nce coverage. It also offers reduced communication congestion because controllers do not have to advise of aircraft in the vicinity. On the ground, ADS-B provides some of the same benefits as it does in the air such as reduced communications, situational awareness, and it also provides for reduced taxi and takeoff delays (www.faa.gov 2). ADS-B will increase operational capacity and efficiency by providing more accurate information for the terminal areas. A main disadvantage of the system is that in order for it to work properly, in the air for collision avoidance, all aircraft need to be equipped. Another disadvantage in the system is that there needs to be a system to obtain the aircraft's position from. When compared with TCAS, ADS-B has the disadvantage that very few aircraft are currently equipped with any of the required technology. Many aircraft are already equipped with transponders that TCAS works with. The Traffic Alert and Collision Avoidance System is a self contained device that interrogates the transponders of nearby aircraft and presents this information on a display in the cockpit(www.caasd.org i1). When the internal computer senses that there might be a collision course, it first displays a traffic advisory and then if needed, a resolution advisory. The resolution advisory gives the crew a recommended maneuver such as a climb or decent. TCAS II is required for all aircraft operating in the United States with more than 30 passenger seats. TCAS I is required on all aircraft with 10 - 30 seats. TCAS I is a short range system that can identify traffic within approximately 3 to 5 nautical miles. It consists of a TCAS antenna, a processor, and a cockpit display. TCAS I shows traffic and displays traffic advisories but does not display resolution advisories (Kraus 175).TCAS II utilizes 2 antennas, one on top and one underneath the aircraft. It is capable of identifying and resolving traffic 14 miles to the front of the a...
