BACKGROUND: This article presents the results of an EASA-commissioned study aimed at analyzing the medical causes of grounding of a broad European pilot population and recommending measures to reduce the risk of in-flight incapacitation in commercial air transport pilots.METHOD: European National Aviation Authorities (NAAs) were requested to provide data concerning the total number of pilots that were examined, their age and license category, number of unfit pilots, and the medical causes of each case of grounding. Diagnoses were classified according to the format and definitions laid down in Commission Regulation (EU) No. 1178/2011 Part Med.RESULTS: Analyzed were 82,435 cases assessed by 6 NAAs. Of these cases, 2.1% were assessed as unfit to fly. Frequent causes for grounding a pilot were cardiovascular (19%), psychiatric (11%), neurological (10%), and psychological (9%). Cardiovascular conditions were the most frequent cause for grounding in the older age groups, with 21% in the age 51-60 cohort, 28% in the age 61-65 cohort, and 48% in those beyond 65 yr. Psychiatric and psychological diagnoses were most frequent in the age 20-40 cohort.DISCUSSION: Cardiovascular conditions were the most frequent cause for grounding. Cardiovascular diseases (CVD) are associated with modifiable risk factors. Tackling these risk factors gives aeromedical examiners the opportunity to improve the health of pilots and reduce CVD-related flight safety risks by reducing the number of pilots at risk of in-flight incapacitation. The mandatory periodical medical examination of pilots provides an excellent framework for risk prevention and follow-up of preventive measures.Simons R, Maire R, Van Drongelen A, Valk P. Grounding of pilots: medical reasons and recommendations for prevention. Aerosp Med Hum Perform. 2021; 92(12):950-955.

INTRODUCTION: Due to the risk of hypoglycemia-related incapacitation, diabetic pilots requiring insulin are assessed as unfit according to the International Civil Aviation Organization and most national authorities. Some authorities, such as those from Canada, the United Kingdom, and the United States, permit selected insulin-treated pilots (ITDM-pilots) to fly subject to a protocol requiring pre- and in-flight capillary glucose measurements to show safe levels (>100–<300 mg · dl −1 ). Critics of such permission question the practicability of these in-flight measurements and whether clinically desired glycemic targets can be achieved while keeping glucose levels in the safe range. Subcutaneous continuous glucose monitoring (CGM) has recently been approved by the FDA as a stand-alone method to provide accurate glucose levels and treatment decision guidance in patients. This commentary considers that use of CGM by ITDM pilots facilitates practicability and recording of in-flight glucose measurements and facilitates achievement of clinically desired glycemic targets without increasing hypoglycemia risks. Strollo F, Simons R, Mambro A, Strollo G, Gentile S. Continuous glucose monitoring for in-flight measurement of glucose levels of insulin-treated pilots . Aerosp Med Hum Perform. 2019; 90(8):735–737.

In Nederland worden piloten die insuline gebruiken voor hun diabetes mellitus afgekeurd wegens het risico op een acute incapacitatie door hypoglykemie. De moderne aanpak van diabetes mellitus heeft dit risico echter meer beheersbaar gemaakt, zodat met insuline behandelde werkers in veel veiligheidsgevoelige beroepen (piloten, beroepschauffeurs, machinisten, et cetera) op dit moment niet meer automatisch worden afgekeurd. In het Verenigd Koninkrijk is recent een onderzoek gestart naar de uitvoerbaarheid en haalbaarheid van een protocol om met insuline behandelde beroepsvliegers onder strikte voorwaarden en begeleiding veilig te kunnen laten vliegen. Het experiment vindt geen navolging in Nederland. In het artikel wordt beargumenteerd waarom ook Nederlandse piloten zouden moeten deelnemen aan dit Britse onderzoek.

In September 2012, the Aerospace Medical Association published and distributed recommendations from its Pilot Mental Health Working Group to improve awareness and identification of pilot mental health issues during the aeromedical assessment of pilots. Following the crash of Germanwings Flight 9525 in March 2015 with pilot suicide as the probable cause, the Pilot Mental Health Working Group reconvened to review their recommendations. As a result, the working group revised the recommendations which are provided here and which were distributed worldwide. The Working Group continues to emphasize the importance of assessing and optimizing pilot mental health, while providing additional recommendations on building trust and rapport between the aeromedical examiner and the pilot, on utilizing aviation mental health and aeromedical specialists, and on the balance between medical confidentiality and risk to public safety. The working group encourages all organizations involved in flight safety to review and consider implementing these recommendations within their usual operations.

Since the tragic accident of Germanwings flight 4U9525, there has been discussion about methods to identify and prevent suicidality in pilots. Neurogenetic scientists claim that biomarker tests for suicidality as part of healthcare assessments may lead to early identification of suicidal behavior. In this commentary the value of these gene expression biomarkers for aeromedical purposes is evaluated based on relevant literature. It is concluded that the currently identified biomarkers for suicidality need thorough validation before they can be used. The aeromedical examiner's most important tool is still an anamnesis, in which warning signs of suicidal behavior can be picked up. Simons R. Use of gene expression biomarkers to predict suicidality. Aerosp Med Hum Perform. 2016; 87(7):659-660.

INTRODUCTION:Bilastine is a new oral, second generation antihistamine used in the symptomatic treatment of allergic rhinoconjunctivitis and urticaria. It is considered a nonsedating antihistamine and might be recommended for use in pilots, pending research on the effects on flying-related performance under hypobaric conditions that prevail in an airliner. We assessed the effects of a single dose of bilastine 20 mg on alertness and complex task performance of healthy volunteers in a hypobaric chamber at 75.2 kPa (8000 ft/2438 m cabin altitude).METHODS:In a randomized, double-blind, crossover study, 24 volunteers received a single dose of bilastine 20 mg, hydroxyzine 50 mg (active control), and placebo. Using the Vigilance and Tracking Task, Multi-Attribute Task Battery, and Stanford Sleepiness Scale, assessments were made before and up to 6 h after intake of the study medication.RESULTS:Bilastine 20 mg had no impairing effects on sleepiness levels, vigilance, or complex task performance for up to 6 h post-dose. Hydroxyzine 50 mg (active control) was associated with significant sleepiness and impaired performance across this time period, confirming the sensitivity of the tests.CONCLUSION:Bilastine 20 mg did not cause sleepiness or impaired performance on tasks related to flying. It is anticipated that a single dose of bilastine 20 mg will not affect flying performance. Bilastine may provide a safe therapeutic alternative for pilots suffering from allergic rhinitis or urticaria. Our findings might also have implications for the treatment of allergic disorders of personnel involved in other safety-sensitive jobs. Valk PJL, Simons R, Jetten AM, Valiente R, Labeaga L. Cognitive performance effects of bilastine 20 mg during 6 hours at 8000 ft cabin altitude. Aerosp Med Hum Perform. 2016; 87(7):622-627.

Possible exposure to TriCresyl Phosphates (TCPs) has led to concerns among airline crew members. One isomer, Tri-ortho-Cresyl Phosphate (ToCP) is known to be neurotoxic and exposure to ToCP via contaminated cabin air has been suggested to be associated with the alleged Aerotoxic syndrome. The symptoms associated with Aerotoxic syndrome are diverse, including headaches, loss of balance, numbness and neurobehavioral abnormalities such as emotional instability, depression and cognitive dysfunction. Other ortho-isomers are toxic as well, but the non-ortho isomers are regarded as less toxic. In a collaborative effort to increase insight into the possible association between exposure to TCPs via contaminated cabin air and Aerotoxic syndrome, we performed an exposure- and toxicological risk assessment. Measurements in KLM 737 aircraft have demonstrated the presence of non-ortho isomers in low concentrations, though ToCP and other ortho-isomers could not be detected. Based on this exposure assessment, we established a toxicological risk model that also takes into account human differences in bioactivation and detoxification to derive a hazard quotient. From this model it appears unlikely that the health effects and alleged Aerotoxic syndrome are due to exposure to ToCP. Alternative explanations for the reported symptoms are discussed, but evaluation of the current findings in light of the criteria for occupational disease leads to the conclusion that the Aerotoxic Syndrome cannot be regarded as such. Additional research is thus required to unravel the underlying causes for the reported health complaints.

Insulin requirement affects the careers of diabetic professionals who do safety-sensitive jobs. In most cases, insulin-treated individuals are automatically banned from safety-sensitive jobs because the risk of hypoglycaemia is regarded as incompatible with safety. Recent developments—such as diabetes self-management education, self-monitoring of blood glucose, continuous glucose monitoring, and shortacting and longacting insulin analogues—enable better achievement of individual glycaemic targets and prevention of hypoglycaemia than did management options available previously. 1 American Diabetes AssociationStandards of medical care in diabetes—2011. Diabetes Care. 2011; 34: 11-61 Crossref Scopus (2520) Google Scholar These developments justify reconsideration of the safety risks of airline pilots on insulin. Should a pilot on insulin really fly?In their Comment, Simons and colleagues1 proposed that European aeromedical regulations for insulin-requiring diabetic pilots should be changed. They use the example of the few insulin-treated pilots flying in Canada to show low risk in aviation. The changes proposed by the authors are not medically justified, not ethically and practically admissible, and could jeopardise flight safety. Full-Text PDF

Rationale In party circuits dexamphetamine is frequently used in combination with alcohol. It is hypothesized that co-administration of dexamphetamine to alcohol might reduce the sedative effects of alcohol, but may potentiate risk-taking behaviour. Objectives The study was aimed at assessing the effects of alcohol, dexamphetamine and the combination of both on simulated driving and cognitive performance. Method Eighteen subjects participated in a randomized, crossover, placebo-controlled study employing four conditions: 10 mg dexamphetamine, 0.8 g/kg alcohol, 10 mg dexamphetamine + 0.8 g/kg alcohol, and placebo. Fundamental driving skills and risk-taking behaviour were assessed in a driving simulator. Subjects also completed vigilance and divided attention tasks, and subjective ratings. Results Mean BAC levels during simulated driving were between 0.91‰ and 0.64‰. Subjects using alcohol showed a significantly larger mean standard deviation of lateral position and shorter accepted gap time and distance. Use of alcohol or dexamphetamine + alcohol was associated with a higher frequency of red light running and collisions than the dexamphetamine or placebo conditions. Performance of vigilance and divided attention tasks was significantly impaired in the alcohol condition and, to a lesser degree, in the dexamphetamine + alcohol condition. Conclusion Single doses of 0.8 g/kg alcohol increased risk-taking behaviours and impaired tracking, attention and reaction time during a 3-h period after drinking when BACs declined from 0.9 to 0.2 mg/ml. The stimulatory effects of co-administration of dexamphetamine 10 mg were not sufficient to overcome the impairing effects of alcohol on skills related to driving.

INTRODUCTION:Dutch North Sea helicopter operations are characterized by multiple sector flights to offshore platforms under difficult environmental conditions. In the context of a Ministry of Transport program to improve safety levels of helicopter operations, we assessed effects of pre-duty sleep, pre-duty travel time, and workload factors on the alertness and vigilance of pilots.METHOD:Data of 24 pilots comprising 224 duty days were analyzed. Pilots performed 10-min test sessions after wake up, pre-duty, halfway-duty, end-duty, and at bedtime during normal duty rosters. Test sessions included completion of a vigilance task, vigor and sleepiness ratings, and questions on sleep and operational characteristics. Pilots wore an actometer to objectify sleep data.RESULTS:Vigor scores were high and sleepiness levels were low during the entire flight duty periods (FDPs), while vigilance was impaired only 6.8% in the course of the FDPs. Pre-duty sleep before morning duties was 1.5 h shorter than sleep before duties starting after midday. Longer pre-duty travel time was correlated with shorter pre-duty sleep and lower vigilance levels during duty.CONCLUSION:During the FDPs, pilots maintained alertness and vigilance levels that may be considered safe in terms of alertness-related flight safety. This favorable outcome may be attributed to reasonable length of FDPs, favorable circadian start and end times of duties, sufficient opportunities for restorative pre-duty sleep, and relatively good weather conditions. Appropriate FDP scheduling is an important measure to optimize alertness of helicopter pilots who have to cope with adverse environmental conditions and limited landing and air traffic control facilities.

This study assessed the effects of dexamphetamine with and without alcohol on simulated driving and cognitive tasks. 18 subjects participated in all 4 conditions: 10 mg dexamphetamine and 0.8g/kg alcohol, 10 mg dexamphetamine only, 0.8g/kg alcohol only, and a placebo control condition. A driving simulator was used to assess driving skills and risk taking on different road types. Cognitive performance was assessed using vigilance and divided attention tasks and subjects completed different rating scales. The main effects found were those of alcohol. This related to a larger standard deviation of lateral position, shorter accepted gap time and distance, higher average and maximum driving speeds and more violations of speed limits. A higher percentage of subjects in the dexamphetamine + alcohol condition did not stop for the red traffic lights, or collided with a vehicle. Performance of vigilance and divided attention tasks was impaired in the alcohol condition and impaired to a lesser degree in the dexamphetamine + alcohol condition. The conclusions of this study are that the main effect of impaired driving was found in the effect of 0.8 g/kg alcohol dose at the control level and the maneuvering level. The amphetamine dose did not potentiate risk taking behaviour, but also did not overcome the negative effects of alcohol. The findings of the present study justify the conclusion that drivers using 0.8 g/kg alcohol, or the combination of dexamphetamine with alcohol, pose a considerable traffic safety risk.

In a Notice of Proposed Amendment, the European Aviation Safety Agency proposes to introduce a Leisure Pilot License (LPL). Holders of a LPL for airplanes will be allowed to fly single-engine piston airplanes with a maximum takeoff mass of 2000 kg or less, carrying a maximum of three passengers. In this commentary paper, we express significant concern about the flight safety consequences of the proposed aeromedical requirements of the LPL. We argue that the proposed minimum age, validity period of the medical certificate, and issuance of certificates by general practitioners may increase the flight safety risk. Major revision of the proposed LPL regulation is recommended.

This primary objective of this paper is to discuss the usefulness of melatonin for reducing symptoms of circadian rhythm disturbances in aircrew. Literature and own data of circadian disruptions and symptoms of aircrew were analysed. Considerations concerning the use of melatonin by aircrew are discussed. The main outcomes were as follows. Aircrew experience compound circadian disruptions caused by rapidly alternating time zone transitions, night flying, early departures, and irregular work schedules. While leisure travellers report beneficial effects of melatonin on jet lag symptoms, the case for aircrew is more complicated. In aircrew, jet lag symptoms are masked by operational demands and personal sleep-activity strategies. Aviation authorities disapprove of the use of melatonin by pilots, because of possible adverse effects. Our conclusion was that the effects of melatonin, taken during duty, will be minimal, or counterproductive. However, in some cases melatonin could be useful for aircrew. In that context, thorough scientific research of effects and side effects of melatonin is needed.

SummaryThe mechanism of air travel-related venous thrombosis is unclear. Although immobility plays a pivotal role, other factors such as fluid loss may contribute. We investigated whether fluid loss occurred more in individuals with coagulation activation after air travel than in subjects without. As a secondary aim, we investigated whether fluid loss per se occurred during air travel. In this crossover study, 71 healthy volunteers were exposed to eight hours of air travel, eight hours immobilization in a cinema, and a daily-life control situation. Markers of fluid loss (haematocrit, serum osmolality and albumin) and of coagulation activation were measured before and after each exposure. The study included ll volunteers with and 55 volunteers without coagulation activation during the flight. The change in parameters of fluid loss was not different in volunteers with an activated clotting system from those without (difference between groups in haematocrit: −0.6%, 95% confidence interval [CI]: −1.9 to 0.6). On a group level, mean haematocrit values decreased during all three exposures. However, in some individuals it increased, which occurred in more participants during the flight (34%; 95% CI 22 to 46) than during the daily-life situation (l9%; 95% CI 10 to 28). These findings do not support the hypothesis that fluid loss contributes to thrombus formation during air travel.

Reported percentages of in-flight medical incidents caused by syncope, the medical term for fainting, vary between 15 % and 22 %. Syncope is usually a benign medical event, but it may cause fear and distress among passengers and the individual involved. Incorrectly diagnosed benign syncope may lead to unnecessary flight diversions. In this context, the incidence of in-flight syncope and possible relationships with cabin environmental and passenger factors were studied. In September 2005, questionnaires were handed out to the senior purser on all KLM long haul flights. Pursers were asked to record all cases of in-flight syncope and to answer questions concerning cabin climate. Literature data were analyzed concerning in-flight and passenger factors that may cause or elicit syncope. With a response rate of 79 %, 1625 forms were analyzed. The in-flight syncope risk was 3–9 per 1000 passenger flight hours, depending on type of aircraft. The frequency of syncopal events was weakly correlated with cabin climate conditions. Literature analysis provides evidence that hypoxia is a sufficient cause for syncope in a sub-set of healthy airline passengers. There is evidence that cabin pressure and temperature may contribute to the occurrence of syncope. The syncope risk appears to be higher aboard an aircraft than on the ground. Hypoxia is a sufficient cause for syncope in a sub-set of healthy airline passengers. Airline passengers may become considerably hypoxic due to reduced pulmonary ventilation caused by immobility, drowsiness, and gastro-intestinal distension. In-flight hypoxia may reach levels sufficient to cause syncope. High cabin temperature may further trigger this reaction.

Background. Because malaria in endemic areas presents a serious threat to the health of aircrew, optimal prevention is important. An effective and safe prophylactic antimalarial drug is needed. The combination of 250 mg atovaquone with 100 mg proguanil HCl(atovaquone/proguanil, or A/P) has shown good prophylactic efficacy and tolerance for prevention of falciparum malaria. However, medication for use by aircrew on duty is subject to approval by national and international aviation authorities, who require convincing evidence that the treatment has no negative effects on the flight performance of crews. The purpose of the present study was to evaluate the risk of detrimental effects of atovaquone/proguanil on flight-related performance and alertness in healthy subjects under conditions of aircraft cabin pressure.Methods:A randomized, double-blind crossover study was conducted in which 24 subjects were enrolled to use A/P and placebo, each in a 14-day prophylactic dosing regimen with a 21-day washout phase. Vigilance, alertness, complex information processing, and sleepiness were assessed in a hypobaric chamber at 75.2 kPa, which equals the lower limit of commercial aircraft cabin pressure. Furthermore, duration and quality of sleep at home were recorded during the 14 days of drug administration.Results: Twenty-two subjects completed the study. No significant differences were found between the effects of placebo and A/P on vigilance, alertness, complex information processing, sleep duration and quality, and the occurrence of adverse effects.Conclusions: In-flight performance and alertness of aircrew will not be affected by the prophylactic use of A/P during a period of 14 days.