Preventing Runway Conflicts: The Role ofAirport Surveillance, Tower-Cab Alerts, and Runway-Status Lights

• Runway incursions and conflicts present a persistent problem in airport ground operations. Numerous critical conflicts and several fatal accidents have occurred as a result of unauthorized or otherwise inappropriate entry of aircraft or surface vehicles onto an active runway. This article describes a detailed survey of runway-conflict accidents and high-hazard incidents res,ulting from inappropriate entry onto or movement on an active runway. The patterns that emerge allow us to determine the role that three different safety systems can be expected to play in reducing the incidence or consequences of runway incursions and conflicts. The three systems are a surface-surveillance system (such as a surface radar), a tower-cab alerting system, and runway-status lights. Judging from the history of runway conflicts, it appears that runway-status lights, operating automatically with inputs from a surface radar, can prevent over half of these conflicts. A surface radar alone or comb~nedwith tower-cab alerts promises to be effective in preventing another one-third. The three systems in combination can offer protection in an estimated 90% of high-hazard conflicts.