Test and Evaluation of MALSR Threshold Lights

This Letter Report describes the evaluation of runway threshold lights to be used with Medium Intensity Approach Lights together with Runway Alignment Indicator (strobe) Lights (MALSR) systems. Three different type lamps and fixtures were selected for final evaluation. Based on flight tests and photometric measurements, it was concluded that 120-volt 300PAR56/NSP lamps with standard PAR56 threshold light fixtures, powered from the l20/240-volt MALSR system, would provide the improved visual guidance and threshold conspicuity necessary for operations in visibility conditions as low as Category 1, 2,400 feet Runway Visual Range (RVR).The green threshold lights, spaced 10 feet apart with the outer lights in line with the runway edge lights, will conform to ALSF-l and ICAO criteria.