-class exams, there was no significant association of SI waivers with safety for the overall group. The oldest and youngest pilots in the third-class group and the younger pilots in the first and second-class groups had somewhat elevated accident odds. The significance of these higher odds is uncertain, especially for the younger pilots who have a probable flight time bias.

DISCUSSION

The overall FAA program of special issuance waivers shows no detrimental effect on aviation accidents and enables a large number of pilots to safely continue their aviation pursuits in spite of failure to meet specific regulatory medical standards.Mills WD, Davis JT. The U.S. experience with special issuance waivers. Aerosp Med Hum Perform. 2018; 89(10):905-911.

Cardiac Inflight Incapacitations of U.S. Airline Pilots: 1995-2015

INTRODUCTION

Inflight medical incapacitations are rare events that can result in the loss of lives and aircraft. The potential for an in-flight medical event deserves the attention of certification authorities. Cardiac emergencies are among the most common serious events. The primary focus of this study was to examine whether the proportions of pilots with reported cardiac conditions could be used to identify those who had inflight medical incapacitations.

METHODS

The Civil Aerospace Medical Institute Inflight Incapacitation Registry was searched to identify airline pilots with a cardiac history and an inflight medical event between 1995 and 2015. The Federal Aviation Administration's Decision Support System was searched for airline pilots without an inflight medical event. The cardiovascular history of incapacitated pilots was then compared to that of airline pilots without incapacitation events.

RESULTS

Although a significantly greater proportion of airline pilots with cardiac events had pacemakers than a control group with the same cardiac history who did not have inflight events, no significant difference was found in the proportions of other markers of cardiac health.

CONCLUSION

The proportions of airline pilots with identified cardiac conditions could not be reliably used to identify which pilots had inflight incapacitations.DeJohn CA, Mills WD, Hathaway W, Larcher J. Cardiac inflight incapacitations of U.S. airline pilots: 1995-2015. Aerosp Med Hum Perform 2018; 89(9):837-841.

Understanding Human Error in Naval Aviation Mishaps

OBJECTIVE

To better understand the external factors that influence the performance and decisions of aviators involved in Naval aviation mishaps.

BACKGROUND

Mishaps in complex activities, ranging from aviation to nuclear power operations, are often the result of interactions between multiple components within an organization. The Naval aviation mishap database contains relevant information, both in quantitative statistics and qualitative reports, that permits analysis of such interactions to identify how the working atmosphere influences aviator performance and judgment.

METHOD

Results from 95 severe Naval aviation mishaps that occurred from 2011 through 2016 were analyzed using Bayes' theorem probability formula. Then a content analysis was performed on a subset of relevant mishap reports.

RESULTS

Out of the 14 latent factors analyzed, the Bayes' application identified 6 that impacted specific aspects of aviator behavior during mishaps. Technological environment, misperceptions, and mental awareness impacted basic aviation skills. The remaining 3 factors were used to inform a content analysis of the contextual information within mishap reports. Teamwork failures were the result of plan continuation aggravated by diffused responsibility. Resource limitations and risk management deficiencies impacted judgments made by squadron commanders.

CONCLUSION

The application of Bayes' theorem to historical mishap data revealed the role of latent factors within Naval aviation mishaps. Teamwork failures were seen to be considerably damaging to both aviator skill and judgment.

APPLICATION

Both the methods and findings have direct application for organizations interested in understanding the relationships between external factors and human error. It presents real-world evidence to promote effective safety decisions.

Pilot Decision Making in Weather-Related Night Fatal Helicopter Emergency Medical Service Accidents

INTRODUCTION

In the United States, between 1995 and 2013, night-time visual flight rules (VFR) Helicopter Emergency Medical Service (HEMS) fatal accidents mostly encountered adverse weather, and pilots with <6 yr of HEMS experience showed higher likelihood of a night operational accident. One adverse weather indicator is cloud-ceiling likelihood indicated by temperature dew point spread (TDPS). This study investigated the relationship between TDPS and HEMS pilot years of experience. It was hypothesized pilots with <6 yr HEMS experience were associated with fatal outcomes encountered at lower TDPS.

METHODS

Between 1995 and 2013, 32 single pilot night VFR HEMS fatal accidents occurring in the United States, caused by controlled flight into terrain or loss of control, were analyzed. Using Federal Aviation Administration weather guidance, the 0-4°C TDPS was selected as an indicator of cloud ceiling. Each flight's TDPS was analyzed with pilots' HEMS domain task experience.

RESULTS

There were 27 flights which entered the 0-4°C TDPS range; 20 (74%) were significantly associated with adverse weather. A significant negative linear relationship was found between TDPS of each mission and years of pilot HEMS experience (r = -0.423, P = 0.028). Pilots with <6 yr of experience were significantly associated with fatal outcomes (P = 0.049).

CONCLUSION

Pilots' incremental years of HEMS experience were associated with a TDPS decrement. Fatal outcomes were over nine times higher for pilots with <6 yr of HEMS experience in night VFR operational accidents in those conditions. Interventions for <6-yr pilots are recommended during experience building to prevent likelihood of operational accidents.Aherne BB, Zhang C, Chen WS, Newman DG. Pilot decision making in weather-related night fatal helicopter emergency medical service accidents. Aerosp Med Hum Perform. 2018; 89(9):830-836.

Common mental disorders among US army aviation personnel: Prevalence and return to duty

OBJECTIVES

Assess the prevalence of US Army aviation personnel with common mental disorders, the percentage that return to duty following mental health treatment, and predictors of return to duty.

METHODS

Examined the prevalence over a 5-year period. The percentage of personnel who were granted a waiver to return to flying duty following treatment was also determined.

RESULTS

The results revealed a 5-year prevalence of 0.036 (95% CI = 0.034-0.038) for personnel experiencing one or more of the mental disorders (N = 1,155). Prevalence was highest for adjustment disorders and for nonpilot participants. Overall, personnel were granted a waiver 55.3% of the time and suspended or disqualified 44.7% of the time. Waivers were more likely to be granted for an adjustment disorder and for pilots.

CONCLUSIONS

Discussion focuses on the importance of aviation personnel receiving mental health treatment when problems are not severe to maximize the likelihood of returning to duty.

Cardiovascular Tests for Risk Assessment in Asymptomatic Adults and Implications for Pilots

BACKGROUND

This study aims to examine which marker or testing protocols have been suggested for cardiovascular disease (CVD) risk assessment in asymptomatic populations, at which CVD risk level, and how this can be implemented for CVD risk assessment in pilot populations.

METHODS

A systematic search was performed using Systematic Reviews Subset on PubMed; the OvidSP interface, including all EBM reviews and EMBASE databases; and the G-I-N International Guideline Library. From each recommendation, we extracted data on consideration of the use of a marker or test for cardiovascular risk assessment in asymptomatic populations.

RESULTS

Included were 45 guidelines, systematic reviews, or meta-analyses relevant to cardiovascular risk assessment in asymptomatic populations. The majority (9/12) of the citations recommend coronary artery calcium score (CACS) for CVD risk assessment in intermediate-risk (10-yr CVD risk score of 10-20%) asymptomatic adults. Other cardiac and vascular tests that may also be considered include the measurements of carotid-intima media thickness, supplemented by carotid plaque, and the ankle brachial index for prevention of peripheral artery disease and stroke. Stress myocardial perfusion scan is the potential cardiac functional test to be used with pilots with 5-yr risk of ≥15%. Among laboratory markers, only hs-CRP has a potency to be used in CVD risk assessment in intermediate-risk asymptomatic adults; however, the strength of the recommendation is not adequate.

DISCUSSION

Among the cardiac and vascular testing available, CACS is the most frequently suggested test. The implications of findings for CVD risk assessment in airline pilots are highlighted in this paper.Wirawan IMA, Griffiths RF, Larsen PD. Cardiovascular tests for risk assessment in asymptomatic adults and implications for pilots. Aerosp Med Hum Perform. 2018; 89(7):648-656.

Extended High-Frequency Audiometry (9-20 kHz) in Civilian Pilots

INTRODUCTION

The greater sensitivity of extended high-frequency audiometry (EHFA) than conventional audiometry (CA) for identifying early changes in hearing has been well documented in previous literature. However, no studies about EHFA were conducted on civilian pilots. The aim of this study was to investigate the usefulness of EHFA as an assay to evaluate civilian pilots' hearing status.

METHODS

An observational cross-sectional study was conducted on 134 civilian pilots (case group) and 101 subjects without noise exposure (control group). All of the subjects underwent CA (0.25-8 kHz) and EHFA (9-20 kHz). The potential of EHFA for identifying early changes in hearing was assessed.

RESULTS

The two audiometric tools both showed significantly higher hearing thresholds in the case group for most of the frequencies tested, but the differences were more obvious for EHFA. Compared with the control group, the average thresholds in the case group increased 3.15 dB at CA and 7.83 dB at EHFA for age 20-29. The number was 2.37 dB and 9.90 dB for age 30-39; 3.80 dB and 8.19 dB for age 40-49; and 10.84 dB and 16.86 dB for age 50-59. There were 74.6% of pilots who had hearing loss in at least in one ear and at one frequency in CA and 94.8% at EHFA. Significant differences in EHFA were observed also between pilots and their controls with normal hearing thresholds at CA.

CONCLUSIONS

EHFA is more sensitive than CA and could be useful in detecting subclinical changes of hearing in civilian pilots.Ma F, Gong S, Liu S, Hu M, Qin C, Bai Y. Extended high-frequency audiometry (9-20 kHz) in civilian pilots. Aerosp Med Hum Perform. 2018; 89(7):593-600.

Recurrent On-Duty Sleepiness and Alertness Management Strategies in Long-Haul Airline Pilots

INTRODUCTION

We examined whether long-haul airline pilots without recurrent on-duty sleepiness obtain more prior sleep and use more effective in-flight alertness management strategies than their colleagues with recurrent on-duty sleepiness.

METHODS

There were 51 pilots who flew at least twice from Helsinki to Asia. Of them, 44 flew at least twice back to Helsinki following 1 local night. On-duty sleepiness was measured by the Karolinska Sleepiness Scale (KSS), alertness management strategies by a diary, and sleep by a diary and activity monitor. Pilots who rated KSS ≥ 7 on each, some, or none of the flights were classified as "regularly", "sometimes", and "never" sleepy, respectively. This classification was performed separately for the outbound and inbound flights.

RESULTS

On the outbound flights, 22% of the pilots were "never", 54% "sometimes", and 24% "regularly" sleepy. For the inbound flights, the respective distribution was 25%, 48%, and 27%. Compared to the "regularly" sleepy group, the "never" sleepy group obtained 54 min more night sleep prior to the outbound flights. For the inbound flights, the respective difference was 1 h 23 min. Also, the "never" sleepy pilots slept 31 min more between days off than the "regularly" sleepy pilots. The results of the in-flight alertness management strategies were mixed.

DISCUSSION

The study demonstrates that pilots without recurrent on-duty sleepiness obtain more sleep than their colleagues with recurrent on-duty sleepiness. The result emphasizes the need to investigate whether the sleep of recurrently sleepy pilots can be increased and whether this increase would reduce their on-duty sleepiness.Sallinen M, Åkerstedt T, Härmä M, Henelius A, Ketola K, Leinikka M, Kecklund G, Sihvola M, Tuori A, Virkkala J, Puttonen S. Recurrent on-duty sleepiness and alertness management strategies in long-haul airline pilots. Aerosp Med Hum Perform. 2018; 89(7):601-608.

Chromosome Translocations and Cosmic Radiation Dose in Male U.S. Commercial Airline Pilots

BACKGROUND

Chromosome translocations are a biomarker of cumulative exposure to ionizing radiation. We examined the relation between the frequency of translocations and cosmic radiation dose in 83 male airline pilots.

METHODS

Translocations were scored using fluorescence in situ hybridization chromosome painting. Cumulative radiation doses were estimated from individual flight records. Excess rate and log-linear Poisson regression models were evaluated.

RESULTS

Pilots' estimated median cumulative absorbed dose was 15 mGy (range 4.5-38). No association was observed between translocation frequency and absorbed dose from all types of flying [rate ratio (RR) = 1.01 at 1 mGy, 95% confidence interval (CI) 0.97-1.04]. However, additional analyses of pilots' dose from only commercial flying suggested an association (RR = 1.04 at 1 mGy, 95% CI 0.97-1.13).

DISCUSSION

Although this is the largest cytogenetic study of male commercial airline pilots to date of which the authors are aware, future studies will need additional highly exposed pilots to better assess the translocation-cosmic radiation relation.Grajewski B, Yong LC, Bertke SJ, Bhatti P, Little MP, Ramsey MJ, Tucker JD, Ward EM, Whelan EA, Sigurdson AJ, Waters MA. Chromosome translocations and cosmic radiation dose in male U.S. commercial airline pilots. Aerosp Med Hum Perform. 2018; 89(7):616-625.

Clinical Diagnoses Leading to Suspension in Army Aircrew: An Epidemiological Study

INTRODUCTION

There have been few large-scale epidemiological examinations of military aircrew populations reported in recent literature. This study examined 10 yr of medical records contained in the U.S. Army Aeromedical Electronic Resource Office (AERO) in an effort to identify the most prevalent conditions affecting Army aviator career longevity.

METHODS

This study was a retrospective epidemiological review; data were retrieved on 24,568 rated aircrew patients from the AERO database, of whom 5.2% were women. The dataset was composed of a total of 181,471 cases between June 2005 and June 2015. Age ranged from 17 to 73 yr. The data were examined in terms of raw ICD-9 diagnostic codes, derived systems-based categories, and occupational consequences.

RESULTS

The top 10 diagnoses, causes for waiver, and permanent suspension of aircrew were determined both in terms of the ICD-9 codes and the system groupings. Leading waiver causes included hypertension (11.5%), hearing loss (9.7%), spinal disorder (14.4%), and obstructive sleep apnea (5.2%). Leading permanent suspension causes were psychiatric disorders (28.2%), particularly PTSD, being the leading cause, with spinal pathology (16.1%) second. In almost all diagnostic groupings the Spearman's rho correlation coefficients between age and diagnosis presence were positively related, although often with no association with negative occupational outcome.

DISCUSSION

This study revealed the leading medical causes of waiver and suspension from flying duties, producing evidence to inform leadership understanding of disease prevalence and its subsequent impact on flying status. This is of prime importance to help direct policy and implement strategies for health protection.Curry IP, Kelley AM, Gaydos SJ. Clinical diagnoses leading to suspension in Army aircrew: an epidemiological study. Aerosp Med Hum Perform. 2018; 89(7):587-592.

Metabolic Syndrome in the German Air Force: Prevalence and Associations with BMI and Physical Fitness

BACKGROUND

Metabolic syndrome is a cluster of metabolic abnormalities that can affect a pilot's health. The aim of the study was to establish the prevalence of metabolic syndrome in the German Air Force.

METHODS

All German military pilots are examined regularly at the German Air Force Center of Aerospace Medicine. The data are stored in a special database designed for that purpose. A database query was performed. The following parameters were analyzed: age, duration of observation, BMI, physical working capacity (PWC 170), blood pressure, erythrocyte sedimentation rate (ESR), cholesterol, HDL-cholesterol, triglycerides, fasting blood glucose.

RESULTS

For the time period of 1996 to 2016, the data of 12,014 pilots were analyzed. Overall prevalence of metabolic syndrome was 0.9% (95% CI 0.7-1.1%). Participants with a metabolic syndrome had a significantly higher BMI (28.3 vs. 24.1), lower PWC 170 (2.3 vs. 2.7) and higher ESR (4.7 vs. 3.6, mm first hour) than the healthy participants. On average, BMI gradually increased over the years and PWC 170 decreased over the years in all participants. There was no increase of the prevalence of metabolic syndrome during the observational period.

CONCLUSION

Prevalence of metabolic syndrome among German Military pilots is low and is not connected to the duration of service.Weber F. Metabolic syndrome in the German Air Force: prevalence and associations with BMI and physical fitness. Aerosp Med Hum Perform. 2018; 89(5):469-472.

Lumbar Disc Herniation in Military Helicopter Pilots vs. Matched Controls

INTRODUCTION

Lumbar disc herniation (LDH) is a common injury among active duty service members resulting in missed duty hours and limited duty status. Little is known about the current burden of disease and risk factors for LDH among military rotary wing aviators.

METHODS

A query was made using the Defense Medical Epidemiology Database (DMED), including patient encounters for the U.S. Military from 2006-2015 using the ICD-9 code for LDH. Incidence rates were calculated for patients with the occupation of helicopter pilot and stratified by age, gender, and branch of service, then compared to matched controls using a Poisson regression analysis. Then, data from a 17-yr period were examined for long term trends.

RESULTS

We identified 1218 cases of LDH among 141,383 person-years among helicopter pilots, yielding a 1.22-fold higher incidence rate compared to controls. Significant risk factors identified after Poisson regression analysis were age greater than 30 yr old and Army service branch affiliation. Male gender was not found to be a significant risk factor. Long term data revealed a 2.6-fold increased incidence of LDH among helicopter pilots since 1997.

DISCUSSION

We identified significant increased risk of LDH in rotary wing pilots as compared to their nonpilot peers. Among rotary wing pilots, the incidence of this condition has increased, with both increasing pilot age and Army branch affiliation identified as risk factors. This information will allow targeted prevention strategies and further investigation to potential aircraft-specific causes of increased risk in Army pilots.Knox JB, Deal JB Jr, Knox JA. Lumbar disc herniation in military helicopter pilots vs. matched controls. Aerosp Med Hum Perform. 2018; 89(5):442-445.

A Survey of Fatigue in Army Aviators

INTRODUCTION

Fatigue plays a critical role in mission success due to its effect on a number of performance variables. The purpose of this study was to gauge the extent to which U.S. Army aviators experience subjective fatigue on a regular basis presently as well as their perceptions of their own sleep quality, quantity, and daytime sleepiness. This information is valuable for prioritizing future research lines with respect to injury prevention and fatigue management as well as updating policy.

METHODS

An anonymous, 125-item questionnaire was completed by 214 U.S. Army aviators. A subset of those items (15 questions related to fatigue) are reported in this study. Subjects were primarily male and the mean age was 33 yr.

RESULTS

Results suggest that the majority of subjects sleep less than the recommended 8 h per night and nearly half of them report sleeping less than their own preferred amount of sleep. Approximately 40% of the sample indicated that they believed fatigue to be a widespread problem in the U.S. Army aviation community.

DISCUSSION

Overall, the findings identified factors contributing to fatigue and performance degradation currently experienced by those sampled in this study. Specifically, inconsistent shiftwork, less than optimal levels of rest, and poor sleep quality in the field were identified. Compared to past research, the extent to which fatigue is perceived to be a widespread problem is significantly lower than reported 15 yr prior.Kelley AM, Feltman KA, Curry IP. A survey of fatigue in army aviators. Aerosp Med Hum Perform. 2018; 89(5):464-468.

Copycats in Pilot Aircraft-Assisted Suicides after the Germanwings Incident

Aircraft-assisted pilot suicide is a rare but serious phenomenon. The aim of this study was to evaluate changes in pilot aircraft-assisted suicide risks, i.e., a copycat effect, in the U.S. and Germany after the Germanwings 2015 incident in the French Alps. Aircraft-assisted pilot suicides were searched in the U.S. National Transportation Safety Board (NTSB) accident investigation database and in the German Bundestelle für Flugunfalluntersuchung (BFU) Reports of Investigation database five years before and two years after the deliberate crash of the Germanwings flight into the French Alps in 2015. The relative risk (RR) of the aircraft-assisted pilot suicides was calculated. Two years after the incident, three out of 454 (0.66%) fatal incidents were aircraft-assisted suicides compared with six out of 1292 (0.46%) in the prior five years in the NTSB database. There were no aircraft-assisted pilot suicides in the German database during the two years after or five years prior to the Germanwings crash. The relative aircraft-assisted pilot suicide risk for the U.S. was 1.4 (95% CI 0.3–4.2) which was not statistically significant. Six of the pilots who died by suicide had told someone of their suicidal intentions. We consider changes in the rate to be within a normal variation. Responsible media coverage of aircraft incidents is important due to the large amount of publicity that these events attract.

Glaucoma in U.S. Civil Aviation: 2005-2014

INTRODUCTION

Until recently, glaucoma requiring treatment was disqualifying for U.S. pilots and required an aeromedical special issuance waiver. Since 2013 Aerospace Medical Examiners (AMEs) have been authorized to evaluate third-class pilots with mild glaucoma using similar protocols and issue medical certificates without a waiver if these criteria specified in the AME Guide are met.

METHODS

The FAA's medical database was searched for pilots with glaucoma between 2005 and 2014. The National Transportation Safety Board (NTSB) accident database was then searched to determine which pilots with glaucoma had aircraft accidents during that period. The odds of accidents in the glaucoma pilots were compared with the overall pilot accident odds.

RESULTS

Of 5000 pilots being treated for glaucoma, 78 were involved in aircraft accidents; however, glaucoma was not cited as the probable cause or contributing factor in any of the accidents. A logistic regression model adjusted for age showed that glaucoma had a protective effect on accident odds. The crude accident rate for third-class pilots with glaucoma was estimated to be 7.2 per 100,000 flight hours, with a fatal accident rate of 1.8 per 100,000. Although these point estimates were slightly higher than the estimated general aviation accident rates, the differences were not statistically significant.

DISCUSSION

These findings suggest that third-class pilots with glaucoma are not at significantly greater risk of an accident than the U.S. general aviation community. It also indicates that FAA certification protocols for certifying and following pilots with glaucoma provide an adequate level of flight safety.DeJohn CA, Mills WD. Glaucoma in U.S. civil aviation: 2005-2014. Aerosp Med Hum Perform. 2017; 88(12):1117-1122.

Cross-Sectional Analysis of Commonly Prescribed Medications in Military Aviation

BACKGROUND

Medication use by naval aviators, either prescription or over-the-counter, is not always relayed to the flight surgeon, resulting in unsafe flying environments. Many medications have debilitating effects that prohibit their use during aviation. Education and availability of resources on approved medications for flight status personnel is lacking.

METHODS

A retrospective search of the Department of Defense Composite Health Care System (DoD CHCS) was conducted from five geographic locations. Basic epidemiological information was obtained to determine the most common medications (N = 70) prescribed to active-duty flight status personnel. Analysis determined their medication category, flight status designation, and a generalized location comparison. A similar control medication list for nonflight status personnel was generated from one location.

RESULTS

Analysis found that many medications prescribed to aviators are not approved for use in aviation and are similar to those of nonflight status personnel. There were 8 of the top 15 (53%) and 40 of the 70 (57%) most commonly prescribed medications of flight status personnel which were not approved. Similarly, 49% of total prescriptions (N = 15,652) were not approved. Little difference was found in medications among nonflight and flight status personnel, as 11 of the top 15 prescription medications (73%) were identical.

DISCUSSION

This research demonstrates the need for education regarding certain medications and their prohibited use during flight. Results will provide the Flight Surgeon common medications prescribed to aviators to aid them in providing a safer flying environment.Ropp LG, Haight SP, Prudhomme MB, Ropp EL. Cross-sectional analysis of commonly prescribed medications in military aviation. Aerosp Med Hum Perform. 2017; 88(12):1129-1133.

Pilots using selective serotonin reuptake inhibitors compared to other fatally injured pilots

Selective Serotonin Reuptake Inhibitors (SSRI) were a disqualifying medication for U.S. civil pilots before April 5, 2010. After this date, a Federal Aviation Administration policy was created that allowed airmen, on select SSRIs, a pathway to hold a valid medical certificate. The purpose of this study was to provide a detailed look at SSRIs in the U.S. pilot population since the inception of this new policy. We examined the toxicology results from fatally injured airmen in addition to outcomes concerning pilots who are participating in the program. This study examined data from the Civil Aerospace Medical Institute's Bioaeronautical Sciences Research Laboratory in conjunction with the Medical Analysis Tracking Registry and the Document Imaging and Workflow System. A count-based regression model quantified the relationships between positive SSRI findings with additional factors of interest. These factors included pilot rating, ethanol, and first generation antihistamines. There were 1484 fatally injured airmen over the six year study period, of which 44-tested positive for an SSRI. First-generation antihistamines were statistically associated with positive findings of SSRIs.

Pilot Certification, Age of Pilot, and Drug Use in Fatal Civil Aviation Accidents

INTRODUCTION

This study examined the association between mean age of pilot, pilot license, pilot medical certificate and drug use trends in pilots fatally injured in aircraft accidents. The prevalence of prescription drugs, OTC drugs, controlled drugs and drugs that may be potentially impairing was also examined.

METHODS

This study was a descriptive observational study in which the NTSB Aviation Accident Database was searched from the period beginning January 1, 2012 to December 31, 2014.

RESULTS

During the study period a total of 706 accidents involving 711 fatalities were investigated by the NTSB. This study included 633 of these accidents, involving 646 fatalities. Of these pilots, 42.1% had drugs in their biological samples. The prevalence of prescription drugs, controlled drugs, OTC drugs, opioids, and potentially impairing drugs in the fatally injured pilot population over the study period was 28.9%, 15.0%, 20.1%, 5.1%, and 25.5%, respectively. Pilots with any drugs in their samples were significantly older than those without drugs. Medical certificate held was associated with drug use; pilots who held third class certificates had the highest prevalence at 54.1%. Pilot license was not associated with drug use. In 3.8% of the accidents, drugs were a contributing factor in the cause.

DISCUSSION

Despite current FAA medical regulations, potentially impairing drugs are frequently found in biological samples of fatally injured pilots in the U.S. More education of airmen by aviation medical examiners is needed on the safety of drug use.Akparibo IY, Stolfi A. Pilot certification, age of pilot, and drug use in fatal civil aviation accidents. Aerosp Med Hum Perform. 2017; 88(10):931-936.

Incidence of cancer among licenced commercial pilots flying North Atlantic routes

BACKGROUND

To evaluate cancer incidence among licenced commercial pilots in association with cosmic radiation.

METHODS

Cohort study where ionizing radiation dose of cosmic radiation was estimated from airline data and software program and cancer incidence was obtained by record linkage with nation-wide cancer registry. All licenced commercial male airline pilots were followed from 1955 to 2015, ever or never employed at airline with international routes. Standardized incidence ratios were calculated and relative risk by Poisson regression, to examine exposure-response relation.

RESULTS

Eighty three cancers were registered compared with 92 expected; standardized incidence ratios were 0.90 (95% CI 0.71 to 1.11) for all cancers, 3.31 (95% CI 1.33 to 6.81) for malignant melanoma, and 2.49 (95% CI 1.69 to 3.54), for basal cell carcinoma of skin. The risk for all cancers, malignant melanoma, prostate cancer, basal cell carcinoma of skin, and basal cell carcinoma of trunk increased with an increase in number of employment years, cumulative air hours, total cumulative radiation dose, and cumulative radiation dose sustained up to age of 40 years. The relative risk for the highest exposure categories of cumulative radiation dose were 2.42 (95% CI 1.50 to 3.92) for all cancers, 2.57 (95% CI 1.18 to 5.56) for prostate cancer, 9.88 (95% CI 1.57 to 190.78) for malignant melanoma, 3.61 (95% CI 1.64 to 8.48) for all basal cell carcinoma, and 6.65 (95% CI 1.61 to 44.64) for basal cell carcinoma of trunk.

CONCLUSIONS

This study was underpowered to study brain cancer and leukaemia risk. Basal cell carcinoma of skin is radiation-related cancer, and may be attributed to cosmic radiation. Further studies are needed to clarify the risk of cancers in association with cosmic radiation, other workplace exposure, host factors, and leisure sun-exposure, as clothes, and glass in cockpit windows shield pilots from the most potent ultraviolet-radiation.

A Review of General Aviation Safety (1984-2017)

INTRODUCTION

General aviation includes all civilian aviation apart from operations involving paid passenger transport. Unfortunately, this category of aviation holds a lackluster safety record, accounting for 94% of civil aviation fatalities. In 2014, of 1143 general aviation accidents, 20% were fatal compared with 0 of 29 airline mishaps in the United States. Herein, research findings over the past 30 yr will be reviewed. Accident risk factors (e.g., adverse weather, geographical region, post-impact fire, gender differences) will be discussed. The review will also summarize the development and implementation of stringent crashworthiness designs with multi-axis dynamic testing and head-injury protection and its impact on mitigating occupant injury severity. The benefits and drawbacks of new technology and human factor considerations associated with increased general aviation automation will be debated. Data on the safety of the aging general aviation population and increased drug usage will also be described. Finally, areas in which general aviation occupant survival could be improved and injury severity mitigated will be discussed with the view of equipping aircraft with 1) crash-resistant fuel tanks to reduce post-impact conflagration; 2) after-market ballistic parachutes for older aircraft; and 3) current generation electronic locator beacons to hasten site access by first responders.Boyd DD. A review of general aviation safety (1984-2017). Aerosp Med Hum Perform. 2017; 88(7):657-664.

Incidence of G-Induced Loss of Consciousness and Almost Loss of Consciousness in the Royal Air Force

INTRODUCTION

Exposure to sustained +Gz acceleration with inadequate G protection can result in G-induced loss of consciousness (G-LOC) or almost loss of consciousness (A-LOC). The UK Royal Air Force (RAF) last conducted a survey of G-LOC within their military aircrew in 2005 with interventions subsequently introduced. The aim of this study was to repeat the 2005 survey in order to evaluate the impact of those interventions.

METHODS

An anonymous questionnaire requesting details of G-LOC and A-LOC events was mailed to all RAF pilots (N = 1878) and weapons systems operators (WSOs) (N = 473), irrespective of aircraft currently flown.

RESULTS

The questionnaire was returned by 809 aircrew (34.4% response rate). There were 120 (14.8%) aircrew who reported at least one episode of G-LOC and 260 (32.2%) reported at least one episode of A-LOC. The reported prevalence of G-LOC in the previous 2005 survey was 20.1% (N = 454). There was an increased reporting of G-LOC in the Hawk, Tucano, and Grob Tutor aircraft, with 5 G-LOC and 19 A-LOC events reported in the Grob Tutor compared to none in 2005.

DISCUSSION

The prevalence of reported G-LOC has decreased in the surveyed populations, which may be due to the introduction of centrifuge training, but also may be influenced by patterns of G exposure and other factors. Scope for further reduction remains through correct execution of the anti-G straining maneuver (AGSM) with centrifuge training early in flying training and use of a structured conditioning program to increase the general strength of muscles involved in the AGSM.Slungaard E, McLeod J, Green NDC, Kiran A, Newham DJ, Harridge SDR. Incidence of G-induced loss of consciousness and almost loss of consciousness in the Royal Air Force. Aerosp Med Hum Perform. 2017; 88(6):550-555.