<div class="htmlview paragraph">This paper concerns itself with runway lighting requirements, particularly for Category II operations. It deals with the parameters that must be considered in designing an effective lighting system, and discusses the role of such factors as cockpit-Cutoff angle and background brightness.</div> <div class="htmlview paragraph">In addition, the paper briefly describes a test facility in which landings can be simulated and runway lighting systems, on a reduced scale, can be observed in artificially produced fog of any desired density. It also summarizes the results of extensive tests performed in this facility and describes an effective lighting system evolving from the tests.</div>