Document ID: chunk:federal_register_of_legislation:F2022C00813:reg:300:p12
Version: federal_register_of_legislation:F2022C00813
Segment Type: reg
Provision Reference: reg 300 (pt 12/27)
Character Range: 101718–104731

or GPS distance measurement and ground based azimuth guidance facilities. The procedure is prescribed for particular tracks or sectors and takes the form of a series of descending steps at appropriate distances.

8.3.1.2              The procedure normally uses a DME that is located close to the azimuth facility but in some cases use is made of a remote beacon. Procedures must be contained within the demonstrated coverage of the navigation aids used. Where more than one tracking aid exists at an aerodrome, tracking is normally permitted to either aid. However, only one GPS reference waypoint is nominated as the GPS distance source. The GPS reference waypoint is either the position of the azimuth aid nearest the DME for DME/GPS procedures, or the position of the primary azimuth aid for GPS only procedures. Azimuth and distance tolerances must be accounted for when determining obstacle or airspace clearance.

8.3.1.3              In designing a DME/GPS arrival, allowances are to be made for terrain clearance, navigational tolerances and errors in DME/GPS distance measurement. In addition, steps are to be designed to maintain an aircraft in controlled airspace where this is applicable to the particular route. Details of the allowances are set out in the following paragraphs.

8.3.2                   DME/GPS Arrival Procedure Design

8.3.2.1              DME/GPS arrivals are instrument approach procedures. DME and DME/GPS arrival procedures are not included in ICAO DOC 8168 – OPS/611 Volume II, but are designed using the criteria contained in that document applicable to non-precision approaches and therefore have initial, intermediate and final approach segments. To account for control area steps, the step information is frequently extended beyond the initial approach fix (IAF) into the en-route segment. The method of blending the en-route segment to the procedure is shown in Figure 8‑18. Should the procedure be for a sector, the centreline of Figure 8‑18 is expanded by the size of the sector (Figure 8‑19).
Figure 8‑18: Track DME/GPS arrival
Figure 8‑19: Sector DME/GPS arrival

8.3.2.2              DME/GPS arrivals shall:

(a)         not terminate below the circling minima.

(b)         normally have the following segment lengths (variations must be noted on charts by reference to DME distance):

(i)            initial segment—5 NM;

(ii)          intermediate segment—5 NM;

(iii)        final segment—as required;

Example:

If a procedure is based on a DME which is 1 NM beyond the azimuth aid and the procedure has standard length segments, the DAP would have to show 'IAF 16 DME, FAF 6 DME'.

(c)          be designed with a MAPT;

(d)         assume that manoeuvring across sectors is minimised after the intermediate fix;

(e)         not utilise the 15% horizontal gradient provisions of PANS-OPS Vol II paragraph 2.8.4 for sector procedures except in the final segment.

8.3.2.3              The navigation tolerances applicable to the facility which may be used to