EVALUATION OF TAXIWAY CENTERLINE LIGHTING

The report reviews the taxiing problem during low visibility conditions. In accomplishing the project, comparisons were made among the standard blue taxiway edge lighting, taxiway edge reflective markers, and taxiway centerline lighting. Adequacy of new fixtures, 180 cycle regulators and a control system for taxiway centerline lighting was also evaluated. A specially prepared Mylar film was used in simulating taxiway centerline light visibilities (TCLV) of 1500, 600 and 200 feet on straight and curved taxiways of differing radii. Photometric and environmental tests were conducted over a period of approximately a year and a half on four types of fixtures. It was concluded that taxiway centerline lighting was a significant improvement over conventional edge lighting and that aircraft could accurately taxi in visibilities as low as 200 feet over a taxiway centerline lighting system. None of the fixtures withstood the environment encountered. Taxiway edge reflectors showed promise but further development was recommended. No problems were encountered with the 180-cycle regulators and control system. It was recommended that a Selection Memorandum for taxiway centerline lighting be prepared by applying the results of this evaluation to fixture configuration and spacing. Green was recommended as the color for taxiway centerline lighting to differentiate between it and the white runway centerline lighting.