Small Aircraft Transportation System Research Articles

Innovatively Saving the Future of Transportation: Small Aircraft Transportation System (SATS)

The aviation industry is a rapidly changing entity of the world s economy. Millions of travelers consistently choose aviation as their mode of transportation because it is reliable, time-efficient, and safe. However, high demand has led to delays, cancellations, and gridlock. As the need for efficient travel options increases, passengers will look for other avenues of travel. Fortuitously, the National Aeronautics and Space Administration (NASA) and its partners are developing a unique and innovative alternative to this problem. The solution, known as the Small Aircraft Transportation System (SATS), will likely change the face of general aviation (GA) as it is known today. It is a clear concept, made credible by extensive research. The members of the Public Administration Department and the Aviation Institute of the University of Nebraska at Omaha have committed many of their resources to the successful realization of the SATS concept. These individuals have formed a unique Nebraska SATS research team, devoting their valuable time and effort to seeing the dream of SATS come true.

Identification of application fields for electrical propulsion techniques and personal aerial vehicles

Electric flight is supposed to be the next step towards a more sustainable air transport, especially with respect to unmanned aircraft systems (UAS). However, to determine the revolutionary character of electric flight we have to compare it to aircrafts driven by fossil fuels with respect to their technical abilities. Technical properties determining potential application fields are assumed to be maximum range and maximum speed (travel time). To identify application fields and the competition within we, first, collected the technical properties of 197 vehicles of type personal aerial vehicle (PAV), helicopter, small aircraft transportation system (SAT) and business jets, and second, apply agglomerative hierarchical clustering and density-based spatial clustering of applications with noise (DBSCAN) using range and maximum speed. Electrical propulsion techniques are found to fall into the low range clusters and electrical and hybrid technologies dominate the very short ranges reaching up to 200 km. Though, helicopters are active in these ranges and superior regarding number of passengers plus maximum speed, they cannot compete with PAVs regarding costs, and even more important, environmental sustainability. In addition, the states of development of PAVs competing to helicopters with regard to range are still in scaled prototype or in concept phase. Thus, our findings underline the run for urban air mobility (UAM) as an application of electric propulsion techniques due to short ranges at slow speeds and the possibility of decreasing the environmental impact of mobility. Moreover, we cannot identify any competition of the new PAV technologies with classical aerial vehicles.

Towards Probabilistic Formal Analysis of SATS-Simultaneously Moving Aircraft (SATS-SMA)

The objective of NASA’s Small Aircraft Transportation System (SATS) Concept of Operations (ConOps) is to facilitate high volume operation of advanced small aircraft operating in non-towered, non-radar airports. This system can provide improved and accessible air travel at a lower cost. Given the safety-critical nature of SATS, its analysis accuracy is extremely important. However, the commonly used analysis techniques, like pilot/computer simulation and traditional model checking, do not ascertain an error-free and complete verification of SATS due to the wide range of possibilities involved in SATS or the inability to capture the randomized and unpredictable aspects of the SATS ConOps environment in their models. Another limitation of these studies is that a limited speed range was used in the analysis. To overcome these limitations, we propose to formulate the SATS ConOps as a fully synchronous and probabilistic model, i.e., SATS-SMA, that supports simultaneously moving aircraft. The distinguishing features of our work include the preservation of safety of aircraft while providing a precise timing model, which is closer to reality compared to the previous hybrid analyses. Important insights related to the aircraft take-off and landing operations during the instrument meteorological conditions are also presented.

Small Aircraft Transportation System, Higher Volume Operations Concept and Research Summary

The ability to conduct concurrent, multiple aircraft operations in poor weather at virtually any airport offers an important opportunity for a significant increase in the rate of flight operations, a major improvement in passenger convenience, and the potential to foster growth of operations at small airports. The Small Aircraft Transportation System (SATS), Higher Volume Operations (HVO) concept is designed to increase capacity at the 3400 nonradar, non-towered airports in the United States where operations are currently restricted to “one-in/one-out” procedural separation during low visibility or ceilings. The concept’s key feature is that pilots maintain their own separation from other aircraft using air-to-air datalink and on-board software within the Self-Controlled Area (SCA), an area of flight operations established during poor visibility and low ceilings around an airport without Air Traffic Control (ATC) services. While pilots self-separate within the SCA, an Airport Management Module (AMM) located at the airport assigns arriving pilots their sequence based on aircraft performance, position, winds, missed approach requirements, and ATC intent. The HVO design uses distributed decision-making, safe procedures, attempts to minimize pilot and controller workload, and integrates with today’s ATC environment. This paper summarizes the HVO concept and procedures, presents a summary of the research conducted and results, and outlines areas where future HVO research is required.

Concept Validation Experiment for Small Aircraft Transportation System Higher-Volume Operations

A human-in-the-loop simulation experiment was conducted at the NASA Langley Research Center's Air Traffic Operations Laboratory in an effort to comprehensively validate tools and procedures intended to enable the small aircraft transportation system higher-volume-operations concept of operations. These procedures were developed with the goal of increasing the rate of operations at nontowered, nonradar airports in near all-weather conditions. A key element of the new design is the establishment of a volume of airspace around designated airports at which pilots accept responsibility for self-separation. Flights operating at these airports are given approach-sequencing information computed by a ground-based automated system. The validation experiment was conducted to determine if a pilot could safely and proficiently fly an airplane while performing the newly developed procedures. Comparative measures of flight path error, perceived workload, and situation awareness were obtained for two types of simulated scenarios. Baseline scenarios were representative of today's system using procedure separation, in which air traffic control grants one approach or departure clearance at a time. Test scenarios represented the newly developed approach and departure procedures. Results from the experiment indicate that low-time pilots were able to fly the test procedures in a simulation environment and maintain self-separation as safely and proficiently as flying today's procedures.

Pilot Performance, Strategy, and Workload While Executing Approaches at Steep Angles and With Lower Landing Minima

We examined the willingness and ability of general aviation pilots to execute steep approaches in low-visibility conditions into nontowered airports. Executing steep approaches in poor weather is required for a proposed Small Aircraft Transportation System (SATS) that consists of small aircraft flying direct routes to a network of regional airports. Across two experiments, 17 pilots rated for Instrument Flight Rules at George Mason University or Virginia Tech flew a Cessna 172R simulator into Blacksburg, Virginia. Pilots were familiarized with the simulator and asked to fly approaches with either a 200- or 400-foot ceiling (at approach angles of 3 degrees, 5 degrees, and 7 degrees in the first experiment, 3 degrees and 6 degrees in the second). Pilots rated subjective workload and the simulator recorded flight parameters for each set of approaches. Approaches with a 5 degree approach angle produced safe landings with minimal deviations from normal descent control configurations and were rated as having a moderate level of workload. Approaches with 6 degree and 7 degree approach angles produced safe landings but high workload ratings. Pilots reduced power to control the speed of descent and flew the aircraft slightly above the glide path to gain time to control the landing. Although the 6 degree and 7 degree approaches may not be practical for routine approaches, they may be achievable in the event of an emergency. Further work using other aircraft flying under a wider variety of conditions is needed before implementing SATS-type flights into airports intended to supplant or complement commercial operations in larger airports.

Incorporating data link messaging into a multi-function display to support the Small Aircraft Transportation System (SATS) and the self-separation of general aviation aircraft

One objective of the Small Aircraft Transportation System (SATS) Project is to increase the capacity and utilization of small non-towered, non-radar equipped airports by transferring traffic management activities to an automated system and separation responsibilities to general aviation (GA) pilots. This paper describes the development of a research multi-function display (MFD) to support the interaction between pilots and an automated Airport Management Module (AMM). Preliminary results of simulation and flight tests indicate that adding the responsibility of monitoring other traffic for self-separation does not increase pilots’ subjective workload levels. Pilots preferred using the enhanced MFD to execute flight procedures, reporting improved situation awareness (SA) over conventional instrument flight rules (IFR) procedures.

Overview of the Small Aircraft Transportation System Project Four Enabling Operating Capabilities

It has become evident that our commercial air transportation system is reaching its peak in terms of capacity, with numerous delays in the system and the demand still steadily increasing. NASA, the Federal Aviation Administration, and the National Consortium for Aviation Mobility have partnered together to aid in increasing the mobility throughout the United States through the Small Aircraft Transportation System project This project has been a five-year effort to provide the technical and economic basis for further national investment and policy decisions to support a small aircraft transportation system. The project vision has been to enable people and goods to have the convenience of on-demand point-to-point travel, anywhere, anytime for both personal and business travel. The project has focused its efforts on four key operating capabilities that have addressed new emerging technologies, procedures, and concepts to pave the way for small aircraft to operate in near all-weather conditions at virtually any runway in the United States. The focus of this paper is to provide an overview of the technical and operational feasibility of the four operating capabilities and explain how they can enable a small aircraft transportation system.

Improving Aircraft Sequencing and Separation at a Small Aircraft Transportation System Airport

Ever-increasing traffic levels at the nation’s major airports have led to traffic congestion and flight delays. Capacity must be increased by building more airports at a great cost or by expanding services to some of the 4,500 airports not currently served by scheduled air carriers. A system must be developed to handle the increased traffic at these non-controlled airports, especially when instrument meteorological conditions prevail. Much work has been performed under the NASA Small Aircraft Transportation System program to determine the feasibility of aircraft operation under instrument flight rules in an air-traffic control free environment. This paper presents research, performed as an extension of the SATS program, into self-separation of general aviation aircraft in a self-controlled airport environment. The research focused on two specific areas: (1) improving automatic sequencing of aircraft of different speeds to make the airspace more efficient, saving time, fuel, and money, and (2) assisting the pilot with approach timing decisions to assure safe aircraft spacing while proceeding in an efficient manner. The primary evaluation method was a real-time distributed simulation with test cases performed by multiple pilots flying simultaneously in the simulation environment. Simulations and test scenarios were performed in the Engineering Flight Simulator, a modular, real-time, nonlinear, six degreeof-freedom fixed base simulator, at Texas A&M University. The pilots flew various general aviation aircraft with differing approach speeds under instrument meteorological conditions. Approach speeds ranged from 80 kts. to 140kts. to encompass the majority of aircraft from small trainers up to light jets that will use the potential SATS airports. New spacing rules were implemented to reduce holding times, and Total Holding Time was used as a metric to validate these new rules. Simulations were performed both with and without automated sequencing to validate the new spacing rules and compare the effects of automated sequencing. A human factors analysis was performed to determine the benefits of shifting some spacing functions from the pilot to the onboard systems, and reductions in pilot workload and improvements in pilot performance were measured to assess the safety improvements due to the increased automation. Based on the results presented in the paper, it was concluded that by changing the sequencing procedure to assign airspace entries once the aircraft are closer to the airport, potential bottlenecks can be avoided and holding times reduced. Furthermore, as a result of the increased avionics functionality and a change in approach spacing guidelines, safety is improved, and holding times are reduced. With these two improvements combined, significant holding time reductions are achieved resulting in fuel and cost savings and further make the self-controlled airport a safe and viable transportation alternative.

Small Aircraft Transportation System Higher Volume Operations Flight Experiment

This paper summarizes findings from the Small Aircraft Transportation System Higher Volume Operations Flight Experiment. The higher volume operations concept improves efficiency at nontowered, nonradar airports in instrument meteorological conditions. The success of the higher volume operations concept is based on pilot acceptability as determined through objective and subjective assessments when compared with the procedural control operations in use today at nontowered, nonradar-controlled airfields in instrument meteorological conditions. Flight experiment data indicate that the concept is viable. The experiment, flown on a general aviation aircraft, used a subset of the Higher Volume Operations Simulation Experiment scenarios and evaluation pilots to validate the simulation experiment results. Results reveal that all 12 low-time instrument-rated pilots preferred Small Aircraft Transportation System Higher Volume Operations when compared with current procedural separation operations. These pilots also flew the higher volume operations procedures safely and proficiently without additional workload in comparison to today's system. Detailed results of pilot flight technical error and their subjective assessments of workload and situation awareness are presented.

Introduction: Small Aircraft Transportation System High Volume Operations

Introduction: Small Aircraft Transportation System High Volume Operations

Low-cost, dual-mode enhanced vision sensor prototype

As a member of the Southeast SATSLab Consortium and participant in the NASA Small Aircraft Transportation System (SATS) program, the Rockwell Collins Advanced Technology Center has developed a flyable prototype of a low-cost, dual-mode enhanced vision sensor (EVS). The prototype has been successfully flown on Embry-Riddle Aeronautical University's experimental Cessna 310 light twin aircraft. The dual-mode system incorporates an uncooled long wave infrared sensor and a low-light level visible light imager using a common aperture. The system includes a dichroic beamsplitter that provides the same coaxial field of view to both sensors. This paper describes the design, fabrication, sensor performance, and flight test results of the enhanced vision sensor prototype

Data communications concept for a SATS scenario

The small aircraft transportation system (SATS) concept envisions doorstop to destination transportation in a safe and timely manner. Data communications are a key component in achieving the aviation-related operational performance improvements that are sought. However, data communication doesn't start when you get into the aircraft; it starts back at the location where the flight is planned. In fact, data communications support the pilot in all phases of the flight: flight planning, pre-flight, departure, en route, transition, approach, landing, and rollout as well as for a missed approach. The Internet is being used to perform flight planning activities, and the mobile communications available today support Internet access en route to the departure airfield. On-board the aircraft, data communications provide surveillance and air traffic control (ATC) support to the pilot. The location of other aircraft is available to the pilot and ATC system through automatic dependent surveillance-broadcast (ADS-B) and traffic information service-broadcast (TIS-B) applications that transmit the location of other aircraft in the vicinity. Other aircraft locations are used to forecast potential conflicts and, thus, enhance flight safety. As the aircraft nears a SATS-equipped airfield, the pilot uses data link messages to request a landing sequence. The airport management module (AMM) provides a landing sequence assignment to the aircraft. As the pilot maneuvers the aircraft for a landing, he/she is using data-linked surveillance data to determine the location of other aircraft and maintain a safe separation distance between aircraft even in a low visibility environment.

Maximizing Intra-Agency Relationships through Advanced General Aviation Transport Experiments and Small Aircraft Transportation System

As the United States’s transportation system becomes more congested and time becomes more precious, the National Aeronautics and Space Administration (NASA) has explored ways to address these problems. In the early 1990s, NASA formed the Advanced General Aviation Transport Experiments (AGATE) program to develop technology that would operationalize a small aircraft transportation system (SATS) and take the country into the next century of transportation. This analysis employs the research methodology of the case study to investigate the success of AGATE and relates its description to the continued formation of SATS. AGATE’s success stemmed from facilitating industry cooperation and providing practical application of its outputs. Although AGATE and SATS had different goals and participants, SATS may benefit by recognizing problems the earlier program faced. By examining the lessons learned in AGATE, SATS will be better able to achieve its goals and help the American people take flight.

Preliminary Assessment of Lower Landing Minima Capabilities in the Small Aircraft Transportation System Program

A preliminary assessment is presented of the required lower landing minima (LLM) capabilities needed to support the Small Aircraft Transportation System (SATS) Program. The goal of this analysis is to understand the number of potentially challenged SATS airports and to identify methods to remove obstacles by using technology solutions. Four obstacle removal methods are considered to assess the challenges faced by the SATS Program in providing LLM capabilities to 3,416 U.S. airports. Two views of runway obstacle analysis are presented: a critical object analysis and a detailed multiobject analysis that includes terrain information. A comparison is made between decision altitudes (DAs) derived by approach lighting infrastructure and glide path angle thresholds and DA values considering other airport characteristics such as terrain. A detailed case study is presented to compare the single critical object analysis with the more detailed multiobject analysis, which was performed for Blacksburg Airport, in Virginia.

Scenario-Based Private/Instrument Syllabus versus Traditional Maneuver-Based Syllabi: A Preliminary Descriptive Analysis

In 2003, the Aerospace Department at Middle Tennessee State University and the NASA Langley Research Center agreed to cooperate on the SATS Aerospace Flight Education Research (SAFER) project. The project is part of NASA's Small Aircraft Transportation System (SATS) initiative. SATS envisions high-tech light aircraft flying from smaller, underutilized airports moving both passengers and cargo. Middle Tennessee State University's (MTSU) Aerospace Department wanted to explore how SATS would impact flight training. The SAFER project seeks to determine how to educate the next generation of pilots in the next generation of aircraft. Beginning pilots complete their initial Visual Flight and Instrument Flight in advanced aircraft. Data from these aircraft can be used in scenario-based training, so SAFER researchers decided to use scenario-based syllabi rather than maneuver-based ones. Early results from this project show that basic piloting skills are being mastered using the scenario-based model and that decision-making skills are being increased.

Preliminary Assessment of Lower Landing Minima Capabilities in the Small Aircraft Transportation System Program

A preliminary assessment is presented of the required lower landing minima (LLM) capabilities needed to support the Small Aircraft Transportation System (SATS) Program. The goal of this analysis is to understand the number of potentially challenged SATS airports and to identify methods to remove obstacles by using technology solutions. Four obstacle removal methods are considered to assess the challenges faced by the SATS Program in providing LLM capabilities to 3,416 U.S. airports. Two views of runway obstacle analysis are presented: a critical object analysis and a detailed multiobject analysis that includes terrain information. A comparison is made between decision altitudes (DAs) derived by approach lighting infrastructure and glide path angle thresholds and DA values considering other airport characteristics such as terrain. A detailed case study is presented to compare the single critical object analysis with the more detailed multiobject analysis, which was performed for Blacksburg Airport, in Virg...

REVOLUTIONARY INDUSTRIAL CHANGE IN AIR TRANSPORT — RESEARCH AND STRATEGIC APPLICATION

This paper summarizes and interprets several years of research that considered the National Aeronautics and Space Administration's assertion that the Small Aircraft Transportation System (SATS) will become an economical alternative to automobile and airline travel — a radical paradigmatic shift. However, the literature suggests that revolutionary changes to major techno-economic paradigms should not always be made in singular radical disruptions, but rather, through the commercialization of technologies in series of market niches chosen wisely. Therefore, hypothetical SATS aircraft cost and technical performance characteristics were computer-modeled to simulate SATS in the corporate aviation environment, and in the air taxi industry. Results of exploratory research based on these models are reviewed. From the standpoint of traditional Strategic Management theory, implications are offered regarding the successful incubation of this emerging industry.

Modeling and verification of an air traffic concept of operations

A high level model of the concept of operations of NASA's Small Aircraft Transportation System for Higher Volume Operations (SATS-HVO) is presented. The model is a non-deterministic, asynchronous transition system. It provides a robust notion of safety that relies on the logic of the concept rather than on physical constraints such as aircraft performances. Several safety properties were established on this model. The modeling and verification effort resulted in the identification of 9 issues, including one major flaw, in the original concept. Ten recommendations were made to the SATS-HVO concept development working group. All the recommendations were accepted and incorporated into the current concept of operations. The model was written in PVS. The verification is performed using an explicit state exploration algorithm written and proven correct in PVS.

Small Aircraft Transportation System Concept and Technologies

This paper summarizes both the vision and the early public-private collaborative research for the Small Aircraft Transportation System (SATS). The paper outlines an operational definition of SATS, describes how SATS conceptually differs from current air transportation capabilities, introduces four SATS operating capabilities, and explains the relation between the SATS operating capabilities and the potential for expanded air mobility. The SATS technology roadmap encompasses on-demand, widely distributed, point-to-point air mobility, through hired-pilot modes in the nearer-term, and through self-operated user modes in the farther-term. The nearer-term concept is based on aircraft and airspace technologies being developed to make the use of smaller, more widely distributed community reliever and general aviation airports and their runways more useful in more weather conditions, in commercial hired-pilot service modes. The farther-term vision is based on technical concepts that could be developed to simplify or automate many of the operational functions in the aircraft and the airspace for meeting future public transportation needs, in personally operated modes. NASA technology strategies form a roadmap between the nearer-term concept and the farther-term vision. This paper outlines a roadmap for scalable, on-demand, distributed air mobility technologies for vehicle and airspace systems. The audiences for the paper include General Aviation manufacturers, small aircraft transportation service providers, the flight training industry, airport and transportation authorities at the Federal, state and local levels, and organizations involved in planning for future National Airspace System advancements.