It forms the foundation for NextGen by moving from ground radar and navigational aids to precise tracking using satellite signals. This will be more environmentally friendly and enhance safety and efficiency. It will allow pilots to see what controllers see by showing other aircraft. It will pinpoint hazardous weather and terrain, and give pilots important flight information, such as temporary flight restrictions. It will reduce the risk of runway incursions with cockpit and controller displays that show the location of aircraft and equipped ground vehicles on airport surfaces, even at night or during heavy rainfall. Applications are being developed now that will give pilots indications or alerts of potential collisions. It will provide greater coverage because ground stations are much easier to place than radar installations. Using satellites instead of ground navigational aids means aircraft will be able to fly more directly from Point A to B, saving time and fuel. Improved accuracy and reliability of satellite signals means controllers eventually will be able to safely reduce the minimum separation distance between aircraft and increase capacity.

• Guarantee you will observe all aircraft in your area because aircraft without a transponder or ADS-B OUT will not show up.
• Provide conflict resolutions instructions such as what you see in a TCAS.
• Identify non-ABS-B OUT equipped aircraft that are operating at low altitudes and are outside the range of an ADS-B ground station. Aircraft may also be below radar coverage and not visible to ATC.

TIS-B is a free service available to aircraft operators equipped with ADS-B OUT and ADS-B IN. FIS-B is available free to any operator with the ability to receive and display the data that is broadcast on the Universal Access Transceiver (UAT) or the 978 MHz link and includes

• NEXRAD Radar
• METARs
• TAFs
• Winds Aloft
• PIREPs
• AIRMETs
• SIGMETs
• NOTAMs
• Special Use Airspace
• TFRs

Under the rule, ADS-B OUT performance will be required to operate in:

1. Class A, B, and C airspace.
2. Class E airspace within the 48 contiguous states and the District of Columbia at and above 10,000 feet MSL, excluding the airspace at and below 2,500 feet above the surface.
3. Class E airspace at and above 3,000 feet MSL over the Gulf of Mexico from the coastline of the United States out to 12 nautical miles.
4. Around those airports identified in 14 CFR part 91, Appendix D.