Document ID: chunk:federal_register_of_legislation:F2024C01244:reg:5:p73
Version: federal_register_of_legislation:F2024C01244
Segment Type: reg
Provision Reference: reg 5 (pt 73/225)
Character Range: 503475–506101

intervals not exceeding 45 m; and

(b) if medium-intensity lights are used:

 (i) the lights must be spaced at longitudinal intervals not exceeding 900 m; and

           (ii) at least 3 lights must be displayed as a line of lights, horizontally on the side of an extensive object or structure that is nearest to the runway threshold.

       (7) Shielding of the downward component of obstacle lighting is permitted, and if used must be such that:

(a) no more than 5% of the nominal light intensity is emitted at or below 5 degrees below horizontal; and

(b) no light is emitted at or below 10 degrees below horizontal.

       (8) Subject to subsection (9), for wind turbines in a wind farm, medium-intensity obstacle lights must:

(a) mark the highest point reached by the rotating blades; and

(b) be provided on a sufficient number of individual wind turbines to indicate the general definition and extent of the wind farm, but such that intervals between lit turbines do not exceed 900 m; and

(c) all be synchronised to flash simultaneously; and

(d) be seen from every angle in azimuth.

     Note   This is to prevent obstacle light shielding by the rotating blades of a wind turbine and may require more than 1 obstacle light to be fitted.

       (9) If it is physically impossible to light the rotating blades of a wind turbine:

(a) the obstacle lights must be placed on top of the generator housing; and

(b) a note must be published in the AIP-ERSA indicating that the obstacle lights are not at the highest position on the wind turbines.

       (10) If the top of an object or structure is more than 45 m above:

(a) the surrounding ground (ground level); or

(b) the top of the tallest nearby building (building level);

        then the top lights must be medium-intensity lights, and additional low-intensity lights must be:

(c) provided at lower levels to indicate the full height of the structure; and

(d) spaced as equally as possible between the top lights and the ground level or building level, but not so as to exceed 45 m between lights.

       (11) If high-intensity obstacle lights are used:

(a) on an object or structure that is not a tower supporting wires or cables — the spacing between the lights must not exceed 105 m; and

(b) on an object or structure that is a tower supporting wires or cables — the lights must be located on the tower as follows:

 (i) at the top of the tower;

           (ii) at the point of the tower that is the lowest level of the catenary of the wires or cables;

           (iii) at approximately midway between the 2 levels referred to in subparagraphs (i)