VASIS Signal Transition Zone and Color Modifications

This report covers the results of a portion of the overall project effort to develop an improved Visual Approach Slope Indicator System (VASIS).  A method of decreasing the VASI signal pink transition zone was evaluated and the effect of substituting different color density and hue red filters was studied.  As a result of the testing, it was concluded that the standard VASI signal can be significantly improved by a slight modification to the geometry of the transition bar and by substitution of different filters.

FAA-ARD-72-91
Authors: Robert F. Gates, Thomas H. Paprocki