STATEMENT OF RICHARD L. DAY, SENIOR VICE PRESIDENT FOR OPERATIONS, AIR TRAFFIC ORGANIZATION, FEDERAL AVIATION ADMINISTRATION, ON NEXTGEN: AREA NAVIGATION (RNAV)/REQUIRED NAVIGATION PERFORMANCE (RNP), BEFORE THE HOUSE COMMITTEE ON TRANSPORTATION AND INFRASTRUCTURE, SUBCOMMITTEE ON AVIATION, JULY 29, 2009.

Chairman Costello, Congressman Petri, and Members of the Subcommittee:

Thank you for inviting me here today to discuss the Federal Aviation AdministrationÕs 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 Ònavigation specifications,Ó 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 aircraftÕs 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 pilotÕs 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 Òradius to turnÓ 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 Òradius to turnÓ procedures means air traffic is easier to Òdeconflict,Ó or route in a manner that avoids other air traffic paths.

Text Box: Reserved: Reserved: Reserved: Reserved: Text Box: Increased Airspace
Efficiency
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Use of Airspace
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Flexibility
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Navaids 
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Paths
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Path
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Figure 1. Performance-Based Navigation: RNAV/RNP

 

 

Benefits

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: