A typical ALSF-2 system (High Intensity Approach Lighting System With Sequenced Flashing Lights) consists of 247 steady burning lights: including green threshold lights (49 lights), red side row-bar lamps (9 rows, 54 lamps), and high intensity steady burning white lights (144), plus an additional 15 flashing lights commonly referred to as strobes. The strobes flash in sequence starting with the strobe farthest from the runway and ending with the strobe closest to the runway threshold. The lights are spaced at 100' intervals from the runway threshold outward to 2400'.
ALSF-2 Approach Shelter
FAA Navigation Services Technical Lead:
John Varas - (202) 493-4760
Current Status: There are 153 commissioned facilities in the NAS manufactured by Airflo, Godfrey, NBP, GE, Heavy Duty Substation, and Westinghouse Substation, Hollingsworth are among others.