PAPI (Precision Approach Path Indicators) primarily assists by providing visual glide slope guidance in non-precision approaches environment. These systems have an effective visual range of at least 3 miles during the day and up to 20 miles at night. The row of light units is normally installed on the left side of the runway and the glide path indications are as two red and two white (2 red ) when on proper glide path angle of approach. Light combinations indicate when slightly high (3 white ), significantly high (4 white ), slightly low (3 red ) and significantly low (4 red ).
Video shows the side by side comparison of a series of approaches into an airport. The benefit of the comparison is to see and understand the superior clarity of LED lighting systems over the more traditional incandescent lighting systems.
The video contains no audio.
FAA Navigation Services Technical Lead:
Donald Lampkins - (202) 267-7332