查看更多>>摘要：A preliminary assessment is presented of the required lower landing minima (LLM) capabilities needed to support the Small Aircraft Transportation System (SATS) Program. The goal of this analysis is to understand the number of potentially challenged SATS airports and to identify methods to remove obstacles by using technology solutions. Four obstacle removal methods are considered to assess the challenges faced by the SATS Program in providing LLM capabilities to 3,416 U.S. airports. Two views of runway obstacle analysis are presented: a critical object analysis and a detailed multiobject analysis that includes terrain information. A comparison is made between decision altitudes (DAs) derived by approach lighting infrastructure and glide path angle thresholds and DA values considering other airport characteristics such as terrain. A detailed case study is presented to compare the single critical object analysis with the more detailed multiobject analysis, which was performed for Blacksburg Airport, in Virginia.
查看更多>>摘要：Passenger flow is an important planning factor in an air transportation system. However, forecasting segment (link) and airport flows becomes more complicated in a hub-and-spoke system since segment flows are the aggregations of route flows, and the number of routes increases with hubbing activities. This research develops an equilibrium model considering certain important characteristics of an air transportation system such as distance, airport delay, airline competition, and networks to predict segment and airport passenger flows from the viewpoint of the whole system. The major features of the model include (a) treatment of segment flows and airport delays as endogenous by considering the feedback of assigned segment flows and their impacts on airports; (b) reflecting the flexibility of air networks, a start with all links between all airports as the potential network and determination of the predicted network according to the equilibrium flows on segments; and (c) connection of key elements of the system so that it can evaluate the system impacts of some element changes. The model is demonstrated by applying it to the National Airspace System of the United States. Several characteristics of the model are also investigated. In addition, a policy experiment shows that improvement of an airport not only affects the airport itself but also changes the flows and performance of other airports—the model can be a tool for evaluating systemwide effects. Finally, the model's limitations and possible remedies are discussed.
查看更多>>摘要：The application of a mixed logit approach using stated-preference survey data to the development of itinerary choice models is described. The models include the effects on itinerary choices of airline, airport, aircraft type, fare, access time, flight time, scheduled arrival time, and on-time performance. The empirical results demonstrate the importance of explicitly accounting for traveler preference heterogeneities by using segmentation by trip purpose, interaction effects involving frequent flier status, and random parameter specifications. Explicitly including preference heterogeneity by using the mixed logit specification results in significant statistical improvements and important coefficient differences as compared with using a standard fixed-parameter logit model. The calculated marginal rates of substitution show the relative importance that travelers assign to key service variations among itineraries. All service features that were included in the model had significant values to travelers, and the values were affected, as would be expected, by the traveler's frequent flier status. Although current reservation and ticketing services provide information to prospective travelers on most of these itinerary features, most services do not report on-time performance, which, however, can be an important selection criterion for travelers.
查看更多>>摘要：A mixed multinomial logit model for analyzing choice of departure airport in a multiple-airport system (MAS) is presented. The model aims to capture random taste variations across passengers in response to airport level of service through a set of random coefficients. A case study is carried out for the Baltimore, Maryland-Washington, D.C., MAS. The 1998 Air Passenger Survey database is used to estimate the model. The results indicate significant taste variations in response to flight frequency and airline fare even within smaller segments by both trip purpose and residency status. Analyses of the model provide several insightful results, such as distribution of perceived level of service and time value. In addition, the model is used to simulate the impact of interesting scenarios on market share. Substantial policy implications for airport management are also provided.
查看更多>>摘要：The findings from a disaggregate analysis of the choice of airport, airline, and access mode for business travelers living in the San Francisco Bay Area, California, are presented. Aside from formulation of the multidimensional choice process, the main objective is to explore random taste heterogeneity among decision makers in their evaluation of the attractiveness of the different alternatives. The results indicate that this heterogeneity is present in tastes relating to in-vehicle access time, access cost, and flight frequency. Accounting for this heterogeneity leads to gains in model fit but, more important, leads to important insights into the differences in behavior across decision makers and avoids the bias introduced into trade-offs when fixed coefficients are used in the presence of significant levels of heterogeneity. In terms of substantive results, the models also reveal a significant impact of changes in out-of-vehicle access time, indicate a preference for service on jet over turboprop flights, and show that experience plays an important role in air travel choice behavior.
查看更多>>摘要：Common wisdom is that airplanes make money only when they are in the air. Therefore, turnaround time (turn time) on the ground should be reduced as much as possible. An important contribution to the turn time is airplane boarding time. Many different schemes are in use, from random seat selection to sophisticated boarding groups. A simulation model is described to evaluate different boarding strategies. In contrast to earlier work, it puts special emphasis on disturbances, such as a certain number of passengers not following their boarding group but boarding earlier or later. A surprising result of this work is that the typical back-to-front boarding strategy becomes improved when passengers do not board with their assigned group. Other proposed strategies still consist of small numbers of boarding groups but are both faster and more robust with regard to disturbances.
查看更多>>摘要：Stated preference (SP) analysis is a technique widely used by market research and transportation professionals to understand decision-making behavior and consumer choice models. This discussion covers the role of SP as a tool to enhance understanding of air travelers' preferences and priorities for airline services and the potential for SP research to play a greater role in product development and demand forecasting for different types of airline services. Two case studies of previously conducted research for a major airline in Asia are used to explore how SP data have been used to evaluate passenger preferences and priorities. SP experience gained from other transportation modes (e.g., urban rail and bus services) is also examined and the potential applications of these lessons to the airline industry are suggested.
查看更多>>摘要：The objective of this paper is to present the findings and a set of hypotheses that emerged in the initial steps of an assessment study of air traffic controllers' adoption and adaptation of new technologies, with the user request evaluation tool (URET) as a case study. The hypotheses are the basis for further study on this topic. The importance of this investigation is to provide a better understanding of changes brought about by the use of decision support tools by sector controller teams. The main purpose of URET is to support sector team strategic planning and allow controllers to concentrate on more user-beneficial control actions. Actual improvements depend on the way controllers use the automation tools in their work. Three aspects were noted about URET usage: (a) different sector teams use it in different ways, (b) in many instances URET usage differs from what was intended, and (c) usage varies across centers. Subject matter experts were interviewed to explore how controllers have adopted and adapted URET across the mentioned variations. The goal of this research is to draw lessons from the experience with URET that can inform technology deployments in the future.
查看更多>>摘要：Existing literature suggests that analyses of landing time intervals employ simple statistical models based on time-separation histograms, usually approximated by normal distributions. Although the literature focuses on important issues such as safety, capacity improvements, and separation rules, it does not take into account another important issue: the possible, unique behavior of airlines, pilots, and controllers. In this study such possible, unique behavior is taken into account and a statistical analysis on landing time intervals is performed to find the operational properties of Los Angeles International Airport (LAX), California. On the basis of the properties found, operations of a dominant airline at LAX are compared with those of other airlines by using the Performance Data Analysis and Reporting System (PDARS) database. The PDARS database allows the calculation of landing time intervals on a runway level. A new mathematical model is constructed to fit the probability distribution of landing time intervals, and it is found that the proposed model has the best maximum log likelihood estimations compared with those of existing models. The results also reveal that the behavior of the dominant airline differs from that of the other airlines. The proposed model better approximates the shape of the probability distribution, especially the left-hand side, which usually contains information of greater importance regarding airport operations and especially regarding safety, since all smaller landing time intervals and the landing intervals that fail the safety requirements are concentrated in this part of the probability distribution curve.
查看更多>>摘要：Fleet assignment and aircraft routing are two sequential steps in airline capacity planning. The fleet assignment model allots the scheduled flights covered by a type of aircraft on the basis of aircraft availability, and the aircraft routing model generates a route for each particular aircraft to ensure that the path-specific requirements for maintenance and connection times are satisfied. Although it is known that the sequential method is not able to minimize the overall cost, no results have been reported on the integration of the two steps. Here these two steps are completed simultaneously. A path-based integrated model is presented and tested on real data. A heuristic is proposed to solve the formulation. The numerical test indicates that a significant cost saving can be achieved and that the heuristic shows encouraging promise in solving large-scale real-world problems.
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