Civil Aerospace Medical Institute Research Articles

Cerebral Blood Flow Based Computer Modeling of Gz-Induced Effects

BACKGROUND: There is continued interest in acceleration (G) effects in civil aviation, as G-induced loss of consciousness (G-LOC), impaired consciousness, and visual effects play a role in aerobatic, agricultural, and military aviation accidents.METHODS: A software model [the Civil Aerospace Medical Institute G-Effects Model (CGEM)] based on physical and physiological variables related to in-flight tissue resupply and using oxygen flow as a proxy for supply availability, was developed to evaluate risk of G-LOC and related phenomena in aeronauts. Aeronauts were modeled using several parameters, including sex, cardiovascular fitness, and other common modifiers such as G-suits, positive pressure breathing gear, anti-G straining, and other muscle tensing. The software was validated by comparison with experimental data from the peer-reviewed literature.RESULTS: CGEM predicted physiological effects of Gz exposure accurately, particularly for rapid onset rates. Predicted times to G-LOC and absolute incapacitation periods were consistently within 1 SD of pooled results obtained during centrifuge experiments using U.S. Navy (USN) and U.S. Air Force (USAF) pilots. Predictions of G tolerance based on visual effects onset also compared well with published data, as did evaluation of symptoms expected during a difficult aerobatic maneuver.DISCUSSION: CGEM is a new tool for civil and military aviation. Rather than providing a simple G tolerance number, flight surgeons, pilots, and accident investigators can gain insight into changes in risk-from factors such fatigue, medications, dehydration, and anti-G countermeasures used-through proper selection of parameters.Copeland K, Whinnery JE. Cerebral blood flow based computer modeling of Gz-induced effects. Aerosp Med Hum Perform. 2023; 94(5):409-414.

Cannabinoid distribution in fatally-injured pilots’ postmortem fluids and tissues

The primary psychoactive component of cannabis, Δ9-tetrahydrocannabinol (THC) impairs cognitive function and psychomotor performance, particularly for complex tasks like piloting an aircraft. The Federal Aviation Administration’s (FAA) Forensic Sciences Section at the Civil Aerospace Medical Institute (Oklahoma City, OK) performs toxicological analyses on pilots fatally injured in general aviation incidents, permitting cannabinoids measurement in a broad array of postmortem biological specimens. Cannabinoid concentrations in postmortem fluids and tissues from 10 pilots involved in airplane crashes are presented. Median (range) THC blood concentration was 1.6 (1.0–13.7) ng/mL. Phase I metabolites, 11-hydroxy-THC (11-OH-THC) and 11-nor-9-carboxy-THC (THCCOOH) and phase II glucuronide metabolite, THCCOOH-glucuronide, had median (range) blood concentrations of 1.4 (0.5–1.8), 9.9 (2.2–72.6) and 36.6 (7.1–160) ng/mL, respectively. Urine analyses revealed positive results for THCCOOH, THC-glucuronide, THCCOOH-glucuronide and 11-nor-9-carboxy-Δ9-tetrahydrocannabivarin (THCVCOOH). THC was readily distributed to lung, brain, kidney, spleen and heart. The psychoactive metabolite, 11-OH-THC, was identified in liver and brain with median (range) concentrations 7.1 (3.5–10.5) and 2.4 (2.0–6.0) ng/g, respectively. Substantial THCCOOH and THCCOOH-glucuronide concentrations were observed in liver, lung, brain, kidney, spleen and heart. These cannabinoid concentrations from multiple types of postmortem specimens add to the limited postmortem cannabinoid research data and suggest useful biological matrices for investigating cannabinoid-related deaths.

Stress Management and Air Traffic Control Trainees: Development and Evaluation of a New Training Course

The primary mission of the Federal Aviation Administration (FAA) is to maintain the safety of the National Airspace System (NAS). As part of this mission, the FAA is tasked with ensuring that future air traffic controllers are adequately trained to perform the high-risk job of directing air traffic. The FAA Academy curriculum for newly hired controllers involves 3-4 months of intensive lessons and performance assessments. It has been suggested that this training program is quite stressful, and successful trainees tend to be those who can better manage stress. To support ATC trainees, researchers at the Civil Aerospace Medical Institute (CAMI) have conducted operational research to develop and evaluate a stress management training to help trainees manage their stress during training at the FAA Academy.

Focus on the FAA Civil Aerospace Medical Institute.

Focus on the FAA Civil Aerospace Medical Institute.

Cardiac Inflight Incapacitations of U.S. Airline Pilots: 1995-2015.

Inflight medical incapacitations are rare events that can result in the loss of lives and aircraft. The potential for an in-flight medical event deserves the attention of certification authorities. Cardiac emergencies are among the most common serious events. The primary focus of this study was to examine whether the proportions of pilots with reported cardiac conditions could be used to identify those who had inflight medical incapacitations. The Civil Aerospace Medical Institute Inflight Incapacitation Registry was searched to identify airline pilots with a cardiac history and an inflight medical event between 1995 and 2015. The Federal Aviation Administration's Decision Support System was searched for airline pilots without an inflight medical event. The cardiovascular history of incapacitated pilots was then compared to that of airline pilots without incapacitation events. Although a significantly greater proportion of airline pilots with cardiac events had pacemakers than a control group with the same cardiac history who did not have inflight events, no significant difference was found in the proportions of other markers of cardiac health. The proportions of airline pilots with identified cardiac conditions could not be reliably used to identify which pilots had inflight incapacitations.DeJohn CA, Mills WD, Hathaway W, Larcher J. Cardiac inflight incapacitations of U.S. airline pilots: 1995-2015. Aerosp Med Hum Perform 2018; 89(9):837-841.

Pilots using selective serotonin reuptake inhibitors compared to other fatally injured pilots

Selective Serotonin Reuptake Inhibitors (SSRI) were a disqualifying medication for U.S. civil pilots before April 5, 2010. After this date, a Federal Aviation Administration policy was created that allowed airmen, on select SSRIs, a pathway to hold a valid medical certificate. The purpose of this study was to provide a detailed look at SSRIs in the U.S. pilot population since the inception of this new policy. We examined the toxicology results from fatally injured airmen in addition to outcomes concerning pilots who are participating in the program. This study examined data from the Civil Aerospace Medical Institute's Bioaeronautical Sciences Research Laboratory in conjunction with the Medical Analysis Tracking Registry and the Document Imaging and Workflow System. A count-based regression model quantified the relationships between positive SSRI findings with additional factors of interest. These factors included pilot rating, ethanol, and first generation antihistamines. There were 1484 fatally injured airmen over the six year study period, of which 44-tested positive for an SSRI. First-generation antihistamines were statistically associated with positive findings of SSRIs.

Postmortem Fluid and Tissue Concentrations of THC, 11-OH-THC and THC-COOH.

Marijuana is the most commonly abused illicit drug worldwide. Marijuana is used for its euphoric and relaxing properties. However, marijuana use has been shown to result in impaired memory, cognitive skills and psychomotor function. The Federal Aviation Administration's Civil Aerospace Medical Institute conducts toxicological analysis on aviation fatalities. Due to severe trauma associated with aviation accidents, blood is not always available; therefore, the laboratory must rely on specimens other than blood for toxicological analysis in ~30-40% of cases. However, the postmortem distribution of cannabinoids has not been well characterized. The purpose of this research is to evaluate the distribution of Δ9-tetrahydrocannabinol (THC), and its metabolites, 11-hydroxy-tetrahydrocannabinol (11-OH-THC) and THC-COOH, in postmortem fluid and tissue specimens from 11 fatal aviation accident cases (2014-2015) previously found positive for cannabinoids. Specimens evaluated, when available, included: blood, urine, vitreous humor, liver, lung, kidney, spleen, muscle, brain, heart and bile. We developed and validated (following SWGTOX guidelines) a sensitive and robust method using solid-phase extraction and liquid chromatography-tandem mass spectrometry to identify and quantify THC, 11-OH-THC and THC-COOH in postmortem fluids and tissues. The method readily identified and quantified these cannabinoids in postmortem fluids and tissues below 1 ng/mL. Qualitative cannabinoid results within each case were comparable between blood and non-blood specimens. However, there was no consistent distribution of the cannabinoids between blood and any other fluids or tissues. Therefore, while quantitative interpretation of non-blood postmortem fluid and tissues samples is not prudent, a majority of the non-blood specimens tested could be suitable alternative/supplemental choices for qualitative cannabinoid detection.

Tricyclic Antidepressants Found in Pilots Fatally Injured in Civil Aviation Accidents.

Prevalence of tricyclic antidepressants (TCAs) has not been explored in pilots. The National Transportation Safety Board (NTSB) aviation accident and the Federal Aviation Administration's Civil Aerospace Medical Institute (CAMI) toxicology and medical certification databases were searched for pilots fatally injured in aviation accidents. During 1990-2012, CAMI received bio-samples of pilots from 7037 aviation accidents. Of these, 2644 cases were positive for drugs. TCAs were present in 31. TCA blood concentrations ranged from therapeutic to toxic levels. The NTSB determined that the use of drugs and ethanol as the probable cause or contributing factor in 35% (11 of 31) of the accidents. None of the 31 pilots reported the use of TCAs during their aviation medical examination. The prevalence of TCAs in aviators was less than 0.5% (31 of 7037 cases). There is a need for aviators to fully disclose the use of medications at the time of their medical examination.

Ethanol and Drugs Found in Civil Aviation Accident Pilot Fatalities, 1989-2013.

Biological specimens from pilots fatally injured in civil aviation accidents are analyzed for ethanol and drugs at the Civil Aerospace Medical Institute (CAMI). Prevalence of these substances in the pilots has been evaluated at 5-yr intervals since 1989. In continuation, a fifth 5-yr study (2009-2013) was conducted. The CAMI toxicology/medical certification and National Transportation Safety Board (NTSB) aviation accident databases were searched. During 2009-2013, samples from 1169 pilots were analyzed. Aircraft involved in the accidents were primarily operating under general aviation. Most airmen were private pilots and held third-class medical certificates. In relation to the first 5-yr (1989-1993) period, the pilot fatality cases decreased by 37% and the presence of ethanol and/or drugs in the pilots increased by 239% in the fifth 5-yr period. The ethanol usage was unchanged, but increases were 267% and 583% with illicit and prescription drugs, respectively. The use of ethanol and/or drugs by aviators, along with underlying medical conditions, was determined by the NTSB to be cause/factors in 5% of the accidents. The observed decrease in the fatality cases does not necessarily suggest the decrease in aviation accidents, as active airmen numbers also declined. The increase in the drug positive cases is primarily attributed to the continuous rise in the use of prescription drugs. Although prevalence of ethanol and drugs has been evaluated in fatally injured aviators, such evaluation has not been performed in active pilots not involved in accidents. This type of comparative study would be crucial in assessing aviation safety.

23 years of toxicology testing fatally injured pilots: Implications for aviation and other modes of transportation

Use of over-the-counter, prescription, and illicit drugs is increasing in the United States (US). Many of these drugs are psychoactive and can affect the user’s ability to safely operate a vehicle. However, data about drug use by vehicle operators is typically limited to a small proportion of operators and a short list of drugs. For instance, required testing for commercial vehicle operators following most accidents is limited to a urine test for 11 drugs. By comparison, the Federal Aviation Administration (FAA), routinely tests fatally injured pilots’ blood and tissues for hundreds of compounds. This study used the results from these tests to assess drug use in aviation. MethodsUsing matched data from the FAA’s Civil Aerospace Medical Institute toxicology database and the National Transportation Safety Board’s (NTSB’s) aviation accident database, this study examined trends in the prevalence of over-the-counter, prescription, and illicit drugs identified in toxicology tests of fatally injured pilots between 1990 and 2012.Cases that failed to match or where toxicology testing had not been performed were excluded. Pilots identified by the NTSB investigation as being the “flying pilot” at the time of the accident and results from blood or tissues were included. Toxicology results for ethanol and other alcohols were not included. Positive test results were categorized by drug type and potential for causing impairment. Analysis used SPSS Version 19.1 to perform linear by linear chi-squared statistics. ResultsThe study included 6677 pilots or 87% of the eligible subjects. The large majority were male (98%) and flying general aviation operations (96%) at the time of their fatal accident. There were increasing trends in pilots’ use of all drugs, potentially impairing drugs, drugs used to treat potentially impairing conditions, drugs designated as controlled substances, and illicit drugs. The most common potentially impairing drug pilots had used was diphenhydramine, a sedating antihistamine that is an active ingredient in many over-the-counter allergy formulations, cold medicines, and sleep aids in the US. Although evidence of illicit drug use was found only in a small number of cases, the percentage of pilots testing positive for marijuana use increased during the study period, mostly in the last 10 years.

False carbamazepine positives due to 10,11-dihydro-10-hydroxycarbamazepine breakdown in the GC-MS injector port.

During the investigation of aviation accidents, postmortem specimens from accident victims are submitted to the Federal Aviation Administration's Civil Aerospace Medical Institute (CAMI) for toxicological analysis. A case recently received by CAMI screened positive for the anticonvulsant medication carbamazepine (CBZ; Tegretol(®)) by gas chromatography-mass spectrometry (GC-MS). The CBZ found during this routine screening procedure was subsequently confirmed using a CBZ-specific GC-MS procedure. It was later discovered that the accident victim had been prescribed oxcarbazepine (OXCBZ; Trileptal(®)). OXCBZ is structurally similar to CBZ and is metabolized by cytosolic enzymes in the liver to an active metabolite, 10,11-dihydro-10-hydroxycarbamazepine (DiCBZ). It was determined that the CBZ initially found in this case was present due to the thermal breakdown of DiCBZ in the GC-MS injector port. In the current study, this conversion was investigated and the percentage of CBZ formed at various injector port temperatures was determined. Additionally, these three compounds were quantified in nine fluid and tissue specimens from the case in question. Liquid chromatography-mass spectrometry was also incorporated to further demonstrate the absence/presence of CBZ in these samples.

New Genetic Technology May Help Pilots, Aviation Employees, and Color Vision Researchers

Color vision research is not new for the Federal Aviation Administration (FAA); the Civil Aerospace Medical Institute has been conducting color vision research and publishing the results since 1967 ( 3 ). The FAA originally initiated color vision research because of the emerging use of color coding in the airport environment and the FAA has continued a line of color vision research because of the increasing use of color coding resulting from changing technology inside the cockpit, on air traffic control displays, and in the airport environment. Color can be used to convey meaning without supplemental signage such as the ubiquitous traffic signal that alerts drivers to proceed with caution via a yellow flashing light or to stop via a red flashing light. However, that meaning is only conveyed if the driver can distinguish between the yellow and the red colors. Approximately 8 to 10% of the male population ( 5 ) has a congenital color vision deficiency and, depending upon the type and severity of that deficiency, that task of interpreting the meaning of color coding may be difficult or impossible. Consequently, the FAA has long maintained a color vision standard for aero-medical screening to ensure that pilots and air traffic controllers can perform safety-related tasks without adverse consequences. Throughout the past few years, the FAA has explored a variety of color vision tests, searching for a valid screening test that has high sensitivity and specificity, meaning the ability to detect the presence or absence of the deficiency, respectively. Basically, color vision tests can be categorized as diagnostic, screening, or occupational tests. Diagnostic tests are designed to specifically diagnose the type and degree of deficiency, the screening tests focus on differentiating between normal or deficient color vision, and the occupational tests seek to separate those capable versus incapable of certain tasks such as identifying colors of wires or lights (e.g., the Farnsworth Lantern test that was developed to assess the ability of potential Navy signalmen for identifying red, green, and white lights). A few tests have been developed for the purpose of precisely diagnosing and classifying color vision; however, when color vision test scores are compared to performance on occupational tasks such as identifying or discriminating colors used in signal lights, precision approach path indicator (PAPI) lights, colored navigation lights, color coded map reading tasks, color coded air traffic control displays, and cockpit displays, a specific cut-point on those selection tests has not been found that can fully separate those who can from those who cannot accurately perform the color-coded pilot or air traffic control tasks. Some tests, including new computerized instruments, have been designed to differentiate defects involving the long wavelength sensitive cones (protan-type), middle wavelength sensitive cones (deutan-type), and short wavelength sensitive cones (tritan-type). Congenital protan and deutan deficiencies are, collectively, extremely common, affecting 1 in 12 men and 1 in 230 women; however, recent evidence indicates that tritan defects are virtually never present at birth (e.g., congenital) and the inherited forms involve S cone photoreceptor degeneration that develops later in life with the exact onset depending upon the specific mutation ( 1, 4 ). Thus, the exact frequency of inherited tritan defects is uncertain; however, it is probably less than 1 in 500. In part, because the underlying pathophysiology has not been well understood, few tests have been available that are capable of detecting tritan deficiencies. In the past, those tests included the single Farnsworth F2 pseudoisochromatic plate (PIP), the Moreland anomaloscope, the Hardy, Rand, Rittler PIP test, and, most recently, the Oculus anomaloscope. Consequently, the occupational color vision tests used by most agencies only screen for the most common (protan and deutan) types of defects. The newly developed computerized color vision tests, including the Colour Assessment and Diagnostic Test, the Cambridge Colour Test, the Cone Contrast Test, and the Computerized Color Vision Test, are all designed to detect tritan defects. However, tritan weaknesses have been noted in several of the FAA ‘ s recent studies in much higher than the traditionally expected numbers and diagnostic agreement is low among those tests when tritan deficiencies are involved. In the past, the FAA and other regulatory organizations have not, or have rarely, required tritan color vision screening in their occupational screening because of the following three factors: the rarity of the congenital defect, the unknown number of individuals affected by acquired deficiencies, and the lack of effective, reliable, valid, and affordable equipment with which to diagnose the deficiency.

FAA Air Traffic Control Front Line Manager’s Quick Reference Guide

Air Traffic Control Front Line Managers (FLMs) influence the prevention of operational incidents (OIs) and runway incursions (RIs) through practices that enable safe controller performance and mitigate problems related to specific contributing factors, including controller coordination, controller-pilot communication, and controller memory. FLMs’ proximity and frequent interactions with controllers in the operational environment place them in a unique position to impact air traffic safety through managing controller performance and mitigating OIs and RIs resulting from common contributing factors. With this understanding of the FLM role, The Federal Aviation Administration (FAA) developed the Front Line Managers Quick Reference Guide (QRG). The Civil Aerospace Medical Institute (CAMI) assisted the Air Traffic Organization (ATO) with the organization and evaluation of these materials. The guide was intended to provide a management best practices format specific to Air Traffic Control to assist FLMs in the performance of their job. To determine the utility of the QRG, CAMI developed and administered a survey of FLMs. The survey also provided the ATO with a basis for additions or deletions to the QRG. The FLM QRG was designed as a best practices guide for use by all field FLMs. Survey results and suggestions and recommendations from survey respondents are presented.

Toxicological Findings in Fatally Injured Pilots of 979 Amateur-Built Aircraft Accidents

Specimens from aviation accident pilot fatalities are submitted to the Civil Aerospace Medical Institute (CAMI) for toxicological analyses. Trends of fatal amateur-built aircraft accidents and toxicological findings in the associated pilot fatalities have not been examined. Fatal amateur-built aircraft accidents that occurred during 1990-2009 were evaluated by retrieving information from the CAMI toxicology database. Probable cause/factor in the amateur-built aircraft mishaps were obtained from the National Transportation Safety Board's (NTSB's) aviation accident database. Of 6309 fatal aviation accidents from which CAMI received postmortem samples, 979 (16%) were related to amateur-built aircraft. There was a decreasing trend in non-amateur-built aircraft accidents, but an increasing trend in amateur-built aircraft accidents. In the 979 accidents, 392 pilots (40%) were positive for ethanol and/or drugs. In these 392 accidents also, the review showed a decreasing trend with non-amateur-built aircraft and an increasing trend with amateur-built aircraft. Percentages of pilots with prescription drugs were 26% for amateur-built aircraft, 16% for non-amateur-built aircraft, and 18% for all aircraft. Ethanol/drug use and medical condition were determined to be a cause/factor in 42 (11%) of the 385 ethanol/ drug-positive amateur-built aircraft accidents investigated by the NTSB. Drugs found in the pilots were consistent with commonly used medications in the general population. The contributory role of mechanical malfunction of home-built aircraft cannot be ruled out in the observed increasing trends in their accidents, with or without ethanol and/or drugs. Regardless, the increasing trends of such accidents are of significant concern.

Toxicological Findings in 889 Fatally Injured Obese Pilots Involved in Aviation Accidents*

Prevalence of drugs in fatally injured obese pilots involved in aviation accidents has not been evaluated. Therefore, toxicological findings in such pilots (body mass index ≥30 kg/m(2) ) were examined in a data set derived from the Civil Aerospace Medical Institute's (CAMI's) Scientific Information System for 1990-2005. Aeromedical histories of these aviators were retrieved from the CAMI medical certification and toxicology databases, and the cause/factors in the related accidents from the National Transportation Safety Board's database. In 311 of the 889 pilots, carbon monoxide, cyanide, ethanol, and drugs were found, and glucose and hemoglobin A(1c) were elevated. Of the 889 pilots, 107 had an obesity-related medical history. The health and/or medical condition(s) of, and/or the use of ethanol and/or drugs by, pilots were the cause/factors in 55 (18%) of the 311 accidents. Drugs found were primarily for treating obesity-related medical conditions such as depression, hypertension, and coronary heart disease.

Laser Illumination of Flight Crewmembers by Altitude and Chronology of Occurrence

The illumination of flight crew personnel by lasers while they perform landing and departure maneuvers has concerned the aviation community for the past two decades. This study examines the frequency of illumination events in the United States by altitude and chronology of occurrence to determine where and when aviators and the flying public may be at greatest risk. Reports of aircraft illuminated by high-intensity light sources are maintained in a database at the Federal Aviation Administration's Civil Aerospace Medical Institute. Reports of flight crewmembers exposed to lasers from January 1, 2004, to December 31, 2008, were collected and analyzed. Cockpit illuminations at or below 2000 ft (approximately 610 m) increased from 12.5 to 26.7% over the 5-yr period, while the percentage of illuminations between 2000 and 10,000 ft (approximately 610-3048 m) decreased from 87.5 to 58.4%. The months of November and December had the highest frequency of laser events (23%), while May and June had the least (12%). Sunday was the most likely day for an aircraft to be illuminated (18.3%), while Wednesday was the least likely day for such an incident (15.4%). More than 91% of all aircraft illumination events occurred between 1800 and midnight. The continuing increase in the number of laser illuminations reported at or below 2000 ft (approximately 610 m) represents an escalating threat to aviation safety. Information provided in this study may allow law enforcement to deploy their resources more efficiently to apprehend those responsible for these crimes.

Use of a head component tester to evaluate the injury potential of an aircraft head-up display

Title 14 of the Code of Federal Regulations Part 25, §25.785 requires that seats and adjacent parts of the airplane be designed so that occupants will not suffer serious injury during an emergency landing as a result of expected inertial forces. The Federal Aviation Administration (FAA) guidance material cites several component impact test methods for use in determining whether an item or surface is potentially injurious. A head component tester (HCT) developed at the National Institute for Aviation Research of the Wichita State University was selected to assess the injury potential of a new cockpit-installed head-up display (HUD)'s combiner glass. A test procedure complying with the intent of the FAA guidance material was developed and validated by the Civil Aerospace Medical Institute (CAMI), Oklahoma City, OK. Subsequently, a computer model of the HCT impact into the HUD was developed by The Engineering Institute, Farmington, AR, and was correlated with CAMI test data. This model is useful for evaluating the effect of design parameters on HUD injury potential.

The Screening of Forensic Blood, Urine, and Tissue Specimens for Xenobiotics Using Ion-Trap Liquid Chromatography-Tandem Mass Spectrometry

During the investigation of aviation accidents, postmortem specimens from accident victims including blood, urine, and tissue are submitted to the Federal Aviation Administration's Civil Aerospace Medical Institute (CAMI) for toxicological analysis. The first, and perhaps most important, step in the analysis process is the initial screening of biological specimens for illicit, medically prescribed, and over-the-counter compounds that may be present and potentially be a cause and/or factor in the accident. Currently, our general unknown screening (GUS) procedure involves, in part, both gas chromatography-mass spectrometry (GC-MS) and liquid chromatography (LC) with both diode-array detection (DAD) and fluorescence detection. Both GC and LC techniques have inherent limitations that prevent the detection of certain types of compounds. The decreased specificity and sensitivity of LC-DAD has been an impediment to the existing GUS procedure. Therefore, our laboratory set out to develop and validate an LC-MS-MS procedure that is superior to LC-DAD. The limits of detection of 359 forensically important xenobiotics have been established following solid-phase extraction from whole blood and analysis by LC-MS-MS. Although whole blood was used as the matrix during instrument validation, the method has been successfully applied to both forensic urine and tissue specimens as well.

Effects of Video Weather Training Products, Web-Based Weather Briefing, and Local versus Non-Local Pilots on GA Pilot Weather Knowledge and Flight Behavior

This study explores 1) whether video weather training products significantly affect general aviation (GA) pilot weather knowledge and weather-related flight behavior, 2) use of modern Web-based weather preflight briefing products, and 3) whether local Oklahoma GA pilots differ appreciably from non-local pilots in weather knowledge or weather-related flight behavior. No highly significant, meaningful, simple effects were found for two 90-minute video weather training products on weather knowledge or subsequent flight safety on a simulated flight involving deteriorating weather. A data-collecting emulation of www.aviationweather.gov suggests that mere time spent on preflight briefing, pages viewed, and page view duration alone are not adequate predictors of either quality of preflight briefing nor subsequent flight safety. Finally, no important differences between local and non-local pilots were seen, implying that FAA Civil Aerospace Medical Institute flightdeck studies are generalizable to the national population of U.S. GA pilots.

Resolution of aviation forensic toxicology findings with the aid of DNA profiling

Body components of aviation accident fatalities are often scattered, disintegrated, commingled, contaminated, and/or putrefied at accident scenes. These situations may impose difficulties in victim identification/tissue matching. The prevalence of misidentification in relation to aviation accident forensic toxicology has not been well established. Therefore, the Civil Aerospace Medical Institute (CAMI) toxicology database was searched for the 1998–2008 period for those cases wherein DNA profiling was performed to resolve identity issue of the samples submitted to CAMI for toxicological evaluation. During this period, biological samples from the casualties of a total of 3523 accidents were submitted to CAMI. The submitted samples were primarily from pilots. Out of the 3523 accidents, at least, one fatality had occurred in 3366 (≈96%) accidents; thus, these accidents were considered fatal accidents. Accordingly, biological samples from 3319 pilots (3319 of the 3366 accidents) were received at CAMI for toxicological testing. Of these 3319 pilots, 3275 (≈99%) were fatally injured. DNA profiling was performed in 15 (≈0.5%) of the 3319 accidents. The profiling was conducted upon the requests of families in two accidents, accident investigators in three, and pathologists in four. In six accidents, contradictory toxicological findings led CAMI to initiate DNA profiling. The requests made by families and investigators were primarily triggered by inconsistency between the toxicological results and the history of drug use of the victims, while by pathologists because of commingling of samples. In three (20%) of the 15 accidents, at least one submitted sample was misidentified or mislabeled. The present study demonstrated that the number of aviation accident cases requiring DNA profiling was small and this DNA approach was effectively applied in resolving aviation toxicology findings associated with those accidents.