Due to the unique structure of chimneys, when installing aviation obstruction lights, the lights at the top of the chimney must be positioned between 1.5 to 3 meters from the top. When the height of the chimney (H) exceeds 150 meters, the obstruction lights can be installed within 7.5 meters below the chimney's top.

Reference Standards:
《Annex14 Volume 1 Aerodrome Design and Operations》、《AC 150/5345-43H Specification for Obstruction Lighting Equipment》、《MH/T6012-2015》、《MH5001-2013》

H ≤ 45m: Install one layer of medium-intensity aviation obstruction lights at the top of the chimney, and apply 7 color markers.

45m ＜ H ≤ 105m: The chimney should be equipped with multiple layers of aviation obstruction lights. Install medium-intensity B-type aviation obstruction lights at the top, and medium-intensity aviation obstruction lights on the other layers. The spacing between each layer should not exceed 45 meters and should be as equal as possible.

105 meters ＜ H ≤ 150 meters: Install high-intensity aviation obstruction lights at the top of the chimney, with the spacing controlled between 75 to 105 meters. Medium-intensity aviation obstruction lights should be placed between the layers of high-intensity lights.

The number of aviation obstruction lights to be installed on each layer depends on the external diameter (D) of the chimney. The recommended number of lights is as follows:

D ≤ 6m: Install 3 aviation obstruction lights on each layer.

6m ＜ D ＜ 30m: Install 4 aviation obstruction lights on each layer.

30m ＜ D ＜ 60m: Install 6 aviation obstruction lights on each layer.

D ≥ 60 meters: Install 8 aviation obstruction lights on each layer.