Flight Characteristics Of Aircraft Research Articles

항공기 비행특성 확인을 위한 다자유도 가상비행 및 자유비행 풍동실험 시스템 개발

항공기 개발 과정에서 비행제어시스템(FCS, Flight Control System)을 개발하고 검증하는 것은 매우 중요하며 장기간에 걸쳐 진행된다. 특히 항공기가 불안정한 특성이 발생될 수 있는 고받음각 상황에서 조종상실과 회복 과정 중 비행제어시스템의 정상적인 동작 여부의 검증은 비행시험 단계에서 비행시험의 위험성과 비용을 크게 감소시킬 수 있다. 그러나 비행시험 없이 실제 비행환경을 모사하여 동적 실험을 수행하고 비행제어시스템을 검증할 수 있는 시스템을 구성하는 것은 매우 어렵다. 공군사관학교 아음속 풍동실험실에서는 실제 비행환경과 매우 유사한 환경에서 동적특성을 파악할 수 있는 풍동실험 시스템을 구축하였다. 3자유도 짐벌과 리그를 개발하여 다자유도 가상비행(VFT, Virtual Flight Test) 풍동실험을 가능하게 하였고, 기존 폐회로 풍동 측정부를 개방형으로 개조하여 자유비행 풍동실험을 수행하였으며, 이를 통해 항공기 비행특성을 확인하고 비행제어시스템을 검증하였다.

Development of methods for statistical modeling of air traffic demonstrated through a Winnipeg-area case study

The integration of remotely piloted aircraft systems (RPAS) into shared airspace requires a thorough risk analysis. Specific operations risk assessment (SORA) is a widely adopted approach by international civil aviation authorities to guide RPAS operators in evaluating risks associated with their mission. A critical step in the SORA process is analyzing the airspace where the operation will take place, which requires knowledge of the intruder aircraft's flight characteristics as well as the airspace model. This paper proposes a methodology for developing a statistical airspace model using historical aircraft track data collected in the Winnipeg Manitoba Flight Information Region. The developed methods include data cleaning routines, Kalman filters for track smoothing, and Bayesian networks for synthetic track generation, following an approach similar to that employed by the Massachusetts Institute of Technology Lincoln Lab. Additionally, the developed methodology allows for the analysis of specific models by altitude or aircraft type. The methods presented were subsequently adjusted for a comprehensive analysis spanning across Canada's diverse airspace. The initial statistical model, derived from Canada-wide data, is currently accessible to the public via the National Research Council's GitHub repository [ https://github.com/nrc-cnrc/Canadian-Airspace-Models ].

Evaluation of the effectiveness of the use of hydrocarbon liquid fuels synthesized from natural gas in transport aviation with gas turbine engines

The methodic and mathematical models used to assess the effectiveness of the use of synthetic liquid aviation fuels (SLF) from natural gas in the "aircraft—power plant—fuel" system are presented. The flight performance (FP) of the Il-76TD and An-124 airplanes was investigated, taking into account the effect of replacing aviation kerosene with SLF. It has been shown that the flight characteristics of aircraft powered by SLF are not inferior to the flight characteristics of aircraft powered by aviation kerosene. At the same time, the fuel effectiveness of aircraft powered by synthetic fuels is better, and in terms of environmental performance they are not inferior to aircraft powered by aviation kerosene. Keywords: synthetic fuel, mathematical model, power plant, flight performance, payload, fuel effectiveness, CO2 emission. kaf101@mai.ru, raznoschikov@ciam.ru, maria_yanovskaya@mail.ru

Econometric modeling of cost per flying hour of civil helicopters

Subject. The article addresses factors of the growing cost of flying hour, which is an integral indicator of helicopter efficiency at the stage of its operation. Objectives. The purpose is to develop an econometric model of dependence of cost per flying hour on the main relative aircraft performance characteristics that determine the effectiveness of design and technological solutions for civil and multi-purpose helicopters, to make a decision at the preliminary design stage regarding the efficiency of designed product during the operational phase and the feasibility of R&D. Methods. The study rests on basic provisions of the theory of the firm, the theory of fundamental value of assets, international standards of the aviation equipment operation manual. Results. Based on econometric analysis, the main determinants of cost per flight hour are identified from the set of relative flight characteristics of the helicopter. The paper demonstrates that the number of products in operation, the cost of flight hour, the efficiency and transparency of logistics infrastructure in the provision of maintenance services represent a tool for managing the cost of product life cycle during its operation. Conclusions. The main factors having the greatest impact on the efficiency of after-sales service of products in the aviation industry are fuel efficiency, specific fuel consumption (fuel consumption per unit of power). The cost per flight hour is an integral indicator of the effectiveness of after-sales service and depends on relative flight characteristics of aircraft in operation.

Estimation of Vertical Take-off Unmanned Aircraft Flight Characteristics and Algorithm of Required Roll Angle Calculating for Trajectory Tracking

Estimation of Vertical Take-off Unmanned Aircraft Flight Characteristics and Algorithm of Required Roll Angle Calculating for Trajectory Tracking

Experimental Characterization of a Propulsion System for Multi-rotor UAVs

The propulsion system of a multi-rotor UAV plays a fundamental role in the aircraft flight characteristics. In fact, it generally represents the major contributor to the aerodynamic forces acting on the vehicle. While several approaches for modeling rotor thrust and drag forces exist, the problem of identifying the parameters for these models is still challenging. In this paper we propose a systematic method for identifying a limited number of parameters which guarantee accurate thrust and drag prediction according to Blade Element Theory (BET). Simple experimental tests employing a popular rotor system and a custom-made quadrotor are used both in the identification phase and for the final validation. The discussion of the results illustrates the accuracy of the method, while highlighting the modeling limit of BET. A refinement using Blade Element Momentum Theory is proposed and validated with the support of experimental data.

Multi-objective optimization of high altitude sector operation based on environmental protection

The emission and contrail of flights at high altitude sector have a great impact on the environment. The paper establishes the multi-objective optimization method of high altitude sector operation based on environmental protection, which can reduce the impact of sector air traffic operation on the environment and enhance the operation efficiency of the high altitude sector. According to the operation characteristics of the sector, the aviation meteorological data of the sector are analyzed, and the forming conditions of the contrail are calculated. Considering the air traffic control rules and aircraft flight characteristics, a multi-objective optimization model of sector flight allocation strategy is established, and the influence of aviation meteorological conditions and different allocation strategy combinations on the optimal operation of sector is analyzed. To solve the multi-objective optimization model, the paper uses an evolutionary computation method in intelligence computing and takes non-dominated sorted genetic algorithm-II with elitist strategy (NSGA-II). Shanghai Area No.20 sector (ZSSSAR20) is selected as the case in this paper. Example verification reveals that taking number of contrails, fuel consumption and flight delays as the optimization targets, aircraft are more likely to rely on altitude deployment strategy so as to better reduce the impact of air traffic operation en route on environment, and improve sector operation efficiency en route.

Методические аспекты проведения исследований по нормированию пилотажных характеристик самолетов: применение шкалы пилотажных оценок

Статья посвящена одному из обязательных инструментов исследователя пилотажных свойств самолета – шкале пилотажных оценок самолета. В ней на основе критического анализа существующих зарубежных и отечественных шкал пилотажных оценок самолетов, опыта проведения исследований с их применением в натурных экспериментах предложена пятибалльная шкала качественной оценки пилотажных характеристик самолетов, которая может быть использована при исследованиях по оценке влияния параметров динамики самолета на качество его пилотирования летчиком и их нормирования.

Special Issue on Autonomous Flying Robot

Research on unmanned aerial vehicles (UAVs) has been conducted for quite some time, even though experiments were rather difficult to carry out. However, recent years have seen a proliferation of published reports in this field. This is most likely due to the spread of multicopters, which are easier and safer to operate than fixed-wing aircraft and single-rotor helicopters. Other factors that have made it easier to conduct research on UAVs and thus contributed to the increased number of studies include the wide availability of high-performance flight controllers that are either low cost or offered on an open-source basis, such as ArduPilot and MultiWii. Although this has minimized technological hurdles in conducting research, it has become more difficult to conduct research safely in a social and legal context. Prompted by a 2015 drone incident, Japan’s civil aeronautics law was revised to control UAV flights under stricter regulations. Even so, these regulations are still considered less restrictive than those in most other countries. UAV research includes obvious risks and dangers of operating airborne devices, but also makes it more interesting as a scientific inquiry, generates high expectations about practical utility, and makes a highly significant area of investigation. Placing a high priority on safety will hopefully lead to further research in this area. This special issue covers the latest in UAV research, including <ul> <li> • UAV control system design, </li> <li> • Studies on flight characteristics of aircraft equipped with special mechanisms, </li> <li> • UAV applications, </li> <li> • Studies on operational UAVs. </li> </ul> Readers will find it interesting and rewarding to explore the latest UAV research trends presented in this issue.

Parameter Identification of Tailplane Iced Aircraft Based on Maximum Likelihood Method

Based on the maximum likelihood method, this paper analyzed the influence of tailplane icing on aerodynamic parameters by parameter identification. A nonlinear longitudinal flight dynamics model for aircraft was built, and an identification system was constructed using maximum likelihood method. According to the flight test data of DHC-6 aircraft, the aerodynamic parameters of clean aircraft and two different cases of iced aircraft with particular ice shapes on the tailplane were identified. Eventually, the results of the identification show that the tailplane icing has several adverse effects on the aircraft flight characteristics, including flight performance, elevator effectiveness, stability and safety.

Calibration methods in small-scale and field measurements of ladar characteristics of aircraft on unobstructed paths

We propose a method for small-scale experimental studies of the ladar characteristics of objects using a stationary land-based laser test bench, based on calibration of signals by employing adaptive specular/diffuse reference standards. We describe methods for field measurements of ladar characteristics of aircraft in flight by laser tracking systems for direct detection and heterodyne detection of the reflected signal, with the help of airborne reference standards and a moving object simulator.

Design calculation of superlight piston-engined aircraft flight characteristics

Algorithms for determining fixed-pitch propeller parameters and some flight characteristics of a superlight aircraft at the early stage of designing are described.

Aircraft flight characteristics in conditions of windshear and icing

AbstractComplex weather conditions, especially windshear and icing encounter, have severe effects on aircraft flight safety. The effect of low-altitude windshear and ice accretion on aircraft performance and control has been studied in this paper. With the employment of a windshear model and nonlinear inverse dynamics (NID) method, a low-altitude windshear penetration flight control law is designed. The effect of ice accretion was modeled on the stability and control of an aircraft. Several icing parameters are imported to the small disturbance flight dynamics model to calculate the change of performance, stability and control derivatives between clean and iced aircraft. These derivatives were used to calculate the elevator, the aileron and the rudder step responses to investigate the icing effect.The simulation results indicate that the NID control logic works effectively in the trajectory control of the aircraft during the penetration of windshear. The method used to study the effect of ice accretion on aircraft is valid and it can provide data for real-time calculation for icing encounter.

Digital Flight: The Last CFD Aeronautical Grand Challenge

A case is made for a computational fluid dynamics (CFD) effort to predict aircraft flight characteristics, with a focus on stability and control. Problems in predicting stability and control are discussed. The state-of-the-art in CFD, as it relates to aircraft flight predictions, is reviewed. Problems affecting grid convergence studies are analyzed. The computer resources needed to address flight simulation problems are estimated. The status of critical technologies is briefly discussed.

Objective Analysis of Aircraft Data in Tropical Cyclones

A method for objective analysis of aircraft observations in tropical cyclones has been developed. Quasi-horizontal fields of motion, temperatures, mixing ratios, and D-values are analyzed using a modified version of the method of successive corrections. The weighting functions are specified so that the high degree of circular symmetry characteristic of tropical cyclones is incorporated in the analyses. The analyses are performed on a 25 by 25 Cartesian grid of 5 n mi spacing which is centered on the storm. A special feature is the analysis of vertical motions as determined from aircraft flight characteristics. Three Atlantic storms are analyzed in detail: Hurricanes Inez (1966), Debbie (1969), and Ginger (1971). The analyses show the significant larger-scale features and major asymmetries of these storms. Both Inez and Debbie, which were well organized hurricanes, display characteristic vertical motion patterns in which a ring of strong ascent is found immediately surrounding the eye, with marked descent just outside of the annulus of strong ascent. Maximum ascent and descent rates were each indicated to be a few meters per second in these storms. Ginger was a marginal hurricane with poorly organized eye structure and relatively weak and disorganized patterns of vertical motion.

GASP Simulation of Terminal Air Traffic System

The objective of this study was to develop a simulation model to effectively assist in planning air traffic control operations in the terminal area. The analysis applied unique concepts employing a discrete events simulation philosophy through the proven simulation language known as GASP. In pursuing this objective, the study included pertinent factors associated with actual air traffic operations such as interaction between approaches, aircraft flight characteristics, and landings and takeoffs. An attempt was made to indicate the applicability of the derived solution in such analyses as runway evaluation, system component evaluations, landing sequencing policies, and sensitivity studies. The modeling philosophy was that aircraft were ‘flown’ through the system by indexing them through three nodes—the holding stack, a point on final approach, and touchdown. The system operated on a time basis causing the arrival of an aircraft at a node only at the proper time, and assuring proper aircraft separation throughout the system in time.

A Method for Determining the Radiation Characteristics of Aircraft in Flight

Information on the basic characteristics of aircraft noise sources during flight requires that a methodology be established which can adequately determine total acoustic power, directivity, and frequency characteristics from sound pressure measurements. A procedure is presented for transposing from sound-pressure-time information received at a stationary ground point to information on the radiation characteristics of the moving source. Included are such physical mechanisms as propagation time lags, energy losses through a diverging sound field, atmospheric absorption losses, and Doppler shifts in frequency. A graphical approach is utilized wherever feasible to facilitate calculation. The method is equally applicable to cases where the microphone is in motion parallel to the axis of an axially symmetrical sound source at rest.

Army-Navy Precipitation-Static Project: Part V-The High-Voltage Characteristics of Aircraft in Flight

The important high-voltage electrical characteristics of aircraft in flight are determined from (a) flight operations in precipitation areas; (b) flight operations using a new artificial charger to electrify the airplane in flight; (c) high-voltage experiments on the airplane supported in a giant hangar; and (d) theoretical analysis. It is shown how the fundamental electrical constants of the airplane may be approximately determined and how these may be used to forecast the high-voltage behavior of a flying aircraft. It is shown that, at a given altitude, the current I discharged by an airplane in flight is of the form I = AE + B(E <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> -E <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) where E is the magnitude of the electric field as measured on the belly and A, B and E <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> are constants. The electrical capacitance of an aircraft in flight is about 20 per cent of the wing span expressed in centimeters.