A visual approach slope indicator system (VASIS) consisting of only two light units situated on the left side of the runway, one upwind and one downwind. The aircraft is on slope if the upwind unit shows red and the downwind unit shows white, too high if both units show white, and too low if both units show red. The AVASIS is always set to an eye-to-wheel height (EWH) of 10 ft. abbreviation: AVASIS see also: visual approach slope indicator systems Fr: indicateur visuel de pente d'approche simplifi