Aircraft Size Research Articles

Analysis of Propeller Selection for Unmanned Aircraft

Unmanned aircraft are usually used to perform missions, for example surveillance missions. This mission is not always carried out in a suitable location. Researchers must ensure that the aircraft can take off properly. For this reason, runway distance greatly affects the performance of the aircraft. The aircraft can fail to take off due to the lack of thrust generated by the propeller. The propeller diameter size of each unmanned aircraft can differ from one another and this difference in propeller diameter causes a difference in thrust force. Therefore, it is very important to determine the right propeller diameter to be used on an unmanned aircraft that is adjusted to the runway distance. This propeller selection analysis is carried out using experimental methods, which is tool testing and simulation with Propeller Power Calculator software. The results of this study can be seen that a propeller with a larger diameter will produce a greater thrust force. The size of the diameter and pitch and the number of blades of a propeller can also affect the amount of thrust generated. This will be a consideration for choosing a propeller to be used on an unmanned aircraft. So that the selected propeller can be used optimally by reviewing the amount of thrust that is influenced by the amount of diameter.

Flying in the Strike Zone: Urban Air Mobility and Wildlife Strike Prevention

The number and rate of wildlife strikes continue to increase worldwide. More than 30 years of wildlife strike data indicate that approximately 92% of wildlife strikes for commercial aircraft occur at or below 3500 ft above ground level. Since urban air mobility (UAM) operations are envisioned to carry cargo and passengers up to an altitude of 4000 ft above ground level, UAM operations will face increased exposure to wildlife strike risks throughout their operations. Moreover, the comparatively small size of UAM aircraft, proposed cruising speeds of up to 170 kt, and quieter electric engines are expected to reduce opportunities for threat perception and evasive maneuvers by aircraft operators and wildlife. This paper presents how well-established wildlife strike prevention measures can be adapted to meet the needs of UAM operations and how, with new technology, original equipment manufacturers (OEMs), regulatory agencies, aircraft operators, communities, airspace managers, and vertiport operators can work together to enhance safety.

Aviation fuels of the future − A techno-economic assessment of distribution, fueling and utilizing electricity-based LH2, LCH4 and kerosene (SAF)

This paper investigates the techno-economic implications on air travel when fossil-based kerosene is phased out of the market, specifically focusing on the comparison between liquid hydrogen, liquid methane and renewable kerosene for ten exemplary flight routes to estimate the cost of air travel per passenger and 100 km distance travelled €2020PAX100km for every fuel type. By considering the entire supply chain, including hydrogen production from renewable sources, synthesis, oversea transport, domestic distribution, and utilization, this study addresses the overarching question of whether it is more economical to change the fuel source or the fuel itself to reduce fossil kerosene usage in the aviation industry. It is demonstrated that aircraft acquisition costs play a minor role compared to fuel supply costs and specific fuel demand. The study shows that for electricity-based fuels, liquid hydrogen is the most economic option, even with a potential energy penalty, followed by liquid methane and renewable kerosene. The results for an aircraft with a capacity 180 passengers are 3.08, 4.57 and 5.11 €PAX100km for liquid hydrogen, liquid methane and renewable kerosene, respectively. Challenges regarding storage and isolation requirements for cryogenic fuels in aviation are discussed, with assumptions made that these obstacles can be overcome to realize economic benefits. Additionally, the study suggests potential shifts in aircraft size selection by airlines to mitigate rising fuel prices in the future. The study advocates for the aviation industry's openness to new fuels like liquid hydrogen and liquid methane to alleviate the cost increase associated with phasing out fossil kerosene.

Multimodal aircraft flight altitude inversion from SDGSAT-1 thermal infrared data

Accurately detecting and localizing high-speed aircraft is significant for monitoring global flight activities, conducting searches, and performing emergency rescues. Typically, the spatial position of an air target is obtained through active communication or multi-satellite observation. Here, we propose a multimodal flight altitude inversion method using a single thermal infrared payload (SDGSAT-1 TIS). Space-based longwave thermal infrared is a passive detection method that can measure the surface thermal radiation of objects and capture radiation differences caused by flying aircraft against the background, thereby providing an opportunity for their detection and location. Considering geographic location, time, climate, and aircraft size, we establish a framework to integrate the radiation transmission model with three-spectral-band remote sensing data. This proposed framework elucidates the relationship between flight altitude and top-of-atmosphere radiance, realizing the inversion from thermal infrared remote sensing images to altitude. Validated on 100 aircraft, the proposed framework achieved an average altitude measurement accuracy of 0.508 km compared with Flightradar24. This research provides a unique solution for the all-time passive localization of air targets.

Experiments on watering citrus fruits with a wire supplied drone using RTK-GNSS

In Japanese agriculture, pesticide-spraying drones are becoming more widespread, with the aim of saving labor in pesticide spraying. The size of aircraft has been increasing, and large aircraft capable of spraying 30 liters of chemicals in about 15 minutes have been developed. In orchards, there is a need to spray even larger quantities of chemicals over a longer period. We have developed a large drone that is wired for power and water to enable it to operate for long periods of time. The effectiveness of the system was verified through actual flight tests on citrus fruit.

Stochastic Modelling of Aircraft Ground Time at Soekarno-Hatta International Airport

Ground time plays an important role in keeping flight on-time performance and passenger smooth flow. It varies depending on the aircraft type, procedures, passenger number and/or cargo amount, maintenance requirements, and ground handling service quality. This research aims to explore the ground time distribution pattern at Soekarno-Hatta International Airport. The daily flight historical data is divided into several categories based on the airline’s service type for local airlines, the airline’s origin for foreign airlines, the type of flight, and aircraft size. Ground time data of each flight category is then fitted to all possible distribution types by using the Distribution Fitting app in Matlab. The best-fitted distribution definition uses the Kolmogorov-Smirnov test by comparing the p-value of each distribution. 6 distributions fit 20 flight categories. Almost all local airlines’ ground time except full-service carrier international flights and low-cost carrier international flights with wide-body aircraft fit to Burr distribution. Full-service carrier international flight with narrow and wide-body aircraft, international flight with narrow-body aircraft operated by airlines from China and other countries fit Generalized Extreme Value distribution. Low-cost carrier international flights with wide-body aircraft and private flights fit to Inverse Gaussian distribution. International flights with wide-body aircraft operated by airlines from Korea, Japan, and other countries airlines fit for Nakagami distribution. While the cargo flights fit t Location-Scale distribution for wide-body aircraft and Weibull distribution for narrow-body aircraft. Then the stochastic models are developed based on each flight category’s distribution parameters. These models are expected to be able to guide future research in ground time or apron capacity management as they provide the data distribution without more primary data needed.

Capacity modelling for UAM

The management of the operation of unmanned aircraft systems and their integration into the common airspace faces various challenges, among which those associated with determining the airspace capacity can also be included. This paper focuses on this challenge and proposes an approach to determine the airspace capacity through the utilization of mathematical modelling, algorithmization, and statistical methods. The constructed model accurately determines airspace capacity, considering factors such as aircraft size, control methods, and potential conflicts resolved at the strategic level of traffic management. Results from simulations demonstrate the model’s validity and effectiveness, highlighting its potential application in planning and evaluating services that are provided to unmanned aircraft.

Comparison of Eddy Dissipation Rate Estimated From Operational Radiosonde and Commercial Aircraft Observations in the United States

AbstractThe one‐third power of the energy dissipation rate (EDR), a primary aviation turbulence metric, is calculated using high vertical‐resolution radiosonde data (HVRRD) and compared with flight‐EDR observed from commercial airlines. Comparisons are made along the main flight routes over the United States and at z = 20–45 kft for 6 years (2012–2017). The horizontal distributions of moderate‐or‐greater (MOG) ratio of HVRRD‐EDR show large values over the Rocky Mountains, consistent with those of flight‐EDR. Vertically, the MOG ratios of HVRRD‐EDR show local peaks at z = 20–23 kft and 41–44 kft, while those of flight‐EDR at z = 23–26 kft and 35–41 kft. Temporally, HVRRD‐EDR has maximum MOG values in JJA and minimum values in DJF at z = 20–30 kft, which is opposite to the flight‐EDR. At z = 30–40 kft, HVRRD‐EDR shows nearly no seasonal variation but flight‐EDR has large values in MAM and small values in JJA. At z = 40–45 kft, HVRRD‐EDR (flight‐EDR) shows large values in MAM and small values in SON (DJF). Discrepancies in spatiotemporal distributions between the two data sets likely stem from: (a) turbulence observed from the two data sets cannot be the same event, (b) the limitation of HVRRD‐EDR in capturing shear‐instability under statically stable condition (i.e., Kelvin‐Helmholtz instability) which probably accounts for most flight‐EDR events at upper levels, and (c) limitation in aircraft measurements response to fluctuations at smaller scales than the aircraft size.

Effects of Synthetic Jets on Swirl Inflow in a Variable-Geometry Twin Air-Intake

Air intakes are an integral part of contemporary passenger and military aircraft engines. Their impact on aerodynamic performance across the entire flight envelope is critical to aircraft flight safety, efficiency, and manoeuvrability, especially at high Mach numbers due to shock waves. The high demand for reductions in aircraft weight and size and enhancements in durability, comfort, and thermal and radar signatures compel researchers and engineers to explore new designs and develop efficient air intakes for high-performance aircraft engines. Although a number of studies on air intake have been conducted and reported in the open literature, there is little information available in the public domain on bifurcated twin air intakes using synthetic jet. As a result, the primary goal of this research is to use computational fluid dynamics modelling to investigate the effects of synthetic jets on swirl inflow variable geometry twin air intake aerodynamic performance over a range of Reynolds numbers. Some important parameters (distortion coefficient, non-uniformity index, swirl coefficient, and static and total pressure coefficients) were investigated. Both static and total pressure recovery have been increased at all swirl numbers. A significant decrease in distortion coefficient and swirl coefficient has also been achieved, reaching a 53% reduction in the distortion coefficient and a 62% reduction in the swirl coefficient. The reduction in the non-uniformity index is achieved by 62% for the controlled flow case. The findings show that synthetic jets are effective in controlling the flow separation in the twin air intakes and enhancing aerodynamic performance.

An Approach for Quick Method of Estimating Passenger And Aircraft Demand for Feeder Air Services in India

The recent and the proposed entry of new airlines both in the ‘no-frills’ and in the "full service" categories has completely changed the aviation scenario in India. Obviously this explosive increase in capacity will have a profound effect on the economy of the airlines both in the short term as well as in the long-term period. A growth of over 25% per annum in passenger traffic may not be sustainable for long; thus galloping increase in capacity may result in mergers and strategic alliances of airlines on one side and closing down of some of the airlines on the other side. A point, which is to be noted is that, most of the new entrants also operate in the major trunk routes and serve the metros and the major cities. What appears to have not been tapped is the equally large potential in the regional and short haul sectors, which serve major, and small city pairs and also act as feeders to the major hubs.Realizing the importance of this, the government in its new civil aviation policy has given thrust to regional/ short-haul air travel. In this paper, an attempt is made to review the hierarchy of airline networks in India with respect to trunk, major and feeder routes. The air passenger traffic carried in terms of revenue passenger kilometers (RPK) is compared with upper class rail traffic. The present status of feeder airline services in India is outlined. It is pertinent to study the passenger traffic demand in these feeder routes as compared to upper class rail traffic as some percentage of upper class rail passengers are willing to shift to air travel due to marginal difference between airfare and upper class rail fare and time factor. The future RPKs are forecasted based on the actual RPKs data and the estimated RPKs of earlier market survey. A suitable aircraft size for airline operations in these feeder routes is arrived at based on existing air traffic data by a simplified approach from the basic principles of airline business. A macroscopic measure is used to determine the aircraft demand by assuming average block speed and utilization for each aircraft type. A sensitivity analysis was carried out for various levels of traffic growth keeping in view the sharp increase of air travel in recent years and further growth in air traffic fuelled by feeder sector as the hinterland opens up industry, services and tourism.

Infrared defect recognition technology for composite materials

This study mainly involves the methods and experiments of using infrared thermal wave imaging detection technology to detect internal defects in aircraft composite materials. The results were discussed and analyzed. In this paper, the feasibility of the experiment was verified by simulation. In simulation, the minimum accuracy of detectable defects is 4 mm radius under the mesh division accuracy with a correlation coefficient of 5. On this basis, an accurate detection method and prototype nondestructive testing system for defects of aircraft composite materials based on infrared imaging detection technology were designed, which can realize the identification and positioning of defects in aircraft composite material structures, including type, size and accurate depth of defects. Finally, the data collected by the infrared detection system was recognized through YOLO neural network. The test result shows the confidence level for water point defect is more than 0.9, while the confidence level for crack defect is about 0.5. This research result will expand the use case of infrared nondestructive testing technology around the world, and the transformation of the results will help to solve the maintenance problems of aircraft in general aviation.

Interaction effects of air services on tourism demand

Air transport attributes can affect both budget and time constraints of travelers. Therefore, in addition to income and tourism prices, there is a theoretical case for including airfare, flight frequency, and their interaction, in a given tourism demand model. This study explicates the theoretical framework and empirically tests the significance of these effects. Our study finds that tourists' responsiveness to airfare (flight frequency) intensifies with increase in flight frequency (decrease in airfare) of direct air services. The practical implication is that pricing strategy and capacity expansion reinforce each other in generating tourism demand. Additionally, for research, the findings emphasize the need to disentangle the effects of aircraft size and travel distance in modeling air transport – tourism demand relation.

Parametric model of aircraft external geometry as a component of FAST-OAD aircraft preliminary design system.

Rapid evolutions in fields such as aerospace propulsion, materials engineering, geometry modelling tools or optimization tools provide the opportunity to search for novel configurations of future aircraft in an expanding domain. In order to effectively explore the space of variables of constantly expanding size, one needs tools that give the ability to automate this process. Such a tool is the Future Aircraft Sizing Tool for Overall Aircraft Design or FAST-OAD. FAST-OAD allows for rapid estimation of aircraft size, based on set, so-called Top Level Aircraft Requirements (TLARs) by using multi-disciplinary and multi-fidelity analysis and optimization.An essential component of such a system is a module capable of modelling the external geometry of the calculated case. This article describes an attempt to use a powerful commercial Computer Aided Design software, Siemens NX, to model the aircraft external geometry based on the results of the analysis performed by FAST-OAD. This approach, compared to previous works, brings some limitations but, on the other hand, gives the possibility to base the geometry on a mathematically consistent model and helps to better understand the set of parameters necessary to describe the geometry correctly.The main objective of this research is to provide a tool that allows the automatic generation of aircraft exterior geometry based on the output parameters received from the FAST-OAD package.An additional goal of this activity is to determine the parameter set necessary to properly define the external geometry, but at the same time not containing redundant, dependent geometric parameters. The minimum number of independent parameters necessary to completely describe the external geometry is sought.

Analyzing factors affecting charter flight service demand: A case of Taiwan

Global charter flight demand remined relatively stable over the last decades, and international charter flight is an integrated product of the aviation and tourism industries. To better understand charter flight tourism in Asia, this study analyses key reasons affected Taiwan’s charter flight demand from Japan, South Korea, Malaysia, and Singapore during the period 2009‒2018, with a consideration of aviation- and tourism-related variables. Empirical results show that the reduction in scheduled flight aircraft size stimulated new charter flight demand to Taiwan, offsetting the negative effects caused by scheduled seat increment to a certain degree. This study contributes to literature by exploring the impact of scheduled flight service availability on charter flight demand, and further enriches our understanding of the impact of scheduled flight services on international tourist arrivals in terms of aircraft size. Importantly, it has implications for policymakers and stakeholders involved in charter business, assisting them in facilitating aviation and tourism recovery during the post-COVID-19 era.

Aircraft-LBDet: Multi-Task Aircraft Detection with Landmark and Bounding Box Detection

With the rapid development of artificial intelligence and computer vision, deep learning has become widely used for aircraft detection. However, aircraft detection is still a challenging task due to the small target size and dense arrangement of aircraft and the complex backgrounds in remote sensing images. Existing remote sensing aircraft detection methods were mainly designed based on algorithms employed in general object detection methods. However, these methods either tend to ignore the key structure and size information of aircraft targets or have poor detection effects on densely distributed aircraft targets. In this paper, we propose a novel multi-task aircraft detection algorithm. Firstly, a multi-task joint training method is proposed, which provides richer semantic structure features for bounding box localization through landmark detection. Secondly, a multi-task inference algorithm is introduced that utilizes landmarks to provide additional supervision for bounding box NMS (non-maximum suppression) filtering, effectively reducing false positives. Finally, a novel loss function is proposed as a constrained optimization between bounding boxes and landmarks, which further improves aircraft detection accuracy. Experiments on the UCAS-AOD dataset demonstrated the state-of-the-art precision and efficiency of our proposed method compared to existing approaches. Furthermore, our ablation study revealed that the incorporation of our designed modules could significantly enhance network performance.

The Potential of Structural Batteries for Commuter Aircraft Hybridization

Electric or hybrid electric propulsion systems have received a great deal of attention in recent years in various branches of transportation including aviation. Europe is committed to the ambitious goals of reducing CO2 emissions by 75%, NOx emissions by 90% and perceived noise by two-thirds by the year 2050 compared to the average new aircraft of the year 2000. The main barrier of the electric propulsion is bound to the battery limits in terms of energy and power densities, thus determining a relevant negative impact on payload or aircraft size. It is possible to design and fly an electrically propelled aircraft, as testified by some existing examples, both prototypical and production models, in the categories of ultralight and general aviation aircraft. A novel technology, which allows the electrification process toward heavier categories of aircraft, is constituted by structural batteries. These are similar in structure to carbon fiber composites, where the matrix features dielectric characteristics, making the structure capable of storing electric energy while retaining the capability to withstand mechanical loads. Despite that, it raises relevant issues concerning aircraft sizing procedures that need to be conceived considering the specific characteristics of such multifunctional technology. This research work aims to evaluate the potential benefits the structural batteries have on the fuel burn for a 11-seater commuter aircraft. According to the envisaged technologies (structural batteries), this work will focus on the determination of the best hybridization factors determining the energy requirements for the typical mission of a commuter aircraft.

Government interventions in regional airline markets based on aircraft size—Welfare and environmental implications

Government interventions in regional airline markets based on aircraft size—Welfare and environmental implications

Downsizing the jet: A forecast of economic effects of increased automation in aviation

We develop a theory of optimal aircraft size, where the cost of the flight crew is the primary factor driving the use of larger aircraft, while passenger utility is primary factor driving the use of smaller aircraft. After fitting our model to U.S. data, we perform a counterfactual experiment where the minimum crew size requirement is relaxed from two pilots to one, a policy currently being discussed by aviation experts. Implications are derived for the number of aircraft demanded and its size distribution, demand for pilots, passenger traffic, flight frequency, and where new nonstop service may be introduced.

A plane that powered by a Thor’s hammer

As the number of electric cars in the world surged, it spurred the research on electric vehicle (EV) aircraft in various countries. As a result, a number of small electric airplanes are capable of short-distance flight have been developed. The researches shows that there are many challenges for producing an all-electric jumbo jets. For example, the material of the battery chosen on the aircraft, the composite material for the aircraft covering, how to consist the electric vehicles on the plane in order to save the total mass of the aircraft because the mass of the battery is much heavier than the diesel oil and tank. Moreover, in different countries, the charging modes and standards for the aircraft is different and so on. In this paper, the electric vehicles used in electric-cars would be used as the reference of the challenges for manufacturing the electric jumbo jets. And although there are some small size of electric aircraft (E-Fan aircraft) are created, these aircraft could not afford the commercial purpose, even the international flights by taking hundred of passengers per flight. If these discovered and undiscovered problems are researched and resolved, the electric jumbo jet would be produced in the future and replace the traditional aircraft, which means that people do no need to worry about if the oil would run out any more.

S2CGNet: A Robust Aircraft Detector Based on the Sword-Shaped Component Geometry

Aircraft detection is a challenging task for remote sensing images. The anchor-based methods are of high complexity and the keypoint-based detectors suffer the grouping difficulty. And some line-based models relying on local features are hindered by the adhesion and dis-integrity problems. Moreover, those detection representations rarely take into account the sword-shaped component geometric semantics ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">e.g</i> ., fuselage and the wing) of the aircraft itself, leading to being less robust and unfavorable for downstream tasks, such as ones needing the detailed size and shape of aircraft. Accordingly, we model the sword-shaped component geometry and propose S2CGNet, a more robust appearance-based aircraft detector. The Sword Attenuation Mask (SAM) module is devised to encode a “sword-shaped mask” for each aircraft while exploring more robustness via the geometric surface embedding. The SAM can provide clearer borders to separate different aircraft more precisely. Besides, to address the instance disintegrity problem and further boost the quality of SAM, we propose an Instance Aware Graph (IAG) module to jointly optimize the parameters of the fuselage/wing detection heads. Experimental results show that the performance of S2CGNet can reach the state-of-the-art (SOTA) level. Specifically, it achieves 98.5% in term of AP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">50</sub> on the combined dataset of Aircraft-KP and NWPU VHR-10, boosting 3.8% than the baseline. Besides, S2CGNet boosts the quality of detection results greatly, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">e.g</i> ., it yields a significant improvement of 21.3% on AP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">75</sub> compared to the baseline. Furthermore, the generalization comparisons on FAIR1M dataset strongly demonstrate the robustness of our model surpasses other oriented detectors by a large margin.