Abstracts: 2014-2015


Data-Driven Modeling and Prediction of the Process for Selecting Runway Configurations

Jacob Avery and Hamsa Balakrishnan

Runway configuration is a key driver of airport capacity at any time. Several factors, such as wind speed and direction, visibility, traffic demand, air traffic controller workload, and the coordination of flows with neighboring airports, influence the selection of the runway configuration. This paper infers the utility functions of the nominal decision-making process of air traffic personnel by using a discrete choice modeling approach. Given operational and weather conditions that have already been reported, such as ceiling and visibility, traffic demand, and current runway configuration, the model produces a probabilistic forecast of the runway configuration on a 15-min horizon. The prediction is then extended to a more realistic 3-h planning horizon. Case studies for San Francisco (SFO), California; LaGuardia (LGA), New York; and Newark (EWR), New Jersey, airports were completed by using this approach. Given the weather and airport arrival demand, the model predicts the correct runway configuration at SFO, LGA, and EWR on a 3-h horizon with accuracies of 81.2%, 81.3%, and 77.8%, respectively.

Typology of Travelers Based on Their Annual Intercity Travel Patterns Developed from 2013 Longitudinal Survey of Overnight Travel

Benjamin Bacon and Jeffrey J. LaMondia

The ability to forecast and to plan pro- actively for intercity travel patterns is a critical topic for many metropolitan areas. This paper sets forth, for use in travel demand modeling, a new typology of travelers on the basis of their annual intercity travel patterns. The typology was developed by using the 2013 Longitudinal Survey of Overnight Travel, which provided a year’s data and addressed the non-routine nature of these long- distance trips. Annual summaries of intercity trips were compared, and travelers were categorized into six distinct segments by using the K-means cluster analysis. Each group clearly demonstrated a unique relationship with intercity travel and mode choices. A comparison of the typology with commonly used demographic variables highlighted the fact that such a characterization provided a deeper understanding of traveler preferences and biases than simply using demographics. The distribution of respondent demographics was relatively similar across each cluster and highlighted the need to consider factors beyond basic demographics when factors influencing long- distance travel decisions are being identified. This typology can significantly improve intercity demand models, either as an independent variable in disaggregate intercity travel demand models or as a region-level behavior-based characterization that provides meaningful contributions to the planning process. Specifically, the annual overnight intercity travel typology provides more information on travelers’ motivations and biases than other sociodemographic variables and thereby allows the model to be more responsive to policy and planning analyses and to provide more accurate forecasts.

Demonstration of the Possibilities of Using a Phased Microphone Array as the Next-Generation Airport Noise Monitoring System

Kanthasamy Chelliah, Ganesh Raman, Matthew R. Aldeman, and Hirenkumar J. Patel

Aircraft noise is a form of environmental noise pollution that is a cause for resident complaints, especially near larger airports. Noise monitoring is usually performed by placing single microphones at various locations in neighborhoods that are near air- ports. Single omnidirectional microphones, however, record every sound wave that is incident on the sensor. The sound amplitudes estimated by these single microphones include the contributions from environmental sources other than the aircraft, such as traffic noise, sirens, powered landscaping equipment, and barking dogs. Use of a phased array of microphone in combination with advanced beam-forming algorithms makes possible the selective monitoring of aircrafts’ localized sound amplitudes and thereby more accurately identifies aircraft-specific sound levels while minimizing the contributions from other sound sources. This paper demonstrates the noise source localization abilities of the phased-array sys- tem for the application of aircraft environmental noise monitoring.

Value of Extended Time-Based Metering for Optimized Profile Descent–Based Arrival Operations

Heng Chen and Senay Solak

As one of the key components of the implementation plan for the Next-Generation Air Transportation System, time-based metering delivers a more precise trajectory and has been shown to be more efficient than distance-based metering. In addition, by adding metering points upstream in en route space, extended time-based metering can help reduce flight trajectory deviations at metering points. With these advanced metering procedures, a well-designed metering configuration can improve the efficiency of arrival operations such as optimized profile descent (OPD). This paper aims to identify the optimal metering point configurations for OPD operations at air- ports on the basis of an extended time-based metering concept, as well as the value of such metering in OPD. To this end, the paper adapts a two-phase algorithmic framework to identify the number and locations of metering points under the extended time-based metering setup. Extensive numerical simulations based on OPD implementations at Atlanta (Georgia) International Airport are performed for different extended metering ranges and average arrival rates. Optimal time-based metering configurations are obtained for different extended metering ranges, and corresponding savings are provided. Marginal savings from additional metering ranges are shown to be decreasing, and it may not be value-adding to increase the extended ranges above a certain level. The results are further generalized to the top 10 major airports in the United States, and estimated savings attributable to optimization of extended time-based metering points are calculated to be around $33.4 million, an additional 14% improvement on fuel efficiency over current OPD operations. In addition, the value from usage of extended time-based metering is shown to be around $4.2 million for the top 10 major airports compared with the use of distance-based metering methods.

Resilience Analytics of a Future Supply Chain for Aviation Biofuels

Elizabeth B. Connelly and James H. Lambert

Capacity-building plans for transportation systems must be resilient to disruptions and erroneous assumptions to protect performance outcomes as well as schedule and cost. An example is the future supply chain of aviation biofuels for industry, government, and military applications. The challenges include balancing the aims and assumptions of diverse stakeholders, including regulators, agencies, manufacturers, airlines, fuel companies, and agricultural and husbandry producers. Resilience analytics of the strategic plans should characterize both the influential trends and stressors and the robust initiatives. This paper demonstrates resilience analytics to address varied, evolving, and potentially conflicting stakeholder preferences in the life cycle of supply chains for aviation biofuels. Heterogeneous feed- stocks can be converted to aviation biofuel, although several are more attractive across technological, environmental, and economic criteria. The choice of feed- stocks for conversion to biofuel depends on balancing desired outcomes, including life-cycle costs, avail- abilities, proximities, environmental impacts, and the like. Resilience analytics enables prioritization of feedstocks and other supply chain initiatives, with prioritization that varies by scenario. A technology road map for near- and midterm investment horizons to establish aviation biofuels is described. Poultry waste products are explored by using the above methods for a particular region in the mid-Atlantic area of the United States.

Synthesis of Remote Air Traffic Control System and Air Traffic Controllers’ Perceptions

Makarand Gawade and Yu Zhang

Airports face financial constraints in the use of services of air traffic control (ATC) towers. The remote air traffic control system (RATCS) is anticipated to be an economical and safe alternative to a control tower. RATCS is a concept intended to supply ATC to an airport by providing communication, navigation, and surveillance from a remote location.  This study aims to gain insights about RATCS by conducting a review of existing studies, airport visits, discussions with RATCS technology providers, RATCS demonstration visits, and questionnaire surveys and interviews of controllers. A major inference from non-towered airport visits is that the introduction of RATCS will present many challenges such as pilot readiness to be supervised by RATCS, differences in local conditions, and significant limitations in avail- able infrastructure. The knowledge gained through airport-demonstration visits and meetings with RATCS providers assisted in designing a questionnaire survey and interview. The number of surveys and interviews was limited; hence, conducting a comprehensive quantitative evaluation from responses was difficult. Nevertheless, controllers who participated in the study developed a consensus. The survey outcomes showed that controllers had concerns about RATCS functionality for communication or coordination between controllers and for ATC in high traffic conditions. The controllers provided favor- able responses toward new features of RATCS, such as infrared cameras, high-definition monitors, target tracking functionality, and runway overlays. Potential advantages of RATCS anticipated by some controllers include systems with replay capabilities, situational awareness capabilities in low-visibility conditions, and surveillance capabilities of ground operations.

Leveraging Worker Safety Perceptions to Promote Safe Performance in Airports: Investigating the Framing of Safety Standards and Worker Safety Construal

Jonathan E. Keeney and David A. Hofmann

Airports are complex systems characterized by unique and unpredictable safety challenges. Analyses of safety policies and practices focusing on organizational level (e.g., safety culture and climate) may overlook the importance of individual workers’ safety perceptions. The current research highlights two factors that play important roles in shaping these perceptions: the framing of safety standards and the level of abstraction with which workers conceptualize safety. From the perspective of the individual worker, operational safety is one of many workplace goals that must be balanced and prioritized. Workers are more likely to prioritize safety when safety standards are framed in negative (proscriptive) rather than positive (prescriptive) terms. Workers who tend to conceptualize safety in more abstract terms may prioritize safety appropriately when planning future behavior (i.e., during training) but give way to other considerations (e.g., schedule, cost) when faced with pressing decisions. Workers who view safety in very concrete terms, in contrast, are more attuned to the ethical implications of their choices (i.e., the potential for harm) and are therefore more likely to put safety considerations first. These arguments are supported by an empirical field study conducted in a large aviation services organization and shown to be robust to a variety of individual and organizational factors. Recommendations for airport managers indicate how these findings may be applied to enhance the efficacy of safety messages. Specifically, managers should present safety standards in negative terms; use vivid, concrete language when discussing safety; and continually reinforce the ethical implications of workplace safety.

Unaffordable Fare: Cost of Public Transportation for Low-Income Commuters Working at Chicago, Illinois, Midway International Airport

Carey Anne Nadeau

For airport employers, ensuring that the many low-income people employed as baggage handlers and retail salespeople, among others, can get to work ensures the continued efficient operations of the airport and the prosperity of the regional economy. However, high and increasing costs coupled with low wages make commutes unaffordable and constrain employees’ ability to get to their jobs. By using a case study of Chicago, Illinois, Midway International Airport, this research measures the extent to which low-income employees commuting to work at the airport by public transportation could afford their commute in 2011. The results of this analysis suggest that the cost of commuting on public transportation is beyond the means of a low- income budget. Furthermore, that fewer low-income commuters take public transportation as its afford- ability declines suggests that, although the avail- ability and timeliness of public transportation favor low-income commuters compared with all commuters on average, the cost of public transportation may play a role in determining whether low-income commuters choose to work at the airport. These results promote interventions to increase affordability and expand accessibility to public transportation for low-income commuters to the airport.

Opinion Survey to Reduce Uncertainty in Public and Stakeholder Perception of Unmanned Aircraft

Lauren Bowers Reddy and Daniel DeLaurentis

Although providing significant benefits compared with manned aircraft or ground systems, unmanned aircraft also introduce costs and risks. Because of the rapidly increasing number of unmanned aircraft operating in the United States, the air transportation community must develop a frame- work for maximizing the benefits and minimizing the costs and risks. Public opinion will inevitably shape this framework, but that community’s perception of how the public perceives unmanned aircraft is considerably uncertain. Thus, in this investigation, an opinion survey was administered to assess participants’ knowledge, attitude, and practices about unmanned aircraft. The survey was taken by 400 individuals representing the general public and 135 individuals representing key stakeholder groups. The survey responses illustrate the complexity of stakeholders’ and the general public’s opinions about unmanned aircraft. Most respondents reported that their support or opposition to unmanned aircraft is conditional. Risks, application, environment, and benefits all have a strong impact on support and opposition. A statistical analysis of several questions was completed with a multinomial logit model to determine whether certain demographic or stakeholder groups were more likely to hold a certain position. Some groups with consistent responses to all three questions were identified. In the general public, women were generally less supportive of unmanned aircraft than men, and respondents younger than 36 were more supportive than older respondents. Of the stakeholders, pilots and employees of the airline industry were less supportive. The statistical findings reduce the uncertainty of opinions about unmanned aircraft.

Quantifying the Effects of Uncertainty in a Decentralized National Airspace System

Stephanie Sherman, Leigh McCue, and Billy Roberts

Modernization of the National Air Traffic Control System is on the horizon and with it the likely introduction of autonomous air vehicles into the national airspace. With the increase in air traffic to an already congested management scheme, the implementation of a decentralized control protocol may be the answer to replace the current classical centralized management system. Equipping each air- craft with the information necessary to navigate safely through integrated airspace becomes an information- sharing problem: How much information about other aircraft is required for a pilot to fly the gamut of a heavily populated airspace safely? What paradigm shifts may be necessary for safe and efficient use of avail- able airspace? This paper describes the development of a tool for testing alternative traffic management systems—centralized and decentralized—in the presence of uncertainty. Applying a computational fluid dynamics–inspired approach to the problem both creates a simulation tool to model the movement of traffic within the airspace and allows study of the effects of interactions between vehicles. With incorporation of a model based on smoothed particle hydrodynamics, discrete particle aircraft each carry a set of unique deterministic and stochastic properties. With this model, aircraft interaction can be studied for better understanding of how variations in the nondeterministic properties of the system affect its overall efficiency and safety. The tool is structured to be sufficiently flexible to allow incorporation of different governing equations (right-of-way rules) for aircraft traffic management.

Examining Aviation Navigation Display Symbology in Visual Search

Navaneethan Sivagnanasundaram, Evan Palmer, and Alex Chaparro

This paper investigates properties of air traffic glyphs that may affect speed and accuracy when a navigation display is being searched. Four of these properties were explored: (a) the amount of information represented, (b) the number of aircraft displayed, (c) the amount of information accessed, and (d) the specific set of features representing the information. Two target detection experiments were conducted to measure speed and accuracy. Findings indicate that, generally, increases in the first three items negatively affect speed and accuracy. Further- more, graphical features tend to be identified faster and more accurately than text-based features.