The Airport Movement Area Safety System (AMASS) visually and aurally prompts tower controllers to respond to situations which potentially compromise safety. AMASS is an add-on enhancement to the host?ASDE-3 radar that will provide automated alerts and warnings to potential runway incursions and other hazards. AMASS extends the capability of the ASDE-3 and enhances surface movement safety. The system operates with ground and approach sensor systems to ascertain aircraft locations in approaching and ground movement situations. It uses airport radars, state-of-the-art signal processing, and advanced computer technology to improve airport safety. In this program, 40 systems will be delivered. AMASS is manufactured by Northrop Grumman Corporation. The first AMASS system was tested in 1992 at San Francisco International Airport. However, the program came in for increasing criticism for being over-budget and behind schedule, with not a single unit being operational by the deadline (for installing 40 units) of August 2000. Software development issues and system adoption were mentioned as the key issues with the system. Finally, the first operational AMASS system was installed at San Francisco International Airport on June 18, 2001. AMASS was demonstrated to work as designed in the near-collision of?SkyWest Airlines flight 5741 and Republic Airlines flight 4912, when it alerted the ATC 15 seconds prior to the estimated impact