Artículos de revistas sobre el tema "Helicopter"
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1
Trethewey, Diane. "Development of an index for quick comparison of helicopter costs and benefits". International Journal of Wildland Fire 16, n.º 4 (2007): 444. http://dx.doi.org/10.1071/wf06108.
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A helicopter comparison index was developed to incorporate cost and benefit information for individual helicopters for large wildland fire suppression operations. The costs and benefits for individual helicopters are unique. Costs consist of daily availability and hourly flight rates. Benefits depend on the payload, which depends on the altitude and temperature of operation, weight of the helicopter, equipment on board, crew, and fuel. Because of the complexity of calculating payload, previous methods for deploying helicopters classified helicopters into three types according to their typical payload. The least expensive helicopter of the desired type was deployed. Because this classification system produces a broad range of benefits within each helicopter type, this method may not deploy the most efficient helicopter. The helicopter comparison index can be calculated at representative altitudes and temperatures before it is needed. As the work is done beforehand, the helicopters can be compared quickly when they are needed. The helicopter comparison index allows helicopters to be compared based on the efficiency of the individual helicopters rather than just their cost of operation. Evaluation of Type I helicopters shows that using the helicopter comparison index instead cost of operation has savings potential of 20 to 45 percent.
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Frey, Felix, Jakob Thiemeier, Constantin Öhrle, Manuel Keßler y Ewald Krämer. "Aerodynamic Interactions on Airbus Helicopters' Compound Helicopter RACER in Cruise Flight". Journal of the American Helicopter Society 65, n.º 4 (1 de octubre de 2020): 1–14. http://dx.doi.org/10.4050/jahs.65.042001.
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With the pursuit of extending the flight envelopes of helicopters toward higher cruise speed, helicopter manufacturers increasingly have come up with nonconventional configurations in recent years. Among these, Airbus Helicopters' RACER (Rapid And Cost-Efficient Rotorcraft) is a compound helicopter equipped with a boxwing and lateral pusher rotors. In combination with the main rotor, these additional components determine the aerodynamic characteristics of the helicopter. Thereby, depending on the flight conditions, their individual performance is influenced by a variety of interactions. As the understanding of these interactions is vital for the evaluation of the overall system, the respective mutual influence of main rotor, wings, and lateral rotors is analyzed in this paper for cruise flight. For this reason, high-fidelity coupled aerodynamic simulations are conducted not only for the full RACER configuration but also for reduced setups omitting individual components to isolate the effect of these components on the helicopter's aerodynamic performance.
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Bisták, Andrej y Zdenka Hulínová. "Construction of ropeways in Slovakia in terms of pre-construction design using helicopters (case study)". MATEC Web of Conferences 263 (2019): 01002. http://dx.doi.org/10.1051/matecconf/201926301002.
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Ropeways usually provide access to locations inaccessible to other means of transport. Due to this fact, the construction of ropeways is extraordinarily taxing in terms of both, technology and logistics. The site location is often in terrain difficult to access, which often precludes deployment of common construction mechanisms in ropeway construction. In such case, it is advisable to deploy a transport mechanism independent of the terrain – a helicopter. Functioning as “flying cranes“, the helicopters have been used in construction industry in Slovakia for six decades now. Having amassed positive experience, even the “conventional“ construction industry of the time, especially its ropeway transport segment, started to use the benefits of helicopters, with helicopter deployment subsequently gaining ground and becoming the mainstream technological procedure. Ropeway construction can hardly be feasible without them even nowadays. Throughout the history of helicopter deployment in construction industry, a constant search of improving the efficiency of their work has been under way, necessitated by the helicopter’s sensitivitiy to weather conditions and work procedures alike. The paper presents an analysis of the factors affecting helicopter operation together with a proposed methodology of modeling their work in simulation models and the benefits of such approach.
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Češkovič, Marek, Martin Schrötter, Róbert Huňady, Pavol Kurdel y Natália Gecejová. "Unwanted Supplementary Vibrations of Helicopter Radio Communication Systems". Aerospace 10, n.º 7 (13 de julio de 2023): 632. http://dx.doi.org/10.3390/aerospace10070632.
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A helicopter in flight can be considered an unstable dynamic system with many unwanted vibrations originating from multiple sources, such as the operation of the engines and individual components. These vibrations cause the degradation of the structural and functional components of a helicopter, thereby generally reducing the utility and technical efficiency of the aircraft. During the analysis of frequently recurring errors of medium-heavy helicopters, partial damage to antenna elements with vertical polarisation was detected. These damages provided the basis for the presented research, based on which supplementary vibrations caused by unwanted electromagnetic oscillations were revealed. These oscillations were detected in the process of communication between the helicopter crew and the ground ATC (air traffic control) station. This phenomenon’s existence and negative influence were confirmed via measurements and modal analysis, based on which an exact synergy between harmonic frequencies of the helicopter’s normal vibrations was discovered. The obtained results serve as a theoretical and practical basis for the future monitoring of this phenomenon, especially in the process of determining the “health status” of medium-heavy helicopters.
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Luong, Quoc Viet, Dae-Sung Jang y Jai-Hyuk Hwang. "Semi-Active Control for a Helicopter with Multiple Landing Gears Equipped with Magnetorheological Dampers". Applied Sciences 11, n.º 8 (19 de abril de 2021): 3667. http://dx.doi.org/10.3390/app11083667.
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Due to their extensive use in various applications, helicopters need to be able to land in a variety of conditions. Typically, a helicopter landing gear system with skids or passive wheel-dampers is designed based on only one critical touchdown condition. Thus, this helicopter landing gear system may not perform well in different landing conditions. A landing gear system with magnetorheological (MR) dampers would be a promising candidate to solve this problem. However, a semi-active controller must be designed to determine the electrical current applied to the MR damper to directly manage the damping force. This paper presents a new skyhook controller, called the skyhook extended controller, for a helicopter with multiple landing gears equipped with MR dampers to reduce the helicopter’s acceleration at the center of gravity in off-normal landing attitude conditions. A 9-DOF simulation model of a helicopter with multiple MR landing gears was built using RECURDYN. To verify the effectiveness of the proposed controller, co-simulations were executed with RECURDYN and MATLAB in different initial pitch and roll angles at touchdown. The main simulation results show that the proposed controller can greatly decrease the peak and rms acceleration of the helicopter’s center of gravity compared to a traditional skyhook controller and passive damper.
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Thomson, D. G. y R. Bradley. "The use of inverse simulation for preliminary assessment of helicopter handling qualities". Aeronautical Journal 101, n.º 1007 (septiembre de 1997): 287–94. http://dx.doi.org/10.1017/s0001924000066148.
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AbstractThis paper describes a method for using inverse simulation to obtain a preliminary assessment of helicopter handling qualities. Formal descriptions of standard manoeuvres, defined to establish the handling qualities of military helicopters, are used to drive an inverse simulation of a subject helicopter. The simulation generates the controls and states of the helicopter as it executes the manoeuvre and the results may be used to calculate values of quickness, a parameter defined to measure responsiveness. Initial results reveal that in the context of inverse simulation quickness is independent of vehicle configuration when, as specified in the requirements, the quickness is based on the helicopter's kinematic states. An alternative quickness parameter, associated with the control displacements required to fly the manoeuvre is shown to be capable of discriminating between the pilot workload involved in flying two different configurations through the same manoeuvre.
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Yin, Ze Yong, Bi Bo Fu, Tong Bo Xue, Yong Hong Wang y Jie Gao. "Development of Helicopter Power Transmission System Technology". Applied Mechanics and Materials 86 (agosto de 2011): 1–17. http://dx.doi.org/10.4028/www.scientific.net/amm.86.1.
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The helicopter power transmission system technology is the key technical area for improving the helicopter performance, reducing the noise/vibration level of helicopters and decreasing the cost of life cycle of helicopters. In this paper, the technical characteristics of the helicopter power transmission system are introduced first. Then, the development history and trend of the transmission configuration, the component and the design and analysis technique of the transmission system are described. The advanced material and process technology applied in the helicopter power transmission system are also described. Finally, the power transmission system technology used in the high speed helicopters is briefly presented.
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Szilvássy, László. "Why Does the Attack Helicopter Have More Survival Ability than the Armed Utility Helicopter?" Repüléstudományi Közlemények 34, n.º 3 (2022): 167–80. http://dx.doi.org/10.32560/rk.2022.3.11.
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The author highlights the difference between attack and armed utility helicopters and supports this with professional arguments. He also presents the most common weapon systems of combat helicopters. Points out that an armed transport helicopter or multipurpose helicopter cannot substitute attack helicopters at all.
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Orhan, Ilkay. "Estimation of helicopter emission and greenest helicopters for London". Aircraft Engineering and Aerospace Technology 93, n.º 8 (26 de julio de 2021): 1333–45. http://dx.doi.org/10.1108/aeat-03-2021-0082.
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Purpose This study aims to estimate the greenest helicopters and the emission amount based on the helicopter movement within the London Heathrow and London city control zone. Design/methodology/approach The helicopter flight data recorded by the UK’s specialist aviation regulator Civil Aviation Authority and the helicopter type with engine emission data from the Federal Office of Civil Aviation (FOCA) were used for calculation. Based on the approach adopted, the greenest and the most environmentally friendly helicopters were identified for a light-duty helicopter with single-engine, a light-duty helicopter with twin-engine and a heavy-duty helicopter with twin-engine. Findings Comparing a flight consisting of landing and take-off cycle, and 1-h phase based on helicopters emissions in the FOCA database, B06 with DDA250-C20R single-engine in the light utility, A109 with PT6B-37 twin-engine in the light utility, and the A139 helicopter with the PT6C-67C twin-engine in the high utility has been identified as the most environmentally friendly helicopter. Practical implications This study provides the opportunity to compare between the best and the worst helicopter with engine type according to the emission values released to the environment. Originality/value This study raises awareness of the emission levels caused by helicopter in urban air transport in developed countries in terms of environmental and human health. It also provides justification for the authorities to encourage the development and use of green engines and technologies.
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Oktay, Tugrul, Harun Celik y Ilke Turkmen. "Constrained control of helicopter vibration to reduce motion blur". Aircraft Engineering and Aerospace Technology 90, n.º 9 (14 de noviembre de 2018): 1326–36. http://dx.doi.org/10.1108/aeat-02-2017-0068.
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Purpose The purpose of this paper is to examine the success of constrained control on reducing motion blur which occurs as a result of helicopter vibration. Design/methodology/approach Constrained controllers are designed to reduce the motion blur on images taken by helicopter. Helicopter vibrations under tight and soft constrained controllers are modeled and added to images to show the performance of controllers on reducing blur. Findings The blur caused by vibration can be reduced via constrained control of helicopter. Research limitations/implications The motion of camera is modeled and assumed same as the motion of helicopter. In model of exposing image, image noise is neglected, and blur is considered as the only distorting effect on image. Practical implications Tighter constrained controllers can be implemented to take higher quality images by helicopters. Social implications Recently, aerial vehicles are widely used for aerial photography. Images taken by helicopters mostly suffer from motion blur. Reducing motion blur can provide users to take higher quality images by helicopters. Originality/value Helicopter control is performed to reduce motion blur on image for the first time. A control-oriented and physic-based model of helicopter is benefited. Helicopter vibration which causes motion blur is modeled as blur kernel to see the effect of helicopter vibration on taken images. Tight and soft constrained controllers are designed and compared to denote their performance in reducing motion blur. It is proved that images taken by helicopter can be prevented from motion blur by controlling helicopter tightly.
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Iswariya, S. y J. Valarmathi. "Micro-Doppler Signature Based Helicopter Identification and Classification Through Machine Learning". International Journal of Computers 15 (22 de marzo de 2021): 23–29. http://dx.doi.org/10.46300/9108.2021.15.4.
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This paper focuses on identification of helicopter by exploiting the concept of micro-Doppler effect which is prominent in targets containing rotating, oscillating or vibrating parts in it. Radar received signal is analyzed by Short Time Fourier Transform (STFT) to extract the micro Doppler (mD) signature. From the mD signature, the helicopter parameters are estimated. In a multiple helicopters scenario, estimated parameters will be a mixure, pertaining to the multiple helicopters. These parameters are classified further using a machine learning algorithm, namely k-means clustering to classify the helicopters. Simulated results for the synthesized received signal shows the betted estimates of the helicopter parameter through mD signature. Dataset containing basic parameters like number of blades, blade length and rotational rates of the UN-1N helicopter (rotor with 2 blades), the SH-3H helicopter (rotor with 5 blades) and the CH-54B helicopter (rotor with 6 blades) are considered for the classification. Results show a good classification. When analysed with different SNR level in dataset, at lower SNR, observed some ovelapping in the classification.
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Markova, E. V., A. M. Al-Darabseh, I. E. Daba’bneh, A. R. Ahmed y B. T. Arazveliev. "DEVELOP AN INTEGRATED TECHNICAL SITUATION CONTROL SYSTEM TO CONTROL HIGH QUALITY HELICOPTERS BASED ON FIBER OPTIC TECHNOLOGY". Izvestiya of Samara Scientific Center of the Russian Academy of Sciences 23, n.º 1 (2021): 21–27. http://dx.doi.org/10.37313/1990-5378-2021-23-1-21-27.
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This article draws attention to the difficulties in developing an integrated approach, especially the evaluation and evaluation of the main helicopter technology. Fiber optic technology is a technology that allows you to create a unified system. This allows the measurement of various physical parameters such as vibration, distortion, temperature, volume and other parameters, given the magnitude of optical fiber science. RMB can be integrated into production, which is an important factor in the amount of RMB related to the design and manufacture of helicopters. The test results, the test bench, and the rotor of the helicopter and light using optical fiber transmission in the Prague fiber optic filter emphasize the importance of developing technology to track the helicopter's use of optical fiber. Other embodiments of the use of optical transmission systems that use fiber-optic technology, such as cable warning of explosives and helicopter damage as well as system weight and transitions. The conduction system monitors air technology.
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Wang, Zeyang, Jun Huang y Mingxu Yi. "Acoustic scattering effect prediction of helicopter fuselage based on BEM and convective FW–H equation". Acta Acustica 6 (2022): 24. http://dx.doi.org/10.1051/aacus/2022019.
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The main acoustic noise source of helicopters is supposed to be the rotor blades, but the scattering effect of the helicopter fuselage sometimes cannot be ignored. For the accuracy of acoustic noise prediction and the research on the scattering affections of the helicopter fuselage, an FWH–BEM Method (FBM) based on convective FW–H equation and boundary element method (BEM) is presented for the prediction of the noise scattering effects of helicopter fuselage and the approach to the calculation of a helicopter’s acoustic noise field. In this paper, different fuselage models are adopted for the comparisons of the acoustic noise scattered by different types of fuselages. According to the discovery that helicopter fuselages with sharp edges can bring more significant acoustic scattering effects, a research on the influence of radius of curvature (RC), which reflects the sharpness of fuselage sharp edges, is also carried out. In addition, the acoustic scattering effects of the same type of fuselage but with different length, width and height ratios are also compared for discovering the influences of the fuselage size. The presented FBM is efficient to analyze the acoustic scattering effects of the helicopter fuselage and predict the acoustic noise field, taking both the rotor and the fuselage into account. Besides, the research in this paper leads to the discovery of the influence factors of the acoustic scattering effects and helps the proper selection of the fuselage in a helicopter stealth design.
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Televnyi, I. "CREATION OF MATHEMATICAL MODELS FOR PARAMETRIC IDENTIFICATION DURING TESTS TO DETERMINE THE FUEL CONSUMPTION OF THE HELICOPTER WITH EXHAUST- HEAT SHIELDS". Наукові праці Державного науково-дослідного інституту випробувань і сертифікації озброєння та військової техніки, n.º 8 (29 de junio de 2021): 134–39. http://dx.doi.org/10.37701/dndivsovt.8.2021.14.
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With the increasing effectiveness of guided missile weapons, the problem of protecting helicopters from these means of destruction is becoming increasingly important. To date, the issue of assessing the protection of helicopters in tests of helicopter equipment are insufficiently developed and require more careful consideration. Therefore, the research of the protection of helicopters equipped with an integrated protection system against guided missiles with infra-red target seeker devices and the impact of exhaust-heat shields on the values of flight characteristics of the helicopter is quite relevant.
The article researches the influence of exhaust-heat shields on the flight technical characteristics of helicopters, their change during the installation of exhaust-heat shields. The estimation of the change in geometric, mass and center characteristics of helicopters by the calculation method is given and the method determining the characteristics of fuel consumption by the calculation and experimental method is given. The methodology and results of experimental researches of flight technical characteristics of the helicopter with the established exhaust-heat shield are described.
The basic result of the research is the study of existing methods for determining the impact of exhaust-heat shields on the flight characteristics of helicopters. Methods of parametric identification for determination of fuel consumption are worked out and the analysis of flight technical characteristics of the helicopter is developed. The fuel consumption of the helicopter with exhaust-heat shield is defined. Integrated assessment of the effectiveness of protection of helicopters from guided missiles with infra-red targeting device can be directly used in practice in test systems for the protection of upgraded and the latest models of helicopters. According to the results of research, mathematical models for determining the fuel consumption of a helicopter with exhaust-heat shields have been developed.
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Urbahs, Aleksandrs, Kristīne Carjova, Aleksejs Nasibullins y Dmitry Nedelko. "Research on the Propagation of AE Signals in Helicopter Structural Components". Transport and Aerospace Engineering 3, n.º 1 (1 de diciembre de 2016): 5–14. http://dx.doi.org/10.1515/tae-2016-0001.
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Abstract The paper contains results of experimental research carried out helicopter bench. In order to create an attenuation chart for AE signal amplitude in helicopter fuselage, a number of experiments were performed on the frame and stringers, inside the fuselage. Later helicopter test bench was used to develop defect localization methodology of helicopter structure fatigue damage technical diagnostics. Analysing helicopter structural defects for different helicopters types it is concluded that the joint elements of helicopter tail boom are still exposed to fatigue crack formation. AE method shows highly effective results predicting fracture of helicopter joint elements.
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Dergachev, A. N. y M. V. Klychnikova. "Geometric constraints system formation for helicopter construction". E3S Web of Conferences 458 (2023): 03028. http://dx.doi.org/10.1051/e3sconf/202345803028.
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The paper presents a methodology of forming a system of geometric constraints in helicopter design. The methodology is based on the synthesis of the requirements in terms of ensuring operation on marine vessels, transportability, and capacity of the cargo (transport) cabin of the helicopter. The universality of this approach allows to adapt the formed system of geometrical constraints to helicopters of different purposes, both to newly developed and modernised helicopters. This methodology allows to define general geometrical characteristics of the helicopter, nomenclature of units requiring simplification of mounting and dismounting procedure of separate units and reduction of their inspection and maintenance periodicity, as well as configuration of helicopter ground and deck service facilities and recommended places of their installation.
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Matsumoto, Hisashi, Tomokazu Motomura, Yoshiaki Hara, Yukiko Masuda, Kunihiro Mashiko, Hiroyuki Yokota y Yuichi Koido. "Lessons Learned from the Aeromedical Disaster Relief Activities Following the Great East Japan Earthquake". Prehospital and Disaster Medicine 28, n.º 2 (22 de enero de 2013): 166–69. http://dx.doi.org/10.1017/s1049023x12001835.
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AbstractIntroductionSince 2001, a Japanese national project has developed a helicopter emergency medical service (HEMS) system (“doctor-helicopter”) and a central Disaster Medical Assistance Team (DMAT) composed of mobile and trained medical teams for rapid deployment during the response phase of a disaster.ProblemIn Japan, the DMAT Research Group has focused on command and control of doctor-helicopters in future disasters. The objective of this study was to investigate the effectiveness of such planning, as well as the problems encountered in deploying the doctor-helicopter fleet with DMAT members following the March 11, 2011 Great East Japan Earthquake.MethodsThis study was undertaken to examine the effectiveness of aeromedical disaster relief activities following the Great East Japan Earthquake and to evaluate the assembly and operations of 15 doctor-helicopter teams dispatched for patient evacuation with medical support.ResultsFifteen DMATs from across Japan were deployed from March 11th through March 13th to work out of two doctor-helicopter base hospitals. The dispatch center at each base hospital directed its own doctor-helicopter fleet under the command of DMAT headquarters to transport seriously injured or ill patients out of hospitals located in the disaster area. Disaster Medical Assistance Teams transported 149 patients using the doctor-helicopters during the first five days after the earthquake. The experiences and problems encountered point to the need for DMATs to maintain direct control over 1) communication between DMAT headquarters and dispatch centers; 2) information management concerning patient transportation; and 3) operation of the doctor-helicopter fleet during relief activities. As there is no rule of prioritization for doctor-helicopters to refuel ahead of other rotorcraft, many doctor-helicopters had to wait in line to refuel.ConclusionThe “doctor-helicopter fleet” concept was vital to Japan's disaster medical assistance and rescue activities. The smooth and immediate dispatch of the doctor-helicopter fleet must occur under the direct control of the DMAT, independent from local government authority. Such a command and control system for dispatching the doctor-helicopter fleet is strongly recommended, and collaboration with local government authorities concerning refueling priority should be addressed.MatsumotoH,MotomuraT,HaraY,MasudaY,MashikoK,YokotaH,KoidoY.Lessons learned from the aeromedical disaster relief activities during the Great East Japan Earthquake.Prehosp Disaster Med.2013;28(2):1-4.
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Givens, Adam. "“The Enthusiasm Expressed by Our Industry Friends”". Vulcan 8, n.º 1 (18 de diciembre de 2020): 100–124. http://dx.doi.org/10.1163/22134603-08010005.
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Abstract This article analyzes the groundbreaking 1952 plan by US Army leadership to develop a sizeable cargo helicopter program in the face of interservice opposition. It examines the influence that decision had in the next decade on the Army, the helicopter industry, and vtol technology. The Army’s procurement of large helicopters that could transport soldiers and materiel was neither a fait accompli nor based on short-term needs. Rather, archival records reveal that the decision was based on long-range concerns about the postwar health of the helicopter industry, developing the state of the art, and fostering new doctrinal concepts. The procurement had long-term consequences. Helicopters became central to Army war planning, and the ground service’s needs dictated the next generation of helicopter designs. That technology made possible the revolutionary airmobility concept that the Army took into Vietnam and also led to a flourishing commercial helicopter field.
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Нерубасский, Вадим Владимирович. "РЫНОК И ПЕРСПЕКТИВЫ ЛЕГКИХ ВЕРТОЛЕТОВ С ГАЗОТУРБИННЫМИ ДВИГАТЕЛЯМИ". Aerospace technic and technology, n.º 5 (29 de agosto de 2020): 5–12. http://dx.doi.org/10.32620/aktt.2020.5.01.
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In the introductory part of the article, it is provided brief information about the main activity of JSC “Element”- developer and manufacturer of electronic control systems for aircraft engines, in particular unit RDTs-450M for AI-450M helicopter turboshaft gas turbine engines, created by SE “Ivchenko-Progress”. JSC ”Element”, together with its partners - SE “Ivchenko-Progress” and JSC “Motor-Sich” – for more than 10 years involved in the modernization of Mi-2 light helicopter.In the next section is gave the classification of helicopters, as well as a segment of light helicopters with turbine engines. It is outlined the scope of light helicopters. It is noted that the segment of light helicopters with turbine engines – the most popular in the world market of civil helicopters and provides a forecast of the supply of these helicopters for the next 10 years.Lists the world's major developers and manufacturers of light helicopters, and the technical characteristics of 12 models of light helicopters with turbine engines are depicted. It is noted that most helicopter models are not entirely new developments and have been modernized over many years. The characteristic design features of light helicopters with turbine engines, especially the layout of plant and equipment are depicted. There is a trend of using one model of helicopter multiple engine types.Lists the world's major developers and manufacturers of engines for light helicopters, as well as the technical characteristics of the six models of gas turbine engines are depicted. The main structural and compositional features of gas-turbine engines of different manufacturers and types of a helicopter on which they installed are described. Separately, brief information about the Ukrainian gas-turbine engines: AI-450M and MS-500V. It is noted that all, without exception, mentioned in the article, engines are equipped with a digital single or dual-channel FADEC type control system with hydro-mechanical redundancy.Brief information about individual conceptual samples of rotary-wing technology introduced in recent years is given. The main directions of work in the field of helicopter engines are described.In conclusion, the Ukrainian helicopter and Aero-engine industry are in a difficult economic situation, but remain competitive and require assistance and the expansion of the market.
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Stanisławski, Jarosław. "Performance of Quiet Helicopter". Transactions on Aerospace Research 2020, n.º 1 (1 de marzo de 2020): 1–17. http://dx.doi.org/10.2478/tar-2020-0001.
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AbstractNoise generated by helicopters is one of the main problems associated with the operation of rotorcrafts. Requirements for reduction of helicopter noise were reflected in the regulations introducing lower limits of acceptable rotorcraft noise. A significant source of noise generated by helicopters are the main rotor and tail rotor blades. Radical noise reduction can be obtained by slowing down the blade tips speed of main and tail rotors. Reducing the rotational speed of the blades may decrease rotor thrust and diminish helicopter performance. The problem can be solved by attaching more blades to main rotor. The paper presents results of calculation regarding improvement of the helicopter performance which can be achieved for reduced rotor speed but with increased number of rotor blades. The calculations were performed for data of hypothetical light helicopter. Results of simulation include rotor loads and blade deformations in chosen flight conditions. Equations of motion of flexible rotor blades were solved using the Galerkin method which takes into account selected eigen modes of the blades. The simulation analyzes can help to determine the performance and loads of a quiet helicopter with reduced rotor speed within the operational envelope of helicopter flight states.
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Majumdar, A., K. Mak, C. Lettington y P. Nalder. "A causal factors analysis of helicopter accidents in New Zealand 1996-2005 and the United Kingdom 1986-2005". Aeronautical Journal 113, n.º 1148 (octubre de 2009): 647–60. http://dx.doi.org/10.1017/s0001924000003316.
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Abstract Helicopter accidents cause many fatalities, and their avoidance is a major area of work for Civil Aviation safety authorities around the World. This paper uses helicopter accident data from the United Kingdom between 1986 and 2005 for 566 accidents and from New Zealand between 1996 and 2006 for 230 accidents to analyse helicopter accidents according to five categories of causes: airworthiness failure (engine); airworthiness failure (non-engine), operational failure, maintenance failure and mixed failure (i.e. operational and airworthiness combined). Factors associated with accidents, e.g. the engine types and weights of the helicopters involved; the nature of the operations and the phase of flight of the helicopter are also analysed. Operational failures were further analysed by Human Factors Analysis and Classification Scheme (HFACS) and airworthiness failures by a logical scheme of helicopter components. The results indicate that operational failures, especially due to unsafe acts, are the major cause of accidents in both countries followed by airworthiness causes. Light single piston helicopters are by far the major group associated with accidents in both countries, with few accidents for twin turbine helicopters. The majority of accidents were in non-public operations with few in public operations and in both countries, the cruise/flight/circuit phase has the largest number of accidents. Further analyses indicated statistically significant associations: type of helicopter and the cause of accidents; type of helicopter and the phase of flight; cause of accidents and nature of flights; cause of accidents and phase of flights; training flights and inadequate supervision; landing and procedural error and cruise and attention failure.
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Nakanishi, Hiroaki, Sayaka Kanata y Tetsuo Sawaragi. "Improved Stability Using Environmental Adaptive Yaw Control for Autonomous Unmanned Helicopter and Bifurcation of Maneuvering in Turning". Journal of Robotics and Mechatronics 23, n.º 6 (20 de diciembre de 2011): 1091–99. http://dx.doi.org/10.20965/jrm.2011.p1091.
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Adaptation to environmental changes, such as wind, plays a very important role in improving the reliability of autonomous unmanned helicopters. Adaptive yaw (heading) control for an autonomous helicopter is discussed in this paper. The control structure is based on a hierarchal scheme that utilizes an inner yaw feedback control loop plus an outer feedback loop. The outer loop estimates the direction of the airspeed using roll angle and roll angular rate. Stable coupling in yaw and roll motion is induced by the proposed controller to improve the stability of the helicopter’s flight. Turning utilizing the proposed adaptive control system is discussed in particular. Results of flight experiments show that bifurcation of the helicopter’smaneuvering in turning occurs depending on airspeed. The results indicate that the autonomous unmanned helicopter can select a turning maneuver that is suitable for the environmental conditions, thus stabilizing its flight.
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Krivolutsky, Yu V. "Optimization of types and quantity of the national helicopter park as a factor of customer’s cost reduction". Entrepreneur’s Guide 15, n.º 1 (4 de marzo de 2022): 80–83. http://dx.doi.org/10.24182/2073-9885-2022-15-1-80-83.
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The article shows that the main cause, which restrains wide implementation of helicopters, is the incongruity of the current park of helicopters to the character and the high cost of the performing tasks. The solvation of the problem would be a saturation of the helicopter park by the new types of helicopters. The method of calculation of the possible reduction of exploitation expenses under optimization of helicopter types in accordance with market demand is offered. The optimization of types and quantity of helicopters park enables the customers to reduce their costs and widen the possibilities of helicopters exploitation in national economy.
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Xu, Ze Yin, Xiao Hu Xia y Yun Jian Ge. "Research on Unmanned Aerial Vehicles Autonomous Soft Landing Based on Optimal Control". Advanced Materials Research 562-564 (agosto de 2012): 1442–46. http://dx.doi.org/10.4028/www.scientific.net/amr.562-564.1442.
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This paper deals with the autonomous soft landing of unmanned helicopter aiming to enhance its application. Soft landing means to reduce the shock force upon ground during the helicopters land. Helicopter is a multi-input multi-output system and for which optimal control provides graceful and coordinated controls. Firstly, the experimental platform configuration for autonomous soft-landing system is introduced, which is based on the model helicopter. The time-varying gains and time-varying quadratic performance index Linear Quadratic control for autonomous soft landing of miniature helicopter is applied to unmanned helicopter. Simulation shows that the outputs of the system can respond the input signals accurately.
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Li, Jing y Naibo Zheng. "Design and Research of Double-Wheeled Helicopter Tractor". Journal of Physics: Conference Series 2235, n.º 1 (1 de mayo de 2022): 012006. http://dx.doi.org/10.1088/1742-6596/2235/1/012006.
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Abstract Due to the limited wheel size, existing domestic helicopter tractors are only applicable to some small and medium-sized single-wheeled helicopters. This paper introduces a double-wheeled helicopter tractor. The wheel holding mechanism can maximally hold a helicopter with a wheel diameter of 500mm, thus suitable for most common types of general aviation airports, such as Z-9, AS-365N, EC-155, AW -139, AS-332, etc. By improving stable torque output of the motor at low speed, self-developed reducer greatly increases the applicability and safety of helicopter traction.
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MISCHIE, Ioan. "HELICOPTERS IN COMBAT: METHODS FOR HELICOPTER USE IN SPECIAL OPERATIONS". Review of the Air Force Academy 16, n.º 1 (1 de agosto de 2018): 5–10. http://dx.doi.org/10.19062/1842-9238.2018.16.1.1.
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Wu, Chengfeng, Chunhua Wei, Yong Wang y Yang Gao. "Signal Enhancement of Helicopter Rotor Aerodynamic Noise Based on Cyclic Wiener Filtering". Applied Sciences 12, n.º 13 (30 de junio de 2022): 6632. http://dx.doi.org/10.3390/app12136632.
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The research on helicopter rotor aerodynamic noise becomes imperative with the wide use of helicopters in civilian fields. In this study, a signal enhancement method based on cyclic Wiener filtering was proposed given the cyclostationarity of rotor aerodynamic noise. The noise was adaptively filtered out by performing a group of frequency shifts on the input signal. According to the characteristics of rotor aerodynamic noise, a detection function was constructed to realize the long-distance detection of helicopters. The flight data of the Robinson R44 helicopter was obtained through the field flight experiment and employed as the research object for analysis. The detection range of the Robinson R44 helicopter after cyclic Wiener filtering was increased from 4.114 km to 17.75 km, verifying the feasibility and effectiveness of the proposed method. The efficacy of the proposed detection method was demonstrated and compared in the far-field flight test measurements of the Robinson R44 helicopter.
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Kokhan, V., T. Dudnyk, D. Sivoraksha y Т. Televna. "RESEARCH OF POSSIBILITY OF ARMOURING A CABIN OF TYPE Mi-8A HELICOPTER". Наукові праці Державного науково-дослідного інституту випробувань і сертифікації озброєння та військової техніки, n.º 7 (21 de mayo de 2021): 40–48. http://dx.doi.org/10.37701/dndivsovt.7.2021.05.
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Given an urgent need to protect a crew of the type Mi-8 helicopter from firearms in the course of combat missions and lack of transparent armor for this type of helicopter in the Armed Forces of Ukraine, it was decided to conduct a theoretical and experimental research with regard to armouring a cabin of type Mi-8 helicopter.
The first stage of experimental research was laboratory (bench) research.
Samples of bulletproof glass measuring 500x500 mm and 12 and 18 mm thick were provided for testing. The purpose of research bench tests was to determine the degree of protection of the armored glass unit. The samples were fired at with 9 mm pistol bullets, ind. 57-H-181c (Makarov pistol), bullets 7.62 mm pistol cartridge, ind. 57-H-134c (Tokarev pistol) and 5.45 mm bullets, ind. 7H6 (AK-74 assault rifle).
The next stage of experimental research was to conduct research ground tests of armored glass of a Mi-8 helicopter crew cabin.
The purpose of research ground tests was to evaluate the protective properties of armored glass samples, based on the results of their firing with a single 5.45 mm bullet shots, ind. 7H6 (AK-74 assault rifle) at the shooting range.
Samples of armoured glass of the on-board technician and sight (right) glass intended for protection of the flight crew, systems and units of the cabin were presented for ground research tests.
The final stage of experimental research was the stage of research flight tests of the Mi-8MSB-B helicopter with 18 mm thick armored glass.
The purpose of research flight tests was as follows:
to determine changes in the main technical and operational characteristics of Mi-8MSB-B helicopter after installation of 18 mm thick armored glass;
to determine the possibility of using 18 mm thick armored glass on Mi-8 helicopters;
to assess the effectiveness and safety of armored glass for armouring Mi-8 helicopters’ cabins;
to determine peculiarities of using 18 mm thick armored glass on Mi-8 helicopters and peculiarities of Mi-8 helicopter operation with armored glass installed;
to obtain initial data for elaboration of tactical and technical (general) requirements for helicopters Mi-8 (particularly concerning the installation of armored glass), approved by Testing Program and Procedure for research flight tests of Mi-8MSB-B helicopter.
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Hart, J. "MANAGING HELICOPTER RISK". APPEA Journal 45, n.º 1 (2005): 657. http://dx.doi.org/10.1071/aj04049.
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Annually, a million hours are flown by helicopters for the international petroleum industry. About 90% of this flying is offshore, and involves around 10 million passengers. Each year some 25–35 accidents are recorded, an average of 22 passengers and crew lose their lives, and a higher number are injured. Some 45% of these accidents stem from technical causes, a similar number are pilot related, and the remainder are linked to other causes. Helicopter accident rates are 10 times higher than those of airline travel.Strategies to tackle both technical failures and pilot related accidents have emerged, although application of these strategies around the world is inconsistent.One way in which helicopter technical issues have been addressed is by the introduction of Health and Usage Monitoring (HUMS) equipment. To tackle the pilot related accidents, lessons have been drawn from the airline industry’s use of Flight Data Management (FDM) programs, which allow pilots to learn from deviations from pre-defined normal parameters during routine flying. The helicopter version of FDM is the Helicopter Operations Monitoring Program (HOMP). Another important training tool is flight simulator training to allow simulated emergencies to be flown and practiced.Petroleum companies have the opportunity through their own aviation policy and standards to stipulate flight crew experience and training, the technical specifications for their contracted helicopters and the application of advanced safety programs, such as HUMS, and HOMP. Compliance and continuous improvement in line with these standards can be verified and facilitated through operational and technical audit. Only with such active involvement can helicopter risk be managed downwards.
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Rimša, Vytautas y Mykolas Liugas. "Numerical Investigation of the Vortex Ring Phenomena in Rotorcraft". Aerospace 11, n.º 6 (22 de mayo de 2024): 418. http://dx.doi.org/10.3390/aerospace11060418.
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Due to their complex aerodynamics, helicopters may enter different dangerous aerodynamic conditions under certain adverse circumstances. In this paper, we examine one such phenomenon—the Vortex Ring State (VRS). We present a simulation of the formation and evolution of a vortex ring around a helicopter’s main rotor. The calculations were carried out by solving Navier–Stokes equations using the Ansys CFX code. The simulations modeled a real helicopter using the rotor wing concept, assuming that only the main rotor blade’s geometry was modeled. A sensitivity study assessed the impact of the calculation domain and mesh size on main rotor thrust and required moment parameters. Simulations were conducted to determine the VRS region by observing the transition of the helicopter from a level flight, with the main rotor blades held at a fixed pitch position, to a gradual increase in vertical descent. The VRS region was compared with experimental results obtained from other authors, revealing sufficient coincidences. The main characteristics of the identified region were then described.
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AKAY, Abdullah Emin y Ebru BİLİCİ. "EVALUATING THE LOCATIONS OF THE FIRE HELICOPTER PLATFORMS IN THE REGION OF BURSA". ArtGRID - Journal of Architecture Engineering and Fine Arts 4, n.º 2 (31 de diciembre de 2022): 254–63. http://dx.doi.org/10.57165/artgrid.1201452.
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In Turkey, the General Directorate of Forestry (GDF) utilizes helicopters in various forestry activities such as firefighting, forest protection, wildlife management, shipping, and other activities. In firefighting activities, mostly Russian-designed “Mil Mi-8MTV-1” series helicopters are rented by the GDF during the fire season. These fire helicopters are designed to carry up to 20 people and 2.5 tons of water with a special bucket attached underneath. In this study, it was aimed to evaluate the location of the fire helicopter platforms in the border of Bursa Forestry Regional Directorate (FRD). In the solution process, the areas reached by the fire helicopters in the critical response time was determined using proximity analysis in ArcGIS. Accessible areas were also found for productive forest and degraded forest separately. The results indicated that 85.97 % of the total area of FRD was reached by the fire helicopter within the critical response time while it was 84.06 % for the forested areas. In terms of fire sensitivity degrees, 79.18 % of the first degree sensitive forests were accessed within the critical response time, while all of the second and third degree sensitive forests were reached on time. On the other hand, the accessible forest areas were 85.61 % and 81.21 % for productive forest and degraded forest. These results suggested that location of the fire helicopter platforms should be re-evaluate and possible new platforms should be located in Bursa FRD in order to improve the efficiency of the helicopter fleet and access the forest area in the critical response time. In this process, GIS techniques should be employed by the fire managers to evaluate the optimum locations for the fire helicopter platforms.
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Sal, Firat. "Variance constrained trajectory tracking for tandem-rotor helicopters". Aircraft Engineering and Aerospace Technology 92, n.º 3 (20 de enero de 2020): 398–403. http://dx.doi.org/10.1108/aeat-10-2019-0205.
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Purpose This paper aims to present novel results for trajectory tracking of tandem-rotor helicopters via variance-constrained controllers. Design/methodology/approach Regarding these purposes, linearized tandem-rotor helicopter models are benefitted. Findings Variance-constrained controllers are very beneficial for trajectory tracking of tandem-rotor helicopters while there exists variance bounds on outputs of interest. Practical implications Variance-constrained controllers can be used for cheaper tandem-rotor helicopter operations with high trajectory tracking quality. Originality/value Applying variance-constrained control strategy for tandem-rotor helicopters during trajectory tracking. This also causes less fuel consumption and green environment, and good trajectory tracking quality.
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Wei, Yuan, Renliang Chen, Ye Yuan y Luofeng Wang. "Influence of Engine Dynamic Characteristics on Helicopter Handling Quality in Hover and Low-Speed Forward Flight". Aerospace 11, n.º 1 (29 de diciembre de 2023): 34. http://dx.doi.org/10.3390/aerospace11010034.
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This study assesses the influence of engine dynamic characteristics on helicopter handling quality during hover and low-speed forward flight. First, we construct the helicopter–engine coupling model (HECM) based on the power-matching relationship between the engine and the rotor. The impact of the engine is evaluated by comparing HECM with a helicopter model without the engine. To assess the engine’s influence quantitatively, we consider torque response, height response, and collective–yaw coupling characteristics in ADS-33E-PRF handling quality criteria. The results reveal that the engine power output lag can deteriorate the helicopter’s torque and height response handling quality rate (HQR). After the increase in helicopter mass, the torque HQR caused by engine influence improved, and the altitude HQR further deteriorated. The engine dynamic characteristics can also reverse the yaw rate, decreasing collective–yaw coupling HQR. As the helicopter’s flight speed increased, the engine’s impact on the yaw rate increased by 41.8%. This study can provide valuable insight into the effects of engine dynamic characteristics on helicopter handling quality and offer a reference for the design of helicopter–engine coupling control laws.
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Dergachev, A. N. y N. Yu Temicheva. "Influence of geometric constraints on aircraft design". E3S Web of Conferences 458 (2023): 03027. http://dx.doi.org/10.1051/e3sconf/202345803027.
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The paper considers the requirements to helicopter operating conditions, forming geometrical constraints at the design stages and their influence on the geometrical appearance of the helicopter as a whole, structural design and layout of individual components and assemblies of helicopters. The methodology of forming the system of geometrical constraints is based on the generalised requirements to ensure the operational and technical characteristics of the helicopter: ensuring the basing and production of take-off and landing operations on marine vessels, ensuring transportability, ease of access to the cockpit, ease of access to the units during maintenance, reducing the labour intensity of individual helicopter maintenance operations.
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Sun, L., F. Gao, L. Q. L y B. C. Lou. "Research on modelling analysis and design method of helicopter operation requirements based on MBSE". Journal of Physics: Conference Series 2472, n.º 1 (1 de mayo de 2023): 012042. http://dx.doi.org/10.1088/1742-6596/2472/1/012042.
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Abstract Helicopters are characterized by complex missions, high risk, high cost, high reliability and long lead times. In order to adapt to the more complex operational requirements in the future, the thesis addresses the problems of long iterative cycles, low efficiency and model duality in the traditional helicopter operation requirements analysis process, the theory of model-based systems engineering (MBSE) is introduced into operation requirements analysis for helicopter. A modelling analysis and design method for helicopter operation requirements analysis is proposed based on MBSE. The overall framework for helicopter operation requirements analysis based on the model is designed. On this basis, a modelling design method and key implementation process of requirements analysis is established, which provides theoretical and technical support for the positive design of helicopter operation requirements demonstration.
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Ali, F., I. Goulos y V. Pachidis. "An integrated methodology to assess the operational and environmental performance of a conceptual regenerative helicopter". Aeronautical Journal 119, n.º 1211 (enero de 2015): 67–90. http://dx.doi.org/10.1017/s0001924000010253.
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AbstractThis paper aims to present an integrated multidisciplinary simulation framework, deployed for the comprehensive assessment of combined helicopter–powerplant systems at mission level. Analytical evaluations of existing and conceptual regenerative engine designs are carried out in terms of operational performance and environmental impact. The proposed methodology comprises a wide-range of individual modeling theories applicable to helicopter flight dynamics, gas turbine engine performance as well as a novel, physics-based, stirred reactor model for the rapid estimation of various helicopter emissions species. The overall methodology has been deployed to conduct a preliminary trade-off study for a reference simple cycle and conceptual regenerative twin-engine light helicopter, modeled after the Airbus Helicopters Bo105 configuration, simulated under the representative mission scenarios. Extensive comparisons are carried out and presented for the aforementioned helicopters at both engine and mission level, along with general flight performance charts including the payload-range diagram. The acquired results from the design trade-off study suggest that the conceptual regenerative helicopter can offer significant improvement in the payload-range capability, while simultaneously maintaining the required airworthiness requirements. Furthermore, it has been quantified through the implementation of a representative case study that, while the regenerative configuration can enhance the mission range and payload capabilities of the helicopter, it may have a detrimental effect on the mission emissions inventory, specifically for NOx(Nitrogen Oxides). This may impose a trade-off between the fuel economy and environmental performance of the helicopter. The proposed methodology can effectively be regarded as an enabling technology for the comprehensive assessment of conventional and conceptual helicopter-powerplant systems, in terms of operational performance and environmental impact as well as towards the quantification of their associated trade-offs at mission level.
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Go, Jeong-In, Do-Hyung Kim y Jae-Sang Park. "Performance and Vibration Analyses of Lift-Offset Helicopters". International Journal of Aerospace Engineering 2017 (2017): 1–13. http://dx.doi.org/10.1155/2017/1865751.
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A validation study on the performance and vibration analyses of the XH-59A compound helicopter is conducted to establish techniques for the comprehensive analysis of lift-offset compound helicopters. This study considers the XH-59A lift-offset compound helicopter using a rigid coaxial rotor system as a verification model. CAMRAD II (Comprehensive Analytical Method of Rotorcraft Aerodynamics and Dynamics II), a comprehensive analysis code, is used as a tool for the performance, vibration, and loads analyses. A general free wake model, which is a more sophisticated wake model than other wake models, is used to obtain good results for the comprehensive analysis. Performance analyses of the XH-59A helicopter with and without auxiliary propulsion are conducted in various flight conditions. In addition, vibration analyses of the XH-59A compound helicopter configuration are conducted in the forward flight condition. The present comprehensive analysis results are in good agreement with the flight test and previous analyses. Therefore, techniques for the comprehensive analysis of lift-offset compound helicopters are appropriately established. Furthermore, the rotor lifts are calculated for the XH-59A lift-offset compound helicopter in the forward flight condition to investigate the airloads characteristics of the ABC™ (Advancing Blade Concept) rotor.
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Pilipenko, Oleg. "FLIGHT SAFETY OF MI-8 HELICOPTERS AND THEIR MODIFICATIONS". Technical Sciences and Technologies, n.º 1(31) (2023): 14–20. http://dx.doi.org/10.25140/2411-5363-2023-1(31)-14-20.
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The article is an overview and information. The presented statistical data on the safety of flights of Mi-8 helicopters for the period from 1996 to 2011, the number of incidents, flight hours and their distribution for 2015-2019 confirm the feasibility of switching to the operation of helicopters according to their technical condition. The risk of fatal injury changes from its maximum values at 1000-1200 hours of operation per incident and reaches its minimum values starting from 4000 hours of operation.The number of incidents associated with the main gearbox is less for the Mi-8T helicopter compared to the Mi-8MTV(AMT) helicopter. The number of operating hours per incident associated with the operation of the fire alarm system in the area of the engines and the main gearbox also testifies in favor of the Mi-8T helicopter. The probability of an incident occurring per 1 hour of flight for a Mi-8 helicopter is less than that of the aircraft presented in the corresponding chart
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de Voogt, Alex y Keyashia Nero. "Technical Failures in Helicopters: Non-Powerplant-Related Accidents". Safety 9, n.º 1 (22 de febrero de 2023): 10. http://dx.doi.org/10.3390/safety9010010.
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Technical failures in helicopters are a main concern for helicopter safety. The prominence of mechanical failures differs for specific helicopter operations. This analysis used 151 General Aviation accident reports from the National Transportation Safety Board online database from an 11-year time period. The information in each report was collated, including the list of findings for each accident. Possible relations between causes and specific flight operations were analyzed by looking at significant differences between expected and actual values within the dataset of categorical data. It is found that the proportion of fatal accidents in this category of accidents is low (16.6%) compared with the percentage of fatal helicopter accidents in general, as well as those of specific helicopter operations. Instructional flights appear significantly more likely to be associated with maintenance-related causes. Causes related to fatigue of aircraft parts are more often associated with ferry and positional flights, as well as helicopters with turbo-shaft engines. Future research is recommended for these specific associations to further mitigate the number of accidents with non-powerplant failures.
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Minotra, Dev y Karen Feigh. "Eliciting Knowledge from Helicopter Pilots: Recommendations for Revising the ACTA Method for Helicopter Landing Tasks". Proceedings of the Human Factors and Ergonomics Society Annual Meeting 61, n.º 1 (septiembre de 2017): 242–46. http://dx.doi.org/10.1177/1541931213601544.
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The task of landing helicopters on ships is cognitively complex and is bounded by several limitations for safe operation. To design technologies to support helicopter pilots in shipboard operations, a better understanding of cognitive processes underlying helicopter piloting in shipboard landing maneuvers is required. Limitations in prior work on ship-based helicopter pilots motivate more studies to better understand how pilots compensate for difficulties associated with ship motion, air turbulence among other factors. We report a preliminary study that used the Applied Cognitive Task Analysis (ACTA) method. We interviewed three participants who have ground-based helicopter piloting experience. The results indicate that ACTA can be used in eliciting knowledge from helicopter pilots. However, we have identified several caveats with the use of the method for this application. The revised method will be used to interview helicopter pilots with shipboard landing experience. Our study has identified a number of cognitive elements in the task which are associated with task management, divided attention, and noticing anomalies.
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Tarsi, Alessandro y Simone Fiori. "Lie-Group Modeling and Numerical Simulation of a Helicopter". Mathematics 9, n.º 21 (22 de octubre de 2021): 2682. http://dx.doi.org/10.3390/math9212682.
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Helicopters are extraordinarily complex mechanisms. Such complexity makes it difficult to model, simulate and pilot a helicopter. The present paper proposes a mathematical model of a fantail helicopter type based on Lie-group theory. The present paper first recalls the Lagrange–d’Alembert–Pontryagin principle to describe the dynamics of a multi-part object, and subsequently applies such principle to describe the motion of a helicopter in space. A good part of the paper is devoted to the numerical simulation of the motion of a helicopter, which was obtained through a dedicated numerical method. Numerical simulation was based on a series of values for the many parameters involved in the mathematical model carefully inferred from the available technical literature.
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Piriyanont, Busara, Naoki Uchiyama y Shigenori Sano. "Model Reference Control for Collision Avoidance of a Human-Operated Quadrotor Helicopter". Journal of Advanced Computational Intelligence and Intelligent Informatics 15, n.º 5 (20 de julio de 2011): 617–23. http://dx.doi.org/10.20965/jaciii.2011.p0617.
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Because quadrotor helicopter has four fixed-pitch rotors, its control system can be much simpler than that of conventional helicopters; thus, it is expected to find wide application in many remote control situations, such as in hazardous environments. This paper proposes a collision avoidance control for a quadrotor helicopter based on the concept of a social force model. The proposed control incorporates commands given from human operators and compensates for operator mistakes in real time to achieve collision avoidance of a quadrotor helicopter. The proposed method uses distance sensors to achieve real-time collision avoidance. Its effectiveness is shown by experimental results, in which the algorithm successfully drives the helicopter along the desired trajectory without a collision.
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Orchard, M. N. y S. J. Newman. "The compound helicopter — why have we not succeeded before?" Aeronautical Journal 103, n.º 1028 (octubre de 1999): 489–95. http://dx.doi.org/10.1017/s0001924000064526.
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Abstract Compounding offers a way of advancing the performance of the standard helicopter significantly for a moderate increase in complexity through the addition of wings and/or auxiliary propulsion. The compound helicopter configuration has the potential advantages of increased speed, range, agility, productivity and reduced vibration levels over conventional helicopters. Despite several significant efforts, however, no compound helicopter has ever been put into production. This paper looks at three aircraft that came close to being accepted by operators and examines the reasons why they were not ultimately put into production. The cancellation of these projects appeared to be of a political nature rather than technical. Also addressed are the issues that still face prospective designers of compound helicopters and the lessons that can be extracted and applied to modern day efforts to build and sell an aircraft of this configuration.
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Peng, Chen, Bo Zhu y Keqi Wei. "Design and Experimental Verification of Robust Motion Synchronization Control with Integral Action". Mathematical Problems in Engineering 2016 (2016): 1–14. http://dx.doi.org/10.1155/2016/7324508.
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A robust attitude motion synchronization problem is investigated for multiple 3-degrees-of-freedom (3-DOF) helicopters with input disturbances. The communication topology among the helicopters is modeled by a directed graph, and each helicopter can only access the angular position measurements of itself and its neighbors. The desired trajectories are generated online and not accessible to all helicopters. The problem is solved by embedding in each helicopter some finite-time convergent (FTC) estimators and a distributed controller with integral action. The FTC estimators generate the estimates of desired angular acceleration and the derivative of the local neighborhood synchronization errors. The distributed controller stabilizes the tracking errors and attenuates the effects of input disturbances. The conditions under which the tracking error of each helicopter converges asymptotically to zero are identified, and, for the cases with nonzero tracking errors, some inequalities are derived to show the relationship between the ultimate bounds of tracking errors and the design parameters. Simulation and experimental results are presented to demonstrate the performance of the controllers.
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Sun, L., L q l y F. Gao. "Sensitivity analysis of attack helicopter combat indicators based on machine learning". Journal of Physics: Conference Series 2746, n.º 1 (1 de mayo de 2024): 012032. http://dx.doi.org/10.1088/1742-6596/2746/1/012032.
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Abstract This paper focuses on sensitivity analysis in the design of Attack helicopter combat indicators, and combines the advantages of machine learning to propose a combat effectiveness oriented sensitivity analysis method for Attack helicopter combat indicators. Firstly, the steps of sensitivity analysis of Attack helicopter combat indicators based on machine learning are introduced. Secondly, through operational scenarios, constructing indicator systems, collecting relevant data, evaluating effectiveness, and using machine learning algorithms for modelling and training, the sensitivity assessment of the damage probability of Attack helicopter to ground armoured weapons can be achieved. This paper is able to provide reference for the sensitivity analysis of weapon equipment system effectiveness, and provide more scientific and reasonable support for the research and application of helicopters in combat systems.
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Ruffner, John W., John E. Padukewicz y John D. Meier. "Joint Shipboard Helicopter Operations: Human Factors Issues and Challenges". Proceedings of the Human Factors and Ergonomics Society Annual Meeting 46, n.º 1 (septiembre de 2002): 46–50. http://dx.doi.org/10.1177/154193120204600110.
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As part of the US military's Joint Force initiative, non-Navy helicopters are increasingly required to conduct operations on Navy ships. Consequently, shipboard helicopter interoperability has become a requirement for all the military forces. Key shipboard helicopter operations include: landings and takeoffs, launch and recovery support activities, ordnance handling, refueling, and external load operations. These operations involve a variety of helicopter types from the different services on all aviation-capable Navy ships, in different sea states, and under changing visibility and environmental conditions. The requirement for shipboard helicopter interoperability involves several unique human factors issues and poses many challenges. In this paper, we discuss the major issues and challenges as they relate to three broad categories: procedures, training, and compatibility. We identify areas where human factors specialists can make significant contributions to improve the effectiveness and safety of shipboard helicopter operations. In addition, we identify opportunities for future research.
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Golub, V., O. Akimov, V. Boyarov, M. Zhdanyuk y R. Kholodnyi. "ASSESSMENT OF THE INFLUENCE OF INDICATORS OF RELIABILITY HELICOPTER SAFETY Ми-8МСБ, Ми-8MT(MTВ) ON SAFETY PERFORMANCE FOR 2017-2021". Наукові праці Державного науково-дослідного інституту випробувань і сертифікації озброєння та військової техніки, n.º 12 (5 de julio de 2022): 24–28. http://dx.doi.org/10.37701/dndivsovt.12.2022.03.
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The article offers a complex approach to determination of long-term trends of quantitative indicators of safety of flights of helicopters Mi-8MSB-V and Mi-8MT (MTV) and influence on them of operational reliability.
The integrated approach is to determine the impact of the failure of the functional systems of helicopters on operational reliability and flight safety: average failure rate, mean failure rate, probability of helicopter flight reliability in one hour, Average aircraft accident, probability of absence.
Proposals have been developed to improve the reliability and safety of helicopter flights based on information about the technical condition during military operation, which will allow adjusting the terms of maintenance, repair, extending the service life and provide for areas for upgrading aviation equipment.
In order to take into account objectively the impact of helicopter systems on the reliability and safety of aircraft equipment flights, information on the flight hours of aircraft equipment should be provided, taking into account the level of functional systems upgrade. Recommendations for improving flight safety and reliability of elements of helicopter systems limiting the reliability of aviation equipment are given.
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Kurnaz, Salim, Aşkın Özdağoğlu y Murat Kemal Keleş. "METHOD OF EVALUATION OF MILITARY HELICOPTER PILOT SELECTION CRITERIA: A NOVEL GREY SWARA APPROACH". Aviation 27, n.º 1 (28 de febrero de 2023): 27–35. http://dx.doi.org/10.3846/aviation.2023.18596.
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Helicopter is a very important defence and attack tool for a country’s armed forces (army) (air force). With the rapid progress of technology, the designs of helicopters, the hardware and software elements in the helicopter have also been renewed and developed in parallel with advanced technology. Therefore, it is expected that the pilots who will use helicopters, which are an important flight tool of armed forces, will also have the qualifications to provide the necessary knowledge, skills, and criteria. The aim of the study is to determine the military helicopter pilot selection criteria and to find the importance levels of these criteria. For this purpose, three main criteria as “Health”, “Psychomotor” and “Education and Training” and thirteen sub-criteria were determined. The weights of the determined criteria were found by the Grey SWARA method, which is a current multi criteria decision making tool. According to the results of the analysis, it is found that the most important sub-criteria was “Practical Training”, while the lowest important criteria was the “Height and weight limits” criterion. With this study, the weights of the military helicopter pilot selection criteria were found for the first time with the Grey SWARA method.
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Zhang, Chi, Cheng Dong Xu, Xin Pei y Chun Sheng Hu. "Information Acquisition of Maintenance, Repair and Overhaul/Operations System for Helicopters". Applied Mechanics and Materials 220-223 (noviembre de 2012): 2150–55. http://dx.doi.org/10.4028/www.scientific.net/amm.220-223.2150.
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The helicopter Maintenance, Repair and Overhaul/Operations (MRO) system enables the best sharing of the maintenance resources and maintenance ability in a wide area, so as to promote the specialization of the helicopter maintenance organizations. Information acquisition is an important and difficult part of the helicopter MRO system. This paper systematically analyzes the condition monitoring methods which are used to monitor the rotational speed, temperature, pressure, vibration and flight parameter in different parts of a helicopter, and then it puts forward some improved ways for information acquisition. Considering the helicopter’s features, the process of information acquisition is illustrated. In addition, this paper presents the basic requirements of data sampling, and it also shows a detailed discussion on data format and data transmission in the helicopter MRO system. At the end of the paper, a system mode and architecture of helicopter MRO system are proposed.
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Zhang, Su Ning, Wen Qiang Ding y Yong Hong Wang. "Development Solution of Civil Helicopter Transmission Train Vibration Monitoring System". Applied Mechanics and Materials 86 (agosto de 2011): 342–47. http://dx.doi.org/10.4028/www.scientific.net/amm.86.342.
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Health & Usage Monitoring System (HUMS) is designed for improving airworthiness, reliability and effective maintenance management of helicopter by analysis of detected / diagnosed operation data internal/external environment data collected from the helicopter. Vibration monitoring system plays as an important part of entireness integrated HUMS, which offers a considerable improvement to conventional monitoring techniques. This paper covers development solution of civil helicopter transmission train Vibration monitoring system. Vibration monitoring system (VMS) constantly checks the performance of safety-critical components, provides warnings in advance of potential equipment failures and collects valuable data for routine maintenance of the helicopters.