Document ID: chunk:federal_register_of_legislation:F2024C01244:reg:5:p76
Version: federal_register_of_legislation:F2024C01244
Segment Type: reg
Provision Reference: reg 5 (pt 76/225)
Character Range: 511026–513858

of the cycle time mentioned in the same row in column 2.

     Table 9.34 (5)   High-intensity obstacle light flash rates
Flash interval between   Proportion of cycle time
middle and top light     1/13
top and bottom light     2/13
bottom and middle light  10/13

       (6) Unless otherwise directed in writing by CASA, the installation setting angles for high‑intensity obstacle lights must be in accordance with Table 9.34 (6) so that for an obstacle light at a height mentioned in a row of column 1, the angle of the peak of the light beam above the horizontal is the value mentioned in the same row in column 2.

     Table 9.34 (6)   High-intensity light installation setting angles
Height of light above terrain  Angle of the peak of the beam above the horizontal
greater than 151 m             0°
122 m to 151 m                 1°
92 m to 122 m                  2°
less than 92 m                 3°

9.35 Floodlighting of hazardous obstacles

Note   Where the installation of obstacle lights in accordance with this MOS is not possible, or is undesirable for aesthetic or other reasons, floodlighting of obstacles may be an appropriate alternative. However, floodlighting may cause a hazard to pilots and a review and acknowledgment process is required (see subsection 9.35 (1)). In general, floodlighting is not suitable if:
       (a) the structure is skeletal, as a substantially solid surface or cladding with satisfactory reflectance properties is required; or
(b) there is high-level background lighting.

       (1) Floodlighting may be used for a hazardous obstacle instead of obstacle lights, but only if CASA approves in writing receipt of an aerodrome operator's explanation of why the installation of obstacle lights is not possible, or is undesirable for aesthetic or other reasons.

       (2) If floodlighting is used:

(a) the colour must be white; and

(b) illumination of the object or structure must:

 (i) cover all directions of azimuth over the full height portion of the object or structure which needs to be illuminated; and

 (ii) be uniform around the circumferences of the object or structure.

       (3) For subsection (2), the minimum level of luminance must be 5 cd/m² at all points.

Note   Based on a reflectance factor of 50% for white paint, this would require illuminance of at least 10 lux. For concrete with a typical reflectance factor of 40%, the required illuminance would be at least 12.5 lux. Materials with reflectance factors less than 30% are unlikely to be suitable for floodlighting.

       (4) For subsection (2):

(a) each floodlight fitting must be located evenly around the object or structure, at not more than 120 degrees from any adjacent floodlight fitting; and

(b) at each location:

 (i) there must be at least 2 floodlight fittings; and

 (ii) each fitting must