With ADS-B, pilots in equipped aircraft now have access to services that provide a new level of safety and efficiency.
Operators equipped with ADS-B Out will enjoy more efficient spacing and optimal routing in non-radar environments, including the busy airspace in the Gulf of Mexico, mountainous regions of Colorado and the lower altitudes of Alaska.
Aircraft equipped with ADS-B out enhance the Air Traffic Controller's awareness of aircraft in the airspace. Radars can take anywhere from 5 to 12 seconds to update an aircraft's position, but ADS-B equipment provides air traffic control (ATC) with updated aircraft information almost every second. This enables controllers to identify and resolve potentially hazardous situations quickly and effectively. Because of FAA's requirements for ADS-B service, in many areas of the U.S., coverage exists at lower altitudes than current ATC radars.
ADS-B In gives pilots access to Traffic Information Service–Broadcast (TIS-B), which provides altitude, ground track, speed and distance of aircraft flying in radar contact with controllers, and within a 15-nautical mile radius, up to 3,500 feet above or below the receiving aircraft's position. All of this greatly enhances pilot safety.
Aircraft equipped with a Universal Access Transceiver (UAT) ADS-B In receiver also have access to Flight Information Service–Broadcast (FIS-B), which broadcasts graphical weather to the cockpit as well as text-based advisories, including Notices to Airmen (NOTAM) and significant weather activity.
Pilots of ADS-B In-equipped aircraft can see the location of surrounding aircraft on their cockpit displays. Pilots with a UAT receiver can also see graphical weather on their cockpit displays. This information is similar to what air traffic controllers see, creating an environment of shared situational awareness and crucial see-and-avoid capability. ADS-B Out information can be broadcast on two frequencies, 1090 MHz and 978 MHz. Automatic Dependent Surveillance-Rebroadcast (ADS-R) rebroadcasts data from one frequency to the other, providing aircraft operating on both ADS-B links the ability to see each other on their traffic displays.
The FAA FIS-B service (available on UAT ADS-B In) also transmits notices of important flight information, such as temporary flight restrictions (TFRs) or closed runways. Cockpit displays capable of supporting ADS-B In can often also support terrain maps, to help pilots avoid terrain in low-visibility situations.
These ADS-B pilot advisory services are provided at no cost to the user.
Search and Rescue
The highly precise GPS-based surveillance provided by ADS-B also improves the ability to perform life-saving search and rescue missions. Air traffic controllers tracking aircraft with ADS-B Out have more accurate information about last reported positions, helping to take the "search" out of search and rescue. The smaller footprint of ADS-B ground radios enables their placement in areas where a radar site would be unfeasible, such as mountainous terrain. Air traffic controllers have better information about an airplane's last position, thereby reducing the critical window of time involved in a search and rescue operation.