Precision approach path indicator (PAPI) lights are essential for helping pilots land safely. They are used to help pilots visually determine whether or not their approach to the landing strip is vertically accurate, which is essential when transitioning from instrument-based flying to visual-based flying upon approach.

These lights are usually situated adjacent to the start of the glide path on the lefthand side and let pilots know if they are too high, too low or at the right altitude upon approach. Sometimes, PAPI lights can be installed on both sides of the runway.

How Do PAPI Lights Work?

Typically, PAPI light units have two lamps each, which shine either white or red depending on the vertical angle, with a sharp distinction between the two colours to avoid confusion. White light indicates a high altitude or angle, while red light indicates a low angle.

In a four PAPI light system, two white and two red lights visible indicate an accurate approach on the glide path. Three or four white lights indicate that the plane is coming in too high, whereas three or four red lights indicate that the plane is approaching too low.

Sometimes a two PAPI light system is also used, where the same ratios and general principles would apply.

Why Aerolight’s PAPI Lights?

At Aerolight, we have partnered with OCEM, a market leader in airfield ground lighting (AGL) systems, to supply top-quality PAPI lighting systems to airports across Australia.

These OCEM-made PAPI lighting systems have been rated to run for 1 000 hours at full intensity, or about 3 000 hours in average operating conditions out in the field.

These 200 W units have four legs to provide stability, as opposed to the usual two or three legs found on many other models. These aluminium legs each have a breakable coupling to ensure the frangibility of the PAPI lights in the case of a collision. Moreover, the legs can come in varying lengths to compensate for uneven ground conditions if needed.

They also include a section of stainless steel threaded rod towards the upper section, allowing the lights to be adjusted, elevated and levelled with precision.

To get expert advice, sales and installation on a variety of top-quality AGL systems, including PAPI lights, contact Aerolight today.