INTRODUCTION: Spatial disorientation (SD) remains the leading contributor to Class A mishaps in the U.S. Navy, consistent with historical trends. Despite this, SD training for military aircrew is ...largely confined to the classroom and experiential training replicating SD illusions
is limited and infrequent. Static flight simulators are most commonly used for training but offer no vestibular stimulation to the flight crew, omitting the source of vestibular-mediated SD.BACKGROUND: We first cover vestibular-mediated SD illusions which may be replicated through
galvanic vestibular stimulation (GVS) in a static environment. GVS is a safe, reliable, low-cost avenue for providing vestibular sensory stimulation. We review the underlying mechanisms of GVS such as the excitement and inhibition of the afferent neurons innervating the vestibular system,
particularly in the binaural bipolar electrode montage.APPLICATIONS: Two approaches for how GVS may be used to enhance SD training are examined. The first is a means for providing unreliable vestibular sensory perceptions to pilots, and the second details how GVS can be leveraged
for replicating vestibular-mediated SD illusions.DISCUSSION: We recommend GVS be pursued as an enhancement to existing SD training. The ability to disorient aircrew in the safe training environment of a static flight simulator would allow for aircrew familiarization to SD, serving
as an opportunity to practice life-saving checklist items to recover from SD. A repeatable training profile that could be worn by military aircrew in a static flight simulator may afford a low-cost training solution to the number one cause of fatalities in military aviation.Allred AR,
Lippert AF, Wood SJ. Galvanic vestibular stimulation advancements for spatial disorientation training. Aerosp Med Hum Perform. 2024; 95(7):390-398.
General aviation aircraft driven by aviation piston engines (APE) have gained a broad range of applications. Aviation fuels blended with long-chain alcohols is a promising means for APE to mitigate ...its dependency on fossil fuel. Herein, the combustion and emission characteristics of an aviation compression ignition engine burning a baseline diesel, the RP-3 kerosene, and a synthetic Fischer-Tropsch (FT) fuel were analyzed. The engine tests were carried out under different conditions via varying pentanol additive ratio (PAR), fuel injection timing and engine load variables. The Response Surface Method (RSM) was utilized to quantify the effectiveness of independent variables on the target responses of indicated thermal efficiency (ITE), nitrogen oxides (NOx) and particulate matter (PM) emissions. Compared to the baseline diesel, burning the pentanol-FT blends (40% PAR) significantly reduces NOx by 81% and PM by 75% with a prominent increase of ITE by 7.2%. Based on the analysis of variance, the RSM-derived model demonstrated that the fuel type predominantly determines ITE and NOx, while PAR primarily alters PM emissions. The binary effects of independent variables on the target responses were further resolved quantitatively. Moreover, the RSM was well validated to implement effective prediction on the engine performance/emission characteristics.
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•Combustion/emission characteristics of an aviation piston engine was analyzed.•Pentanol addition elevated combustion efficiency and reduced emissions.•RSM models unraveled important variables on ITE and NOx and PM emissions.
The increasing interest in environmentally sustainable aviation has led to the topic becoming popular in aviation management literature. However, to the best of our knowledge, no research analyzes ...aviation environmental management (AEM) literature in a comprehensive manner. This study aims to bridge this gap by conducting a retrospective examination of environmental sustainability studies in literature using the bibliometric analysis method. Identifying potentially important gaps and drawing a comprehensive picture of the dynamics and the state of the literature is an important task to drive future studies in the field. Results drawn from 511 publications indexed in the Web of Science (WoS) database indicate a recent and rapid growth in the literature. Greenhouse gas emissions and noise emissions are dominant research themes while waste and water management topics are not well established. Studies investigating alternative fuels, emission mitigation strategies, energy conservation, and noise abatement are prevalent in the literature.
Collisions between birds and military aircraft are common and can have catastrophic effects. Knowledge of relative wildlife hazards to aircraft (the likelihood of aircraft damage when a species is ...struck) is needed before estimating wildlife strike risk (combined frequency and severity component) at military airfields. Despite annual reviews of wildlife strike trends with civil aviation since the 1990s, little is known about wildlife strike trends for military aircraft. We hypothesized that species relative hazard scores would correlate positively with aircraft type and avian body mass. Only strike records identified to species that occurred within the U.S. (n = 36,979) and involved United States Navy or United States Air Force aircraft were used to calculate relative hazard scores. The most hazardous species to military aircraft was the snow goose (Anser caerulescens), followed by the common loon (Gavia immer), and a tie between Canada goose (Branta canadensis) and black vulture (Coragyps atratus). We found an association between avian body mass and relative hazard score (r2 = 0.76) for all military airframes. In general, relative hazard scores per species were higher for military than civil airframes. An important consideration is that hazard scores can vary depending on aircraft type. We found that avian body mass affected the probability of damage differentially per airframe. In the development of an airfield wildlife management plan, and absent estimates of species strike risk, airport wildlife biologists should prioritize management of species with high relative hazard scores.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Reducing aviation emissions is important as they contribute to air pollution and climate change. Several alternative aviation fuels that may reduce life cycle emissions have been proposed. ...Comparative life cycle assessments (LCAs) of fuels are useful for inspecting individual fuels, but systemwide analysis remains difficult. Thus, systematic properties like fleet composition, performance, or emissions and changes to them under alternative fuels can only be partially addressed in LCAs. By integrating the geospatial fuel and emission model, AviTeam, with LCA, we can assess the mitigation potential of a fleetwide use of alternative aviation fuels on 210 000 shorter haul flights. In an optimistic case, liquid hydrogen (LH2) and power-to-liquid fuels, when produced with renewable electricity, may reduce emissions by about 950 GgCO2eq when assessed with the GWP100 metric and including non-CO2 impacts for all flights considered. Mitigation potentials range from 44% on shorter flights to 56% on longer flights. Alternative aviation fuels’ mitigation potential is limited because of short-lived climate forcings and additional fuel demand to accommodate LH2 fuel. Our results highlight the importance of integrating system models into LCAs and are of value to researchers and decision-makers engaged in climate change mitigation in the aviation and transport sectors.
To reduce carbon emissions, the European Union has implemented the Emissions Trading Scheme (ETS) since 2012 for intra-European commercial flights. In response, airlines have explored various means, ...including sustainable jet fuels. This article investigates how similar ETS policy would affect domestic carbon emissions when implemented in the United States. The study integrates a model of airlines operations optimization and multi-feedstock biojet fuels life cycle assessment to simulate decisions of biojet fuel and commercial aviation industry responding to an emission policy. We conduct a Monte-Carlo simulation on two scenarios of domestic emission schemes to investigate the adoption of biojet fuels and its impacts on carbon emissions. Our model indicates that implementing an emission policy for U.S. airlines could incentivize adoption of biofuels - a median value of 10% of total fuels in 2050- while only marginally reduce travel demand. Because of a combined effect of emission policy and improved aircraft technology, the emissions in 2050 would only increase 1.37 times the 2005 level despite passenger demand grows by a factor of 2.75. A non-parametric sensitivity analysis suggests that the price of oil, economic growth, and carbon price are the three most significant factors in affecting the fleet-level carbon emissions.
•Emissions trading scheme for U.S. airlines results in the adoption of biojet fuels.•In 2050 passenger demand will grow 2.75 (median value) times the 2005 level.•The emissions in 2050 will increase 1.37 (median value) times the 2005 level.•Oil price, economic growth, and carbon price are the three most significant factors.
At the Dawn of Airpower: The U.S. Army, Navy, and Marine Corps' Approach to the Airplane, 1907-1917 examines the development of aviation in the U.S. Army, Navy, and Marine Corps from their first ...official steps into aviation up to the United States' declaration of war against Germany in April, 1917.
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•Blendstocks from aromatic amines, aromatic hydrocarbons, and MTBE with different percentages were blended.•Characteristics of produced fuel 100UL were as close as possible to the ...properties of commercial Avgas 100VLL.•Concentrations of m-toluidine and MTBE were within the range that has been tested on an industrial scale.
Even though tetraethyl lead (TEL) is the most effective of the known antiknock additives, especially in aviation gasoline, there has been a clear tendency to abandon its use. This present work investigates the creation of a novel promising technique for producing an unleaded aviation gasoline 100UL through studying the influence of various aromatic amines, aromatic hydrocarbons, and MTBE on the antiknock characteristics of model blends of isooctane and n-heptane. Additionally, a nonlinear change in the antiknock performance of aromatic amines was established as the detonation resistance of the base fuel increased with the essential role of the structure of the aromatic amine. The results indicated that the optimal composition of the produced fuel was contained 57 wt% of isooctane, 10 wt% of isopentane, 10 wt% of toluene, 5 wt% of isopropylbenzene 15 wt% of MTBE, 2 wt% of m-toluidine, and 1 wt% of isopropyl alcohol. What’s more, its characteristics were as close as possible to the properties of commercial aviation gasoline 100VLL and it did not contain other metal-containing additives. Finally, the concentrations of non-hydrocarbon additives, such as m-toluidine and MTBE were within the range that has been tested on an industrial scale during the operation of an automotive equipment in many countries of the world.
Ultrafine particles (UFP) contribute to adverse health outcomes such as asthma, obstructive pulmonary disease, cardiovascular disease, and lung cancer. Recent research draws attention to elevated ...ambient UFP number concentrations near airports. In this study, high time-resolution UFP measurements were conducted along public roads near Mohammad Ali International Airport (SDF; Louisville, KY) which is a commercial passenger airport and a major air cargo hub. Short-duration (∼3 h) measurements with two instrumented vehicles were designed and executed to capitalize on the distinct features of the air cargo hub including periods of high flight activity (and either all landings or all take-offs) at night and early morning when the atmospheric mixing layer depth is shallow. We present preliminary measurements for quantifying individual aircraft contributions and showcase the complexities involved in interpreting these data. For example, during periods with high arrivals frequency, UFP plumes from multiple aircraft on approach are superposed and it is challenging to apportion impacts to individual aircraft. Ground-level impacts for individual aircraft on climb-out are difficult to discern because the planes rapidly ascend above the atmospheric mixed layer height and take different flight paths soon after take-off. Elevated UFP concentrations are observed downwind of the airport, in some cases admixed with approach/climb-out emissions. Although from these data UFP concentrations are difficult to associate with specific aircraft characteristics, UFP concentrations are elevated downwind of the airport. These impacts decrease with increasing distance from the airport yet are clearly discernible at least 3 km downwind.
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