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.

INTRODUCTION: Physical conditioning may improve aircrew performance during exposure to high +G_z acceleration, although few studies have directly assessed this. The present study investigated the effects of a 12-wk Aircrew Conditioning Programme (ACP) on markers of G tolerance. The ACP comprises aerobic and muscle strengthening exercise performed twice weekly and targets improved fitness and reduced injury risk.METHODS: There were 36 UK Royal Air Force and Royal Navy aircrew who volunteered; 17 performed the ACP (Ex) and 19 acted as a control group (Con). Centrifuge testing was performed before and after the intervention. Relaxed G tolerance (RGT) and straining G tolerance (SGT), which had the addition of muscle tensing, were assessed. G endurance was also determined via repeated simulated air combat maneuvers (SACMs). During these centrifuge runs a number of physiological variables were recorded.RESULTS: During the G profile to determine RGT, neither RGT, HR, nor blood pressure responses were affected by the ACP. During SGT profiles, a lower HR at a given +G_z (+5.5 G_z) level following the ACP was observed (Ex: pre 146.0 ± 4.4, post 136.9 ± 5.6 bpm; Con: pre 148.0 ± 3.2, post 153.1 ± 3.3 bpm). BP was maintained and there was a tendency toward an improved SGT. The ACP increased the proportion of individuals completing the number of SACM profiles, although no meaningful differences were found between groups in other variables.CONCLUSION: Overall the ACP has no negative effect on RGT, reduced the physiological strain associated with a given level of +G_z (during SGT), and tended to improve the ability to tolerate repeated G_z exposure.Slungaard E, Pollock RD, Stevenson AT, Green NDC, Newham DJ, Harridge SDR. Aircrew conditioning programme impact on +Gz tolerance. Aerosp Med Hum Perform. 2019; 90(9):764–773.

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.

INTRODUCTION: Critical mission tasks for Martian exploration have been identified and include specific duties that astronauts will have to perform despite any adverse effects of chronic microgravity. Specifically, astronauts may have to perform an emergency capsule egress upon return to Earth, which places specific demands on compromised cardiovascular and neuromuscular systems. Therefore, the purpose of this project was to determine the relationship between cardiorespiratory fitness and simulated capsule egress time.METHODS: There were 15 subjects who volunteered for this study. Vo_2peak and peak power output (PPO) were determined on cycle and rowing ergometers. Critical power (CP) was determined by a 3-min all-out rowing test. Subjects then performed an emergency capsule egress on a mock-up of NASA’s Orion space capsule. Peak metabolic data were compared between the cycling and rowing tests. Pearson’s correlation was used to identify relationships between egress time and Vo_2peak, PPO, and CP.RESULTS: Vo_2peak, Vco_2peak, and minute ventilation were not different between cycling and rowing tests. Cycling elicited a greater PPO than the rowing test. Egress time was negatively correlated to rowing PPO (r = −0.60), but not cycling or rowing Vo_2peak, cycling PPO, or CP.CONCLUSIONS: Rowing PPO/kg correlates with egress time. Although individuals with higher PPO/kg were able to finish the task in less time, individuals with low fitness levels (Vo_2peak ≤ 20 ml · kg⁻¹ · min⁻¹) could complete the egress within 2 mins. These results suggest that cardiorespiratory fitness should not limit emergency egress and that this can be assessed using rowing exercise.Alexander AM, Sutterfield SL, Kriss KN, Hammer SM, Didier KD, Cauldwell JT, Dzewaltowski AC, Barstow TJ, Ade CJ. Prediction of emergency capsule egress performance. Aerosp Med Hum Perform. 2019; 90(9):782–787.

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.

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

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

INTRODUCTION: The previous Spacecraft Maximal Allowable Concentrations (SMACs) for methanol were established by characterizing minor effects upon cognitive functions as a no-observable adverse effects level (NOAEL). However, an increasing awareness of the risk posed by Space-Associated Neuro-ocular Syndrome (SANS) has caused NASA Toxicology to reexamine SMACs for methanol because exposure to it can also adversely affect ocular health. An updated review of the literature indicates that no adjustments to the SMACs due to SANS complications were required, while confirming that effects upon the central nervous system remain the appropriate basis for the SMACs for methanol. Our review, however, identified several issues that provide justification for modest SMAC reductions. It has recently been recognized that inhaled methanol may reach the brain via the olfactory system and be absorbed there into the highly toxic metabolite formaldehyde. A benchmark dose (BMD) for an extra risk of 10%, derived from an analysis of the incidences of neurological lesions in monkeys chronically exposed to methanol, is an order of magnitude less than the Environmental Protection Agency’s (EPA’s) reference concentration for chronic inhalation of methanol. Reports calling attention to the relative insensitivity of traditional methods of assessing cognitive function erode confidence that adverse effects at the concentration reported as a NOAEL would have been recognizable. Therefore, an additional modest safety factor of three is applied to SMACs for methanol.Scully RR, Garcia H, McCoy JT, Ryder VE. Revisions to limits for methanol in the air of spacecraft. Aerosp Med Hum Perform. 2019; 90(9):807–812.

INTRODUCTION: Body composition (BC) measurements are used to determine qualification for enlistment and to ensure active members are meeting standards. Although there is extensive research on BC in active-duty military, very few have examined ROTC cadets. The purpose of this study was to identify and quantify differences in BC between freshman/sophomore [underclass (UND)] and junior/senior [upperclass (UPP)] ROTC cadets by using bioelectrical impedance spectroscopy (BIS).METHODS: UND (N = 21) and UPP (N = 15) Air Force ROTC cadets volunteered for this study. BIS was used to measure fat mass percentage (FM%), fat free mass percentage (FFM%), total body water percentage (TBW%), extracellular fluid percentage (ECF%), and intracellular fluid percentage (ICF%). Separate one-way ANOVAs were run between UND and UPP for all dependent variables with a Bonferroni correction factor. Additionally, a Pearson correlation between abdominal circumference (AC) and FM% was conducted.RESULTS: No significant differences were observed between the UND and UPP groups’ BMI. However, significant differences were observed for ECF%, ICF%, TBW%, FFM%, and FM% in which the UPP had a higher TBW%, ICF%, FFM%, and a lower ECF% and FM% compared to the UND.CONCLUSIONS: This study observed significant differences in BC across class ranks in ROTC cadets. Findings from this study suggest that due to an increased exposure to ROTC training, UPP cadets have a more ideal body composition (FFM% and FM%) when compared to UND cadets.Johnson QR, Mackey CS, Muddle TD, Smith DB, DeFreitas JM. Body composition comparison of upper- and underclass Reserve Officers Training Corps cadets. Aerosp Med Hum Perform. 2019; 90(9):813–818.

INTRODUCTION: Spaceflight can strain astronaut physical, physiological, and mental well-being, whereas maintaining astronaut operational performance remains an essential goal. Although various cognitive tests have been used for spaceflight assessment, these have been challenged on their lack of operational relevance.METHODS: To address this gap, we developed and characterized the Robotic On-Board Trainer for Research (ROBoT-r) system, based on the Robotic On-Board Trainer (ROBoT) currently used for astronaut training on Canadarm2 track-and-capture activities. The task requires use of dual hand-controllers (6 degrees of freedom) to grapple an incoming vehicle in free-drift in a time-limited setting. After developing a platform for conducting research studies, characterization testing of ROBoT-r was completed by 14 astronaut-like volunteers (35 ± 11 yr; N = 5 women) over 16 sessions each.RESULTS: We describe the design and capabilities of the ROBoT-r system for conducting operationally relevant research on human performance. Version 6.2 of the system supports H-II Transfer Vehicle track-and-capture operations within a multimillion component, physics-enabled 3D model using NASA’s DOUG graphics platform. It has configurable task initialization and auto-run capabilities, saves 38 variables continuously at 20 Hz throughout each run, provides the user quantitative feedback after each run, and provides summaries after each session. Detailed performance characterization data is reported for future experimental planning purposes.DISCUSSION: ROBoT-r’s range of performance variables enables detailed and quantitative performance assessment. Its use in spaceflight will help provide insight into operational performance, as well as allowing investigators to compare these results with more traditional cognitive tests to help better understand the interaction between individual cognitive abilities and operational performance.Ivkovic V, Sommers B, Cefaratti DA, Newman G, Thomas DW, Alexander DG, Strangman GE. Operationally relevant behavior assessment using the Robotic On-Board Trainer for Research (ROBoT-r). Aerosp Med Hum Perform. 2019; 90(9):819–825.

Beauvais A, Tate J, Kluesner JK. You’re the flight surgeon: hypoglycemia. Aerosp Med Hum Perform. 2019; 90(9):826–829.