Ahr Aviation
Ahr Aviation
  • ADS-B

    What is ADS-B?

    ADS-B stands for Automatic Dependent Surveillance-Broadcast.  Most aircraft will be required to have ADS-B Out capability by 2020. It’s really just a new way to manage air traffic; it will eventually replace radar as Air Traffic Control’s (ATC) primary tool for separating aircraft. 

    Do I have to comply?

    Not all pilots will have to upgrade to ADS-B Out- it depends on how you use your aircraft and where you fly. The rule is that by 2020, all aircraft will be required to have ADS-B ‘Out’ equipment to fly in Class A, B and C airspace, plus Class E airspace above 10,000 feet but not below 2,500 feet. 


    In general you’ll need ADS-B ‘Out’ to fly to most of the places you need a Mode C transponder today.

    How does ADS-B work?

    ADS-B is made up of two main parts: ADS-B Out and ADS-B In.


    ADS-B ‘Out’ is mandatory; ADS-B ‘In’ is optional. ‘Out’ is of interest to air traffic controllers, while ‘In’ is mostly of interest to pilots. 

    • ADS-B ‘Out’ reports your aircraft’s position, velocity and altitude once per second. 
    • ADS-B ‘In’ lets you receive weather and traffic on a cockpit display, if equipped. 

    There are two different datalink technologies that meet the ADS-B requirement: 1090 MHz ES and 978 MHz UAT.

    • 1090 MHz ES is the only technology accepted for use above 18,000 feet, and is the accepted technology for use outside the US. There is traffic but no weather datalink on 1090 MHz.
    • 978 MHz is sometimes called UAT, for Universal Access Transceiver. This is only for use below 18,000 feet, and only for use within the US. There is traffic and weather datalink available on 978 MHz.

    If you fly above 18,000 feet or outside the US, 1090ES is your only option. If you don’t, a 978 UAT could work.


    What does it cost?

    The cost to comply varies widely: a lot depends on the equipment you already have installed, and if you want just ‘Out’ or ‘In/Out’. 


    For ‘Out’ solutions, you need an ADS-B Out transmitter and a WAAS GPS source.  


    ‘Out’ solutions have to be permanently installed, certified systems: ‘In’ can be a portable solution.


    We will be happy to discuss your options and provide you a quote: we need to know the type of aircraft, what equipment you already have installed, where you fly, and if you want just 'Out' or 'Out/In', so give us a call or send us an email.

    What equipment should I buy?

    Here are some of the more popular options we offer:

    • Garmin GDL82 – a 978 MHz UAT (ADS-B Out) datalink transceiver, with internal GPS.
    • Garmin GDL 84 – a 978 MHz UAT and 1090ES (ADS-B Out/In) datalink transceiver, with internal GPS and Flight Stream for viewing weather on your iPad.
    • Garmin GDL 88 – a 978 MHz UAT (ADS-B Out/In) datalink transceiver, available with or without an internal GPS.
    • Garmin GTX 335/345 – a 1090ES transponder (ADS-B Out), with internal GPS. 
      • The 345 adds 978MHz ADS-B ‘In’ capability and a Bluetooth connection for tablets.
      • If you already have a GTX 330 or GTX33 Mode S Transponder, it can be upgraded to ES.
    • Appareo Stratus ESG – a 1090ES transponder (ADS-B Out), with internal GPS.
    • L3 Lynx NGT-9000 – a 978 and 1090ES transponder (ADS-B Out/In), with internal GPS.
    • Honeywell / Bendix-King KT 74 – a 1090ES (ADS-B Out) transponder that is a “plug and play” replacement for the KT 76A/C.  Requires a separate GPS source.