Medium Intensity Dual Light

Medium Intensity Dual Light

Medium intensity dual light or obstruction lights are usually found in tall buildings or high terrains to signal pilots about impending danger, especially in low light areas or at night time.

During daytime, medium intensity dual lights are used to signal pilots. Its intensity is reduced during twilight and night time operations for the lights to become more visible.

If you have been wondering what those lights are that you see on top of tall towers or high terrains, those are the obstruction lights, and they came in different colors for different purposes. White lights are usually used during daytime and red lights during night time. These lights are not one-directional but visible 360° for the pilots to see it from a long distance.

Aside from the color, obstruction lights do also have different purposes depending on the intensity of light emitted.

Different Uses of Obstruction Lights

The low-intensity obstruction light, for instance, is used when the obstruction covers a small area and can be found in not more than 45 meters above ground.

The medium intensity obstruction lights, on the other hand, is used when the obstruction is covering an extensive area and placed above 45 meters of the obstruction area. Lastly, the high-intensity obstruction lights are used to mark the obstruction that is higher than 150 meters.

Apart from obstruction lights, airports also use other markers such as flags and colored patterns to give signals.

Advantages of Having Obstruction Lights

While transportation modernization brings us comfort and speed to travel from one place to another, history has recorded many fatal aviation tragedies. These incidents include airplane crashes due to minimal to zero visibility, engine failure, adverse weather conditions, among others.

As aviation technology advances, safety measures to travel by air are also improved.

These safety measures are the markers and the signal lights placed in areas that offer poor visibility to pilots. Places like tall buildings, satellite towers, and even highland terrains. With these lights and markers, low-flying aircraft pilots can see this to avoid unnecessary accidents.

There are some issues concerning obstruction lights, and for transparency’s sake, we will also discuss them here.


Towerkill is one of the known issues after obstruction lights are placed on top of towers. Tall towers (from television, radio, and telecommunications) where obstruction and signal lights were placed caused bird’s mortality rate to increase.

It happens when birds collide with the wires of the tower or even with different birds as the lights of these towers attract the birds, especially at night time.

Light Pollution

Signal and obstruction lights also produce what is known as the light pollution. Light pollution is the excess use of light. This excessive light use, especially at night time, affects the nocturnal animals that are used to having no light at night.  

However, there are no long-term adverse effects on the use of obstruction lights. And the benefits outweigh the risks.

Drake Lighting is the premier distributor of Obstruction Lights, from low-intensity dual light, medium intensity dual light, and high-intensity light, in the aviation industry. Contact us for a free consultation and quotation. 

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