Document ID: chunk:federal_register_of_legislation:F2024C01244:reg:5:p72
Version: federal_register_of_legislation:F2024C01244
Segment Type: reg
Provision Reference: reg 5 (pt 72/225)
Character Range: 500965–503720

lights.

       (7) Despite paragraph (6) (b), a medium-intensity flashing red light may be used if necessary to avoid an adverse environmental impact on the local community.

9.31 Location of obstacle lights

       (1) This section applies for any hazardous obstacle that must be provided with obstacle lighting, as illustrated in Figures 9.31 (1)-1, 9.31 (1)-2, 9.31 (1)-3 and 9.31 (1)-4.

Note   For objects or structures that must be provided with obstacle lighting, see sections 9.27, 9.28 and 9.29.

       (2) Obstacle lights must be located:

(a) as close as possible to the top of the object or structure; and

(b) in such numbers, and in such arrangements, as to ensure that the lights clearly indicate at least the points or edges of the object or structure that are highest above the obstacle limitation surface.

       (3) Subject to subsection (4), for the following objects or structures:

(a) a structure to the top of which an appurtenance is attached, for example, a lightning rod, flag, antenna, or aerial;

(b) a structure from at or near the top of which a contaminating substance is emitted, for example, smoke, gas or fumes;

        the top lights must be placed as close to the top of the structure as is consistent with minimising the likelihood of visual obstruction from:

(c) the attachment; or

(d) the emissions.

Note   Normally, the lights should be located 1.5 m to 3 m from the top of the structure.

       (4) If an appurtenance, for example, a lightning rod, flag, antenna, or aerial, on a tower-like structure (including an antenna):

(a) extends more than 12 m above the structure; and

(b) is such that it is impossible to attach a high-intensity obstacle light to the top of the appurtenance;

        then the high-intensity obstacle light must be attached to the highest possible point of the appurtenance.

       (5) For the following:

(a) an extensive object or structure;

(b) a group of closely-spaced objects or structures;

        the obstacle lights must be located in such numbers, and in such arrangements, as to ensure that the lights clearly indicate at least:

(c) the points or edges of the object or structure that are highest above the obstacle limitation surface; and

(d) the general definition and extent of the object or structure; and

(e) if 2 or more edges are at the same height — the edge nearest to the runway threshold.

       (6) For subsection (5):

(a) if low-intensity lights are used — the lights must be spaced at longitudinal 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