The Medium Intensity Approach Light System with Runway Alignment Indicator Lights, or MALSR, is an important tool for pilots during landing. This system is set up along the extended centerline of the runway to help with visual guidance. It offers essential information about runway alignment, height perception, roll guidance, and horizontal references. These features are crucial for the visual part of an instrument approach.
MALSR has three main components. First, there are the threshold lights, which include between 18 to 33 steady burning green lights. The number depends on the width of the runway. Next, we have the steady burning lights, arranged in nine sets known as light bars. Each light bar contains five steady burning white lights. Seven of these light bars are placed at 200-foot intervals along the extended centerline, while two others are positioned to the left and right at the 1000-foot mark.
Lastly, the system includes sequenced flashers. This part consists of five white flashing lamps located at 200-foot intervals, starting just beyond the last light bar. When these lights flash together, they create the effect of a moving ball of light approaching the runway. Overall, the layout of the MALSR is designed to provide clear visual cues to pilots as they prepare to land.
