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Interactive Briefing

A Web Based Tool on the Cutting Edge of RNAV Route Design for En-Route and Terminal Environments

RNAV-Pro‘s Login Screen

As the use of RNAV to increase the flexibility of the world’s airspace grows, system users and designers are taking a hard look at how to best utilize RNAV technology. In response to this need, Air Traffic Simulation, Inc. (ATSI) has developed RNAV-Pro™, a powerful new design and evaluation tool, to cover a wide range of RNAV route design issues. Along the way, ATSI has paid particular attention to easing the burden on the designer by making the process user-friendly. As Dr. David Lankford of the United States Federal Aviation Administration (FAA), has said, “If you can use a computer mouse, you can use RNAV-Pro™.”

RNAV-Pro™ is a universal, powerful, and user-friendly RNAV tool to satisfy both the needs of the FAA as well as other user groups in the U.S. and abroad. As the design matured, RNAV-Pro™ was customized to FAA requirements under a contract with AFS-440 at the Mike Monroney Aeronautical Center in Oklahoma City, Oklahoma. In accordance with ATSI’s tradition of creating flexible tools for an international audience, RNAV-Pro™ was specifically designed to use any database and criteria available for the system.

RNAV-Pro‘s display area showing
worldwide airports and DME facilities
from the DAFIF database.

Today, RNAV-Pro™ on the web is FAA’s Flight Standards-approved tool to be used to evaluate key RNAV and RNP route elements. These elements include TERPS Criteria Screening, Flyability Screening, DME/DME Screening, Radar Coverage Screening, and Communication Coverage Screening.

A key element in the design of RNAV-Pro™ is allowing the user to access databases in a useful manner. In the Display module, the user has the ability to display a wide variety of data. Airports, runways, navigation aids, airways, sectional charts, and many other items are available to the user to aid in the design and screening of RNAV routes. Additionally, RNAV-Pro™ allows the user to search the available databases to locate a specific facility and display detailed information. DTED terrain information is also available to the user in the form of topographical maps and active tracking of the mouse cursor. Each item on DrawSpace™, RNAV-Pro‘s fully geodetic display area, is mouse-sensitive and allows the user to display all applicable information available in the database. Measuring WGS84 geodetic distances and azimuths has never been easier than with RNAV-Pro‘s assortment of mouse controls.

DME/DME Screen of an RNAV Departure

RNAV-Pro™ is well-suited to both the en-route and terminal areas. RNAV-Pro™ is specifically designed to handle the many different concerns that arise in the various environments. All of the screening options available in the software can be automatically specified based on the en-route or terminal procedure, including DME/DME RNP value, inertial navigation system settings, and surveillance system usage.

RNAV-Pro‘s sophisticated generic FMS model allows the user to easily input almost any existing or proposed procedure. In a basic description of the design process and evaluation, an RNAV route can be established by choosing a runway of departure and then clicking the mouse wherever a waypoint is to be placed. After the route is entered, RNAV-Pro™ puts its flight model to work “flying” the route to evaluate it from several different perspectives. The sophistication of the analysis is at the heart of what makes RNAV-Pro™ such a valuable tool.

DME/DME Screen of an RNAV En-Route

Flyability Screening prevents designing a route with waypoints placed at locations aircraft will not be able to follow. RNAV-Pro™ detects these problems for a variety of aircraft categories and flight conditions and notifies the user of the necessary changes.

Screening for availability of DME/DME coverage is another essential analysis performed by RNAV-Pro™. In order to fly the route, a satisfactory DME/DME geometry must be retained to achieve the desired navigational accuracy. The ability to receive those DME signals depends on various factors, such as the minimum proposed RNAV route altitude, the number of DMEs in the area, their relative positions with respect to the RNAV route, and individual DME facilities service volumes and restrictions. Terrain obstructions, co-frequencyinterference, and other obstacles can also prevent the aircraft from receiving the necessary DME signal. RNAV-Pro™ analyzes all of these factors to obtain the most realistic assessment of the navigational accuracy available to the RNAV route in all phases of flight, including en-route and terminal areas.

DME/DME Area analysis

In addition to DME/DME analysis, RNAV-Pro™ has an inertial navigation system model to allow the user to evaluate navigation on aircraft with certified inertial navigation systems. Beyond screening specific routes, entire areas may be evaluated for DME coverage at a given altitude or range of altitudes with the DME Area Analysis option. In order to ensure exact signal availability, RNAV-Pro‘s DME/DME analysis results have been designed to interface with the FAA’s Flight Inspection Aircraft.

Radar coverage screening may also be important in the design of an RNAV route. For low-altitude or extremely remote routes, the user may want to verify radar coverage. Communications capability with ATC can be a concern for RNAV routes as well, so RNAV-Pro™ combines both Radar and Communication coverage screening in its in-depth analysis system. Detailed results are available including precise areas of the route for which radar and communication facilities are not available.

TERPS criteria pre-screening is included in RNAV-Pro™ for terrain and obstruction evaluation. Multiple TERPS criteria, including 8260.40B, 8260.44A, 8260.50, and 8260.51A, allow the user to evaluate terminal and en-route environments.

DME/DME Results

The demand for RNAV procedures will increase as more aircraft become equipped with navigation systems that can take advantage of the flexibility RNAV provides. Because of the complexity of designing viable RNAV routes, RNAV-Pro™ is an essential tool to automate the design and analysis process. Beyond this, RNAV-Pro‘s design has been tailored to be user-friendly so that the complexities of the analysis are complemented by the simplicity of its operation.

RNAV-Pro™ is a web-based application. An authorized user can access the system from virtually any computer connected to the internet. This greatly helps the process of responding to changes in criteria, keeping critical databases current, and ensuring the latest data is available to all users.

Because of its highly modularized design, RNAV-Pro™ can be customized to meet the needs of different customers. For more information of the system’s specific capabilities, please visit the online training system at In order to experience the system first hand, users meeting eligibility requirements may obtain a trial username and password by sending an email with name, organization, and contact information to RNAV-Pro™ can be customized for specific needs to meet special requirements. For more information on system customization, please email