Helping You Understand ICAO Obstruction Compliance

Obstruction lights are vital markings for pilots, and the most commonly used regulation standard is ICAO. Annex 14 of ICAO regulations gives necessary lighting requirements for any structure.

Low-Intensity Obstruction Lights are the first stage of lighting required, warning of the presence of obstacles up to 45m height.

Medium-Intensity Obstruction Lights are more complex, designed to warn the presence of obstacles with a height between 45m and 150m.

High-Intensity Obstruction Lights are used to warn the presence of obstacles with a height above 150m or when an aeronautical study indicates such lights as mandatory for the correct warning of an elevated structure.

Obstruction lighting is used in multiple applications. These include but are not limited to: telecommunication towers, wind turbines, chimneys, cranes, buildings, bridges, high tension pylons and other buildings.

There are lots of details and types of lights that are included in these broad specifications. This article distils the main groupings, helping you understand what ICAO light you will need for your application.

Low-Intensity

Low-Intensity Obstruction Lights are the simplest devices according to ICAO standards. There are a few main characteristics you need to know before selecting your light. These include:

• Type A (intensity >10cd, steady red burning) can be used alone;
• Type B (intensity >32cd, steady red burning) can be used either alone or in combination with medium-intensity obstacle lights Type B, Type A and B or with high-intensity obstacle lights Type A and B;
• Type E (intensity >32cd, red flashing) can be used either alone or with Type B medium-intensity obstacle lights. The flashing rate is set at the same rate as other flashing beacons installed on the structure.

Medium and Combined Medium-Intensity

Medium-Intensity Obstruction Lights include three types of beacons as stated by the ICAO standards. Each has different intensity, with combinations of characteristics and used in particular situations. These include:

• Type A (intensity 20.000cd, day-mode white flashing; 2.000cd, night-mode white flashing) should be used alone;
• Type B (intensity 2.000cd, night-mode red flashing) should be used either alone or in combination with Low-Intensity Obstacle Lights, Type B or Type E;
• Type C (intensity 2.000cd, night-mode red steady burning) should be used either alone or combined with Medium Intensity Obstacle Lights, Type AC.
• Combined Type A and B (intensity 20.000cd, day-mode white flashing; 2.000cd, night-mode red flashing) should be used in conjunction with Low-Intensity Obstacle Lights, Type B or Type E;
• Combined Type A and C (intensity 20.000cd, day-mode white flashing; 2.000cd, night-mode red steady burning) should be combined with Medium Intensity Obstacle Lights, Type C.

High-Intensity

High-Intensity Obstruction Lights include two types of beacons with different characteristics and uses. High-Intensity lights are used infrequently, only for specialised applications when mandated by the National Aviation Authorities.

• Type A (intensity 200.000cd, day-mode white flashing; 20.000cd, twilight-mode white flashing; 2.000cd, night-mode white flashing);
• Type B (intensity 100.000cd, day-mode white flashing; 20.000cd, twilight-mode white flashing; 2.000cd, night-mode white flashing).

What light is right for my application?

It all depends on what you are marking and the framework of your local aviation authority. It is best to make a consultation with a professional in your area or with your aviation authority. Complying with your local regions specifications is challenging, and Avlite Systems is always here to assist with any questions.

There is a lot of complexity in regulation, so we have simplified the ordering to include all available configurations available with our upcoming lighting range. This includes our new AV-OL-LI Type E light, a first for Avlite.

Avlite continues to lead in features and functionality because of our ability to offer an entire integrated system. This includes controllers designed for our lighting, solar add-ons for areas with inaccessible power and asset monitoring and control via our Star2M Web Portal.

Stay tuned for our upcoming infographic series, ‘Unraveling ICAO Obstruction Regulations’.