Air Transport

Warning lights placed at runway ends and at the intersections between taxiways and runways are "a viable technology for preventing runway incursions", says the US Department of Transportation's Office of Inspector General (OIG).

In report published last week, the OIG revealed that during the 29 months after a prototype Runway Status Light (RWSL) system was installed on one runway at the Dallas/Fort Worth International Airport (DFW) runway in 2005, incursions decreased by 70% compared to the previous 29 months, from 10 incursions down to three.

The DFW system determines vehicle and aircraft locations using Airport Surface Detection Equipment-Model X (ASDE-X) with inputs that include terminal and surface radar as well as transponder multi-lateration. If the ASDE-X software predicts an incursion, the system commands the RWSL to activate red lights on the runway surface in the appropriate location to alert pilots or drivers of the potential conflict.

The report states that RWSL works without human intervention, providing pilots with an independent, direct warning of a conflict. As such, the system does not increase controller workload or "interfere with the normal flow of airport traffic or rhythm of controller movement of traffic".

ASDE-X is operational at 11 US airports and will ultimately be in place at 24 additional airports by 2012, according to FAA plans.