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.

BACKGROUND: Circulating blood volume (BV) and maximal oxygen uptake (Vo_2max) are physiological characteristics important for optimal human performance in aerospace and military operational environments. We tested the hypothesis that BV and Vo_2max are lower in older people independent of sex.METHODS: To accomplish this, a “data mining” effort of an historic database generated from NASA and U.S. Air Force experiments was conducted. BV, red cell volume, plasma volume, hematocrit, and Vo_2max were measured in 84 healthy individuals (24 women, 60 men) across an age range of 23 to 65 yr to assess the interrelationship between sex, age, BV, and Vo_2max. Subjects were classified in age groups by < 40 yr and ≥ 40 yr; these groups identified women as pre- vs. postmenopausal.RESULTS: Consistent with our hypothesis, comparisons revealed that men had higher BV, red cell volume, hematocrit, and Vo_2max than women when standardized for body mass. Against expectations, BV was not different in older compared with younger men and women. Vo_2max was not different in older compared with younger women, while Vo_2max was lower in older men.CONCLUSION: We conclude that physiological mechanisms other than BV associated with aging appear to be responsible for a decline in Vo_2max of our older men. Furthermore, factors other than menopause may also influence the control of BV in the women. Our results provide evidence that aging may not compromise men or women in scenarios where BV can affect performance in aerospace and military environments.Koons NJ, Suresh MR, Schlotman TE, Convertino VA. Interrelationship between sex, age, blood volume, and Vo_2max. Aerosp Med Hum Perform. 2019; 90(4):362–368.

INTRODUCTION: Prior research suggests there may be gender differences with regards to hypoxia resilience. Our study was designed to determine whether there were differences between genders in neuronal electrical activity at simulated altitude and whether those changes correlated with cognitive and aviation performance decrements.METHODS: There were 60 student Naval Aviators or Flight Officers who completed this study (30 women, 30 men). Participants were exposed to increasing levels of normobaric hypoxia and monitored with dry EEG while flying a fixed-base flight simulation. Gender differences in brainwave frequency power were quantified using MATLAB. Changes in flight and cognitive performance were analyzed via simulation tasks and with a cognitive test validated under hypoxia.RESULTS: Significant decreases in theta and gamma frequency power occurred for women compared to men with insidious hypoxic exposures to 20K, with an average frequency power decrease for women of 19.4% compared to 9.3% for men in theta, and a 42.2% decrease in gamma for women compared to 21.7% for men. Beta frequency power correlated highest between genders, with an average correlation coefficient of r = 0.95 across seven channels.DISCUSSION: Results of this study suggest there is identifiable brain wave suppression for both men and women with hypoxic exposure and, moreover, there are significant differences in this suppression between genders. Beta frequency power was most sensitive for both genders and highly correlative compared to other brainwave frequencies. The implications of these findings are important considerations for next-generation aviation helmets, which may employ this technology as an early warning mechanism.Rice GM, Snider D, Drollinger S, Greil C, Bogni F, Phillips J, Raj A, Marco K, Linnville S. Gender differences in dry-EEG manifestations during acute and insidious normobaric hypoxia. Aerosp Med Hum Perform. 2019; 90(4):369–377.

BACKGROUND: Tolerance to central hypovolemia is dictated by exhaustion of the physiological capacity to compensate called the compensatory reserve. Such physiological compromise can have detrimental impact on performance in aerospace environments as well as survival from hemorrhage on the battlefield. We induced central hypovolemia using progressively stepwise lower body negative pressure (LBNP) in women during various phases of the menstrual cycle to test the hypothesis that similar tolerance across all menstrual cycle phases would be reflected by similar changes in compensatory reserve.METHODS: Based on self-reporting of the last menstrual period, 40 healthy women, matched by demographics, were classified into 1 of 5 menstrual cycle phases: early follicular (EF, Days 1–7; N = 10), late follicular and ovulatory (LF, Days 9–15, N = 6), early luteal (EL, Days 16–18, N = 6), midluteal (ML, Days 19–25, N = 8), and late luteal (LL, Days 26–30, N = 10). All subjects had a 28–30 d menstrual cycle and were not taking oral contraceptives. Tolerance to central hypovolemia was measured as time (seconds) from baseline to the onset of presyncopal symptoms induced by LBNP.RESULTS: Time to presyncope as well as hemodynamic and compensatory reserve responses were statistically indistinguishable across all menstrual cycle phases.DISCUSSION: Consistent with our hypothesis, compensatory reserve with associated hemodynamic responses and tolerance to central hypovolemia was not affected by menstrual cycle phases. Our findings indicate experimental comparisons of responses to central hypovolemia involving the participation of healthy women with normal menstrual cycles and not taking oral contraceptives can be conducted independent of menstrual cycle phase.Convertino VA, Schlotman TE, Stacey W, Hinojosa-Laborde C. Capacity to compensate for central hypovolemia and effects of menstrual cycle phases. Aerosp Med Hum Perform. 2019; 90(4):378–383.

BACKGROUND: Fear of flying is one of the most common phobias. It hinders people in performing their work and hampers family relations. Even though flight traffic has increased, there are new fears. Valid studies are needed to answer whether there have been changes in the prevalence of flight anxiety, are there sex differences in relation to fear of flying, use of alcohol, and tranquilizers, which situations cause the most flight anxiety, and whether the above factors have changed compared to a similar study from 1986.METHODS: A questionnaire was distributed to a representative random sample of the Norwegian population (N = 5500), where 36% answered. To assess flight anxiety across the time period, we used similar instruments to those we used in 1986.RESULTS: The prevalence of an assumed flight phobia decreased from 8% in 1986 to 3% in 2015. The percentage of those reported to never fly had decreased from 5% in 1986 to 0.5% in 2015. There were 11.0% who always used alcohol in 1986 and 7.5% in 2015 and 3% and 2%, respectively, always used tranquillizers. More women reported being afraid of both flying and other situations compared to men. Turbulence, unknown sounds, and fear of terror attacks caused the most anxiety.DISCUSSION: Flight anxiety still affects a considerable proportion of the Norwegian population and more women than men report that they are afraid of flying. However, in spite of methodology, people are significantly less afraid of flying than in 1986.Grimholt TK, Bonsaksen T, Schou-Bredal I, Heir T, Lerdal A, Skogstad L, Ekeberg Ø. Flight anxiety reported from 1986 to 2015. Aerosp Med Hum Perform. 2019; 90(4):384–388.

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.

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

BACKGROUND: Handling cases of chest pain aboard commercial flights is challenging for crewmembers, onboard medical volunteers, and ground-based doctors providing remote advice. Obtaining an electrocardiogram (ECG) in-flight could help in dictating the management of such cases. The ability to diagnose or rule out ST-segment elevation myocardial infarction (STEMI) would have clinical and prognostic implications. The feasibility of obtaining good quality ECG tracings by flight attendants in flight is not known.METHODS: A series of 200 consecutive ECG tracings transmitted to a ground-based medical support provider were independently reviewed by four observers who ranked the ECG tracings according to a quality score (QS) criteria, as well as trying to identify or rule-out cases of STEMI.RESULTS: ECG quality was considered good enough to extract useful information in 170 of 200 tracings (85%). Seven cases of STEMI were identified. A STEMI was confidently ruled out in 104 cases. Additional abnormalities of variable clinical importance were also detected.DISCUSSION: ECGs are essential in the prehospital management of chest pain cases. ECGs obtained in flight by airline flight attendants were mostly of diagnostic quality, allowing confirmation or ruling out of STEMI, as well as detecting arrhythmias of clinical significance in case management.Alves PM, Lindgren JA, Streitwieser DR, Anzola E, Ahmed N, Nerwich N. Quality of electrocardiograms obtained in flight by airline flight attendents. Aerosp Med Hum Perform. 2019; 90(4):405–408.

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.

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

Chua QH, Tan K, Gan WH. You’re the flight surgeon: multiple sclerosis in a young Asian aircrew. Aerosp Med Hum Perform. 2019; 90(4):419–422.