Initially used in military settings, NVGs, an acronym for Night Vision Goggles, have over the years found application in contexts where it is necessary to conduct emergency or security operations even in the dead of night.

In particular, they have proven suitable for piloting helicopters which, unlike aircraft with dedicated runways, have to land in contexts where the surface is not artificially illuminated and therefore in low light.

This is why, in addition to the military world, even civil regulations on obstacle lighting for aircraft have, in some countries, integrated new functions designed specifically for the use of NVGs.

In their operation, NVGs amplify the limited visible light, and the infrared radiation band defined as near-infrared (NIR). Recall that infrared radiation is a part of the electromagnetic spectrum with a wavelength longer than that of visible light, specifically between the wavelengths of red light and microwaves.

Aircraft warning lights (AWL) follow specific standards (ICAO/FAA) that indicate both their performance in terms of candela and light emission angle, and how to use them to mark buildings or significant obstacles such as chimneys, pylons, or wind turbines.

To date, the ICAO reference regulation for aircraft warning lights requires only visible white or red light marking for buildings and obstacles.

However, to meet specific customer needs, Cortem Group has developed a model of low-intensity aircraft warning light that integrates the emission of infrared rays.

In designing this new XLFE-LIB /.. /IR model, the FAA information circular [1] was taken as a reference, which specifies the type of emission, the wavelength, and the emission angle of the lamp.

Based on these minimum requirements, a special version of the low-intensity lamp was developed that integrates infrared-emitting LEDs in the band established by the FAA, i.e., with a wavelength between 800 and 900 μm. This range of the electromagnetic spectrum coincides with the nominal spectral response range of the main NVG systems regardless of the lens filter class used.

The emission exceeds the minimum required IR intensity of 4 mW/sr, with a vertical distribution angle greater than 10°. This allows for greater pilot safety in low-visibility conditions for obstacle identification during flight.

Cortem Group's AWL systems include all the lamps required for the creation of air obstruction signalling systems in areas at risk of explosive atmospheres.

The low intensity type B lamps, XLFE-LIB, with a stable red colour [2], the medium intensity type B lamps, XLFE-MIB, with a flashing red colour and the medium intensity type A lamps, XLFE-MIA, with a flashing white colour. They are also equipped with control panels that manage the synchronisation of the flashes, the possible redundancy of the lamps with main lamp and spare lamp and other features on request (e.g., synchronisation via GPS). 

Today, to these specific requests, we can add the supply of low-intensity air obstruction lighting fixtures equipped with additional emission in the infrared band.

[1] FAA Advisory Circular 150/5345-43J published by the Federal Aviation Administration

[2] The low intensity type B lamp can also be used as a low intensity type A lamp