Document ID: chunk:federal_register_of_legislation:F2022C00813:front:0:p15
Version: federal_register_of_legislation:F2022C00813
Segment Type: other
Provision Reference: 
Character Range: 42184–45067

a specified altitude(s) to validate the obstacle data used and to determine whether there are any unforeseen obstacles extending above the specified altitude. Such a case would indicate that the unforeseen obstacle is higher than the controlling obstacle and that it may affect the procedure. If such an unforeseen obstacle is observed, its location and observed height AMSL must be recorded for subsequent detailed analysis by the procedure designer.

7.1.10              25 and 10 NM Minimum Sector Altitude

7.1.10.1         Each 25 NM sector, or the 25 NM circle, and the 10 NM circle must be checked at their specified altitudes. 25 NM and 10 NM MSAs include obstacles out to 30 NM and 15 NM respectively from the navigation aid or ARP upon which the MSA is based. Checks must include the controlling obstacle in addition to other obviously high terrain or obstacles. Where the sector/circle does not exhibit greatly differing terrain elevations, judgment may be exercised regarding the tracks flown to provide a full coverage of the area.

7.1.11              Terminal Arrival Altitude (TAA)

7.1.11.1         Each Terminal Arrival Altitude (TAA) sector must be checked at its specified altitude. TAAs include obstacles out to 30 NM from the initial approach fix upon which the TAA is based. Checks must include the controlling obstacle in addition to other obviously high terrain or obstacles. Where adjacent TAAs do not have greatly differing terrain elevations, judgement may be exercised regarding the tracks flown to provide a full coverage of the area.

Note: This paragraph is included in anticipation of Terminal Arrival Altitudes being included in the next amendment to PANS-OPS.

7.1.12              DME/GPS Arrival Procedures

7.1.12.1         Controlling obstacles will be determined by the procedure designer for each segment within each sector of the arrival procedure. These obstacles must be checked at the specified altitude. Additionally, each step in the final and intermediate segments must be flown at the OIS altitude. Each step must be flown around the radius of the step plus 1 NM, between the lateral limits of the sector splay. The controlling obstacles for these steps can be checked during the process of flying the steps.

7.1.13              Circling Area

7.1.13.1         The circling area must be checked by flying around the lateral limit of the circling area for the lowest supported aircraft category or group (usually CAT A/B) at the specified altitude for that category and looking in towards the airfield. In this manner, both the controlling obstacle and any unforeseen obstacles will be seen in the one action.

7.1.13.2         The same procedure is then used to check obstacles in the circling area for the next highest supported aircraft category or group (CAT C/D). By conducting the inner check first, obstacles that may affect all