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.

Flight Performance During Exposure to Acute Hypobaric Hypoxia.

INTRODUCTION: The purpose of the present study was to examine the influence of hypobaric hypoxia (HH) on a pilot's flight performance during exposure to simulated altitudes of 91, 3048, and 4572 m (300, 10,000, and 15,000 ft) and to monitor the pilot's physiological reactions. METHOD: In a single-blinded counter-balanced design, 12 male pilots were exposed to HH while flying in a flight simulator that had been placed in a hypobaric chamber. Flight performance of the pilots, pilot's alertness level, Spo2, heart rate (HR), minute ventilation (VE), and breathing frequency (BF) were measured. RESULTS: A significant difference was found in Flight Profile Accuracy (FPA) between the three altitudes. Post hoc analysis showed no significant difference in performance between 91 m and 3048 m. A trend was observed at 4572 m, suggesting a decrease in flight performance at that altitude. Significantly lower alertness levels were observed at the start of the flight at 4572 m compared to 91 m, and at the end of the flight at 4572 m compared to the start at that altitude. Spo2 and BF decreased, and HR increased significantly with altitude. DISCUSSION: The present study did not provide decisive evidence for a decrease in flight performance during exposure to simulated altitudes of 3048 and 4572 m. However, large interindividual variation in pilots' flight performance combined with a gradual decrease in alertness levels observed in the present study puts into question the ability of pilots to safely fly an aircraft while exposed to these altitudes without supplemental oxygen.Steinman Y, van den Oord MHAH, Frings-Dresen MHW, Sluiter JK. Flight performance during exposure to acute hypobaric hypoxia. Aerosp Med Hum Perform. 2017; 88(8):760-767.

Fitness to Fly Testing in Patients with Congenital Heart and Lung Disease.

BACKGROUND: During commercial air travel passengers are exposed to a low ambient cabin pressure, comparable to altitudes of 5000 to 8000 ft (1524 to 2438 m). In healthy passengers this causes a fall in partial pressure of oxygen, which results in relative hypoxemia, usually without symptoms. Patients with congenital heart or lung disease may experience more severe hypoxemia during air travel. This systematic review provides an overview of the current literature focusing on whether it is safe for patients with congenital heart or lung disease to fly. METHODS: The Pubmed database was searched and all studies carried out at an (simulated) altitude of 5000-8000 ft (1524-2438 m) for a short time period (several hours) and related to patients with congenital heart or lung disease were reviewed. RESULTS: Included were 11 studies. These studies examined patients with cystic fibrosis, neonatal (chronic) lung disease and congenital (a)cyanotic heart disease during a hypoxic challenge test, in a hypobaric chamber, during commercial air travel, or in the mountains. Peripheral/arterial saturation, blood gases, lung function, and/or the occurrence of symptoms were listed. DISCUSSION: Based on the current literature, it can be concluded that air travel is safe for most patients. However, those at risk of hypoxia can benefit from supplemental in-flight oxygen. Therefore, patients with congenital heart and lung disease should be evaluated carefully prior to air travel to select the patients at risk for hypoxia using the current studies and guidelines.

Modern Air Combat Developments and Their Influence on Neck and Back Pain in F-16 Pilots.

INTRODUCTION: Neck and back pain in fighter pilots remains a serious occupational problem. We hypothesized that recent advances such as the joint helmet mounted cueing system (JHMCS) in modern air combat might contribute to the development of spinal complaints in F-16 pilots. METHODS: Surveyed were 59 F-16 pilots of the Royal Netherlands Air Force who were compared to 49 F-16 pilots who filled in a similar questionnaire in 2007. The prevalence of neck and back pain, work situations, and capacity of the pilot were analyzed. RESULTS: The self-reported 1-yr prevalence of regular or continuous neck and lower back pain in 2014 were 22% and 31%, respectively, compared to both being 12% in 2007. Age, military flying experience, total number of flying hours, flying hours on the F-16, and total number of hours flown with night vision goggles (NVG) were significantly higher in 2014. In 2014, 95% flew with JHMCS, compared to 0% in 2007. Flying with JHMCS (88%), NVG (88%), type of flight (63%), and sitting posture (50%) were the most reported causes of flight-related neck pain. Sitting posture (89%), duration of flight (56%), and seat (44%) were among the reported causes of back pain. DISCUSSION: The increasing trend of neck and lower back pain might be caused by multiple changes in both the work situation and capacity of the pilots since 2007. Future innovations will increase the load on the pilot's spine. To successfully address their spinal problems in the future, fighter pilots must be monitored continuously.

The effect of an optimised helmet fit on neck load and neck pain during military helicopter flights.

The main purpose of this study was to improve the helmet fit of military helicopter aircrew members and evaluate its effect on the experienced helmet stability (helmet gliding), neck load, neck pain, hot spots (pressure points), irritation/distraction, and overall helmet comfort during night flights. A within-subject design was used over a three-month period that consisted of two consecutive interventions of optimising the fit of the aircrew's helmets: 1) a new helmet fit using a renewed protocol and 2) replacement of a thermoplastic inner liner with a viscoelastic foam inner liner. A total of 18 pilots and loadmasters rated the outcome measures using the Visual Analogue Scales immediately after their night flights, for three night flights in total per measurement period. The optimised helmet fit resulted in a significant decrease in the experienced helmet gliding, neck load and pressure points, a decrease trend in the experienced neck pain and irritation/distraction, and a significant increase in the experienced overall helmet comfort during flight. These results demonstrate the importance of achieving an optimised helmet fit for military helicopter aircrew and that an optimised helmet fit might have implications for both health and safety concerns.

Neck strength, position sense, and motion in military helicopter crew with and without neck pain.

INTRODUCTION: Neck pain in military helicopter pilots and rear aircrew is an occupational health problem that may interfere with flying performance. The aim of the present study was to investigate possible differences in the physical abilities of the cervical spines of helicopter pilots and rear aircrew with and without neck pain during the previous year. METHODS: The study included 61 male helicopter pilots and 22 rear aircrew without neck pain (Sx-) and 17 pilots and 17 rear aircrew with neck pain (Sx+). Active cervical range of motion (flexion-extension, right-left rotation, and right-left lateral flexion), neck position sense (reposition error back to neutral and defined positions after submaximal cervical movement), and maximum isometric neck muscle strength (flexion, extension, and right and left lateral flexion) were measured. Two-way factorial analyses of variance were performed, in which the fixed factors were occupation (pilot or rear aircrew) and neck pain state (Sx+ or Sx-). RESULTS: On average, there was a trend toward lower values in strength [extension: 55 (19) Nm vs. 58 (20) Nm; flexion 22 (8) Nm vs. 24 (12) Nm] and smaller cervical range of motion [flexion-extension: 132 degrees (19 degrees) vs. 137 degrees (15 degrees); rotation: 156 degrees (14 degrees) vs. 160 degrees (14 degrees)] in the total Sx+ crew, compared to their Sx- colleagues. However, the two-way factorial ANOVA revealed neither significant main effects nor significant interaction effects in any of the measured physical abilities. CONCLUSION: The results suggest that having experienced neck pain was not significantly associated with differences in the physical abilities of the cervical spines of helicopter crew, as assessed in this study.

Neck pain in military helicopter pilots: prevalence and associated factors.

Our aim is to estimate the self-reported one-year prevalence of neck pain in military helicopter pilots and to compare work-related, individual, and health-related factors in the pilots with (neck pain group) and without (reference group) regular or continuous neck pain. A questionnaire was completed by 75% (n = 113) of all military helicopter pilots of the Royal Netherlands Air Force and Navy. The reported one-year prevalence of any neck pain was 43%, and 20% for regular or continuous neck pain. Besides some significant differences in individual and health-related factors (also often reported in the general population), flying hours were significantly higher in pilots with neck pain compared to their colleagues without neck pain. The findings in this study suggest that neck pain in military helicopter pilots is a significant occupational problem and may be a consequence of longer exposure to flying.

Usefulness of temazepam and zaleplon to induce afternoon sleep.

UNLABELLED: Insufficient daytime sleep may result in reduction of effectiveness and safety during overnight military missions. The usefulness of temazepam and zaleplon to optimize afternoon sleep and their effects on performance and alertness during a subsequent night shift were studied. METHOD: In a randomized double-blind within-subjects design, 11 subjects took 20 mg of temazepam, 10 mg of zaleplon, or placebo before a 5:30-10:00 p.m. sleep period. Sleep length and quality were measured. Subjects were kept awake throughout the night while alertness, cognitive performance, and muscle power were repeatedly measured. RESULTS: Temazepam provided significantly longer and qualitatively better sleep than zaleplon or placebo. During the night, sleepiness increased and muscle power was impaired in all conditions. Better sleep was correlated with less sleepiness during the night. CONCLUSION: Temazepam is useful to optimize a 4.5-hour afternoon sleep before overnight missions. Irrespective of hypnotic treatment, sleepiness and fatigue increased during the night shift.