Lighted X Runway Closure Marker—Flight Testing

On July 7, 2017, an Airbus A320 nearly collided with another aircraft on Taxiway C at San Francisco International Airport. The A320 mistakenly aligned with the taxiway instead of the parallel runway on which they were cleared to land. Because of this incident, the National Transportation Safety Board (NTSB) made a safety recommendation to improve the conspicuity of closed runways, particularly under nighttime conditions when at least one parallel runway remains in use. The Federal Aviation Administration (FAA) Office of Airports tasked the National Institute of Standards and Technology (NIST) to evaluate different configurations of Lighted X (LX) systems. NIST’s laboratory experiments with pilot participants…