National Air Transportation System Research Articles

Data-driven trajectory prediction with weather uncertainties: A Bayesian deep learning approach

Trajectory prediction is an essential component of the next generation national air transportation system. Reliable trajectory prediction models need to consider uncertainties coming from multiple sources. Environmental factor is one of the most significant reasons affecting trajectory prediction models and is the focus of this study. This paper propose an advanced Bayesian Deep Learning method for aircraft trajectory prediction considering weather impacts. A brief review of both deterministic and probabilistic trajectory prediction methods is given, with a specific focus on learning-based methods. Next, a deterministic trajectory prediction model with classical deep learning methods is proposed to handle both spatial and temporal information using a nested convolution neural network, recurrent neural network, and fully-connected neural network. Following this, the deterministic neural network model is extended to be a Bayesian deep learning model to consider uncertainties where the posterior distributions of parameters are estimated with variational inference for enhanced efficiency. Both mean prediction and confidence intervals are obtained giving the last on-file flight plans and weather data in the region. The proposed methodology is validated using air traffic and weather data from the Sherlock data warehouse. Data pre-processing procedures for big data analytics are discussed in detail. Demonstration and metrics-based validation are performed during severe convective weather conditions for several air traffic control centers. The results show a significant reduction in prediction variance. A comparison with existing methods is also performed. Several conclusions and future works are given based on the proposed study.

High Lift Device Modifications for Reducing Airport Noise - A Review

Aircraft noise has been one of the top environmental issues at and near airports across the country because of its negative impact on communities. The growth of the nation's air transportation system is restricted predominantly due to regulations on limiting aircraft noise generated around airports. Reducing aircraft noise will lead to wider community acceptance of new or larger airports, lower airline operating costs by reducing noise quota fees, and increase air traffic growth through operating more flights. One of the most significant contributors to aircraft noise, structural vibrations caused by air flow across its frame, are high lift devices. A review of high lift devices, such as flaps, and methods to reduce their noise levels will be presented. Solution reviews will focus on reducing flap trailing-edge scattering and flap side-edge vortices.

Using Risk-Based Security to Quantify the Number of Firearms Missed at Airport Security Checkpoints

The Transportation Security Administration (TSA) is responsible for protecting the nation's air transportation system. Risk-based security is a paradigm for aligning security resources (i.e., personnel, technology, and time) with security risks. PreCheck is one approach that the TSA uses to implement this strategy. Given that passengers enrolled in PreCheck undergo background checks and fingerprinting, they experience expedited screening at airport security checkpoints, with standard screening lanes dedicated to passengers not enrolled in PreCheck. This difference can favorably impact the TSA’s ability to detect threat items like firearms. This paper uses publicly available data on firearm detection, number of passengers screened, and the fraction of passenger screenings in PreCheck lanes to estimate the number of firearms missed at airport security checkpoints in the United States. To achieve this, it defines risky firearms as firearms carried by passengers not enrolled in PreCheck and assumes that only standard screening lanes are where such firearms are brought to checkpoints. Under this assumption, the number of risky firearms missed in the recent past is estimated, given more current risky firearm detection rates. This analysis suggests that increasing the number of PreCheck passenger screenings may reduce the number of undetected risky firearms passing through security checkpoints.

Modeling Crew Itineraries and Delays in the National Air Transportation System

We propose, optimize, and validate a methodological framework for estimating the extent of the crew-propagated delays and disruptions (CPDDs). We identify the factors that influence the extent of the CPDDs and incorporate them into a robust crew-scheduling model. We develop a fast heuristic approach for solving the inverse of this robust crew-scheduling problem to generate crew schedules that are similar to real-world crew-scheduling samples. We develop a sequence of exact and heuristic techniques to quickly solve the forward problem within a small optimality gap for network sizes that are among the largest in robust crew-scheduling literature. Computational results using four large real-world airline networks demonstrate that the crew schedules produced by our approach generate propagation patterns similar to those observed in the real world. Extensive out-of-sample validation tests indicate that the parameters calibrated for one network perform reasonably well for other networks. We provide new insights into the perceived trade-off between planned costs and delay costs as reflected by actual airline crew schedules. Finally, we present a general approach to estimate the CPDDs for any given network using our methodological framework under a variety of data availability scenarios. The online appendix is available at https://doi.org/10.1287/trsc.2018.0834 .

Modeling Probability Distributions of Primary Delays in the National Air Transportation System

Flight delays impose enormous costs that are exacerbated by propagation effects. Development and evaluation of advanced schedule planning approaches for mitigating propagated delays require primary delay distribution models with a long prediction horizon of several weeks to months. This paper presents a hybrid modeling approach combining logistic regression and quantile regression. Two large data sets, each consisting of approximately 6 million flights, were used as training and testing samples to identify types of factors affecting primary delay distributions. Several insights were obtained into the factors affecting delay distributions. Coefficient estimates were found to have a high statistical significance and intuitive interpretation of their signs and relative magnitudes. Results from model estimation, validation, and testing show that fit values are stable across data sets, avoiding overfitting. The relative explanatory power of various types of predictive factors—including distance factors, seasonality factors, time-of-day factors, airport factors, and airline factors—is quantified. A new method is provided for quantifying the fit of the joint model in the form of the log likelihood of the observed data, and the model provides a considerable improvement in log likelihood.

Теоретичні аспекти функціонування авіатранспортної системи України в умовах кризи

The article deals with theoretical aspects of air transport, characterized by major categories reflecting the territorial structure of the air transport system of Ukraine. The features of the structure of the air transport system, which are the Polystructural and linear-nodal character. Also in the paper focuses on the basic elements and backbone connections, providing a stable organization and functioning of the national air transportation system. The influence of macro-economic and socio-cultural factors on the activity of the air transport system today are destructive.

Modeling Passenger Travel and Delays in the National Air Transportation System

Many of the existing methods for evaluating an airline's on-time performance are based on flight-centric measures of delay. However, recent research has demonstrated that passenger delays depend on many factors in addition to flight delays. For instance, significant passenger delays result from flight cancellations and missed connections, which themselves depend on a significant number of factors. Unfortunately, lack of publicly available passenger travel data has made it difficult for researchers to explore the nature of these relationships. In this paper, we develop methodologies to model historical travel and delays for U.S. domestic passengers. We develop a multinomial logit model for estimating historical passenger travel and extend a previously developed greedy reaccommodation heuristic for estimating the resulting passenger delays. We report and analyze the estimated passenger delays for calendar year 2007, developing insights into factors that affect the performance of the National Air Transportation System in the United States.

Opportunities and Obstacles in Obtaining Air Connectivity for Residents of Federally Designated Essential Air Service Communities

The Essential Air Service (EAS) program was established in 1978 to guarantee air connectivity for residents of small communities to the national air transportation system. Currently, more than half of EAS communities are within 70 highway miles of another airport, leading to passenger leakage at EAS airports and rising program costs. Five case studies of EAS communities examine the reasons for local support of air service that is rarely used. The case studies present three main findings: (a) the EAS program is a gateway to the federal airport infrastructure funds of the Airport Improvement Program; (b) there is an information gap between the U.S. Department of Transportation and the EAS communities regarding the existing risky alternate programs; and (c) local politics and airport administrators' concern about their professional future sustains support for local air service. EAS communities in a multi-airport region, therefore, are most susceptible to passenger leakage and continue to struggle in the program. The obstacles also deter the establishment of transportation options that best fit communities and their residents. The study provides insights into policy changes that address the importance of small airports and rural air connectivity.

Expanding Regional Airport Usage to Accommodate Increased Air Traffic Demand

Small regional airports present an underutilized source of capacity in the national air transportation system. This study sought to determine whether a 50 percent increase in national operations can be achieved if demand growth at large hub airports is limited, as is current practice for a small number of airports in the United States. Instead, traffic levels were grown at the surrounding regional airports. This demand scenario for future air traffic was generated and used as input to a 24-hour simulation of the national airspace system. Results of the demand generation process and metrics predicting the simulation results are presented, in addition to the actual simulation results. The demand generation process showed that sufficient runway capacity exists at regional airports to offload a significant portion of traffic from hub airports. Predictive metrics forecast a large reduction of delays at most major airports when demand is shifted. The simulation results then show that offloading hub traffic can significantly reduce nation-wide delays.

Next Generation Air Transportation System: Data Communications

The Next Generation Air Transportation System (NextGen) is an ambitious enterprise that promises to transform the national air transportation system by 2025. One hallmark of NextGen is the use of data, instead of voice, communications. The Federal Aviation Administration (FAA) Planning and Operations Office (AJP-6), Concept Development & Validation group (AJP-66) has been working with government, industry, and academia leaders to test the efficiency, safety, and usability of data communications via human-in-the-loop and part task studies. This symposium includes a portion of the work conducted in this research program.

The law of airline subsidies and incentives in the USA: Recent developments and future outlook

The financial challenges facing the aviation industry have brought uncertainty about many routes flown by commercial carriers. Some carriers have ceased operating altogether, and legacy and low-cost carriers alike have eliminated low-yield and unprofitable routes. In some cases, service reductions have cut off communities entirely from the national air transportation system. One means of attracting and sustaining scheduled passenger service is to subsidise or incentivise those routes considered necessary or desirable by the local community but which may not be profitable for an air carrier. The system of permissible subsidies and incentives in the USA is highly fractured — legally, politically and practically. The federal government provides subsidies and air service development grants under a costly and controversial programme. State and local governments provide subsidies and support to airlines as an alternative or in addition to federal support. Airport operators are strictly prohibited from directly subsidising air carriers, and instead must rely on a complex and ill-defined suite of options for supporting and promoting scheduled passenger service. This paper summarises the state of the law on airline subsidies and incentives, and offers observations on the likely future of the various programmes and approaches. The paper specifically examines airport incentives, state and local government subsidies and incentives, federal subsidies under the Essential Air Service programme, and federal grants under the Small Community Air Service Development Program.

King County: A Case Study Model for Strategic Planning in College Aviation Learning

King County: A Case Study Model for Strategic Planning in College Aviation Learning

Air Travel Consumer Protection

The raison d'être for the national air transportation system (ATS) is the movement of passengers and cargo. Thus, passenger trip time performance is positively correlated with passenger satisfaction, airfare elasticity, and airline profits. Regulatory consumer information available to airline passengers provides measures of trip performance by using the percentage of on-time flights or on-time percentage (OTP) (e.g., 15-OTP metric). Researchers have shown that these flight-based metrics are poor proxies for passenger trip time performance. First, these metrics do not include the trip delays accrued by passengers rebooked because of canceled flights (which account for 40% of the overall passenger trip delays). Second, the metrics do not quantify the magnitude of the delay (only the likelihood) and thus fail to provide the consumer with a useful assessment of the impact of a delay (such as missed connections on next mode of transportation). A new consumer protection metric, expected value of passenger trip delay (EV-PTD), is described; it accounts for (a) canceled flights and (b) both the probability of delay and the magnitude of the delay. The EV-PTD for all 1,030 routes between 35 Operational Evolution Plan airports in 2005 ranged from 11.5 min (best) to 155 min (worst). The average route EV-PTD was 35 min. By treating passenger trip delay as a random variable it can be shown that the transportation process is not a fair game and that passengers and service providers (e.g., airlines, air traffic control, airports) cannot beat the system until the variance is significantly reduced. The implications of these results and the use of the EV-PTD metric by consumers for purchasing tickets and for consumer protection are discussed.

Impact of slot controls with a market-based allocation mechanism at San Francisco International Airport

This paper presents an empirical analysis of the possible impact of the application of slot controls as a demand-management measure at San Francisco International Airport (SFO). We examine the specific case of slot controls allocated with a market-based mechanism. The paper first describes the nature of the delay problem at SFO and how slot controls would work to manage demand, briefly reviewing their history in the US. We then describe the methodology used to analyze their potential impact given the assumption of a market-based allocation mechanism and present our findings on their predicted impacts on arrival delays and the nature and level of scheduled passenger air service at the airport. Finally, we present conclusions as to the overall potential of slot controls to alleviate delay at SFO and their non-delay consequences. The methods presented in the paper facilitate a detailed analysis of the incidence of the impact of slot controls on passengers, airlines and individual communities that depend on SFO for access to the national air transportation system.

Perspective on Our National Air Transportation System: Past, Present, and Future

This presentation contains a discussion of the reconfiguration of the route structure and growth of the U.S. air transportation system from 1970 to 2000. It highlights the evolution and importance of the regional airline industry in providing feeder service to hub airports and service to small- and medium-sized communities. It discusses the expected growth of the demand for air transportation during the period 2001 to 2011. It reviews the situation with respect to airport delay and the factors contributing to these delays and discusses the impact of both demand and capacity changes on airport delay. It contains an indication of recent initiatives to address airport terminal planning issues related to level of service. Finally, it presents a review of aviation security and the implications of the events of September 11 on the airlines and passengers.

The Airport and Airway Trust Fund: A Continuing Controversy

Despite calls for increased outlays from the Airport and Airway Trust Fund to help finance improvements in the nation's air transportation system, the fund's surplus continued to grow during the Reagan years. It becomes readily apparent, when the issues surrounding the trust fund and its surplus are analyzed, that placing the blame solely on deficit considerations is too simplistic. Instead, partisan politics, the congressional budget process, delays in technology development, and budget pressures are responsible for the growing surplus.

Improving Air Traffic Controller Training

In recent years, the nation's air transportation system has undergone a series of profound changes. One aspect of the system which has received some scrutiny is the role of the air traffic controllers and the need to increase the staffing of control facilities. This article examines the field of air traffic control and the characteristics necessary to work in the field. Then, using sound educational and training theory, suggests some ways that air traffic controller training may be improved.