Numerical method of static aeroelastic correction and jig-shape design for large airliners

In this paper,a coupled CFD-CSD method based on N-S equations is described for static aeroelastic correction and jig-shape design of large airliners.The wing structural flexibility matrix is analyzed by a finite element method with a double-beam model.The viscous multi-block structured grid is used in aerodynamic calculations.Flexibility matrix interpolation is fulfilled by use of a surface spline method.The load distributions on wing surface are evaluated by solving N-S equations with a parallel algorithm.A flexibility approach is employed to calculate the structural deformations.By successive iterations between steady aerodynamic forces and structural deformations,a coupled CFD-CSD method is achieved for the static aeroelastic correction and jig-shape design of a large airliner.The present method is applied to the static aeroelastic analysis and jig-shape design for a typical large airliner with engine nacelle and winglet.The numerical results indicate that calculations of static aeroelastic correction should employ tightly coupled CFD-CSD iterations,and that on a given cruise shape only one round of iterative design is needed to obtain the jig-shape meeting design requirements.

Investigation of lateral-directional aerodynamic parameters identification method for fly-by-wire passenger airliners

A new identification method is proposed to solve the problem of the influence on the loaded excitation signals brought by high feedback gain augmentation in lateral-directional aerodynamic parameters identification of fly-by-wire（FBW） passenger airliners. Taking for example an FBW passenger airliner model with directional relaxed-static-stability, through analysis of its signal energy distribution and airframe frequency response, a new method is proposed for signal type selection, signal parameters design, and the appropriate frequency relationship between the aileron and rudder excitation signals. A simulation validation is presented of the FBW passenger airliner＇s lateral-directional aerodynamic parameters identification. The validation result demonstrates that the designed signal can excite the lateral-directional motion mode of the FBW passenger airliner adequately and persistently. Meanwhile, the relative errors of aerodynamic parameters are less than 5%.

The Influence of Price Discrimination from Airports on the Route Development Behavior of Airlines

Given the prominence and magnitude of airport incentive schemes,it is surprising that literature hitherto remains silent as to their effectiveness.In this paper,the relationship between airport incentive schemes and the route development behavior of airlines is analyzed.Because of rare and often controversial findings in the extant literature regarding relevant influencing variables for attracting airlines at an airport,expert interviews are used as a complement to formulate testable hypotheses in this regard.A fixed effects regression model is used to test the hypotheses with a dataset that covers all seat capacity offered at the 22 largest German commercial airports in the week 46 from 2004 to 2011.It is found that incentives from primary choice,as well as secondary choice airports,have a significant influence on Low Cost Carriers.Furthermore,Low Cost Carriers,in general,do not leave any of both types of airports when the incentives cease.In the case of Network Carriers,no case is found where one joins a primary choice airport and receives an incentive.Insufficient data between Network Carriers and secondary choice airports in the time when incentives have ceased means that no statement can be given.

A panel data model to predict airline passenger volume

Airline passenger volume is an important reference for the implementation of aviation capacity and route adjustment plans.This paper explores the determinants of airline passenger volume and proposes a comprehensive panel data model for predicting volume.First,potential factors influencing airline passenger volume are analyzed from Geo-economic and service-related aspects.Second,the principal component analysis(PCA)is applied to identify key factors that impact the airline passenger volume of city pairs.Then the panel data model is estimated using 120 sets of data,which are a collection of observations for multiple subjects at multiple instances.Finally,the airline data from Chongqing to Shanghai,from 2003 to 2012,was used as a test case to verify the validity of the prediction model.Results show that railway and highway transportation assumed a certain proportion of passenger volumes,and total retail sales of consumer goods in the departure and arrival cities are significantly associated with airline passenger volume.According to the validity test results,the prediction accuracies of the model for 10 sets of data are all greater than 90%.The model performs better than a multivariate regression model,thus assisting airport operators decide which routes to adjust and which new routes to introduce.

Evaluating the Drivers of Airlines Profitability in Nigeria Domestic Network

A firm’s profitability is critical to its competitiveness and sustainability. This research looked at the elements that influence airline profitability in Nigeria. From 2005 to 2019, two airlines were picked, and their data were retrieved from Nigerian Civil Aviation Authority (NCAA). From estimated quarterly panel data using E-views 8 and SPSS 22, the overall findings of the regression study demonstrate that with ROA used as a proxy for profitability, the R-square is 83.6 per cent and 89.4 per cent, respectively for Aero contractors and Medview airline, representing 83.6 per cent and 89.4 per cent of the changes in profitability of the Aero contractors and Medview in the sample, respectively, could be explained by changes in the study’s independent variables, namely growth, liquidity, leverage, lease, tangibility, fuel cost and personnel cost. Besides the total of the explanatory variables, growth, leverage and tangibility are statically significant at a 5% level of significant Aero Contractors. Growth, leverage, leasing cost, fuel cost, and staff cost, on the other hand, are statistically significant at the 5% level of significance for Medview airlines. Profiteering, expansion, leverage, and tangibility are the primary activities of any airline firm. Lease cost, fuel cost, and staff cost show a statistically significant positive link with the profitability metric ROA. As a result, stakeholders of Nigerian airlines should prioritize profitability over other criteria in this study. Airline executives should do a comprehensive analysis of all potential elements impacting their company’s profitability in the literature, including aspects other than economic variables. According to the findings of this study, political issues account for a greater proportion of the reasons why airlines fail in Nigeria.

Grey Incidence Analysis Applied to Civil Aircraft Customization Process

The airlines need to select the optional equipment according to their individual development demands and the manufacture′s standard specification manual when purchasing a new airplane.For this customization process,the selection theory is mainly based on qualitative analysis and quantitative analysis.The grey incidence analysis(GIA)is used for modeling,which evaluates the correlations between optional equipment and airlines′individual demands.Meanwhile,the customization demands are quantitatively processed as different weights in evaluation index system with analytical hierarchy process.Then,the value of grey incidence degree is obtained which shows whether the optional equipment is on the purchasing list or not.Finally,two airlines′customization demands are applied in the example of aircraft cabin′s seats,so two different purchasing priorities and equipment installation lists can be obtained.The results and comparisons verify the reasonable of modeling,which provides an objective scheme of aircraft equipment selection.

Vulnerability of Regional Aviation Networks Based on DBSCAN and Complex Networks

To enhance the accuracy of performance analysis of regional airline network,this study applies complex network theory and Density-Based Spatial Clustering of Applications with Noise(DBSCAN)algorithm to investigate the topology of regional airline network,constructs node importance index system,and clusters 161 airport nodes of regional airline network.Besides,entropy power method and approximating ideal solution method(TOPSIS)is applied to comprehensively evaluate the importance of airport nodes and complete the classification of nodes and identification of key points;adopt network efficiency,maximum connectivity subgraph and network connectivity as vulnerability measurement indexes,and observe the changes of vulnerability indexes of key nodes under deliberate attacks and 137 nodes under random attacks.The results demonstrate that the decreasing trend of the maximum connectivity subgraph indicator is slower and the decreasing trend of the network efficiency and connectivity indicators is faster when the critical nodes of the regional airline network are deliberately attacked.Besides,the decreasing trend of the network efficiency indicator is faster and the decreasing trend of the maximum connectivity subgraph indicator is slower when the nodes of four different categories are randomly attacked.Finally,it is proposed to identify and focus on protecting critical nodes in order to better improve the security level of regional airline system.

A Comparative Study of Managing a Project Using Traditional Management Techniques and a Critical Chain Project Management Methodology in Aircraft Maintenance Field

Aircraft on ground or down-time for its maintenance is a clear loss in revenue for an airline operation. With never ending competition and growing operating costs of aircraft, airlines continuously need to explore opportunities to reduce the aircraft down-time in order to remain sustainable. Due to round the clock operation feature of scheduled airlines, aircraft maintenance operations are generally carried out using traditional management methodologies instead of considering it as a project. Though aircraft heavy maintenance checks consist of several major tasks that can last from few weeks to a year, the maintenance organisations do not adopt modern project management methodologies. Therefore, this paper models a heavy maintenance check of an Airbus aircraft as a typical project and adopts contemporary project management methodology to explore the possibility of reducing the downtime. To this end, a case study has been done at an aircraft maintenance company to analyse the potential of this project management method in aircraft maintenance industry.

Quantifying the Microeconomic and Macroeconomic Impact of the Recent Crude Oil Price Fluctuations

This study analyzed the potential impact of the increased oil volatility on the industries and the global economy. Specifically, it separated the oil price fluctuations into positive and negative components, and modeled the return of industry portfolios with them. Next, the sensitivity of the airline industry to oil price was investigated to gauge the effectiveness of their hedging strategies, with the hope that the methodology can be extended to other industries. In addition, this paper explored the macroeconomic impact of oil price movements by examining the benchmarks such as GDP and CPI.

Analysis of high-speed rail and airline transport cooperation in presence of non-purchase option

We study cooperation between the airline and high-speed rail(HSR) sectors by formulating their joint profit as a maximization problem using a multinomial logit choice model in a three-node setting. We allow the nonpurchase option as an outside option available to consumers. The demand for each choice is not only a function of the price but also the service quality, such as the total trip time, frequency of service, and ease of connecting from the hub to a nearby HSR station. As a result, the following findings are presented. First, regardless of the service quality of either sector and the non-purchase option,cooperation decreases the total volume of the domestic market of a country. Second, when the attractiveness of the outside option is high, the HSR and air sectors can prevent a large reduction in the total volume by cooperation in the connecting market. However, this is not the case in the domestic market. Third, if the non-purchase quality in the domestic market is high, then cooperation increases the social welfare of the whole market. If the non-purchase quality is low, then cooperation increases the welfare of the whole market only in cases where the number of potential customers in the connecting market is relatively large. We also show the effect of improving air–rail service quality on each market share and on the total profit.

An Improved Genetic Algorithm for Crew Pairing Optimization

Crew pairing is a sequence of flights beginning and ending at the same crewbase. Crew pairing planning is one of the primary processes in airline crew scheduling;it is also the primary cost-determining phase in airline crew scheduling. Optimizing crew pairings in an airline timetable helps minimize operational crew costs and maximize crew utilization. There are numerous restrictions that must be considered and just as many regulations that must be satisfied in crew pairing generation. The most important regulations—and the ones that make crew pairing planning a highly constrained optimization problem—are the the limits of the flight and the duty periods. Keeping these restrictions and regulations in mind, the main goal of the optimization is the generation of low cost sets of valid crew pairings which cover all flights in the airline’s timetable. For this research study, We examined studies about crew pairing optimization and used these previously existing methods of crew pairing to develop a new solution of the crew pairing problem using genetic algorithms. As part of the study we created a new genetic operator—called perturbation operator.Unlike traditional genetic algorithm implementations, this new perturbation operator provides much more stable results, an obvious increase in the convergence rate, and takes into account the existence of multiple crewbases.

Airline Partner Selection Optimization Based on an Improved QSI Model

This paper studies airline partner selection.The international airline operation involves considerable cooperations with other airlines at home and abroad.How to choose the most suitable partners is a realistic issue for Chinese airlines.In this paper the quality of service index(QSI)model is improved by applying more necessary indexes based on the analysis of large scale of data.A partner selection model is established to help airlines identify the best partner(s)in a scientific and effective way among potential candidates.Finally,real data from an airline company in China is applied to test the model.The outcome verify the effectiveness of the partner selection model proposed in this paper.The model can be helpful for selecting more suitable partners and increasing coordination value through cooperation with the partners.

Airline Alliance Revenue Distribution Considering Horizontal and Vertical Competition

Considering the existence of multi-level fares in the alliance,and the existence of horizontal competition and vertical competition at the same time,this paper intends to maximize the revenue of airline alliance and fairly distribute the revenue to member airlines.Firstly,a model is built under the centralized mechanism,in which all airlines in the alliance are regarded as a whole.By solving the model,the shadow price of each flight leg on the code-sharing route is gotten.It is used to calculate the proportion of the revenue distribution.Then,the centralized model is decomposed into the single airline model by the proportion.The seat allocation among airlines and distributed revenue can be gotten by solving the model.Three typical examples are designed to test it.The results show that,the model can effectively reflect the managerial principal of the airline alliance,that is maximizing total revenue and fairly distributing the revenue among member airlines.

Forecasting the Probability of Heat Related Failures in Powered Ground at an Equipment Major Airline

Ｆａｉｌｕｒｅｓ ｉｎ Ｐｏｗｅｒｅｄ Ｇｒｏｕｎｄ ａｔ ａｎ Ｅｑｕｉｐｍｅｎｔ Ｍａｊｏｒ ＡｉｒｌｉｎｅTXＭａｉｎｔｅｎａｎｃｅｉｓａｖｅｒｙｉｍｐｏｒｔａｎｔａｎｄｎｅｃｅｓａｒｙｆｕｎｃｔｉｏｎｉｎｍａｎｙｉｎｄｕｓｔｒｉｅｓ．Ｉｆｉｔｉ...

An Optimized Deep Learning Approach for Improving Airline Services

The aviation industry is one of the most competitive markets. Themost common approach for airline service providers is to improve passengersatisfaction. Passenger satisfaction in the aviation industry occurs whenpassengers’ expectations are met during flights. Airline service quality iscritical in attracting new passengers and retaining existing ones. It is crucialto identify passengers’ pain points and enhance their satisfaction with theservices offered. The airlines used a variety of techniques to improve servicequality. They used data analysis approaches to analyze the passenger pointdata. These solutions have focused simply on surveys;consequently, deeplearningapproaches have received insufficient attention. In this study, deepneural networks with the adaptive moment estimation Adam optimizationalgorithm were applied to enhance classification performance. In previousstudies, the quality of the dataset has been ignored. The proposed approachwas applied to the airline passenger satisfaction dataset from the Kagglerepository. It was validated by applying artificial neural networks (ANNs),random forests, and support vector machine techniques to the same dataset. Itwas compared with other research papers that used the same dataset and had asimilar problem. The experimental results showed that the proposed approachoutperformed previous studies. It has achieved an accuracy of 99.3%.

Economic analysis of spider web airline networks

The distinct network organization, management, service and operating characteristics of US Southwest Airlines are key elements of its success compared with other airlines. As a network organization type, the spider web airline network has received more attention. In this paper, we analyzed the relation between the spider web airline network and spider web, and the structure of spider web airline network, built the assignment model of the spider web airline network,and investigated the economics concerned.

A Dynamic Evolution Model of Airline Networks

Empirical data show that most of the degree distribution of airline networks assume a double power law. In this work, firstly, we assume cities as sites, flight between two cities as an edge between two sites, and build a dynamic evolution model for airline networks by improving the BA model, in which the conception of attractiveness plays a decisive role in the course of evolution of the networks. To this end, we discuss whether the attractiveness depends on the site label s or not separately, finally we obtain analytic degree distribution. As a result, if the attractiveness of a site is independent of the degree distribution of sites, which will follow the double power law, otherwise, it will be scale-free. Moreover, degree distribution depends on the parameters of the models, and some parameters aye more sensitive than others.

Impact of sustainability on financial distress in the air transport industry:the moderating effect of Asia–Pacific

The tremendous impact of the coronavirus pandemic on the global aviation industry has led to many cases of airline financial distress and bankruptcy.The Asia–Pacific region(APAC)contains more than half of the world’s population,and its airlines had the highest profit margin of any region.In this study,we investigate whether corporate sustainability practice can reduce the financial distress risk of air carriers,and,if so,what would the effect be in APAC?We first examine the relationship between environmental,social,and governance disclosure and the likelihood of financial distress of airlines as measured by the Altman Z″-score.Second,we analyze the moderating role of being an APAC airline in this relationship.The findings support the claim that implementing environmental actions may increase financial distress risk,and by improving social and governance activities,airlines can mitigate the risk of financial distress.The negative influence of the environmental pillar and the positive influence of the social pillar can be smaller for APAC airlines.Our study provides empirical evidence of the influence of environmental,social,and governance(ESG)on the likelihood of financial distress in the airline industry.Moreover,we analyze the moderating role of being an APAC airline in the relationship between sustainability and financial distress.This study has significant implications for executives,managers,and policymakers in the aviation industry on ESG strategy decisions and the general issue of sustainability.

Strategy-Based Forecasting Model for Civil Airlines

Airlines usually pay more attention to maintenance cost for efficiency improvement and consumption reduction. However, airlines, especially the domestic airlines, can hardly predict the cost exactly due to the uncertainty and complexity until now. In practice, the cost is calculated by collecting and calculating the invoices afterwards. To settle the problem, a maintenance cost forecasting model is proposed in this paper. Maintenance activities are classified into scheduled maintenance and unscheduled maintenance. Scheduled maintenance is periodic, in which the required materials and man-power hours can be obtained properly in advance. Nevertheless, it is impossible to acquire the necessary information of unscheduled maintenance. According to the specific characteristics of each, Activity-Based Costing (ABC) and Cost Estimating Relationships (CERs) are introduced to attack the building of forecasting models, respectively. Then practical cases, the 3C check of MD-90 and the engine shop visit are adopted to verify the cost forecasting models proposed. The results show that the models not only can predict the actual maintenance cost successfully, but also are helpful to drawing up the maintenance program and managing the maintenance funds efficiently.

China's Airline Industry

With the fast growth of China’s economy in the past dozen years, its airline industry has experienced a 20% average annual growth rate. By the end of 1994, the annual total mileage reached 6 million ton/km; the number of air routes jumped from 162 in 1978 to over 600; the number of transport aircraft stood at more than 300; and the maior flight force is up to the