Document ID: chunk:federal_register_of_legislation:F2022C00813:reg:300:p14
Version: federal_register_of_legislation:F2022C00813
Segment Type: reg
Provision Reference: reg 300 (pt 14/27)
Character Range: 107106–110039

of approach it may be decided to integrate the DME/GPS arrivals with a procedure already prescribed in AIP DAP.

8.3.6                   Missed Approach

8.3.6.1              The MAPT is either the azimuth facility or a point prior to this facility, and is identified for each procedure together with the 'Missed Approach' instruction on the procedure plate.

8.3.6.2              The missed approach areas and the obstacle clearance criteria are the same as those for Instrument Approach and Landing Procedures and are outlined in ICAO PANS-OPS, Vol II Part 3 Chap 7.

8.3.7                   Method of Production

8.3.7.1              The following steps must be followed in designing DME/GPS Arrivals.

(a)         Obtain appropriate WAC, 1:250 000 Military Map, 1:100,000 MAP, ERC (Area Chart VTC if available) and instrument approach chart. Ensure that the latest issue of each chart is obtained.

(b)         Plot the required track or sector on the WAC and largest scale map available.

(c)          Plot the primary and secondary axes around the required track or section in accordance with Figure 8‑18 and Figure 8‑19.

(d)         From the ERC or Area Chart determine En-route, LSALT and airspace steps (CTA).

(e)         List the elevation and DME/GPS distances of terrain and obstructions in descending order within the tolerance areas, commencing at the point where descent below the LSALT first becomes possible. In the calculation of obstacle heights, additional clearance should be made for chart error, mountainous terrain, vegetation and built-up areas.

(f)            Add to the identified obstacles the applicable MOC required by paragraph 8.3.3.

(g)         Plot the obstacles on a sheet of graph paper, after the determination of a suitable DME distance v Altitude scale. Then, at the top of each obstacle construct a vector parallel to the DME/ALT line and toward the navigation aid, equal to the applicable DME or GPS tolerances (see paragraph 8.3.2.3).

(h)         Construct MOC DME/GPS steps by drawing a broken line from en-route LSALT to each of the corrected obstacle positions to minimum altitude (see Figure 8‑21).
           Figure 8‑21: DME/GPS steps

(i)            If the route or sector is in controlled airspace, it will be necessary to arrange the descent steps so that an aircraft is kept 1,000 ft or 500 ft (as applicable) above the lower limit of the controlled airspace at all times, as well as maintaining the minimum terrain clearance.

(j)            It is desirable to provide a steady rate of descent through the steps, (that is, one that can be comfortably achieved by unpressurised aircraft and easily achieved by pressurised aircraft). For this purpose 160 ft per NM is a satisfactory figure. This rate of decent, represented by the full line in Figure 8‑21, extends to the minimum altitude without infringing any of the terrain clearance steps that are represented by the dotted