Paired overbounding and application to GPS augmentation

The Federal Aviation Administration (FAA) is investigating the feasibility of using the Global Positioning System (GPS), together with local augmentation as the primary navigation system for the Category II and III precision approach of aircraft. This augmented system would be known as a local area augmentation system (LAAS) because it would place subsystems on the ground at or near an airport to greatly enhance the performance of airborne GPS receivers approaching that airport. The LAAS would complement space-based augmentations of GPS, such as the wide area augmentation system. When complete, the integrated system will meet stringent requirements on accuracy, integrity, continuity, and availability. Indeed, the LAAS will improve the airborne accuracy from approximately 100 m for stand-alone GPS to better than 1 m. This high accuracy is required so that LAAS can guarantee the integrity and continuity of the aircraft guidance during the approach phase of flight. Integrity requires the LAAS to detect any situations which threaten the safety of the landing, and notify the aircraft within 2 s of such a threat. Continuity is a competing consideration-it requires that the total number of alarms, true plus false, sent to the aircraft is very small. High continuity guarantees that the total number of aborted approaches is manageably small. Finally, availability is the fraction of the time during which LAAS is operational-providing position fixes with the specified accuracy, integrity and continuity. This paper describes the LAAS which has been proposed by the FAA. It discusses the fundamental operation of the LAAS.

The Local Area Augmentation System (LAAS) is the Federal Aviation Administration's ground-based augmentation system (GBAS) for local-area differential Global Positioning System (DGPS). It will support all categories of precision approach. LAAS is currently under advanced development and specification. The purpose of this paper is to provide an update on the LAAS program strategy and a technical description of the LAAS. The LAAS program involves a government-industry partnership, specification of the Ground Segment, and FAA in-house development of a test prototype containing all of the LAAS features. The technical section contains both top-level and intermediate-level descriptions of LAAS, with emphasis on the Ground Segment. Three distinguishing advances are described in more detail: multipath limiting antenna, airport pseudolite, and a method for transforming integrity parameters from the pseudorange domain to the position domain.

This paper addresses topics concerning the development of future Unmanned Aerial Vehicles (UAV) so that they can operate safely within the community of the Federal Aviation Administration (FAA) and the International Civil Aviation Organization (ICAO). Studies by the Defense Science Board; the Office of Science and Technology; Government Accountability Office; and the Congressional Research Service: Library of Congress; have all emphasized that soon there will be a significant number of UAVs operating sideby- side with manned civil aircraft in the FAA’s National Airspace System (NAS). It is anticipated that future UAVs will start to perform many of the dull, dirty, and dangerous civilian missions. In 2006, about 600 UAVs are expected to be manufactured in the US alone. Therefore, there is an urgent need for developers of UAVs to understand safety certification for operations in the NAS, and that safety certification starts with the safety requirements; safety design; safe development process; safety verification; and safe operating procedures in the planned operational environment. This paper presents and discusses the experiences and lessons gained by the authors on the development of end-toend aviation safety; from the safety requirements to their final safety certification in the planned operational environment. The authors’ previous and ongoing works include the Global Navigation Satellite Systems (GNSS) systems such as the GPS; WAAS; LAAS; MSAS; GPS III; and different operational environments at different airports such as Incheon International Airport. The FAA started with the two traditional safety certifications processes: airborne system certification and ground system certification; governed mostly by Federal Aviation Regulations (FAR) and FAA’s Acquisition Management System (AMS), respectively. However, when FAA started to implement GNSS, the lines between airborne and ground systems became blurred, and as a result many current Communications, Navigation, Surveillance, and Air Traffic Management (CNS/ATM) systems have to follow both processes. We will also discuss the current Safety Management Systems being developed by both FAA and ICAO as an integrated, systematic, and harmonized approach and process to sort out the differing safety requirements from FAA, SAE-ARP, MIL-STD, RTCA, ASTM, ICAO, etc. to provide the eventual safe operations within the NAS. The discussion will then focus on the real world of institutional, operational, and technical issues for safety certification worldwide. Despite the numerous standards and guidance documents, many past safety analyses and studies were guided by best practices that had been used successfully in the past to streamline the process of providing all the required documentations and verifications. One such area is in the use of the “Integrity Panel of Experts” that had been used successful in the implementation of safety for the FAA’s Wide Area Augmentation System (WAAS) and Local Area Augmentation System (LAAS) programs. In many areas of the world, safety certification from a technical point of view is only the first step to achieving safety certification to fly in their national and sovereign airspace. Finally, we will show the first steps that UAV manufactures need to consider if they want their UAVs to be approved to fly safely in different national civilian airspace.

Some deficiencies of the system of exciting satellite navigation augmentation are analyzed in the application of civil aviation. Since there is no local monitoring in Wide Area Augmentation System (WAAS), the protect level is increased, and the availability is reduced, so it could not satisfy the requirement of the precise approach. Moreover, because the Local Area Augmentation System (LAAS) could not solve the problem brought by ionosphere storms, the LAAS certification becomes complex and expensive. The basic principle of the new satellite navigation augmentation system named Local Airport Monitor (LAM) proposed by Federal Aviation Administration (FAA) is introduced. And the error distribution characteristic of LAM is discussed by sorting three conditions. Moreover, the expressions of LAM protection level and availability are studied. Some conclusions are obtained by simulations. In normal condition, the position accuracy of LAM is better than the one of WAAS and similar to LAAS and the availability of LAM is better than the one of WAAS and worse than LAAS. When there are ionosphere storms, the position precision and availability of LAM and WAAS reduce a little, but the position precision and availability of LAAS reduce 20.5% and 19.3% respectively. Furthermore, the availability of LAM is analyzed and simulated. And some conclusions are obtained: airborne user should first choose satellites whose elevation is lower than 10 degree and bigger than 70 degree. Reference station and airborne should use GAD-A and AAD-B receiver respectively, thus, the availability of LAM could bigger than 99.99%

The Runway Incursion Prevention System (RIPS) program is an ongoing National Aeronautics and Space Administration (NASA) research effort intended to reduce the number of runway incursions at airports throughout the National Airspace System (NAS). The RIPS program flight tests and demonstration of technologies activities at the Dallas/Fort Worth (DFW) International Airport were completed in October 2000. The demonstration involved the application of both airborne and ground based technologies, as well as the integration of these technologies to form a complete runway incursion prevention system. This paper presents information on the research activities conducted at DFW related to the Ohio University Avionics Engineering Center (AEC) installed Global Positioning System (GPS) Local Area Augmentation System (LAAS) ground facility (LGF), it's use, the preliminary results obtained, and observations or conclusions when appropriate. A description of the RTCA DO-247 Surveillance and Guidance Sensor requirements is provided. Details of the DFW LAAS upgrade for NASA RIPS testing, AEC GPS LAAS test van equipage, and the Rockwell Collins Multimode LAAS receiver integration activities are presented. Data analysis activities have just been initiated.

This paper develops code multipath error budgets for land-based Joint Precision Approach and Landing System (JPALS) ground station receivers. The approach is similar to that used for the civil Local Area Augmentation System (LAAS), with modifications for P(Y)-code tracking and the use of beam-steering antenna arrays. The budget includes two error allocations, one for receiver noise and one for code multipath, both of which are defined as a function of satellite elevation. The noise allocations are based on an analytical model that is fit to JPALS test data, while the multipath allocations are based on test data alone. The results show that JPALS ground stations have some advantages over LAAS ground stations due to antenna differences and the more limited multipath susceptibility of the P(Y)-code. We also investigate code multipath biases by way of simulations. The results indicate that the multipath allocations developed herein capture multipath biases for the expected environments.

Observations of extreme spatial rates of change of ionospheric electron content and the characterization strategy for mitigation applied by the U.S. local area augmentation system are shown. During extreme ionospheric activity, the gradient suffered by a global navigation satellite system user a few kilometers away from a ground reference station may reach as high as 425 mm of delay (at the GPS L1frequency) per km of user separation. The method of data analysis that produced these results is described, and a threat space that parameterizes these possible threats to user integrity is defined. Certain configurations of user, reference station, global navigation satellite system satellite, and ionospheric storm-enhanced density may inhibit detection of the anomalous ionosphere by the reference station.

Synthetic vision has the potential to improve safety in aviation through better pilot situational awareness and enhanced navigational guidance. The technological advances enabling synthetic vision are GPS based navigation (position and attitude) systems and efficient graphical systems for rendering 3D displays in the cockpit. A benefit for military, commercial, and general aviation platforms alike is the relentless drive to miniaturize computer subsystems. Processors, data storage, graphical and digital signal processing chips, RF circuitry, and bus architectures are at or out-pacing Moore's Law with the transition to mobile computing and embedded systems. The tandem of fundamental GPS navigation services such as the US FAA's Wide Area and Local Area Augmentation Systems (WAAS) and commercially viable mobile rendering systems puts synthetic vision well with the the technological reach of general aviation. Given the appropriate navigational inputs, low cost and power efficient graphics solutions are capable of rendering a pilot's out-the-window view into visual databases with photo-specific imagery and geo-specific elevation and feature content. Looking beyond the single airframe, proposed aviation technologies such as ADS-B would provide a communication channel for bringing traffic information on-board and into the cockpit visually via the 3D display for additional pilot awareness. This paper gives a view of current 3D graphics system capability suitable for general aviation and presents a potential road map following the current trends.

As part of the agency's broader noise research program, the Federal Aviation Administration (FAA) has undertaken a multi-year research effort to quantify the impacts of aircraft noise exposure on communities around commercial service airports in the United States (U.S.). The overall goal of the study was to produce an updated and nationally representative civil aircraft dose-response curve; providing the relationship between annoyance and aircraft noise exposure around U.S. airport communities. To meet this goal, the FAA sponsored a research team to help design and conduct a national survey, known as the Neighborhood Environmental Survey (NES). By assessing the results of the NES through both internal review and input from public comment, the FAA seeks to better inform its noise research priorities and noise policies. This paper will outline the FAA's motivation to conduct the NES as well as how its findings will help inform ongoing work to address aircraft noise concerns. Additional information describing the noise methodology and survey methodology are provided in companion papers.

The United States (US) aviation industry provides a potentially useful mental model for dealing with certain cost-benefit decisions in aesthesiology. The Federal Aviation Administration (FAA), the national aviation authority of the United States, quantifies a price for the value of a human life based on the U.S. Department of Transportation's (DOT) value of a statistical life (VSL) unit. The current VSL is around $9.6 million, indexed to grow with consideration given to inflation and wage changes from the 2016 baseline of $9.4 million [1]. To illustrate the concept, if the FAA estimates that 100 people are likely to die in the future given the current practice standards then the monetary cost of this loss will be $940 million. The FAA uses this estimated monetary value as an official reference point in its regulatory decisions, and the agency publishes in detail how it derives the estimated value. When proposing new regulations, the FAA bases its decisions on comparisons of the human life cost associated with the existing regulation versus the alternative cost that the industry stakeholders will incur subsequent to the adoption of the regulation. In this example, if the cost incurred by the industry is more than the $940 million cost then the FAA will not adopt the proposed regulation and hence will not require the industry to undertake this cost.

On October 1 1, 1994, the Federal Aviation Administration (FAA) published Advisory Circular (AC) 120-63, Helico~ter Simulator Oualification. The evaluation criteria and standards constituted the fust such formal document within the United States. An overview is presented of the process undertaken by the FAA's National Simulator Program (NSP) in the formulation of the advisory material with emphasis on development of helicopter simulation standards and the principal issues addressed regarding helicopter simulation. The FAA's incorporation of internationally agreed upon airplane simulator standards into US standards as AC 120-40C, Airplane Simulator Qualification is addressed. Additionally, the update of AC 120-45A, Airplane Flieht Training Device Oualification, will also be addressed. Topics within this paper include the role of simulation in training programs and FAA efforts in addressing airplane and helicopter simulation needs, working groups formed to develop helicopter and airplane simulation standards. Additionally, the November 1994 National Transportation Safety Board (NTSB) recommendation to require the existence of a high fidelity simulator to be a condition for issuance of an Airworthiness Certificate for future aircraft is reviewed and discussed.

As air traffic in the United States has grown over the last several years, traffic demand has begun to outstrip capacity. As of 2005, the Federal Aviation Administration (FAA) had no effective approach for strategically managing a weather event that has been very disruptive to the national aviation system—large-scale thunderstorms that block the major flight routes in the northeastern United States. The operations research team that supports the FAA's efforts to provide innovations in air traffic management, led by researchers at Metron Aviation, Inc. and the Volpe Transportation Center, recognized the consequence of this operational deficiency and set out to resolve it. In this paper, we show how this team (1) developed and applied system-simulation models to quantify the extent of the traffic flow management problem and convey its magnitude to the FAA and to the aviation industry; (2) designed the Airspace Flow Program (AFP), a new approach to managing air traffic that could correct the problem within the limitations of a short development cycle and a change-resistant culture; (3) designed and developed an interactive simulation system that could be and was used to refine and perfect this concept prior to deployment by developing policies on the use of a decision support system; (4) engaged FAA and airline traffic management experts in a series of interactive exercises using the simulation system to develop the final software design, operational procedures, and decision rules for deployment and use; and (5) provided a clear and convincing postdeployment benefits assessment for the new traffic management approach. The deployment of this new capability was an enormous success that both the FAA and the airline community heralded widely. The postdeployment impact assessment showed benefits to the aircraft operators and the flying public of almost $190 million in 2006 and 2007, the first two years of use, compared to less than $5 million in design and development costs. Broader usage of AFPs and new applications for them show a projected 10-year benefit of approximately $2.8 billion.

This synthesis study is intended to inform airport operators, including planners and environmental documentation managers, about successful practices used to integrate airport development and federal environmental review processes. Experience shows that when an airport sponsor fails to consider environmental issues during the airport planning process, delays in the Federal Aviation Administration (FAA) environmental decision-making processes often occur. Those delays occur because the FAA is unable to meet its National Environmental Policy Act (NEPA) obligations based on the data available. This may result in the FAA having to commission additional evaluation because: a) While the primary project was identified, the projects that were necessary to enable the primary project were not identified; b) Insufficient information is available to support the need for the project; and c) Impacts to resources protected by special purpose laws (i.e., wetlands, floodplains, parklands, historic resources, etc.) were not known and thus alternatives were not explored that would avoid affecting the resources. These issues are often referred to as a between the NEPA process and the steps that precede it. The airport community and the FAA have attempted to address the disconnect with improvements to the guidance and conferences to discuss the guidance and remaining issues. However, disconnect-related issues have continued to persist. In 2008, interested parties presented a synthesis project request to the Airport Cooperative Research Program (ACRP) to examine this disconnect, which resulted in this project research. Seventeen case studies were collected and reported. The surveys and case studies identified activities that airports performed to integrate planning and environmental review processes of projects at airports throughout the United States. Seven general themes can be drawn from the survey work: Early Coordination and Consultation; Knowing Your Airport (know the on-site environmental features); Appropriate Range of Alternatives; Good Lines of Communication; Public Involvement Strategy; Coordinating State and Federal Environmental Review Processes; and Funding an FAA Position.

While aircraft account for less than 10% of United States (U.S.) transportation energy consumption, it is the only mode expected to see sustained growth in energy demand through 2050. Currently, commercially available aircraft rely heavily on either jet fuel or leaded aviation gasoline. Over the past few decades, concerns have grown over the contributing effects that greenhouse gases, which are produced from fossil fuels, have on the environment. Due to these concerns, many aircraft manufacturers are pursuing the development of new generation aircraft that can leverage alternative, renewable fuels. The Federal Aviation Administration (FAA) is presently working toward certifying multiple novel aircraft and developing an environment to safely support this innovation. For airports and aircraft original equipment manufacturers (OEMs) that choose to be early adopters of hydrogen technology, the FAA needs to provide guidance for the associated support infrastructure. The FAA is collaborating with the National Renewable Energy Laboratory (NREL) on this research project to evaluate the impact of the anticipated demand for hydrogen as a fuel source on existing airport infrastructure. This study is intended to help reduce market barriers involving uncertainty in standards and operational requirements of hydrogen technology and airport infrastructure. By defining system-wide best practices in refueling systems and facility layouts, manufacturers, airports, and communities can be better prepared to participate in this emerging industry. Section 2 of this document is the culmination of a literature review that describes the current state and the anticipated future of hydrogen-related technology across various government organizations, industries, and academia. This work identifies existing goals and the maturity level of the industry to help define a realistic strategy and approach to implement hydrogen systems into the airport environment within a realistic timeframe. The technology areas cover production, storage, transport, and fueling as a supply chain of hydrogen. This report also briefly investigates hydrogen propulsion systems, such as fuel cell and combustion engines. Furthermore, this work organizes safety codes and standards to identify gaps in our current understanding. Presently, there are detailed standards regarding hydrogen technology, airport safety, and aircraft fueling. However, they are not consolidated as a unified set of codes and standards suitable for the airport environment. Preventive safety measures and emergency procedures must be identified as hydrogen will begin to be transported on to airport sites. These safety requirements must continue to mature as the airports adopt hydrogen technology in their proximity. Sections 3 and 4 of this study focus hydrogen aircraft demands, and airport infrastructure needed to support hydrogen technology. The examination of hydrogen production, storage requirements, delivery methods, refueling services, and safety requirements are critical to accommodate novel hydrogen aircraft in the airport environment. Learnings are applied to the LAX, SEA, PDX, and SFO airports to gain insight on: 1) space requirements for hydrogen infrastructure, 2) airport hydrogen infrastructure placement, and 3) cost and economic impacts of hydrogen infrastructure at each airport. Results show that each airport has space for hydrogen infrastructure, especially at hydrogen demand levels of around 1,000 kg/day. We also find that both hydrogen infrastructure cost and economic impacts become more favorable as hydrogen demand at the airports scale. This study is intended to provide a comprehensive understanding of hydrogen infrastructure that will enable energy-savings and emissions-reductions while illuminating pathways to transition from legacy systems to next generation aviation. The study should be used as a guide by airport and government officials, as well as industry leaders, to gain insights on how hydrogen and hydrogen infrastructure can be utilized for advance air mobility applications.

Investigations following two separate and deadly crashes of Boeing 737 8 Max aircraft revealed that America’s most trusted manufacturer had failed to notify pilots and airliners alike of a new Maneuvering Characteristics Augmentation System, commonly known as MCAS. What had first seemed like an accident unfortunately had a deeper and traceable history. Through relatively new United States legislation, Boeing was essentially permitted to oversee their own operations and grant airworthiness certifications for their own aircrafts. This practice is wholly unlike the detailed certification process of the European manufacturing giant, AirBus, by the European Aviation Safety Administration (EASA). This comment sheds light on the decades long build-up to these horrific crashes, how this series of events could have been prevented, and the ways in which the United States Federal Aviation Administration (FAA) and Boeing can follow EASA and AirBus’s lead and return to the gold standard of civil aviation. Analyses of United States Codes, Federal Regulations, and International Safety Agreements leads to the conclusion that the United States and the FAA must apply more scrutiny to manufacturers within the 50 states. Alterations to the agreements and codes mentioned in this comment will aid in the overall safety practice of civil aviation.