Simplified Visual Approach Slope Indicator (VASI).
Abstract:
The purpose of this operational test and evaluation was to determine the value of a simplified visual approach slope indicator VASI system to the USAF Special Operations Force by accomplishing three test objectives formulate and document construction criteria, establish user acceptancerejection, and incorporate an air-transportable capability. Two types of systems were designed and constructed for user evaluation. Both were identical except for the support arrangement. One system was embedded in the ground, and the other was anchored to the ground by using sandbags. Both systems could be transported by air. Two hundred and eighty approaches were flown against the systems by 61 different pilots. The majority of pilots indicated that the systems were effective beginning at distances ranging from 12 to 1 mile and ending at 25- to 50-foot altitude approximately 450 to 950 feet in front of the boards during night or daytime operation. The best color combination was determined to be black stripe on white background. It was recommended that USAF Special Operations Force retain the two systems for potential future use during deployments to austere bases, temporary airfields, and landing zones not equipped with standard VASI. Author