Modification of Visual Approach Slope Indicator Baffles at Pearson Field Airpark, Vancouver, WA

This report describes a research effort that was accomplished to correct a safety deficiency with a Visual Approach Slope Indicator (VASI) system at the Pearson Field Airpark in Vancouver, Washington. During a recent inspection flight, the VASI system was found to be emitting signals that could potentially draw an approaching aircraft dangerously close to an obstruction near the final approach path. As a result, the system was shut down. Engineers from the Airport Technology Research and Development Branch visited the site to analyze the problem, collect data on the geometry of the obstruction, the baffles, and the general layout of the airport, and finally install and test the new baffles to make sure they operate properly. Engineers designed, constructed, and installed aluminum baffles that blocked the signal from the obstruction area, and provided a 2 degree margin of safety between the obstruction and the visible signal of the VASI.

DOT/FAA/AR-TN-07-12
Author: James W. Patterson, Jr.