Aviation

Urban Air Mobility Research Challenges and Opportunities

Raja Sengupta
Bulusu, Vishwanath
Mballo, Chams Eddine
Onat, Emin Burak
Cao, Shangqing (Albert)
2025

This article reviews the literature on urban air mobility (UAM), examining both the research challenges it presents and the transformative opportunities that make these challenges worth addressing. While UAM has historical precedents, the current iteration is born of novel aircraft technology, primarily electric vertical takeoff and landing (eVTOL) and electric short takeoff and landing (eSTOL) aircraft. These advances raise new questions in aerodynamics, control, and integration with urban infrastructure. We explore several key research areas, including aircraft design, vertiport...

Economic Benefits of Increased En Route Sector Capacity from Controller-Pilot Data Link Communications

Bennett, Michael J.
Knorr, Dave
Jasenka Rakas
2004

The En Route Controller-Pilot Data Link Communications (CPDLC) program is designed to enable digital data communications between controllers and pilots. CPDLC Build 1A has been proposed as the first step in the nationwide rollout of this program to en route airspace by implementation in eight air route traffic control centers. Because CPDLC will automate several routine air-ground communications tasks, one potential benefit is reduced controller workload, which could lead to increased sector capacity and thus reduced flight times for flights traversing busy sectors. To quantify the...

User Request Evaluation Tool and Controller–Pilot Data Link Communications: Integration Benefits Assessment

Jasenka Rakas
Mark Hansen
Jirajaruporn, Wanjira
Bolic, Tatjana
2003

Explored are the benefits of integrating User Request Evaluation Tool (URET) and Controller-Pilot Data Link Communications (CPDLC). Controller-pilot voice-communication messages and aircraft traffic flows and conflicts are analyzed in great detail in one representative, URET-operating en route sector. On the basis of the mapped URET data and the real-world communication messages, a base case and two alternative scenarios were analyzed to estimate the number of clearances that are given to pilots to resolve aircraft conflicts a sufficient time before the start of the conflict, and to...

Controller-Pilot Radio Channel Utilization and Cognitive Issues

Bolic, Tatjana
Jasenka Rakas
Hansen, Mark
2005

This paper introduces a new metric, termed cognitive utilization, which tries to capture the percentage of time in which a controller has to “think” about certain aircraft. In that sense, cognitive utilization sums all the time intervals during which a specific communication “transaction” is underway. Voice-communication messages for fifteen 30-minute sector samples, and traffic count data are analyzed in order to determine whether cognitive utilization affects sector capacity. First, we investigate the relation between physical radio channel utilization and sector capacity, and then,...

Procedural and Operational Consequences of Navigational Equipment Outages: Exploration of Airport Performance

Jasenka Rakas
Yin, Huifang
Mark Hansen
2005

This paper explores the impact of unscheduled navigational and surveillance equipment outages on airport performance during visual flight rules and instrument flight rules at San Francisco International Airport and Phoenix Sky Harbor International Airport. The following most common unscheduled short outages, which occurred during January 2000–December 2002, are analyzed in detail: very high frequency omnidirectional range (VOR), approach lighting system type 2 (ALSF-2), the secondary radar Mode , and air traffic control radio beacon system (ATCRBS). We explore the air traffic control...

Deterministic Models for Degraded Airside Capacity and Delays

Jasenka Rakas
Schonfeld, Paul
2004

This paper presents deterministic models for estimating airspace and airport capacity and delays during equipment outages. The National Airspace System (NAS) is very complex and consists of almost 48,000 reportable facilities and services that support air traffic control with very diverse functions and technologies. To better understand NAS performance and develop a methodology for estimating degraded capacity, previous studies about equipment outages and about airspace and airport performance are first reviewed. A deterministic aircraft separation model is used to estimate degraded...

Does Periodic Maintenance Cause Unscheduled Outages?: Investigation of National Airspace System Equipment Outages

Berkeley, Emily
Jasenka Rakas
Handal, Jady
2006

It has been suspected for some time that unscheduled outages of National Airspace System equipment increase during core working hours; to date, however, no research has been done to determine their cause. First, aggregate trends in scheduled periodic maintenance (PM) activities and unscheduled outages are examined for calendar years 2000 through 2004. The reported increase in unscheduled outages is postulated to be due to increased levels of maintenance activities that may occur during this period. A detailed analysis is presented, and the individual pieces of equipment that suffer...

Statistical Modeling and Analysis of Landing Time Intervals: Case Study of Los Angeles International Airport, California

Jasenka Rakas
Yin, Huifang
2005

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...

Trends in Aircraft Sizing and Fleet Mix

Jasenka Rakas
2007

This paper analyzes current trends in aircraft characteristics and fleet mix and the implications of these trends on airport design. The airline industry is continuously exploring new ways of efficiently and economically operating their fleets in order to overcome the economic and financial pressures of a competitive operating environment. In response to these challenges, airlines are introducing aircraft into their fleets with lower fuel consumption and geometric characteristics to improve aircraft performance and efficiency. In the near future, the efficiency of gate operations and other...

Estimating Infrastructure Condition from a Biased Sample

Gupta, Gautam
Jasenka Rakas
Mark Hansen
2009

In this paper, we address the problem of making inferences about a population of infrastructure facilities from a subset that is a biased sample. We consider the case in which the sample is biased toward facilities in worse condition or requiring more expensive repair. Two methods are developed that incorporate a model of the process through which the sample is selected. One of the methods is based on well-known truncated distributions, whereas the other assumes that the bias operates continuously. The methods are applied to a class of facilities under the Federal Aviation...