Analysis of Factors for Incorporating User Preferences in Air Traffic Management: A system Perspective

This paper presents an analysis of factors that impact user flight schedules during air traffic congestion. In pre-departure flight planning, users file one route per flight, which often leads to increased delays, inefficient airspace utilization, and exclusion of user flight preferences. In this paper, first the idea of filing alternate routes and providing priorities on each of those routes is introduced. Then, the impact of varying planning interval and system imposed departure delay increment is discussed. The metrics of total delay and equity are used for analyzing the impact of these factors on increased traffic and on different users. The results are shown for four cases, with and without the optional routes and priority assignments. Results demonstrate that adding priorities to optional routes further improves system performance compared to filing one route per flight and using first-come first-served scheme. It was also observed that a two-hour planning interval with a five-minute system imposed departure delay increment results in highest delay reduction. The trend holds for a scenario with increased traffic

Evolution of a Simulation Testbed into an Operational Tool

This paper describes the evolution over a 20-year period of the Future ATM (Air Traffic Management) Concepts Evaluation Tool (FACET) from a National Airspace System (NAS) based simulation testbed into an operational tool. FACET was developed as a testbed for assessing futuristic ATM concepts, e.g., automated conflict detection and resolution. NAS Constraint Evaluation and Notification Tool (NASCENT) is an application, within FACET, for alerting airspace users of inefficiencies in flight operations and advising time- and fuel-saving reroutes.It is currently in use at American Airlines Integrated Operations Center in Fort Worth, TX. The concepts assessed,research conducted, and the operational capability developed, along with the NASA support and achievements are presented in this paper

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Analysis of Factors for Incorporating users Preferences in Air Traffic Management: A Users' Perspective

This paper presents an analysis of factors that impact user flight schedules during air traffic congestion. In pre-departure flight planning, users file one route per flight, which often leads to increased delays, inefficient airspace utilization, and exclusion of user flight preferences. In this paper, first the idea of filing alternate routes and providing priorities on each of those routes is introduced. Then, the impact of varying planning interval and system imposed departure delay increment is discussed. The metrics of total delay and equity are used for analyzing the impact of these factors on increased traffic and on different users. The results are shown for four cases, with and without the optional routes and priority assignments. Results demonstrate that adding priorities to optional routes further improves system performance compared to filing one route per flight and using first-come first-served scheme. It was also observed that a two-hour planning interval with a five-minute system imposed departure delay increment results in highest delay reduction. The trend holds for a scenario with increased traffic

Development of miles-in-trail passback restrictions for air traffic management

This paper presents modeling of miles-in-trail passback restrictions for use in air traffic management. Generally, FAA managers employ miles-in-trail as a traffic management initiative when downstream traffic congestion at airports or in sectors is anticipated. In order to successfully implement the miles-in-trail at airspace fixes or navigational aids, it is desired that restriction values be computed for passing back to upstream facilities at specific boundaries. This paper presents a model which can be used for that purpose. This model improves on a previous version using traffic manager feedback resulting in significant improvement in guidance. The modeling approach is described along with lessons learned and improvements made during model development. Results for two sample traffic and one real traffic scenarios are presented. Additional operational considerations required by the traffic managers to implement the passback restrictions, namely maximum ground delay and absorbable airborne delay are incorporated in the model. A main result of this research is that absorbing small amount of ground and airborne delays are sufficient to handle the imposed constraint. Another finding is that implementing the passback restrictions provides the traffic managers ways to alleviate traffic constraints to help reduce excessive airborne delay for current traffic conditions

Simulations of Credits Concept with User Input for Collaborative Air Traffic Management

This paper describes the procedure and outcome of a human-in-the-loop simulation experiment. The purpose of the simulation was to study feasibility of incorporating user flight preferences in air traffic demand and capacity management. Five airline dispatchers specified flight priorities for multiple routes. These priorities were used for airspace constraint management by creating a new credit ranked flight departure schedule. One air traffic manager prescribed and managed the airspace constraints. The dispatchers were trained on the system using different traffic scenarios. A realistic data set with convective weather was used for generating final results. Based on the experiment results, the credits concept allowed users to prioritize their flights and to distribute delays as per their preference. It was also observed that the delays could be reduced and better distributed among users with respect to a first-come-first served schedule, without violating airspace constraints. The study elicited several factors for prioritizing flights from the users’ perspective, which could be used in future fast-time simulations

Methods for Initial Allocation of Points in Flight Prioritization

Prior research has suggested that the allocation of scarce National Airspace System capacity could be improved if aircraft operators were able to exchange the priority in which their flights will be handled by the air traffic control system to reflect how much they value timeliness for specific aircraft flights. The current priority allocation system is based on a first-come first-served mechanism. FAA and users have made some modifications to firstcome first-served to give operators more control over the priority in which their own flights get served through Collaborative Decision-Making. There are also programs which allow a carrier to give up a flight time slot that it will not use without having to go to the “end of the line,” which is called slot credit substitution. Significant research has been done into ways to further improve demand-capacity balance in the National Airspace System while taking users’ flight priorities into account. Many researchers have proposed market-based allocation systems, which are used when airport slots are bought and sold. Other researchers propose quasi-market systems that could be developed using a points system. This paper illustrates how the initial allocation of priority points among carriers influences how they use these points in establishing the priority for their flights to reduce their delays. The paper then reports the results from the human-in-the-loop simulation of aircraft operators’ decisions that show how the delay reduction differences for each operator vary among the different methods used to allocate the points. In general, the paper finds that a system which uses the number of flights in the allocation tends to benefit operators of smaller aircraft, while systems that use passengers and distance in the allocation favor operators of larger aircraft