Aviation Management Associates, Inc. News

The Aviation iPAD Revolution

Wed, 11 Jan 2012 11:57:25 -0500

The Aviation iPAD Revolution.pdf provides the latest aviation perspective on the introduction of disruptive technology.

You may have heard all the fuss recently when Alec Baldwin made national news when his American Airlines flight was stalled on the tarmac when he refused to turn off his cell phone because he was playing Words with Friends. In the aviation news sources, there was even more discussion around American Airlines receiving approval to use the iPad in the cockpit but not allowing passengers to use the same device until reaching 10,000 feet.

Those sound bites are merely noise. The real news is about the evolution, if not revolution, taking place across the aviation industry; the use of the iPad in the cockpit. The ease of use, elegance of the applications, flexibility and quality of display and finally, cost of adoption is driving revolution.

Aircraft Access to SWIM (AAtS) User and Stakeholder Outreach Report

Tue, 10 Jan 2012 09:37:26 -0500

Purpose
Aircraft Access to SWIM User and Stakeholder Outreach.pdf paper provides a summary of findings and recommendations of a more extensive report concerning the Aircraft Access to SWIM (AAtS) outreach initiative. It explores concepts of future aeronautical data management, transport and aviation users by researching current technologies, user requirements and business cases from government, commercial and operator viewpoints.

The outreach effort gathered stakeholder input from 18 organizations, which included commercial data transporters, data managers, government information providers and aviation users. Aviation Management Associates (AMA) conducted a survey of the pilot user community (AOPA, NBAA and commercial airlines) to understand the market need.

Commercial Perspective
Market Demand
Responses from AOPA and NBAA (96 and 244, respectively) and meetings with Air Transport Association, United Airlines, Virgin America, American Airlines, NetJets, Alaska Airlines, and Flight Options indicate considerable interest in receiving more FAA generated data in more usable formats that do not increase cockpit workload and are presented in a user-friendly manner. The revolution of the use of electronic tablets like the iPad, and its associated easy to understand and use graphical user interface (GUI), are evidence of this interest.

In a related study conducted by the FAA Aviation Weather Group to determine perspectives of weather in the cockpit for GA revealed a strong interest in display of data versus voice dissemination and the ability for the pilot to integrate data points and make aeronautical decisions. AOPA conducted a survey of its members that indicated a strong desire for new tools and data above what is available today via the Flight Service Program. Coincidentally, the FAA is currently seeking user and vendor comments affecting the Future of the Flight Service Program (FFSP).

2025 Operational Scenarios Supporting Alternative PNT

Sun, 20 Jun 2010 13:56:59 -0400

This work. 2025 Operational Scenarios Supporting Alternative PNT.pdf, is in support of the development of alternatives for dealing with interference of the Global Navigation Satellite System. To help frame requirements, it is necessary to project forward in time and describe operational environment in the Next Generation Air Transportation System (NextGen) in the 2025 timeframe and discuss, in narrative for representative nominal flights that are then impacted by an interference event. Information has been extracted and updated from previous work performed by Aviation Management Associates for the Raytheon Company, who is under contract with the NextGen Institute in support of the Joint Planning and Development Office (JPDO). The Raytheon team’s efforts were in support of an integrated communications, navigation and surveillance architecture development activity. The advantage to the Federal Aviation Administration and the JPDO is that by re-using the scenarios, prior architecture development work can be leveraged.

Factors Affecting Air Traffic Services in the North Atlantic

Fri, 19 Dec 2008 15:54:06 -0500

Critical issues affecting both North Atlantic traffic, demand, capacity and complexity were identified and assessed to aid FAA in identifying potential barriers to both demand and capacity growth. The identification of these issues in the study of EU-US Open Skies North Atlantic Traffic will provide an opportunity for FAA to begin to develop relevant metrics and track trends that could have pejorative effects upon future system performance. This monitoring and reporting of issues and trends then provides the FAA ATO opportunities to make strategic plans and institute proactive actions to optimized investments and resources while providing the highest levels of air navigation services across the North Atlantic.

System Wide Information Management Human Factor Issues

Fri, 3 Oct 2008 16:04:30 -0400

In early 2008 Aviation Management Associates, Inc. commissioned this paper, User Centered SWIM for the Future , from Embry-Riddle Aeronautical University to document selected human factor concerns associated with the build out of the Federal Aviation Administration’s System Wide Information Management infrastructure.

Along with the increasing information load faced by those working within the National Airspace System (NAS) come new risks and challenges. These user-related risks and challenges call for the integration of user support into the NAS and its subsidiary systems as they are upgraded during Next Generation Air Transportation System (NextGen) transformations. For illustrative purposes, we focus on ways in which user support could be integrated into capabilities being developed within one of the main NextGen programs, the System Wide Information Management (SWIM) program. User-support strategies such as these, if implemented with attention to human factors guidelines and lessons learned, will help to ensure the safety, efficiency, and satisfaction of NAS users, as well as the resilience of the system as a whole.

NextGen: New Role for Air Traffic Controllers

Wed, 27 Feb 2008 13:30:17 -0500

In today’s National Airspace System it is the responsibility of air traffic controller’s to provide separation assurance between known participating aircraft operating under instrument flight rules. In other words, use computer, radar and communication tools and apply procedures, knowledge and skills to insure that commercial aircraft do not collide on runways, taxiways or in the air.
It is not an easy job to learn, nor is it an easy job to do. It is a uniquely human centric endeavor with little tolerance for error. Unfortunately, the system of air traffic control of today is bounded by its current design and the human limits the current design imposes. As the air transportation system has demonstrated so clearly with disruptions and delays, it has reached the end of its design life. As a nation, we must reach out with new visions, innovations and concepts to develop, deploy and operate a new next generation air transportation system not bound by human limits. A system that is both safer and more efficient with the capacity for significant and efficient future growth.
NextGen Promises Air Transportation Efficiency and Growth
In 2003 the Congress of the United States passed Public Law 108-176 known as Vision 100 – Century of Aviation Reauthorization Act. Embodied in this act was a requirement to create an organization called the Joint Planning and Development Office to develop and carryout an integrated plan for a next generation air transportation system. This office is currently working to collaborate an architecture for future system development.

A key question in support of the development and implementation of this Next Generation Air Transportation System is, what will the roles and responsibilities of today’s air traffic control workforce become? Contrary to some popular beliefs and thoughts, air traffic controllers will play a critically important role in NextGen. Duties, authorities and responsibilities will grow to meet more demanding system needs. Employment numbers will increase as well as newfound efficiencies and capacities will spur continuing growth in air transportation demand and services. The information age shepherded in by the explosion of computers and automation has created significant new business opportunities, not eliminated them. This economic vitality and growth should be embraced and not feared.

NexGen Future Vision

The air traffic controllers of NextGen will ultimately retain management responsibility for aircraft separation and related safety. While controllers today separate aircraft directly, the controllers of the future will manage the separation of aircraft. That is, a controller will determine the best methods of assuring separation while managing around priorities to optimize air transportation systems resources. In other words, what strategies, tactics and techniques should be applied to optimize the use of airspace and runways while meeting user goals of fuel conservation and national goals of environmental protection. While automated tools will provide the controller with decision aids, ultimately a human - an air traffic controller - must adjudicate and balance dynamic competing and complex needs. Thus far, automation systems have not been designed or developed that demonstrate they can ever replace the human in this role.

For example, a controller can choose to manually instruct a trailing aircraft to slow down to avoid overtaking a leading aircraft as we do today, or a controller can delegate a minimum spacing distance to maintain between to cooperatively equipped aircraft (ADS-B In with CDTI) for a designated route length or time. It is the controller that manages the parameters of this delegation to meet, say, a clearance to conduct a continuous descent arrival. Another example would be reviewing alternatives present by decision support tools to manage traffic flows. This is not so that aircraft into the same major terminal airspace are lined up one behind the other for 200 to 400 nautical miles as done today, but done to look at strategies and tactics the keep aircraft capable of flying high and fast with high descent rate capabilities segregated from less capable aircraft. The objective is to merge the flows on final approach 3 miles from the runway and not 400 miles from the runway of intended landing.

NextGen Survival

There are many, many examples of how future air traffic controllers can contribute to the safe and efficient operation of NextGen. Related duties, authorities, roles and responsibilities need to be carefully thought out, developed and demonstrated today, not as an after thought of technologically innovative solutions. Otherwise, we have an end-state we cannot achieve because there is no path to get there. We cannot effectively build for the future by alienating those that are so needed to make that transform to the future a doable reality.

National Air Transportation Demand 2025

Wed, 1 Aug 2007 11:42:20 -0400

This 2007 briefing focusing on 2025 NAS Demand.pdf reviewed future air transportation demand trends.

Air Carrier Aircraft IFE Communications Equipage

Thu, 28 Dec 2006 12:17:23 -0500

Aviation Management Associates, Inc. (AMA) was contracted by the Ohio Aerospace Institute to conduct research on the current state of Air Carrier IFE Equipage and functionality on the turbojet fleet to include communication between air and ground and between personnel on the aircraft. This research included the collection of aircraft seating configurations for each airline and airframe type as well as in-depth surveys of U.S. major airline operators regarding the types of communications and in-flight entertainment (IFE) equipment with which each airframe type is equipped. The survey also investigated airline plans and desires for adding, removing, upgrading and replacing such systems. Primary focus was placed on the major airline companies rather than regional and commuter operators. This report summarizes the findings of this research and provides insight crucial to the establishment of the current baseline and roadmap for communications capabilities in the U.S. airline fleet.

Network Enabled Security at Airports

Tue, 28 Nov 2006 08:22:33 -0500

Airport operators must seek to develop command and control systems which (a) draw on all available data and communications at the airport to capture a comprehensive common operation picture (COP), (b) freely coordinate data and information with adjacent municipal and federal agencies (intelligence, indicators and warnings, and planning information), and (c) use the tools and technologies available today to fuse this information in a simple, yet decisive manner. Embracing today’s technology, including web-enabled voice, data and imagery transmissions, coordinated command and control, and external information sharing models in an integrated fashion is what must be accomplished. Airports are increasingly installing CCTV throughout the facility, however in many cases, they are not self-alarm o alert enabled. Communications is equally disconnected where there is limited or non-existent capability to communicate with adjacent mutual aid responders. Procedurally, many airports have yet to embrace or practice the concepts underpinning the National Incident Management System (NIMS), and Incident Command System (ICS) where effective command and control sets aside issues of jurisdiction while focusing on function. These issues must be combined in a comprehensive approach to developing the Network Enabled Command, Control, Coordination and Security at Airports.pdf.

GPS Backup for Position, Navigation and Timing

Wed, 6 Sep 2006 07:10:13 -0400

This white paper on GPS Backup for Position, Navigation and Timing serves as a continuation of the Federal Aviation Administration’s (FAA) Navigation and Landing Transition Strategy, originally issued in August 2002 that introduced the issues and strategies associated with reducing the cost of navigation (through
decommissioning), the future dependency on satellite-based navigation, and options to provide
backup for navigation. Since that time, the FAA has also decided to pursue acquisition and
deployment of automated dependent surveillance – broadcast (ADS-B) as the primary means of
surveillance. This dependent surveillance relies on satellite navigation to provide precision
position reports.

The Joint Planning and Development Office (JPDO) responsible for defining the Next
Generation Air Transportation System (NGATS) has also identified precision performance and
four-dimensional (4-D) trajectory-based separation. This new way of dealing with aircraft
separation introduces the use of time to what has previously been longitudinal, lateral and
vertical separation.

What has also changed since 2002 is a thorough technical and infrastructure upgrade to Loran C,
introducing new capabilities that can make Loran C a viable candidate as a backup for both
navigation and surveillance. This new Loran is called Enhanced Loran, or eLoran.
This paper updates information from the 2002 Navigation and Landing Transition Strategy,
presents strategies for backups, and discusses key policy decisions around precision navigation,
timing, and surveillance.

To avoid confusion when addressing Loran, there are three distinctions that are made:
Loran-C is a method of navigation that uses a master station and a chain of stations tied to that
master station to derive position.

Loran modernization is the physical upgrade of existing transmitters and associated equipment to
improve performance and provide lower maintainability costs. A modernized Loran station still
supports Loran-C.

Enhanced Loran adds to the performance of the stations and introduces a new avionics design
called “All-in-View” that treats every Loran station transmitter as if it were a GPS satellite
bolted to the ground. Enhanced Loran is the basis for the breakthrough in avionics performance
necessary to support a position and navigation backup to GPS.

A Look at Systemwide Information Management

Wed, 17 May 2006 14:24:49 -0400

The System-wide Information Management (SWIM) was spawned by the Federal Aviation Administration (FAA) in 1997 as a concept to provide a seamless method of exchanging and managing critical safety data throughout the National Airspace System (NAS). One related concept focused on aircraft surveillance data has become a SWIM sub-net known as the Surveillance Data Network (SDN). These SDN and SWIM concepts have developed and grown with parallel efforts by the Department of Defense known as net-centric Network Enabled Operations (NEO).

In its broadest sense, these terms mean the right information will be available and given to the right person at the right time. Data will be collected from sources that have it, processed and then disseminated to planners and decision-makers who need, want or desire it. From an aviation perspective, any entity giving data or any entity receiving information will become nodes on the aeronautical “internet” network. Aircraft will become mobile "nodes" integral to this information network, not only using and providing information, but also capable of routing messages or information sent from another aircraft or a ground source. Information will be "pushed" to known users and "pulled" by others through a philosophy of publish and subscribe.

Network Enabled Operations is about creating and architecting a seamless, scalable, robust, secure, efficient and cost-effective communications system. This means designing and deploying a network that meets current and future needs as opposed to attempting the difficult and costly challenge of rebuilding legacy systems and networks. The physical nature and characteristics of contemporary networks are well known, both wire and wireless. Commercial systems, sub-systems and components are becoming available that can meet SWIM requirements including performance, availability, reliability and integrity. Notwithstanding, some architectural risks exist in development and deployment of domain specific needs for air-to-air and air-to-ground infrastructure as well as large regional ground-ground and air-ground communication switches. While risks seem manageable, they are nevertheless considerable in every dimension as documented in this paper. It is extremely important that FAA work closely with the Department of Defense (DOD), in conjunction with the World Wide Consortium for the Grid (W2COG), in terms of lessons learned and the creation and adoption of standards, technologies and policies.

The Federal Government’s commitment by the Office of Management and Budget (OMB) to migrate to an improved internet based communication protocol known as TCP/IPv6, or Transmission Control Protocol/Internet Protocol Version Six, by June 2008 as a de facto standard for transmitting data over networks provides a significant justification for the FAA to develop and deploy a SWIM network embodying TCP/IPv6 protocol. In fact for IPv6 transition, FAA is under OMB direction to complete inventories of IP complaint devices as well as complete an impact analysis of fiscal and operational risks as of June 30, 2006.
The current generation of IP version 4 (IPv4) has been in use for more than 20 years and has supported the Internet’s growth over the last decade. With the transformation of the Internet in the 1990s, from a research network to a commercialized network, there is no doubt that IPv4 cannot accommodate emerging demand, especially the anticipated demand for Internet addresses.
IPv6 will enable an enormous increase in the number of Internet addresses currently available under IPv4. Demand for such addresses will increase as more and more of the world’s population request Internet access. Continued growth in mobile data services via wireless telephones and data terminals, such as personal data assistants (PDAs), will also expand demand for Internet addresses. The situation may become critical if, as some project, a market emerges for in-home devices (e.g., “smart appliances” and entertainment systems) that are accessible from outside the home via the Internet.
Beside affording exponentially expanded address space, IPv6 has been designed to provide other features and capabilities, including improved support for header options and extensions, simplified assignment of addresses and configuration options for communications devices, and additional security features. All things being equal, most observers agree that IPv6-based networks would be superior to IPv4-based networks. As noted above, IPv6 would adequately accommodate increased demand for IP addresses in the event that a proliferation of end-user devices or the emergence of a “killer application” outstrips the existing supply of IPv4 addresses.
Department of Defense Leadership
The Department of Defense (DOD), who developed the concepts of Network Centric Operations and deployed them with devastatingly effective results in the last Iraq conflict, is also pioneering Federal deployment of IPv6. The DOD is further leading the way in developing future seamless electronic networks through the Global Information Grid (GIG) vision that makes fundamental shifts in information management, communication, and assurance. The GIG system provides authorized users with a seamless, secure, and interconnected information environment, meeting real-time and near real-time needs of both the government and the business user. The GIG uses commercial technologies augmented to meet DOD's mission-critical user requirements. The work of the GIG, through the World Wide Consortium for the Grid, is building the foundation of networked enabled operational architectures that will transcend virtually all legacy networks and associated applications.
The W2COG is an international, collaborative association of networking technology and operational experts focused exclusively on accelerating the development and availability of tools to support secure, net centric operations for global security and peaceful commerce, delivering tangible solutions quickly and cost effectively. This DOD sponsored organization is supported by a number of government agencies, including DOD and NASA, commercial enterprises, academia and individual technical experts. Unfortunately, the FAA is not a participating member of the W2COG, notwithstanding its need to adopt the GIG philosophy, access GIG knowledge and experience, and lever GIG investments in development of the FAA’s System-wide Information Management (SWIM) systems.

The Defense Information Systems Agency (DISA), part of the Department of Defense, is moving forward to implement Net-enabled Command Capabilities (NECC), formerly known as the Joint Command and Control Program. The objective, not unlike that of FAA Traffic Flow Management, is to provide a comprehensive suite of information services that will enable decision-makers to make better, faster and more coordinated decisions in a real-time and stressful environment.

Benefits

Often operational systems and information technology systems have been acquired by the FAA without regard for their ability to work in a transparent operational environment. As a result, extra layers of redundancy and common systems have been put in place to support operations, but without the ability to easily and quickly exchange data. SWIM should “globally interconnect end-to-end sets of information capabilities, associated processes, and personnel for collecting, processing, storing, disseminating, and managing information,” much the same way as the Internet has transformed industry and society on a global scale. SWIM’s role is to create an environment in which users can access data, on demand at any location, without having to rely on (and wait for) organizations in charge of data collection to process and disseminate the information. Data could emanate from a variety of sources, including passengers, aviation operators and infrastructure support systems such as aeronautical information systems, surveillance systems, navigation systems and communications systems. Ultimately, most of the current aviation non-interoperable legacy systems can and will become part of SWIM. With greater data access and a more robust communications infrastructure, SWIM will enable more timely execution of operations, collaborative mission planning and execution, common views of the National Airspace System, and more timely assessments of its condition and performance, actual and predicted. In addition, SWIM would reduce the substantial resources and logistics needed to bring command, control, and communications systems to the air traffic flow management environment.

SWIM needs to be much like the Internet, but with less dependence on ground-based fixed systems and equipment to transmit and route data and more dependence on space-based and mobile, ad hoc systems to carry out these functions. At the core are communications satellites, next-generation radios, and an installations-based network with significantly expanded bandwidth. These will provide the basic infrastructure through which data will be routed and shared. In addition, the SWIM would employ a variety of information technology services and applications to manage the flow of information and ensure the network is reliable and secure. Various information technology tools would be available to help users determine what information is available, where to find it, and how best to use it. It is envisioned that communities of interest would be developed, linking users with common interests who would collaborate on analyzing and sharing information. Ultimately, most of SWIM’s operational and support systems, including business systems, and systems belonging to decision makers, would be tied into the SWIM network—serving as both users and providers of data.

The benefits and goals of SWIM should be defined so users and applications can discover the existence of data assets through catalogs, registries, and other services. All data assets are advertised or made visible by providing metadata, which publishes the asset. Users and applications post data in shared space. Posting data implies that: (1) descriptive information about the asset (metadata) has been provided to a catalog that is visible to the enterprise; and (2) the data is stored or transported such that users and applications in the enterprise can access it. Data assets are made available to any user or application except when limited by policy, regulation or security. Data approaches are incorporated into processes and practices and the benefits of enterprise and community data are published throughout the user community.

Key to success, and therefore benefit, is that users and applications can comprehend the data, both structurally and semantically, and readily determine how the data may be used for their specific needs. User and applications can determine and assess the authority of the data source because of pedigree, security level, and access control level of each data asset. Many-to-many exchanges of data can occur between systems through interfaces that are predefined or even unanticipated. Metadata will be available to allow mediation or translation of data between interfaces, as needed. Perspectives of users, whether data consumers or data producers, are incorporated into data approaches via continual feedback to ensure performance.

Challenges

The most critical challenge ahead for FAA is defining, architecting and building the functional requirements to make SWIM a reality. While FAA has taken some preliminary steps to define its vision and objectives for the SWIM, on paper and in policy, it is not fully known how SWIM will meet broader objectives, particularly with respect to setting investment priorities, providing management attention and oversight, transforming operations, and advancing technologies. FAA faces risks inherent with the nature and scope of the effort it is undertaking, for example, risks related to protecting data within the hundreds of systems that will be integrated into the network. FAA recognizes some of these challenges, and many of the actions it is taking to implement SWIM are needed to address them. However, it is too early to assess how successful SWIM will be in addressing the challenges and overcoming long-standing organizational impediments, especially stove-piped programs that do not lever nor integrate other program investments or capabilities.

Some of the key management challenges for SWIM implementation include: (1) deciding what capabilities are affordable; (2) deciding what capabilities are unaffordable or not in line with FAA’s vision for SWIM and enforcing these decisions among hundreds of systems and users; and (3) assuring management attention and oversight is provided to assess the overall progress and determine whether it is providing a worthwhile return on investment, particularly in terms of enhancing aviation operations.

Operationally, the FAA needs to decide when, how, and how much information should be posted on the network and used as well as establish rules to ensure SWIM can work as intended without reducing the benefits of flexible and dynamic information sharing. Importantly FAA must convince its own data owners of the value of sharing data with a broader audience and trusting the network enough to post data. Data ownership and access has been a very significant impediment to improving agency performance. Longstanding technical challenges of developing new technologies and advancing them on schedule remain paramount. FAA must also assure common agreement on technical, as well as information assurance standards and requirements, including developing the means to protect the network. There are also many unknowns concerning how FAA will meet its requirements and vision in terms of people, processes, and, ultimately, operations.

FAA has yet to determine how much information should be posted on the network; when it should be posted; and how and where it should be used. Once these factors are determined, FAA must develop rules of operation to ensure the network can work as intended without precluding the benefits that can be derived from more flexible and dynamic information sharing. FAA needs to be working through questions on whether unlimited amounts of data should be made available through SWIM, including unprocessed or raw data, without the benefit of some assimilation and analysis. These are important questions that need to be addressed in the near future because they could affect the direction of investments in network centric operations and non-network systems as well. Even after these questions are settled, significant operational challenges remain. Executives and managers may need to find ways to adapt to an environment where data can be more readily obtained and shared by subordinates in the chains of command. New operational concepts need to be developed to guide how operations are to be conducted in this enhanced technology environment. They will need to be followed by associated policies and procedures.

FAA also faces a formidable task in persuading the managers and users of the network to rely on information technology applications and services being developed by third parties. This includes developing and providing key voice, video, and data connectivity through core enterprise services for SWIM, such as data query (search or discovery) capabilities and information assurance. In the past, individual FAA offices and programs have preferred to procure their own telecommunications networks and commercial satellite bandwidth services because they were dissatisfied with the level of service provided by the agency as well as the cost and length of time it took to procure these services centrally. While FAA’s Telecommunications Infrastructure (FTI) was supposed to address this issue, FTI has proven problematic in terms of escalating costs and diminishing performance.

Building a reliable, secure network, that will operate on the move, virtually anywhere and provide the necessary information and services to permit network-enabled operations, presents considerable technical challenges. To mitigate these risks, FAA can utilize existing commercial communications and networking technologies, which have advanced significantly in recent years. In many cases, contemporary commercial networks exceed the most stringent FAA safety requirements for safety of life services in availability, reliability, speed, bandwidth and integrity.

SWIM does require FAA to advance a number of key technologies, develop a series of complex systems and software, field them without delay so schedules for other dependent systems are not disrupted, and develop the means to effectively manage and protect the network and its data. It is imperative that FAA be intimately aware and closely aligned to the continuing developments and deployment of the DOD’s GIG. As a first deployment of NEO, the GIG lessons learned are critically important to reduce FAA SWIM costs, technical and schedule risks. In addition, FAA can receive considerable benefit from policy, procedural and technology development of the GIG. This includes the development and deployment of commercial capabilities supporting the GIG. To control risks and costs FAA must be a market taker, not a market maker.

For example, networking, network management, and secure network management challenges are considerable and current mobile networking is limited, mainly to narrowband, fixed infrastructures, and relatively stable user groups. SWIM should require new wideband waveforms that can handle the expected high data rates, throughput of information, and ability to transmit integrated voice, data, and video simultaneously. In addition, dynamic networking capabilities that can automatically adjust to changing circumstances, such as intrusions or node failures, are needed; however, the scalability of network management technologies for a network like the SWIM, with such a large number of nodes, is yet unproven. To facilitate timely and prioritized access to information from a wide variety of sources, the network will require enhanced quality of service mechanisms and algorithms to manage bandwidth allocation and handle the flow of information and security. Furthermore, advances will be needed in several other technological areas, such as antennas, power sources, and the miniaturization of components to facilitate mobile communications.

The increased bandwidth capability conceived by SWIM may not be fully realized if compatible technologies and protocols in upgrading networks are not used. Even if the technologies and protocols are compatible, bandwidth may be limited if these networks are not properly designed and integrated to manage voice, data, and imagery transmissions. Network management policies may pose challenges if common agreement cannot be reached across the government agencies and industry on standards and information assurance requirements.

In the case of the DOD and the intelligence community, they have not yet reached agreement on how they will exchange information and verify security credentials on the GIG network. Further, the complexity and magnitude of enabling hundreds of systems and applications to operate in a secure, Web-based environment will require careful planning and coordination. Comprehensive plans will be needed to ensure that sensitive data and communications are safeguarded across diverse platforms. This will require FAA to identify sensitive data as well as applications, databases, storage subsystems, and media used to process and store the data. Once systems have been examined, data access models must be applied to determine proper security levels for information and how integration can occur across platforms without disrupting network and near-real time operations. It is likely that no one security solution will address GIG or SWIM requirements. Lastly, the enterprise information services planned for the GIG pose timing challenges. For example, in the near-term, DOD has established a goal to complete the transition to Internet Protocol Version 6 by fiscal year 2008. Also, the transition will not be completed until a developed set of performance and technical criteria can be met. In addition, because of the enormous amount of data that will become available, new data fusion methods will need to be developed to help users rapidly identify, access, and make sense of available information.

At this time, however, FAA is pushing ahead on several SWIM component programs without an overall understanding or definition for the total network, its functions and its architectures. Unfortunately, many believe that the SDN and its Flight Objects are synonymous with SWIM. While SDN is a critical SWIM component, it is no more critical than the Aeronautical Information Network. Both are, in fact, a subset of SWIM.

NEO Architecture

The current National Airspace System can be characterized by a number of isolated systems (i.e., communication, navigation, surveillance, infrastructure) and sub-systems (i.e., VHF communications, HF communication, Terminal Radar, En Route Radar, etc.) with little, if any, integration or interoperability. Most of these systems are legacy systems with functions and applications dating from the 1950s and 1960s. The $45 billion spent on modernizing the National Airspace System and its air traffic control component over the last twenty-years has been to infuse old systems with new technology based on a justification of continuing supportability.

To sustain and improve the National Airspace System new visions and paradigms are needed. A path of innovation, automation, integration and consolidation rings as the mantra of transformation as envisioned by the Joint Planning and Development Office (JPDO) for the Next Generation Air Transportation System (NGATS).

The first step in this transformation is the development of a future vision from which concepts of use or concepts of operations can be constructed based upon the identification of user needs, wants and desires. Following a Design for Six Sigma process, this results in a matrix of functional requirements and associated performance metrics. Functional requirements are then translated and iterated into detailed specifications for performance and system/sub-system design. Of course the parts, or sub-systems, must never be segregated from the whole, or system of systems. All parts must work together to optimize performance across all domains and systems.

Current investment requirements and mandates by the OMB in Federal Enterprise Architecture (FEA) play a significant role in vetting SWIM as an architecture that has a sound business case with positive benefits.

FEA has been developed to equip OMB and Federal agencies with a common language and framework to describe and analyze IT investments, enhance collaboration and ultimately transform the Federal Government into a citizen-centered, results-oriented, and market-based organization as set forth in the President’s Management Agenda (PMA). The FEA consists of a set of interrelated “reference models” designed to facilitate cross agency analysis and the identification of duplicative investments, gaps and opportunities for collaboration within and across agencies. The true driver behind E-Government, as stated in the E-Government Act of 2002, is the need to improve the Federal Government’s delivery of services and information to the public and to decision makers. In order to improve citizen services and successfully address issues that transcend single departments, the agency-centric systems and processes characterizing government must be replaced with integrated, citizen-centric applications and processes. The FEA, through its support of the Presidential E-Government initiatives, Lines of Business and other cross-agency efforts, is a key component of the citizen-focused transformation of government. It is critical to note that one of the major objectives of FEA is to address the issue of multiple Federal investments for similar functions, to wit, DOD’s GIG and FAA’s SWIM.

During the last four years, development of the FEA has led to the release of the five FEA reference models to establish a common language for diverse agencies to use while seeking to collaborate on common solutions for services. The Performance Reference Model (PRM) looks at enterprise inputs, outputs and outcomes with uniquely tailored performance indicators. The Business Reference Model (BRM) defines lines of business for agencies, customers and partners. The Service Component Reference Model (SRM) addresses service domains and types as well as business and service components. The Data Reference Model (DRM) focuses on data standardization and cross agency information exchanges. Finally, the Technical Reference Model (TRM) looks at service component interfaces, interoperability, and technologies. Unfortunately, the benefits of FEA are not applicable, relevant or visible at most sub-system levels that characterize FAA’s current investment portfolio. However, at a system or system of system level – meaning the DOD’s GIG or the FAA’s SWIM – the FEA becomes a meaningful and potentially beneficial effort.

The W2COG has suggested that NEO architectures, such as SWIM, share mutual enterprise characteristics and service standards as a Service Oriented Architecture (SOA) that guarantee interoperability through the use of seamless high performance non-proprietary systems that are both reliable and secure. To support this objective the W2COG Institute supports a list of standards propose by the Net-Centric Enterprise Services (NCES) Program Office. It is envisioned that the NCES standards will garner industry support and be sufficient, practical, sustainable and testable.

It is noted that a services approach to system design, implementation and provisioning is based upon an ability to define business or technology capabilities well within a defined boundary that interacts with end users and other services though industry-based standards and message-based protocols. This includes SOA based on software components that implement services, as well as Service Oriented Enterprises (SOE), that are organizationally driven to lever a layered architecture for business process, service oriented applications, service oriented infrastructure (SOI) of virtual resources managed as a utility and service management. An essential part of the approach is explicitly accepting standards for Extensible Markup Language (XML) based protocols, such as Simple Object Access Protocol (SOAP), Web Services Language (WSDL) and Universal Description, Discovery and Integration (UDDI), as a part of the SOA.

Unfortunately, dedication to standards are challenging. Standards may be in flux, cumbersome, implemented differently, sub-optimal, not cost effective or manageable. Notwithstanding, adoption of core standards are appropriate, but only with careful consideration. Thus far six major architectural SOA component areas have been defined. These are: (1) Management; (2) Security; (3) Portal and Presentation; (4) Transactions and Business Process; (5) Messaging; and (6) Metadata. Each of these has related standards as well as core standards recommended by NCES. Emerging standards in security, infrastructure, distributed management and business process coordination continue to add to adoption of migrating standards.

Testing to standards is on a critical path and therefore must be cost effective and timely when considering deployment of critical networks such as SWIM. It appears that a technique known as “test-centered design” is particularly appropriate for SOA because it contains a rigorous definition of interface specifications for XML-based protocols. Automated tools and the generation and execution of unit and integration tests are essential along with “stateless testing” that possessed rapid rollbacks to previous testing states or conditions. Finally, the use of continuous improvement techniques, such as “six sigma” are needed to measure and lower defect rates in production and provisioning.

FAA and SWIM

Notwithstanding, FAA first developed the concept of SWIM in 1997, and FAA is still in the preliminary planning stages for its SWIM version of a Network Enabled or Net-centric System. For example, as of May 2006, FAA was still working on a conceptualization of what is otherwise a network applications layer that is characterized as a National Airspace System-wide information distribution and access mechanism for current and new applications. This delay, or caution, reflects the significant nature and scope of the efforts to totally revise FAA’s infrastructure affecting its mission and culture supported by communication methods, techniques, procedures, policies, hardware and software and personnel.

FAA has stated that SWIM is built on top of the FAA Telecommunication Infrastructure (FTI) to address issues of network connectivity and security without regard to an analysis of FTI’s ability to meet emerging DOD and other federal agency requirements for government-wide standards, including data integrity, seamless interoperability and security.

Another major challenge facing FAA is in rationalizing or justifying SWIM in the context of a broader FEA requirement as mandated by the OMB. While the FEA purports intergovernmental leveraging of technology and investment, it will be difficult for the FAA to couple its SWIM architecture and associated investment with the DOD’s GIG, albeit the mission requirements and network architectures, standards and requirements are virtually identical only diverging at the network applications layer.

FAA’s narrow air traffic control system provider and user perspective in its Concept of Use for SWIM appears too narrow given the intended and stated objective of “information management to support improved operations and productivity of the National Airspace System.” On the contrary, the scope of SWIM, as currently proposed by the FAA, appears to fall short of that proposed and being implemented by the DOD. For example, the failure to include business processes denies real-time management metrics and performance to non-operational FAA managers.

Currently, FAA is defining SWIM objectives and their potential benefits as well as creating wiring diagrams of related systems and applications. While this is an essential first step in exploring, visualizing or conceptualizing SWIM, this high level of detailed network understanding for the Open System Interconnection (OSI) seven layer Network Model, or the TCP/IP four layer network model, is inadequate to assess meaningful risks, costs and benefits with unknown schedules and technologies.

FAA, with the help of contractors such as ITT, has been investigating and developing a SWIM physical architecture development process loosely connected to some minimal network standards. Although functional analysis and NAS level requirements have been outlined, there is a concern that FAA will not monitor parallel DOD efforts to build a compatible and consistent interoperable network. This may mean that FAA may be assuming unneeded cost, schedule and technical risks by building its applications architecture on an “FAA unique” network design requiring specialized FAA-only software and hardware solutions. In some cases, SWIM Architecture Design Issues highlight notable difference between an FAA and a DOD approach to addressing network centric and enabled operations.

Historically, the FAA has a strong cultural bias to seek unique technical and programmatic solutions given the belief that FAA’s safety mission transcends all others. This, coupled with a propensity to insist on total control of designing, building, deploying and maintaining systems, results in FAA creating approaches to plans and programs that fail to lever, or even seriously consider, non-FAA knowledge or experience. In other words, the FAA has a strong tendency to reject commercial alternatives in favor of reinventing technologies or solutions that are in the marketplace or in control of other government agencies. This creates the significant cost and schedule risks and associated consequences that have been an integral part of FAA’s modernization efforts for the last 20 years.

Another area of concern, not uniquely FAA’s, is the program management structure that has been created has a de facto autonomy without overlying integration control among multiple FAA programs and disciplines. This continues to force FAA to duplicate costly program capabilities throughout the agency. The fact that FAA has paid for eight different air traffic controller radar trackers from eight different FAA programs testifies to this point. The development of SWIM will highlight and exacerbate the lack of program integration across and among communication, navigation, surveillance and infrastructure programs. The fixes needed to provide for the baseline interoperable functionality promised by SWIM may very well drive SWIM implementation costs and delays beyond all reasonable expectations.

FAA’s approach to SWIM deployment is critical to its success. Efforts to create a SWIM network by re-mediation of legacy systems, such as the Y2K approach of providing virtually an open checkbook to incumbent vendors to “modify” their hardware and software, is potentially disastrous. Continuing to modernize by wrapping layers of antiquated and outdated system components with new contemporary hardware, software and protocols to function is like building a skyscraper in quicksand. An alternative approach is simply to create a new, independent backbone network meeting all of the NEO requirements and standards. Once this network is validated, new applications can be developed as an integral part of this network and legacy systems can be interfaced only to the extent necessary to meet NEO requirements. This approach creates a new solid foundation for building the future instead of continuing to band-aid the past.

Summary of Benefits

The successful adoption and implementation of FAA SWIM as a network centric and enabled architecture is key to the future National Air Transportation System transformation. From a user perspective, differentiation between wired and wireless communications will blur as data networks become ubiquitous, transparent and homogenous. Spectrum barriers for aviation communication, navigation and surveillance (CNS) will dissolve without today’s functional allocation that hoards unused portions of spectrum. All facets of aviation will benefit, from passengers to pilot to air traffic controllers to managers, as data is contemporaneously provided and near real-time information is instantly received to the millions of nodes on the System-wide Information Management Network. System-wide costs will be reduced and efficiency improved as the timeliness and quality of critical decision-making is improved through future networked enabled operations.

Multilateration Low-cost Surveillance for the Transition to ADS-B

Wed, 17 May 2006 14:15:50 -0400

What is Multilateration?
Multilateration uses Time Difference of Arrival (TDOA) techniques that triangulate on the signals emitted from the aircraft’s transponder and received by multiple ground stations. The time of travel of the signal is compared between these receivers by a central processor and aircraft position is derived. In essence, this is the equivalent of an “inverted GPS” where the aircraft is the satellite and multiple ground stations derive position. Since the transponder response to an interrogation travels at the speed of light, the different arrival times at different receivers can be measured. With TDOA between two receivers on the ground, they form mathematical hyperboloid shapes on which the aircraft is located. With three receivers hearing the same aircraft emission, the aircraft’s position can be determined. Figure 1 illustrates the concept. If the aircraft is also reporting its altitude (Mode C or Mode S) a 3D position can be derived. With four ground receivers, the 3D position of the aircraft can be calculated based on the intersecting hyperbolas.
A processor converts the information received at each receiver and coordinates time differences to derive position. The update rate on aircraft position is based on aircraft interrogation replies and can be a frequent as every 1/2-second. Aircraft with TCAS emit the Mode S squitter and this emission is used in the air and on the ground for surface movement surveillance.
Who Uses Multilateration?
Multilateration is an integral part of the FAA’s ASDE-X surface movement safety system. It is used as the primary means of surveillance and is backed up by ground movement radar. Wide-area multilateration (WAM) has been tested by NASA in the Gulf of Mexico for tracking both low-altitude helicopter operations and high altitude en route flights in experiments examining the performance of multilateration and ADS-B, separately and in combination with each other. Results showed that the surveillance is as good as that from the air traffic control beacon interrogator Model 6 (ATCBI-6), or secondary surveillance radar (SSR).

A multilateration system for terminal arrival is being installed in Juneau, Alaska, where combined with a required navigation performance approach (RNP) will support terminal operations. In addition, engineering trials in St. Louis have shown that a multilateration system can replace the electronically scanned precision runway monitor (PRM). Using multilateration for PRM makes a strong business case for deployment of more units because of the substantially lower cost of multilateration over radar. The St. Louis trials are leading to use in Detroit and Cleveland.

Within the United States, most of the development and use has been on and near the airport. In Europe and Asia, multilateration is starting to be used as an alternative to ATCBI’s and as a substitute for primary radar. The first operationally approved system provides surveillance for the Innsbruck Valley in Austria, an area where traditional surveillance would not work because of terrain and cost. Using nine remote unit receivers and antennas for coverage, wide area coverage accuracies of 10 to 50 meters are being achieved. For Innsbruck, each remote unit has its own accurate timing clock synchronized to a reference transponder. Austro Control is reporting annual operating costs of 150,000 Euros against an estimated 13,000,000 Euro cost if the system used the traditional SSR configuration.

EUROCONTROL has included multilateration in its surveillance strategy and the Czech Republic and Germany are demonstrating that the technique can be used for terminal and en route surveillance. Wide-area Multilateration or WAM operational trials by Skyguide, Germany’s DFS and Austro Control have begun. The Central European WAM project includes coverage from Zurich via Nürnberg, Salzburg to Innsbruck. Europe is also using multilateration for height verification using a 5-receiver system in a grid for reduced vertical separation (RVSM) with a 25-foot height measurement accuracy.

Mongolia, Tibet and China are investing in multilateration, first to provide terminal area coverage, then to link together systems for en route coverage. Multilateration has the advantage of substantially lower cost, an update rate of typically once every second, and has sufficient accuracy to match or out-perform SSR.
How Accurate is Multilateration?
While SSR suffers from range and azimuth errors, a multilateration system suffers from dilution of precision that relates to the geometry of the ground stations and the position of the aircraft. On a typical airport, positional accuracy is on the order of 10 to 23 feet. Within 10 miles of the airport, accuracy is around 30 to 40 feet. Based on testing by EUROCONTROL, multilateration had an effective range of approximately 170 nautical miles (at 35,000 feet elevation) with a 5-receiver system suitable for en route separation. Figure 2 compares the WAM accuracy with SSR and ADS-B using GPS/WAAS.

The advantage to multilateration is the improved update rate of 1-second or less. This significantly reduces target-tracking errors that exist with rotating radars. This is why multilateration can replace an electronically scanned PRM or an SSR for en route and terminal operations. While good enough for existing separation standards, ADS-B can reduce separation over SSR and WAM; however, WAM provides the backup to fully aircraft-dependent surveillance.
Multilateration’s Relationship to ADS-B
This is a good news, bad news story. The bad news is that many of the capabilities that create benefits for ADS-B also create benefits for multilateration. The big difference is that multilateration requires no new avionics equipage. Does multilateration steal away the operational allure of ADS-B? No, but it will slow ADS-B equipage until such time that operational policies and procedures are created that advantage ADS-B. ADS-B using GPS will be far more accurate than WAM across all flight domains and surface operations. However, the greatest benefits of ADS-B come with common situational awareness in the cockpit. The ability to space your aircraft relative to another for passing, station keeping and tailored arrivals will produce the more significant benefits than improved surveillance. Reduction in separation in remote and oceanic airspace brings benefits from ADS-B and common situational awareness. But for some early applications that rely on improved surveillance, requirements can be met with RNP and multilateration.

This is not an “either-or” relationship. Multilateration needs to be viewed as a transition step to ADS-B that produces some modest benefits. The multilateration ground receivers are the same receivers that will be used for ADS-B. A network of these ground receivers will convert the ADS-B information and track data into a format that existing air traffic automation systems can use. In a mixed equipage environment (some with ADS-B and most without) multilateration provides for comparable services as envisioned for  ADS-B Out – the broadcast of position without the benefits of cockpit display of traffic information. The WAM ground infrastructure is the ADS-B ground infrastructure as well.

WAM around terminals can provide the foundational infrastructure for transition to  ADS-B. En route, WAM can provide independent verification of ADS-B position reporting and provide a secondary means of surveillance if the navigation solution on the aircraft is lost due to GPS vulnerabilities. Just as WAM is being evaluated for RVSM compliance, it can be used for ADS-B compliance.

EUROCONTROL and others have identified a number of roles that multilateration could play in direct support of ADS-B:
♣ Verification of navigation accuracy – checking the position used in ADS-B against TDOA-derived position.
♣ ADS-B integrity monitoring – WAM can monitor the integrity of the ADS-B position reports. It would be used initially to gather data for the safety case on ADS-B performance on in-service avionics systems leading to more complex uses of ADS-B. An error in one aircraft’s ADS-B position report can have serious safety implications with the aircraft showing a location different from its actual position.
♣ Anti-spoofing – ADS-B is vulnerable to spoofing. False targets could be broadcast. Multilateration can verify that the aircraft do not exist in the airspace and can identify the source of the spoof transmissions.
♣ Migration path to ADS-B – using WAM receivers that operate on the 1090 extended squitter, WAM can provide SSR equivalent surveillance for both equipped and non-equipped aircraft at lower costs. Surveillance transition becomes transparent to air traffic control.

Multilateration represents a stable and mature surveillance technique that bridges the uncertainties of early implementation of ADS-B. By providing an independent means of monitoring navigation and position reporting, WAM can provide the additional safety margin that would not be there if ADS-B alone were used for separation. But WAM’s cost is significantly less than comparable surveillance beacon coverage.

Unlike most avionics, the operational procedures for the use of ADS-B technology are yet to be invented, tested and proven safe. What multilateration does is provide the underlying surveillance safety services for the anticipated significant changes of how aircraft will operate in the future with ADS-B – a safety transition until full maturity of the ADS-B procedures can be attained.
Recommendations

It often appears that multilateration and ADS-B are in direct competition with each other. While there is some trade-offs on early benefits, the transition cost to ADS-B is mostly in avionics. Since the ground infrastructure for multilateration and ADS-B receivers can be the same, the cost differential to the FAA is minor compared to the transition benefits and possible back-up strategies while ADS-B matures and equipage rises.

While the FAA is clearly committed to multilateration as part of surface movement surveillance and for a replacement to PRM, there is no stated policy to deploy multilateration capabilities as the FAA deploys a network of ADS-B receivers. The NASA Helicopter IFR Tracking System (HITS) operational trials in the Gulf of Mexico demonstrated that ADS-B and multilateration (individually and together) bettered or equaled SSR performance. EUROCONTROL has shown the same results with multilateration over SSR.

FAA should deploy multilateration as an integral element of any ADS-B deployment. WAM and ADS-B should be common elements of the FAA-funded ADS-B program. By networking together the ADS-B ground stations and adding a timing source or reference fixed transponder, WAM can be implemented and benefits can be realized for aircraft with a 1090 or Univeral Access Transceiver ADS-B configuration as well as existing aircraft with a Mode A, C or S transponder.

In responding to ADS-B rulemaking initiatives, FAA should identify the cost and benefit segments attributable to 1) multilateration only, 2) ADS-B only, and 3) a multilateration/ADS-B combination. This allows users and the FAA to better understand the benefits and business case for their own avionics investments.

FAA should encourage wider use of multilateration as a cost-effective alternative to radar-based PRM. This opens up additional airports for independent parallel approaches and simultaneous offset instrument approaches. This will encourage direct user benefits and aid in procedural development in the transition to ADS-B.

FAA should encourage users to consider multilateration and ADS-B as one, with the focus on development of operational procedures over development of the technology. Supporting ADS-B at the expense of ADS-B multilateration only encourages indecisiveness. Multilateration is a step on the transition to ADS-B that 1) provides equivalent surveillance to SSR while providing safety services as ADS-B moves forward, 2) supports early benefits (e.g., additional PRM systems) without additional equipage, and 3) provides surveillance backup to ADS-B globally.

FAA should develop a surveillance strategy that sets time lines and locations for elimination of existing surveillance infrastructure that reduces service life extensions for primary radar and SSR systems not required for national security and homeland defense. Existing surveillance (other than weather radar) should be phased out and replaced with the lower-cost alternatives of multilateration and ADS-B.

Automatic Dependent Surveillance

Wed, 12 Apr 2006 09:42:56 -0400

Currently there is a divergence of government and industry positions concerning concepts, applications, costs and benefits for automatic dependent surveillance broadcast (ADS-B) development, deployment and regulatory status. Most of the potential controversy exists because there is no integrated systems approach that addresses a direct benefits driven transition plan for ADS that enables transformation of the National Airspace System from a ground centric to an airborne centric system.

Marginal Airline Benefits

ADS-B was initially developed and deployed to transmit an aircraft’s position information received from the Global Positioning Satellite System (GPS) to be displayed and used by air traffic control in areas of non-radar coverage. In a broader application, the current ADS-B deployment being discussed by the Federal Aviation Administration (FAA) is a system that can provide potential direct cost reductions to the FAA by replacing older radar systems with this newer and more cost effective technology.

The fact that current FAA domestic radar systems provide virtually 100% coverage of airline operations means that a replacement of radar systems with ADS-B as envisioned by the FAA will unlikely provide any additional widespread benefits to the airlines in terms of air traffic control services or safety. Further, some of the ADS-B potential system enhancements strongly supported by general aviation replicates longstanding airline capabilities, such as airborne electronic collision avoidance and in-flight weather. However, at least one commercial air cargo carrier has found some direct benefits and has adopted ADS-B as a technology that can provide airborne situational awareness to permit for self sequencing and spacing between company aircraft arriving at their airport hub during peak demand in late evening hours. Notwithstanding, broad airline industry direct benefit of ADS-B equipage, at an industry wide estimated cost of $400 million, cannot be found within the current Federal Aviation Administration ADS-B architecture.

The Big Winner

The primary recipient of potential benefit from ADS-B deployment as currently designed is the FAA. ADS-B as a radar replacement technology can provide surveillance information with higher resolution and more frequent position updates at a lower cost than older FAA ground based radar systems. Replacement of the current radar system infrastructure, estimated to cost $371 million annually, by ADS-B systems, estimated to cost $257 million annually, could save the FAA $114 million per year. When and if such savings occur, and when and if the FAA will pass these savings to the users supporting the cost of the air traffic control system is unknown. There are large cost risks associated with a transition that concurrently operates both the traditional radar systems in parallel with a new ADS-B deployment. Notwithstanding the risks, these potential savings may be enough to encourage FAA to mandate ADS-B equipage for all classes of air traffic control system users.

Other Beneficiaries

General aviation is also one of the major beneficiaries of ADS-B deployment with the addition of associated traffic information (TIS-B) and weather services (FIS-B) using a unique general aviation universal access transceiver, called UAT, for communications. These associated services provide general aviation aircraft with electronic airborne collision warning and near real-time severe weather information and substantially adds to general aviation comfort, convenience, economy and safety. Unfortunately, the increased functionality to provide these benefits adds to FAA infrastructure and user avionics costs. To diminish these costs general aviation wants ADS-B transmitted position and altitude to replace future aircraft requirements for standalone avionics transponders. These transponders are currently used with FAA radar systems to provide electronic position and altitude to FAA air traffic control as well as used by airlines for collision avoidance systems. While general aviation supports this ADS-B enhanced deployment concept, a near term regulatory mandate by the FAA is not expected to receive a widespread general aviation endorsement.

Challenges

ADS-B, with an associated UAT function, is a new surveillance technology without direct interoperability or compatibility with traditional secondary radar surveillance systems. This system sends electronic signals from the radar site to an aircraft transponder that receives them. The aircraft transponder then transmits a uniquely coded identification signal at a frequency of 1090 MHz back to the radar site establishing or verifying the aircraft's identification, position and altitude to air traffic control. Unlike less complex Mode 3A/C general aviation transponders, airlines are equipped with Mode S Transponders that also provide airborne threat notification and collision avoidance information and resolution. The most significant safety benefit either transponders or ADS-B avionics broadcasting on 1090 MHz provide is the signal that enables airline TCAS to provide threat notification and collision avoidance information and resolution independent of a ground radar infrastructure.

Unfortunately, general aviation aircraft without a transponder and equipped only with ADS-B and UAT cannot be directly detected by airline aircraft equipped with a standard Mode S Transponder and associated TCAS system. However, general aviation aircraft equipped with ADS-B and UAT will be notified from an associated ground radar site of all aircraft in their vicinity, both ADS-B as well as those transponder equipped. This of course assumes that all aircraft of interest are within areas of radar or transceiver site coverage. To maintain an equivalent level of safety in or out of ground radar coverage the deployment of ADS-B UAT either forces the airlines into a higher level of ADS-B equipage known as ADS-B In with UAT or forces general aviation into retaining or upgrading transponder capabilities. It should be noted that airline aircraft equipped with ADS-B 1090ES could receive ADS-B UAT positional information from a ground transceiver, but only if both aircraft were within a ground radar coverage and transceiver coverage area.

ADS-B Out is a broadcast of position and altitude using the Mode S transponder frequency of 1090 MHz. While ADS-B Out does enable future FAA approved applications of Cockpit Display of Traffic Information (CDTI), it produces no immediate direct airline benefits, although it does allow an eventual decommissioning of traditional FAA radar systems assuming 100% ADS-B Out equipage by all users, commercial, private and military.

Unfortunately, An ADS-B Out strategy of using 1090ES in lieu of UAT by general aviation would deny FIS-B and TIS-B. While, TIS-B and FIS-B could conceivably be deployed with compatibility on the transponder uplink frequency of 1030 MHz, serious safety concerns of competition for limited bandwidth and associated frequency congestion has resulted in moving TIS-B and FIS-B to the UAT protocol and a frequency of 978 mHz.

Airline Alternatives

One alternative to resolve the part of the apparent ADS-B equipage dilemma between FAA, general aviation and the airlines is a transition bridge called multilateration. Multilateration deploys a capability to receive altitude information and triangulate position from all types of aircraft transponders (i.e., Mode 3A/C, Modes S) and ADS-B systems (1090ES and UAT) to present FAA air traffic control surveillance positional accuracy at update rates superior to traditional radars. This means airlines could avoid ADS-B equipage until such time as demonstrable direct benefits to airlines existed. With an FAA deployment of multilateration in conjunction with a ground ADS-B deployment, both airlines and general aviation users can choose an ADS-B equipage solution commensurate with their needs and benefits.

Notwithstanding the benefits of multilateration, the incompatibility between airline Mode S and general aviation ADS-B UAT equipage for airborne collision avoidance still needs to be addressed. For an airlines’ collision avoidance systems to function, an electronic 1090 MHz signal must be received from all possible threat aircraft. This means that general aviation aircraft, even equipped with ADS-B UAT Out or In, must have an operating transponder to be identified. One solution to avoid this dual ADS-B and transponder equipage is to integrate a 1090mHz broadcast feature into the general aviation’s ADS-B. In other words, the general aviation suite would become ADS-B In with TIS-B, FIS-B and a 1090ES Out option for traditional transponder elimination or replacement.

Future Developments

The need for common situational awareness between all airborne aircraft is a foundational safety requirement. In addition, future developments in air traffic control system capacity and efficiency must be accommodated. A continuing evolution of ADS-B In, permitting suitable situational awareness to provide for sequencing, spacing and station keeping between airborne aircraft without ground intervention, is on the path to the next generation air transportation system. The ability of aircraft to automatically negotiate and contract with ground air traffic control systems for four dimensional flight profiles to optimize airspace and runway use and allow air traffic controllers to monitor by control by exception is also on a critical ADS-B In development path to the future.

In terms of a functional architecture, ADS-B is an enabling technology that must be able to migrate as part of an integrated system of systems to meet future system needs as the air traffic control system transitions from a human-centric ground based infrastructure to an automated airborne centric network. The major functions and interfaces are represented in Figure 1. First, the ADS function must be configurable to migrate and accept one or more positioning and/or timing sources. Second, the ADS function must be configurable to migrate and accept one or more two-way communication links with differing protocols, rates and frequencies. Third, the ADS function must support user benefits for comfort, convenience, safety and economy for deployment of 4D trajectory management and aeronautical information, such as TIS-B and FIS-B.

As a keystone for transformation, ADS can drive new paradigms for air traffic control as well as new management opportunities to optimize resources and seek high levels of program integration. This ranges from supporting network enabled operations, to restructuring frequency spectrum allocation and use, to introducing new security initiatives such as geo-encryption.

Recommendations

The development and deployment of ADS technology and its associated benefits will be neither fast nor easy. It must be sustained by a transition driven by recurring incremental near term benefits. The following recommendations are provided as a best compromise to enable the FAA to move forward as quickly as possible to (1) modernize it surveillance capability without pejoratively affecting its customers costs and at the same time (2) implement new safety, efficiency and capacity benefits to improve its customers safety and economic performance.

1. Regulatory mandate of ADS-B with FIS-B and TIS-B for part 91 aircraft only. Additionally, the elimination of the transponder requirement for general aviation aircraft equipped with ADS-B containing integrated 1090 MHz broadcast received by TCAS equipped aircraft.

This recommendation recognizes the ADS-B benefits that accrue to general aviation to enhance safety. It also recognizes the lack of airline industry direct benefit associated with the current ADS-B design.

2. Deployment of multilateration as an initial and integral part of any mandated ADS-B deployment.

This allows the FAA to go forward with ADS-B deployment and associated radar decommissioning without affecting current airline equipage or driving airline costs without direct and tangible benefits. While this may marginally affect FAA equipment costs, the cost impacts are believed far greater to airlines than the FAA if airlines are prematurely forced into a non-beneficial equipage requirement.

3. Develop an ADS-B standard that has a certifiable path with functionality that creates direct benefits to Part 121 operators.
Since the FAA proposed ADS-B architecture is predominantly without direct airline benefit, with an estimated cost of $400 million to a majority of ATA members, a navigable path to future direct benefits must be defined by FAA and industry. The value of this approach is that ATA does not reject ADS-B as a basic concept with its indirect benefits, but rather attempts to refocus ADS-B development and efforts into functionality that creates growth, over time, of tangible direct benefits to ATA members and justifies the cost of equipage and associated upgrades through direct demonstrable benefits.

No New Money for FAA

Sat, 28 Jan 2006 10:54:46 -0500

AMA’s Mike Harrison recently produced an outstanding treatise on the impact to the FAA if no new moneys were made available for future system investments. Mr. Harrison further explores how FAA can achieve cost reductions in response to this no new money scenario. This document is available for download as No New Money.pdf