Document ID: chunk:federal_register_of_legislation:F2022C00813:reg:300:p10
Version: federal_register_of_legislation:F2022C00813
Segment Type: reg
Provision Reference: reg 300 (pt 10/27)
Character Range: 96495–99398

the navigation tolerance area.

(b)         where heights are shown on charts as spot heights, contours and hypsometric tints—the highest spot height within the navigation tolerance area or, where there is no spot height, the highest terrain within the intruding contours.

8.2.3.3              As spot height information shown on charts may not necessarily indicate the highest terrain in that area, it is necessary to examine the contour information to ensure that no higher terrain exists that would control the LSALT. Further, whenever contour intervals are used to determine the highest terrain, then the highest terrain must be assumed to be at the level of the next higher contour.

8.2.3.4              Obstacles shown on Australian produced WACs are generally limited to those having a height of 360 ft (110 m) or more. Therefore, whenever these charts are used for the determination of LSALTs an obstacle allowance of 360 ft must be made. Further, due to this allowance, caution must be exercised when a published tower/mast appears at first to be the critical obstacle. With the addition of the 360 ft obstacle allowance it is possible that the corrected highest terrain within the navigation tolerance area may be higher than the tower/mast first identified as the critical obstacle.

8.2.4                   Altitude Tolerance

8.2.4.1              Where the corrected highest terrain (refer paragraphs 8.2.3.3 and 8.2.3.4) in the navigation tolerance area for a particular route or route segment is not above 500 ft, and there are no obstacles above 500 ft, the LSALT must be 1,500 ft.

8.2.4.2              In Australia, where the corrected highest terrain or obstacle in the navigation tolerance area for a particular route or route segment is above 500 ft, the LSALT must be 1,000 ft higher than the corrected terrain or obstacle.

8.2.4.3              For operations outside Australia where the highest terrain or obstacle in a particular route or route segment is:

(a)         above 500 ft but not above 15,000 ft, the LSALT must be 1,000 ft higher than the highest terrain or obstacle, except that where the topographic reliability as shown in the WAC for any portion of the navigation tolerance area for the route or route segment is not 'A' (that is, compiled from accurate topographic maps and surveys), the LSALT must be 2,000 ft higher than the highest terrain in the navigation tolerance area;

(b)         above 15,000 ft, the LSALT must be 2,000 ft higher than the highest terrain or obstacle in the navigation tolerance area.

8.2.4.4              The altitude calculated in accordance with the above must be rounded up to the next highest 100 ft increment.

8.2.5                   Navigation Tolerance Area Construction—Examples
Figure 8‑4: Overlapping nav-aid coverage on route segment with each coverage half length of segment or more or coverage of destination nav-aid