Chapter 20. Air Traffic Service Routes

Section 5. Area Navigation (RNAV) Routes

20-5-1. PURPOSE

Area navigation (RNAV) is a method of navigation that permits aircraft operation on any desired flight path ­within the coverage of ground- or space-based navigation aids, or within the limits of the capability of ­self-contained aids, or a combination of these. The potential advantages of RNAV routes include:

  1. Time and fuel savings;
  2. Reduced dependence on radar vectoring, and speed assignments allowing a reduction in required ATC ­transmissions; and
  3. More efficient use of airspace.

20-5-2. RNAV ROUTE CRITERIA

  1. Refer to FAA Orders 8260.3, United States Standard for Terminal Instrument Procedures (TERPS); ­8260.19, Flight Procedures and Airspace; and 8260.58, United States Standard for Performance Based ­Navigation (PBN) Instrument Procedure Design, for criteria and procedures applicable to RNAV route ­development.
  2. The basic width of an RNAV route is 8 NM (4 NM each side of the route centerline).
  3. Operational and airworthiness guidance regarding operation on U.S. Area Navigation routes may be found ­in AC 90-100, U.S. Terminal and En Route Area Navigation (RNAV) Operations.

20-5-3. WAYPOINTS

  1. A waypoint is a predetermined geographical position defined in terms of latitude/longitude coordinates, ­using a degrees, minutes, seconds, and hundredths of a second format.
  2. RNAV waypoints are used not only for navigation references, but also for ATC operational fixes. ­Waypoints are to be established along RNAV routes at:
    1. The beginning and end points of the route;
    2. Points where a route changes direction;
    3. Holding fixes; and
    4. Points required due to the maximum distance allowed between NAVAIDs, fixes or waypoints.
  3. Waypoint names must consist of a single, five-letter pronounceable name. Five-letter names are assigned ­by AIS (see paragraph 3-3-4 in this order).

20-5-4. LATERAL PROTECTED AIRSPACE CRITERIA FOR RNAV EN ROUTE SEGMENTS

The primary en route obstacle clearance area has a width of 8 NM; 4 NM on each side of the centerline of the ­route. Primary, secondary, and turning area criteria are found in FAA Orders 8260.3, United States Standard for ­Terminal Instrument Procedures (TERPS); 8260.19, Flight Procedures and Airspace; and/or 8260.58, United ­States Standard for Performance Based Navigation (PBN) Instrument Procedure Design, as applicable.

20-5-5. RNAV ROUTE DESCRIPTIONS

  1. RNAV route descriptions are published in Order JO7400.11. RNAV routes consist of points that may be ­defined as waypoints, fixes, and/or ground-based navigation aids.
  2. RNAV route descriptions must be formatted as follows:
    1. On line one:
      1. The route number; and
      2. The route start/end points (i.e., point name, state, and NAVAID ID as required);
    2. On subsequent lines for each point that makes up the route:
      1. The point name, state, and NAVAID ID as required;
      2. The type of point (i.e., WP, Fix, or NAVAID type); and
      3. The geographic coordinates of each point expressed in degrees, minutes, seconds, and hundredths of ­a second.
    3. On the last line, if applicable: Any exclusions from the route (e.g., “Excluding the airspace within ­Canada”).
  3. See Section 1 of this chapter for information on route numbering.
  4. Examples of RNAV route descriptions: