4-1-5. FIX USE

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  • 4-1-5. FIX USE

    Request aircraft position reports only over fixes shown on charts used for the altitude being flown, except as follows:

    NOTE: Waypoints filed in random RNAV routes automatically become compulsory reporting points for the flight unless otherwise advised by ATC.

    1. Unless the pilot requests otherwise, use only those fixes shown on high altitude en route charts, high altitude instrument approach procedures charts, and SID charts when clearing military turbojet single-piloted aircraft.
    2. Except for military single-piloted turbojet aircraft, unpublished fixes may be used if the name of the NAVAID and, if appropriate, the radial/course/ azimuth and frequency/channel are given to the pilot. An unpublished fix is defined as one approved and planned for publication which is not yet depicted on the charts or one which is used in accord with the following:
      • FAA Order 8260.3C, United States Standard for Terminal Instrument Procedures (TERPS), Chapter 17, Basic Holding Criteria.
      1. Unpublished fixes are formed by the en route radial and either a DME distance from the same NAVAID or an intersecting radial from an off-route VOR/VORTAC/TACAN. DME must be used in lieu of off-route radials, whenever possible.
      2. Except where known signal coverage restrictions exist, an unpublished fix may be used for ATC purposes if its location does not exceed NAVAID altitude and distance limitation, and when off-route radials are used, the angle of divergence meets the criteria prescribed below.

        NOTE: Unpublished fixes should not negate the normal use of published intersections. Frequent routine use of an unpublished fix would justify establishing a fix.

      3. Do not hold aircraft at unpublished fixes below the lowest assignable altitude dictated by terrain clearance for the appropriate holding pattern airspace area (template) regardless of the MEA for the route being flown.
      4. When the unpublished fix is located on an off-route radial and the radial providing course guidance, it must be used consistent with the following divergence angles:
        1. (a) When holding operations are involved with respect to subparas (b) and (c) below, the angle of divergence must be at least 45 degrees.
        2. (b) When both NAVAIDs involved are located within 30 NM of the unpublished fix, the minimum divergence angle is 30 degrees.
        3. (c) When the unpublished fix is located over 30 NM from the NAVAID generating the off-course radial, the minimum divergence angle must increase 1 degree per NM up to 45 NM; e.g., 45 NM would require 45 degrees.
        4. (d) When the unpublished fix is located beyond 45 NM from the NAVAID generating the off-course radial, the minimum divergence angle must increase 1/2 degree per NM; e.g., 130 NM would require 88 degrees.
    3. Fixes contained in the route description of MTRs are considered filed fixes.
    4. TACAN-only aircraft (type suffix M, N, or P) possess TACAN with DME, but no VOR or LF navigation system capability. Assign fixes based on TACAN or VORTAC facilities only.

      NOTE: TACAN-only aircraft can never be held overhead the NAVAID, be it TACAN or VORTAC.

    5. DME fixes must not be established within the no-course signal zone of the NAVAID from which inbound holding course information would be derived.