CHAPTER 2
ADS
-B O
VER
VIE
W
ADS-B Pilot’s Guide
Page 2-2
091-00057-001 REV A
2.1 ADS-B Out – The Mandate
ADS-B is the automatic broadcast of position reports by aircraft, and vehicles on the
ground equipped with ADS-B transmitters that are in proximity to aircraft. ADS-B out
provides ATC with a more accurate position reporting than traditional radar, which will
allow ATC to more accurately position and separate aircraft in flight.
There are a number of requirements aircraft need to meet the ADS-B out Mandate.
Aircraft are required to have either a Mode S with extended squitter (1090MHz) or a UAT
(978MHz) transponder and a WAAS GPS to meet the mandate.
Aircraft equipped with a Mode S + ES and WAAS GPS are approved for flight at any
altitude. This equipment is also a requirement for flight above 18,000’ and for aircraft
flying internationally. Whereas aircraft equipped with 978MHz (UAT) out and a WAAS
GPS meet the ADS-B out mandate below 18,000’.