Army Aircrew Research Articles

Obstructive Sleep Apnea Among Army Aircrew.

INTRODUCTION: Obstructive sleep apnea (OSA) is a condition characterized by disrupted sleep and excessive daytime fatigue. Associated cognitive and psychomotor decrements pose a threat to aviators' performance and flight safety. Additionally, the longer term health effects associated with the disease can jeopardize an aviator's career and negatively impact operational outputs. This study reviews OSA prevalence, related comorbid conditions in Army aviators, and analyzes the aeromedical dispositions of affected individuals.METHODS: The U.S. Army Aeromedical Electronic Resource Office (AERO) database was interrogated for all cases of OSA from June 2005 through June 2015 using ICD-9 code 327.23. Prevalence rates for OSA and other comorbid conditions were then calculated using the total number of aviators in the AERO database.RESULTS: A total of 663 unique instances of OSA were found among the aviator population (N = 24,568), giving a point prevalence of 2.69%. Four cases affected women. Mean age of initial presentation was 42.62 yr and mean Body Mass Index was 28.69. The top five most prevalent comorbid conditions were hypertension, lumbago, degeneration of a lumbar or lumbosacral intervertebral disc, PTSD, and testicular hypofunction.DISCUSSION: Prevalence of OSA among aviators is lower than the general population but is not uncommon. A positive diagnosis requires a waiver or can result in suspension if not managed effectively, potentially leading to a reduction in aviator numbers. Aggressive health promotion and robust medical surveillance and aeromedical disposition management by the aeromedical community is essential to reduce OSA numbers, maintain aviator health, and maximize flight safety.Goldie C, Stork B, Bernhardt K, Gaydos SJ, Kelley AM. Obstructive sleep apnea among army aircrew. Aerosp Med Hum Perform. 2022; 93(5):415-420.

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

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. 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. 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. 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.

Reported Back Pain in Army Aircrew in Relation to Airframe, Gender, Age, and Experience.

Back pain has remained an issue of significance among aircraft crewmembers for decades, occurring in the majority of military helicopter pilots with potential deleterious effects on performance, safety, and operational readiness. This exploratory, correlational survey study was designed to evaluate the presence of patterns and relationships that may require further examination to understand causal factors. The study population consisted of U.S. Army aviation crewmembers. Subjects (467) completed an anonymous survey, including questions regarding demographics, airframes, experience, pain history and severity, ergonomics, mitigation strategies, and duty limitations. Overall, 84.6% of participants reported back pain at some time during their flying career, with 77.8% reporting back pain in the last calendar year. Age was found to significantly correlate with earlier time to pain during flight, higher pain rating after flight, and occurrence of grounding. A stepwise linear regression model was used to explore the relationships between age, flight hours, and years of aviation experience, demonstrating age to be the significant variable accounting for the observed variance. Aircrew reported wear of combat-related survival equipment and poor lumbar support to be the most notable contributors. Back pain rates were consistent with previous studies. The relationship of age to back pain in this study may highlight unique pathophysiological pathways that should be further investigated within an occupational context to better understand the etiologic role. Enhanced seated lumbar support and combat-related survival equipment remain relatively low-cost/high-yield topics worthy of further investigation for exploiting efficient means to improve health, safety, and operational performance.Kelley AM, MacDonnell J, Grigley D, Campbell J, Gaydos SJ. Reported back pain in army aircrew in relation to airframe, gender, age, and experience. Aerosp Med Hum Perform. 2017; 88(2):96-103.

Assessment of an Alternative Army Aircrew Eyewear.

Currently, Army aircrews needing refractive correction are issued the HGU-4/P aviator spectacles. However, a recently published survey found dissatisfaction with the current spectacle frame. The Aircrew Flight Frame (AFF) has been used by the Air Force for over 14 yr, with the AFF-OP (Operational) style used the longest. The purpose of this study was to evaluate AFF-OP performance and compatibility among U.S. Army aircrew under operational conditions. At 1-, 6-, and 12-wk intervals, 73 Army aircrew members wore the AFF-OP eyewear and completed a Likert scale survey. There were 14 outcome measures surveyed, with the main outcome measure being frame preference. The AFF-OP was preferred significantly more than the HGU-4/P spectacle. Overall, 94% of aircrew responses preferred the AFF-OP and the three highest subjective reasons for AFF-OP preference were: 1) comfort around the ears without helmet or headset; 2) comfort around the ears with helmet or headset; and 3) the effect on ear cup seal. There were no statistically significant differences in responses over the three surveyed time intervals. Army aviation aircrew preferred the AFF-OP over the current HGU-4/P spectacles. Two of the top three highest subjective reasons for AFF-OP preference coincided with two of the top three operational eyewear problems reported in the recently published survey. If Army aircrew do not wear their issued eyewear, they may purchase their own frame "out of pocket." However, this can lead to use of a frame that has not been tested for compatibility and may compromise performance of aircrew life support equipment.

Military Aircrew Eyewear Survey: Operational Issues

Army aircrew are required to operate under stressful conditions within a degraded visual environment. To gain an understanding of current eyewear mission needs, we surveyed aircrew regarding operational issues associated with the current U.S. Army-issue aircrew eyewear. An anonymous online survey was completed by 976 U.S. Army aircrew personnel recruited through an invitational e-mail. Of the respondents, 34% reported wearing corrective lenses. Nearly 50% of them reported dissatisfaction with the HGU-4/P Aviator spectacles. The leading problems reported were discomfort (15%), "hot spots" around the ears (13%), and break of the earcup seal (11%). Nearly 41% of the respondents wore multifocal lenses and, of those, 16% reported that the HGU-4/P's restricted field of view (FOV) adversely affected duty performance. Of those who wore Modified HGU-4/P Apache spectacles, 79% had an unacceptable FOV with the helmet display unit. A similar number of aircrew modified the Apache eyewear to increase the FOV. In addition, wind and dust created eye discomfort or affected the vision of 46% of all respondents when performing flight duties. Over 82% expressed the need for an improved aircrew spectacles and 73% desired aviation-compatible protective eyewear. The current Army HGU-4/P Aviator and the Modified HGU-4/P Apache spectacles have significant operational deficiencies and compatibility issues. Such deficiencies have led to poor wear compliance and unauthorized modification of the Army-issue Aviator eyewear, posing readiness and safety issues. The results of this survey formally identify the need for military combat eye protection that is compatible with flight systems.

Assessing the Safety of Anthrax Immunization in US Army Aircrew Members via Physical Examination

Anthrax in weaponized form is the bioterrorism agent of most concern. Questions raised about the safety of the anthrax vaccine can be addressed by comparing immunized and unimmunized people in population-based studies. A retrospective evaluation of data from periodic physical examinations collected on anthrax-immunized and -unimmunized US Army aircrew members between 1998 and 2005 was performed to evaluate the safety of anthrax immunization. Mean changes in variables found on physical examination and laboratory analysis were compared by use of t tests. Multiple linear regression predicted change in outcome from baseline characteristics. We compared 6,820 immunized subjects and 4,145 unimmunized controls based on US Army aircrew physical examination and screening laboratory tests. No association between anthrax immunization and a clinically relevant change in a tested physiologic parameter was detected. No attributable risk of anthrax immunization was observed in this group of Army aircrew members.

Incidence and Outcomes of Total Hip Arthroplasty among U.S. Army Aviators

Among Army aviators, the incidence of total hip arthroplasty (THA) is unknown. This study analyzes the incidence and aeromedical disposition of THA among Army aviators. The U.S. Army Epidemiology Data Register was queried for a 10-year period from calendar year 1987 to 1996. The aviators selected for this study cohort were all qualified and on active flight status before undergoing THA. Data collected included age, gender, diagnoses, and aeromedical dispositions. There were 214,003 aviator-years of observation. Eleven aviators underwent 14 THAs. The overall incidence of THA was 0.05 per 1,000 aviator-years of observation. Of the 11 aviators who underwent THA during the study period, 4 received aeromedical suspension from flying duties (36%). THA is a rare medical event among Army aircrew members. Most are able to return to full flying duties with a waiver. Aircrew members younger than 50 years with THA are more likely to be suspended from aviation duties.

Confidentiality and the Psychological Treatment of U.S. Army Aircrew Members

The present article addresses the issue of confidentiality in U.S. Army psychological services and the special considerations affecting the confidentiality afforded to Army aviation personnel receiving such services. The author reviews Army regulations and American Psychological Association ethical standards relevant to the issue of confidentiality for aircrew members. Recommendations are offered for mental health professionals who provide services to Army aviation personnel, and a hypothetical clinical case is presented to illustrate the concepts discussed.

A Survey of Hearing Loss in Army Aircrew

Military aircrew are exposed to excessive noise at work, with the concurrent risks of acquiring Noise Induced Hearing Loss (NIHL). Past studies have related aircrew NIHL to a variety of factors; however, no clear causal relationship has been shown. The difficulty of establishing NIHL due to flying remains when many other confounders are present, especially age and exposure to firearms noise in the military environment. A cross sectional prevalence study of hearing loss in Army Air Corps aircrew has been undertaken. One hundred and twenty one aircrew who had more than ten years flying experience were studied and the results show that there appears to be a threshold shift in excess of that expected from the ISO levels for otologically normal males of the same age. The hearing threshold shift was found to correlate with the number of years flying and aircrew age, with the number of flying hours being less significant.

Noise induced hearing loss in military helicopter aircrew--a review of the evidence.

Noise Induced Hearing Loss (NIHL) has been recognised for some time. In the military environment one group of personnel at risk are Army helicopter aircrew who are exposed to continuous noise levels of up to 100 dB(A) in flight. The evidence for the damaging effect of this occupational noise is reviewed and some of the difficulties in drawing conclusions are highlighted. The current protection offered for the Mk 4 helmet is discussed and the incorporation of Active Noise Reduction (ANR) is suggested as a likely way of ensuring that the in-flight noise exposure in Army aircrew is kept as low as possible.

Subjective assessment of contact lens wear by army aircrew.

Because 23% of Army aviators are ametropic, contact lenses have drawn increased attention as a spectacle substitute to solve system compatibility problems. From November 1988 until October 1991, a series of contact lens research protocols were conducted to develop a comprehensive database on contact lens wear in varied environments. Questionnaires were used to assess suitability and acceptability of routine contact lens wear. Responses from 202 subjects were obtained from September 1989 through September 1991. The questions explored operational and safety of flight issues of contact lens wear. Subjects overwhelmingly approved of contact lens use in all settings: 95% expressed greater combat readiness and effectiveness with contact lenses, 98% felt contact lens use (and maintenance) in the cockpit had no adverse impact on safety of flight, and 98% endorsed the routine use of contact lenses. These data highlight Army aircrew acceptance of contact lens use.

Health-risk behaviors of Army aircrew.

Data from the US Army Health Risk Appraisal Program were used to compare health and fitness levels in flight and nonflight personnel. Survey data collected from an aviation brigade, consisting of 428 aircrew and 899 support personnel, were compared with US Army summary statistics. Flight personnel scored better on evaluation of hypertension, stress, weight standards, and seatbelt use. However, the prevalence of smokeless tobacco use, heavy alcohol consumption, and driving after drinking or riding with someone who consumed alcohol was significantly higher in flight personnel. This study suggests that although Army aircrew have better lifestyle habits overall, high-risk behaviors have been identified that warrant further evaluation.

A Secondary Analysis Comparing Subjective Workload Assessments with U.S. Army Aircrew Training Manual Ratings of Pilot Performance

The present research effort sought to determine the validity of subjective workload estimates for Aircrew Training Manual (ATM) tasks for the UH-60 helicopter generated via a modified Delphi technique. Delphi weights were found to predict performance ratings on the ATM tasks; ATM tasks associated with accidents also had higher Delphi weights than did those not so associated.

The use of contact lenses by Army air crew.

The use of contact lenses by Army air crew.