Courtin, Christopher; Burton, Michael; Butler, Patrick; Yu, Alison; Vascik, Parker D.; Hansman, R. John
Electric Short Takeoff and Landing (eSTOL) vehicles are proposed as a path towards implementing an Urban Air Mobility (UAM) network that reduces critical vehicle certification risks and offers advantages in vehicle performance compared to the widely proposed Electric Vertical Takeoff and Landing (eVTOL) aircraft. An overview is given of the system constraints and key enabling technologies that must be incorporated into the design of the vehicle. The tradeoffs between vehicle performance and runway length are investigated using geometric programming, a robust optimization framework. Runway lengths as short as 100-300 ft are shown to be feasible, depending on the level of...
Chappelle, Christine A.; Li, Clement; Vascik, Parker D.; Hansman, R. John
Air Emergency Medical Service (Air EMS) provides unique and important medical trans- port capabilities to society. Air EMS can move patients or live organs more rapidly than surface modes over long distances or congested areas. Air EMS also provides unparalleled access to accident scenes in regions where surface transportation is compromised such as in the backcountry or during disaster scenarios. However, despite these unique capabilities, Air EMS is currently provided to only a small minority of the most critical medical cases. This is due to the high historical cost and risk of airborne operations. Air EMS costs are driven primarily...
Vascik, Parker; Hansman, R. John
The scalability of the current air traffic control system, the availability of aviation ground infrastructure, and the acceptability of aircraft noise to local communities have been identified as three key operational constraints that may limit the implementation or growth of Urban Air Mobility (UAM) systems. This paper identifies the primary mechanisms through which each constraint emerges to limit the number of UAM operations in an area (i.e. the scale of the service). Technical, ecosystem, or operational factors that influence each of the mechanisms are also identified. Interdependencies between the constraints are shown. Potential approaches to reduce constraint severity through adjustments...
Jensen, Luke L.; Hansman, R. John
Aircraft noise is a growing source of community concern around airports. Despite the introduction of quieter aircraft, increased precision of onboard guidance systems has resulted in new noise impacts driven by overflight frequency effects. Noise issues present a potential barrier to the continued rollout of advanced operational procedures in the US. This thesis presents a data-driven approach to simulating and communicating noise effects in the flight procedure development and modernization process, with input from multiple stakeholders with varying objectives that are technical, operational, and political in nature.
First, a system-level framework is introduced for developing novel noise-reducing arrival and departure flight...
Vascik, Parker; Hansman, R. John
This paper investigated three key operational constraints anticipated to impact On-Demand Mobility for Aviation markets in the Los Angeles basin including: community acceptance issues resulting from aircraft noise, the availability of takeoff and landing areas, and the scalability of operations under Air Traffic Control. The analysis provided insight into the nature of each of these constraints and potential approaches to their mitigation. First, existing ground infrastructure in Los Angeles that may support ODM Aviation operations was identified. A variety of proposed techniques to increase the geographic distribution and throughput capacity of ODM Aviation infrastructure were also evaluated. Second, ASDE-X radar...
Hansman, R. John; Vascik, Parker
On-Demand Mobility (ODM) for Aviation is an emerging concept that proposes to provide aircraft-based, point-to-point transportation to consumers within a metropolitan area. This paper explicitly identified key operational constraints facing ODM Aviation networks and assessed how new vehicles and technologies could mitigate or reduce the severity of these constraints. An exploratory case study was developed to evaluate hypothetical ODM Aviation services in Los Angeles and the greater Southern California region. Promising early adopter markets were identified based upon current commuting and wealth patterns. A concept of operations (ConOps) was proposed for twelve reference missions that serviced a representative subset of...
Hansman, R. John; Jensen, Luke; Thomas, Jacqueline; O’Neill, Greg; Yu, Alison
Recent developments in navigation and surveillance technology have enabled new high-precision approach and departure operational procedures using GPS and Required Navigation Performance (RNP) standards. These procedures have proven effective for reducing fuel consumption and streamlining some aspects of air traffic control. However, flight tracks that were previously dispersed over wide areas due to less precise navigation or ATC vectoring are more concentrated on specific published tracks with effects on underlying communities.
This study is an initial investigation to identify potential modifications to approach and departure procedures at Boston Logan International Airport (BOS) which would reduce community noise impact in areas which...
Cho, HongSeok, R. John Hansman
The aim of this paper is to understand how designs of the automated driving system influence the driver's automation use decisions, and to provide design recommendations for SAE level 2 or 3 automated driving systems that would promote appropriate decisions of the driver. A risk-based framework, "decision matrix" is developed to represent the driver's decisions in terms of two variables: 1) perceived reliability of the automation, and 2) perceived consequence of the automation's potential unreliable behavior. Each block of the matrix represents a level of the perceived risk and an accompanying automation use decision of the driver; 1) use, 2)...
Abel, Brandon; Hansman, R. John
Divergence is an inconsistency between the human’s system state awareness and the actual system state. This research investigated divergence potential in air traffic controllers and identified controller divergence causes and consequences. Based on this investigation, approaches to minimize controller divergence and its consequences were identified for current air traffic control systems and future systems where unmanned aircraft will be integrated.
Prior studies identified pilot divergence as a factor in several recent aircraft accidents and could be a factor for controllers. The future addition of unmanned aircraft in national airspace is a significant change which will affect the pilot and controller relationship...
Brenner, Morrisa A.; Hansman, R. John
Community opposition to the noise concentration from precise NextGen Performance-Based Navigation (PBN) aircraft arrival and departure procedures poses a significant threat to the future of these procedures in the U.S. National Airspace System. A substantial number of complaints concerning airport noise come from locations outside the 65dB Day-Night Level (DNL) contour considered the significant noise exposure threshold in U.S. federal regulation. This indicates that this threshold does not sufficiently capture areas that experience annoyance related to more concentrated, lower level overflight noise at distances farther from the airport. This thesis assesses the effectiveness by which different noise analysis methods capture...
Brooks, Callen; Hansman, R. John
The implementation of Performance Based Navigation (PBN) routes across the National Airspace System (NAS) has caused a significant concentration of flight tracks. This flight track concentration also creates a concentration of noise impacts on the communities surrounding airports, which has led to an increase in noise complaints at many airports that have implemented these routes. In order to understand these changes in noise, and to design procedures that could help mitigate any negative effects, it is important to have modeling tools capable of capturing the noise impacts of flight track variability. This thesis develops a model for this purpose. First,...
Required Navigation Performance (RNP) instrument procedures guarantee high levels of navigation precision through highly accurate navigation sources (e.g. GPS) and real-time monitoring of position estimation accuracy. In recent years, the Federal Aviation Administration (FAA) has developed and published public RNP approach procedures at airports across the country. These RNP procedures offer unique capabilities such as curved segments (radius-to-fix,
or RF legs), narrow containment areas, and constant descent profiles that are not seen combined in other categories of instrument approaches. Because of these capabilities, RNP approaches are regarded as highly flexible procedures that can be designed to meet specific stakeholder requirements (e.g....
Kolos-Lakatos, Tamas; Hansman, R. John
The air transportation industry continues to grow worldwide, but demand is often limited by available airspace and airport capacity. This thesis focuses on evaluating new air traffic procedures: specifically, new and emerging wake turbulence separation rules that could potentially increase runway capacity based on today’s knowledge of wake vortex turbulence and technological capabilities. While legacy wake separation rules establish aircraft-classes based on weight of aircraft, these new separation rules can define separation standards by considering other aircraft parameters and dynamic wind conditions.
A fast-time runway system model is developed for studying these wake separation rules,
using Monte-Carlo simulations, to provide accurate and...
Vascik, Parker; Hansman, R. John
On Demand Mobility (ODM) is an emerging transportation concept that leverages pervasive telecommunication connectivity to enable the real-time matching of consumers with transportation service providers. Having experienced rapid adoption in ground transportation markets, numerous entities are now investigating opportunities to provide aircraft-based ODM within metropolitan areas. Previous research efforts have focused primarily on the technical capabilities of novel electric propulsion aircraft and sought to characterize the market potential for these vehicles.
This thesis complements these initial efforts by adopting a broad view of anticipated aircraft-based ODM services to identify operational constraints and evaluate near and far-term mitigation opportunities. A systems-level analysis...
Thomas, Jacqueline; Hansman, R. John
Increasing concerns regarding aircraft noise has encouraged the push to reduce noise via operational adjustments. The objective here is thus to expand analysis capabilities to enable modeling of the impact on aircraft noise due to advanced operational approach procedures, such as delayed deceleration approaches and thrust cutback scheduling on takeoff, for both current and future aircraft designs. Current industry standard noise models rely on flight test data interpolation and do not fully capture noise impacts from airframe configuration or advanced operational techniques. This is critical for noise assessment because airframe noise becomes a significant factor relative to the low thrust...
Rabe, Matthew; Hansman, R. John
As an ever-greater share of our national military airborne resources transition from manned to unmanned aircraft (UA) the issues associated with unmanned aircraft operations become more and more important. This study seeks to understand the difficulties associated with controlling both the unmanned aircraft and an onboard video sensor.
Traditional unmanned aircraft involve multiple operators controlling multiple control displays that are often oriented on misaligned reference frames. One example unmanned aircraft mission includes a target described on a north-up reference frame, such as a map. The pilot plans a flight path, to this target, on a north-up map, but controls the aircraft...
Bachwich, Alexander; Wittman, Michael
The effects of “low-cost carriers” (LCCs) such as Southwest Airlines and JetBlue Airways on the competitive landscape of the U.S. airline industry have been thoroughly documented in the academic literature and the popular press. However, the more recent emergence of another distinct airline business model—the “ultra-low-cost carrier” (ULCC)—has received considerably less attention. By focusing on cost efficiencies and unbundled service offerings, the ULCCs have been able to undercut the fares of both traditional network and low-cost carriers in the markets they serve. In this paper, we conduct an analysis of ULCCs in the U.S. aviation industry and demonstrate how these...
Tran, Henry; Hansman, R. John
The North Atlantic Tracks represent one of the highest density international traffic regions in the world. Due to the lack of high-resolution radar coverage over this region, the tracks are subject to more restrictive operational constraints than flights over the continental U.S. Recent initiatives to increase surveillance over the North Atlantic has motivated studies on the total benefit potential for increased surveillance over the tracks. One of the benefits of increased surveillance is increased accessibility of optimal altitude and speed operations over the track system. For a sample of 4033 flights over 12 days from 2014-2015, a fuel burn analysis...
Silva, Sathya; Hansman, R. John
Divergence is defined in this thesis as an inconsistency between the human operator’s assumption of the system state and the actual state of the system, which is substantial enough to have consequential effects on the outcome of the situation. The purpose of this thesis is to explore the concept of divergence and develop a framework that can be used to identify the consequential causes of divergence in cases involving human-system interaction.
Many recent aircraft accidents involve divergence between the crew state assumption and the actual system state. As aircraft systems and automation become more complex, it’s possible that the consequential effects...
Yan, Chiwei; Vaze, Vikrant; Vanderboll, Allison; Barnhart, Cynthia
In this paper, we analyze the effectiveness of the 2010 Tarmac Delay Rule from a passenger - centric point of view. The Tarmac Delay Rule stipulates that aircraft lift-off, or an opportunity for passengers to deplane, must occur no later than three hours after the cabin door closure at the gate of the departure airport; and that an opportunity for passengers to deplane must occur no later than three hours after the touchdown at the arrival airport. The Tarmac Delay Rule aims to protect enplaned passengers on commercial aircraft from excessively long delays on the tarmac upon taxi-out or taxi-in,