Approach lighting system (ALS) consists of bar lights and stroboscope light installed on a runway. They enable a pilot to easily identify a runway and set an aircraft to the right landing position. State-of-the-art lighting systems are very advanced and guarantee safety during flight operations.
A lighting system used at an airport depends on a runway category. One can distinguish non-instrument and instrument runways – category I, II and III. In each case, the approach lights can be controlled by a pilot (via radio) or a control tower. Also, the light intensity can be adjusted to current visibility conditions. The approach lighting system includes a bar light, the so-called “decision bar" that is placed 100 meters from the threshold and makes it easier for a pilot to switch from tool navigation to visual navigation.