Test of Glide Slope Guidance With and Without Simplified  Abbreviated  Visual Approach Slope Indicator

In a flight test at a small airport, rectangular aiming-point markings with and without the additional use of a low-cost version of the red/white simplified abbreviated visual approach slope indicator (SAVASI) served as daytime approach guidance aids. Results showed that approaches made with the SAVASI were less variable in measured approach slope, and approaches made in the last half-mile before landing were nearer the 4 degree
SAVASI glidepath angle. On average, approaches made either with or without the SAVASI were steeper than 4°, and tracking of itinerant aircraft not informed of the testing confirmed that the usual approach for small aircraft at this runway was in the 5 degree to 6 degree range. This indicates that future installations of SAVASI or related guidance aids should be made after measuring the normal practice at a given airport. Test pilot opinion was that the SAVASI was easy to use and provided good guidance in the vertical plane and that the rectangular aiming-point markings were beneficial.