Designed to meet the special requirements of helicopter landings
The Helicopter Visual Approach Slope Indicator (VASI) was developed as landing aid for helicopter flight, to accommodate their steeper angles of descent and deliberate speeds, as compared to the conventional fixed wing VASI systems.
Three wide horizontal beams of different colored light are projected in fan shaped array into the incoming flight pattern. The top beam (yellow) indicates a too high altitude of approach. The center beam (green) is the correct altitude and the lower beam (red) is a too low altitude. By staying within the green light beam, the correct slope is maintained to touchdown. An ideal control for training students.
The LED lamp is of very high intensity and has a rated life of at least 50,000 hours. It is powered by 90 to 264 volts AC current with a frequency range from 47 to 63Hz. The LED lamp consumes a tenth of the power of the regular halogen bulb, which creates a big saving in power consumption.
The VASI is normally placed on the border of the safety area on the near side, facing into the landing pattern. It has a low profile, being 12 inches high, 8 inches wide and 16 inches long and is constructed of heavy cast aluminum that is weather tight and finished in an orange polyester power coating.