1. For wind turbines less than 150m in overall height(hub height plus vertical blade height)need install medium intensity aviation obstruction lights.
2. For wind turbines from 150m to 315m in overall height, a second light serving as an alternate should be provided in case of failure of the operating light.
3. In addition, for wind turbines from 150m to 315m in overall height, an intermediate level at half the nacelle height of at least three low-intensity type E lights should be provided. If an aeronautical study shows that low-intensity type E lights are not suitable, low-intensity Type A or B lights may be used.
4. When blade rotation might block the aviation obstruction light, installation of 2 units on two sides with a distance greater than the width of the blade is required.
Towers, which are defined as tall structures, should be equipped with aviation obstruction lights to warn aircraft. All the obstruction lights allocation should be strictly in compliance with the regulations such as CAAC in China, and most common international regulations are ICAO’s and FAA’s. Installation recommendations according to tower height is shown below:
Standard: CAAC、ICAO、FAA 《MH/T6012-2015》《MH5001-2013》
H ≤ 30m Top with 1 low intensity obstruction light
30m < H ≤ 45m Top with 1 dual low intensity aviation obstruction light
45m < H ≤ 90m Top with 1 medium intensity aviation obstruction light, 1/2 level install 1 low intensity aviation obstruction lights
90m < H ≤ 150m Top with 1 medium intensity type A aviation obstruction light, 2/3 level and 1/3 level install low intensity aviation obstruction lights or medium intensity aviation obstruction lights
H ≥ 150m Top and at intervals of 75-105 meters install high intensity aviation obstruction lights, install medium intensity lights between high intensity aviation obstruction lights
Remark: Medium intensity obstruction light type A for day use and medium intensity obstruction light type C for night use only.
Aviation obstruction lights set in high-rise buildings and buildings should be able to show the outline of the object from all directions. The horizontal direction can also be referenced to set obstruction lights at a distance of about 45 meters. Generally, the obstruction lights should be installed at the top of the building, and the installation height H should be from the horizontal ground.
Standard: CAAC、ICAO、FAA 《MH/T6012-2015》《MH5001-2013》
H ≤45 meters
45< H < 105m
105 ≤ H < 150m
H ≥ 150m
6m or less 3 Light units /per level
6m to 30m 4 Light units /per level
30 m to 60m 6 Light units /per level
more than 60m 8 Light units /per level
Due to the special structure of the chimneys, the aviation obstruction light's installation should be located 1.5-3m under the top of chimney. When the height of the chimney is more than 150 meters, the obstruction light can be located within 7.5 meters under the top of the chimney.
Standard: CAAC、ICAO、FAA 《MH/T6012-2015》《MH5001-2013》
H ≤ 45m
45<H ≤ 105m
105< H ≤ 150m
H ≥ 150m
The presence of obstacles (towers, buildings, chimneys, cranes, high voltage lines, etc.) are a major risk for aircraft flying at low altitude. The competent authorities have created rules to signal these obstacles in order to obtain a certain degree of safety. Any object that poses a danger to aircraft flying at low altitudes must be marked with beacons. The International Civilian Authority (ICAO) legislated in Chapter 6, the rules regarding the characteristics of the beacon lamps and the ways of their installation. Some of the main points of the regulation, some type of obstacle to be marked and the installation rules are given below.