Document ID: chunk:federal_register_of_legislation:F2023C00696:body:0:p54
Version: federal_register_of_legislation:F2023C00696
Segment Type: other
Provision Reference: 
Character Range: 208931–212382

AUSEP, MNPS, GPSOCEANIC, RNP10 or RNP4.

10.8.2.4         A DME-based lateral separation entry/exit point must be calculated by:

(a)         determining the ground distance from the DME site to the BLSP; then

(b)         if the area of conflict (or part of it) is between the BLSP and the DME site, adding the slant range correction from Table 10.8-1 to the ground distance; then

(c)          applying the correction for DME equipment error from Table 10.8-2 ensuring it is applied to a position outside the area of conflict.

10.8.2.5         Where the navigation tolerance is determined with reference to ground-based navigation aids, GPS distance may be used in lieu of a co-sited DME in the steps above.

10.8.2.6         Where the lateral separation point is less than 60 NM from, and between the area of conflict and the reference DME site, an extra 1NM must be subtracted from the DME-derived distance.

10.8.3              Navigation Tolerances

10.8.3.1         To determine the possible position of an aircraft, the following tolerance areas and range limitations must be applied.

10.8.3.2         When manual means are used for the calculation of lateral separation, the radio navaid tolerances specified below must be rounded up to the next higher half-degree.

10.8.3.3         The minimum tracking tolerance is ±1 NM.

10.8.3.4         The maximum tracking tolerance is ±30 NM in CTA and ± 50 NM in OCA.

10.8.3.5         Slant range corrections are as follows.
Table 10.8‑1
Ground Distance  Slant Range Correction (in NM)
< = FL150        < = FL290                       < = FL460  < = FL600
3 NM             2                               3          6          8
4–5 NM           1                               3          5          7
6–7 NM           1                               2          4          6
8 NM             1                               2          4          5
9–10 NM          1                               2          3          5
11–12 NM         1                               2          3          4
13–14 NM         1                               1          3          4
15 NM            1                               1          2          4
16–24 NM         1                               1          2          3
25–30 NM         1                               1          2          2
31–50 NM         1                               1          1          2
>50 NM           1                               1          1          1

10.8.3.6         Slant Range Error is negligible and corrections need not be applied at or below:

(a)         2,000 FT AGL at distances of 10 NM or greater from the DME site; or

(b)         4,000 FT AGL at distances of 30 NM or greater from the DME site.
Note: Where required for a particular lateral separation problem, Local Instructions may specify a lateral separation point based on a precise slant range correction for the levels concerned.

10.8.3.7         DME equipment error corrections are as follows:
Table 10.8‑2
DME Equipment Error
Tolerance                                 Conditions
± 0.25 NM plus 1.25% of the slant range.  Controllers may use figures from the table below.
                                          DME Equipment Error Correction
Slant Range                               Correction
300 NM or less                            4 NM
220 NM or less                            3 NM
140 NM or less                            2 NM
60