July 29, 2009
Statement of Rick Day, Senior Vice President for Operations, Air Traffic Organization
Before the House Committee on Transportation and Infrastructure, Subcommittee on Aviation on Nextgen: Area Navigation (RNAV)/Required Navigation Performance (RNP)
Chairman Costello, Congressman Petri, and Members of the Subcommittee:
Thank you for inviting me here today to discuss the Federal Aviation Administration's program for area navigation (RNAV) and required navigation performance (RNP) air traffic control routes. RNAV/RNP is a building block for the Next Generation Air Transportation System (NextGen), and has already shown great promise in enhancing safety and efficiency in the National Airspace System (NAS).
Through NextGen, the FAA is addressing the impact of air traffic growth by increasing NAS capacity and efficiency while simultaneously improving safety, reducing environmental impacts, and increasing user access to the NAS. To achieve its NextGen goals, the FAA is implementing new Performance-Based Navigation (PBN) routes and procedures that leverage emerging technologies and aircraft navigation capabilities.
What is Performance-Based Navigation?
PBN is a framework for defining performance requirements in "navigation specifications," that is, to specify that the avionics can function in a particular way or ways, that the pilot is appropriately trained and follows certain procedures in the cockpit. PBN can be applied to an air traffic route, instrument procedure, or defined airspace. PBN provides a basis for the design and implementation of automated flight paths as well as for airspace design and obstacle clearance. Once the required performance level is established, the aircraft's own capability determines whether it can safely achieve the specified performance and qualify for the operation.
What Is RNAV?
Prior to satellite navigation capabilities, i.e. global positioning systems or GPS, aircraft could only navigate primarily by ground-based navigation aids, such as VHF Omni-directional Range (VOR) equipment. This limited the routes that aircraft could take, depending on the location and position of those ground-based aids, and necessarily involved certain inefficiencies during flight, e.g., instead of flying a direct route, an aircraft might have to take a more circuitous route in order to navigate from ground-based point to ground-based point.
Now, with advances in technology, we are able to take advantage of space-based navigation sources that provide for additional navigational coverage. An aircraft using RNAV can fly on any desired flight path within the coverage of ground- or space-based navigational aids, within the limits of the capability of the systems onboard the aircraft, or a combination of both capabilities. As such, RNAV aircraft have better access and flexibility for point-to-point operations. This leads to the potential for flights to reduce the miles flown, save fuel, and enhance efficiency.
RNAV also helps solve operational issues. For example, an RNAV approach may be available in areas where we cannot install or maintain a ground-based navigational aid, such as in Alaska, where the terrain either does not permit the ability to install the navigational aid or the weather conditions preclude us from being able to maintain the operability of the navigational aid.
What Is RNP?
RNP is RNAV with the addition of an onboard performance monitoring and alerting capability. A defining characteristic of RNP operations is the ability of the aircraft navigation system to monitor the navigation performance it achieves and inform the crew if the requirement is not met during a flight operation. This onboard monitoring and alerting capability enhances the pilot's situational awareness and can enable reduced obstacle clearance or closer route conformance without intervention by air traffic control.
Certain RNP operations require advanced features of the onboard navigation function and approved training and crew procedures. These operations must receive approvals known as Special Aircraft and Aircrew Authorization Required (SAAAR), similar to approvals required for operations to conduct Instrument Landing System Category II and III approaches. In addition to certified avionics, the flight crew must be trained and authorized to fly these complex procedures.
The attached chart shows how RNAV and RNP have improved the navigational process. See Figure 1 below. As you can see, using the current ground navaids, the aircraft has to fly from beacon to beacon, often taking an inefficient route in order to pick up the signals at the appropriate place in the air. The dotted boxes indicate the expanse of the area in the sky that the aircraft could be in as it picks up those ground-based signals. This requires our air traffic control to create larger areas of separation between aircraft, in order to maintain safety. In the RNAV and RNP routing, however, the dotted areas are far smaller, indicating that the aircraft can fly a much more precise route in the air. Additionally, the graphic illustrates the RNP "radius to turn" ability, essentially indicating how RNP enables the aircraft to make much tighter, more precise turns in the air. This is particularly useful in areas where the airspace is congested and there are multiple busy airports. The ability of the aircraft to use these "radius to turn" procedures means air traffic is easier to "deconflict," or route in a manner that avoids other air traffic paths.
Figure 1. Performance-Based Navigation: RNAV/RNP
RNAV and RNP capabilities facilitate more efficient design of airspace and procedures which collectively result in improved safety, access, capacity, predictability, and operational efficiency, as well as reduced environmental impacts. Specifically, improved access and flexibility for point-to-point operations help enhance reliability and reduce delays by defining more precise terminal area procedures. They also can reduce emissions and fuel consumption.
RNAV procedures can provide benefits in all phases of flight, including departure, en route, arrival, approach, and transitional airspace. For example, Standard Terminal Arrivals (STARs) can:
- Increase predictability of operations
- Reduce controller/aircraft communications
- Reduce fuel burn with more continuous vertical descents
- Reduce miles flown in Terminal Radar Approach Control (TRACON) airspace
- Reduce interaction between dependent flows in airspace shared for adjacent airport operations.
How are RNAV/RNP Procedures Created?
RNAV/RNP procedures have been developed by the FAA, with the support of industry and MITRE, in a complex, multi-layered process. For Terminal RNAV procedures (those RNAV procedures in the airspace into an airport terminal environment), for example, there is an 18-step implementation process. See Figure 2 below.
Figure 2. 18-Step Guidelines for Terminal RNAV Procedure Implementation
Several offices within the FAA play essential roles in the development of these procedures. Their various duties are outlined below:
Air Traffic Organization:
- Serves as the lead office for implementation and integration of RNAV and RNP routes and procedures into the air traffic environment
- Coordinates policy and implementation activities with industry and within FAA
- Provides guidance for and expedites the development of PBN criteria and standards and implements airspace and procedure improvements
- Collaborates with the U.S. and international aviation communities – government and industry – as a leader in developing PBN concepts, technical standards, operator requirements, and implementation processes to enhance safety, increase capacity, improve efficiency, and reduce the environmental impact of aviation
- Provides technical and operational guidance within FAA. This group also develops and maintains processes and tools to aid the field with RNAV/RNP procedure design
Aviation System Standards
- Oversees the standard development, evaluation, and certification of airspace systems, procedures, and equipment
- Designs and develops instrument flight procedures (IFPs), publishes aeronautical charts and digital products for air carrier and general aviation pilots for use throughout the United States and around the world
- Provides aircraft maintenance and engineering services, operates a fleet of flight inspection aircraft for airborne evaluation of IFPs and electronic navigational signals
- Responsible for procedure design evaluations for airspace and procedures usage, letters of agreement, video map updates, automation coding and controller familiarization and training in accordance with the 18-step RNAV implementation process
- Responsible for designing and using the procedures operationally
Flight Standards Service
- Develops and establishes criteria for civil and military terminal instrument procedures
- Develops rules, standards, policies, and criteria governing the operational aspects of en route, terminal, and instrument flight procedures (except air traffic control procedures)
- Performs operational evaluations, including flight simulation, flight simulator, and in-flight testing of standards and criteria
- Assesses the impact on safety and provides radar separation analysis tools
- Oversees all of flight inspection policy and all instrument flight procedure development
- Administers safety standards governing the design, production, and airworthiness of civil aeronautical products, such as the avionics required for RNAV/RNP
- Oversees design, production, and airworthiness certification programs to ensure compliance with prescribed safety standards
- Provides a safety performance management system to ensure continued operational safety of aircraft
- Works with aviation authorities, manufacturers, and other stakeholders to help them successfully improve the safety of the international air transportation system
Air Traffic Safety Oversight Service
- Establishes safety standards and provides independent oversight of the Air Traffic Organization – the provider of air traffic services in the United States
- Accomplishes safety oversight in a variety of ways including:
- Developing and amending regulations and guidance for regulatory oversight and credentialing functions
- Participating in the development and harmonization of air traffic control international standards
- Providing regulatory oversight of the Air Traffic Organization Safety Management System
What Is the Status of RNAV/RNP?
Currently, we have 159 RNAV routes and 270 RNAV arrival and departure procedures implemented into the NAS and 163 RNP SAAAR approach procedures. By the end of fiscal year 2009, we anticipate that we will have an additional 48 RNAV routes, 35 RNAV arrival and departure procedures, and 29 RNP SAAAR approach procedures in place. Additionally, other PBN procedures such as Localizer Performance with Vertical Guidance approaches throughout the NAS elevate the overall number of Performance Based Procedures to over 8,000.
What Are the Challenges of RNAV/RNP?
The development of RNAV/RNP procedures is a relatively young program at the FAA. The agency only began developing these procedures in 2002. Along the way, we have encountered some challenges and learned from them. We intend to apply those lessons moving forward.
While we have a standard process for developing RNAV/RNP procedures in the Terminal area, we did not have a comparable process for developing procedures elsewhere in the operational environment. We believe this as an area in which we could improve, and have asked for an agency-wide mapping of all PBN processes to standardize how we develop, test, chart, and implement Performance-Based Navigation procedures. I am pleased to report that we should be starting work on that Process Mapping in the next couple of weeks.
As we move forward, there are other challenges that continue to face us in the advancement of RNAV/RNP. For example:
- International Harmonization: What the FAA terms "RNP SAAAR" (defined above), the bulk of the international community refers to as "RNP AR." As always, we want to make sure that our terms and procedures are harmonized with international standards to reduce confusion and enhance safety. As a result, we are transitioning this term to harmonize with the international community's term. We will continue to work with our counterparts internationally in addressing these types of issues.
- Environmental Issues: While many RNAV/RNP procedures are considered "overlays," that is, following essentially the same flight path that air traffic follows today, the implementation of some RNAV/RNP procedures will trigger the need for a detailed quantitative environmental review because the location and number of proposed flight paths may be different from what currently exists. The FAA has a strong commitment to environmental stewardship and doing our best to analyze and mitigate the impact on the public in terms of noise and emissions, while maintaining safety of the NAS. While the FAA understands the frustration felt by industry on the delay to implementation that these environmental reviews may cause at times, we take our environmental responsibilities seriously and will not compromise our environmental stewardship responsibilities for the sake of expediency.
- Hybrid Environment: As the aviation industry moves towards equipping their aircraft to take full advantage of RNAV/RNP benefits, we are bound to see a mix of differing aircraft capabilities in the NAS, flying different types of procedures. This "hybrid environment" will certainly present additional challenges to our controllers, but we are fully confident that they will be able to handle these challenges as we deploy decision support tools, technology, and training. Because equipage remains a challenge to some in the aviation community, the FAA is committed to providing a safe environment in the NAS for all users.
- Third-Party Development: There are several third-party vendors available who are capable of developing RNAV/RNP procedures for specific projects. We are working with two of them (Naverus and Jeppesen) to authorize them to do procedure development, flight validation, and maintenance of Public RNP SAAAR instrument approaches, under FAA supervision. However, the safety of the NAS is the FAA's mission and responsibility. When we do use these third-party resources, FAA is committed to overseeing their work to ensure safe development and implementation into the NAS. We will not abdicate our responsibility to assure safety.
- Prioritization of Procedures: As the benefits of RNAV/RNP become clearer to users of the NAS, we have received increasing requests to add or accelerate new RNAV/RNP procedures more widely in the NAS. The FAA certainly appreciates the validation of our work, but we caution that implementation of new procedures into the NAS must be done carefully and methodically to ensure a cohesive system. Moreover, as the RNAV/RNP program matures, we are discovering that certain procedures may provide greater benefits for industry, the flying public, and the NAS overall. Safe and effective integration of these procedures are of paramount importance to the FAA, and as such, we are working to deploy them in a manner that will maximize the benefits of RNAV/RNP.
Some of our other technical challenges are illustrated in the graphic below. See Figure 3.
Figure 3. RNAV/RNP Implementation and Challenges
As you can see, the FAA has developed a solid foundation of routes and procedures for RNAV/RNP, which serves as a platform of the enhanced safety and efficiency goals of NextGen. Since we have this foundation, we are transitioning from a site-by-site (or runway-by-runway) implementation process toward a NextGen readiness concept that would include development of an integrated system of PBN routes and procedures NAS-wide. This broader view will go further in advancing NextGen and better accommodate our intent to accelerate NextGen as much as possible. In the end this integrated approach will optimize benefits for operators, and ultimately, the traveling public. While we anticipate challenges along the way, we have learned from our work over the past few years and are prepared to meet those challenges effectively.
Mr. Chairman, Ranking Member Petri, Members of the Subcommittee, this concludes my prepared remarks. I would happy to answer any questions you may have.