出典:Wikipedia
出典:『Wikipedia』 (2011/04/20 02:30 UTC 版)
The Visual Approach Slope Indicator (VASI) is a system of lights on the side of an airport runway threshold that provides visual descent guidance information during the approach to a runway. These lights may be visible from up to eight kilometers (five miles) during the day and up to 32 kilometers (20 miles) or more at night.