Document ID: chunk:federal_register_of_legislation:F2024C01244:reg:5:p71
Version: federal_register_of_legislation:F2024C01244
Segment Type: reg
Provision Reference: reg 5 (pt 71/225)
Character Range: 498356–501239

of obstacle marking.

       (6) Obstacle lighting must operate throughout the hours of darkness unless it is within the aerodrome boundary and activated by a PAL.

9.28 Natural obstacles

Note   Natural obstacles such as terrain and vegetation are normally extensive. If they infringe an OLS, the need for obstacle lighting will be assessed by CASA on a case by case basis.

        If CASA so directs in writing, obstacle lighting must be provided for natural obstacles that infringe an OLS as follows:

(a) if the natural obstacle is located within the approach area — the portion of the obstacle within the approach area must be lit in the same manner as artificial objects or structures;

(b) if the natural obstacle is located outside the approach area — the highest features, and the prominent features, of the natural obstacle must have obstacle lighting.

9.29 Temporary artificial obstacles

        At night, or in poor visibility conditions, temporary artificial hazardous obstacles in the approach area or on the movement area must be lit:

(a) with red obstacle lights; and

(b) so that the lights clearly mark the height, extremities and extent of the obstacle.

9.30 Types of obstacle lighting and their use

       (1) The following types of obstacle lights must be used, in accordance with this MOS, to light hazardous obstacles:

(a) low-intensity;

(b) medium-intensity;

(c) high-intensity;

(d) a combination of low, medium or high-intensity.

       (2) Low-intensity obstacle lights:

(a) are steady red lights; and

(b) must be used on non-extensive objects or structures whose height above the surrounding ground is less than 45 m.

       (3) Medium-intensity obstacle lights must be:

(a) flashing white lights; or

(b) flashing red lights; or

(c) steady red lights.

Note   CASA recommends the use of flashing red medium-intensity obstacle lights.

       (4) Medium-intensity obstacle lights must be used if:

(a) the object or structure is an extensive one; or

(b) the top of the object or structure is at least 45 m but not more than 150 m above the surrounding ground; or

(c) CASA determines in writing that early warning to pilots of the presence of the object or structure is desirable in the interests of aviation safety.

Note   For example, a group of trees or buildings is regarded as an extensive object.

       (5) For subsection (4), low-intensity and medium-intensity obstacle lights may be used in combination.

       (6) High-intensity obstacle lights:

(a) must be used on objects or structures whose height exceeds 150 m; and

(b) must be flashing white 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