ADS-B

 

Everything you didn’t want to know but you better understand now.

 

Consider just the continental USA for the moment.  By 2020 aircraft must be broadcasting ADS-B out data (altitude, location, direction, speed, ID, etc) in class A, in or above class B and C airspace and within a 30 NM radius of B and C airports or in class E at an altitude above 10,000 MSL, but not at an AGL of 2500 or less (in class E).  In other words, if you fly out in the weeds and never go anywhere important, forgetaboutit.

 

Uh, there are special non-compliance allowances for aircraft with no electrical system, balloons and gliders.  So heads up out there.   

 

Information may be broadcast on the UAT frequency of 978 MHz or on the current transponder frequency of 1090 MH commonly known as Extended Squitter (ES). Oops, there’s special mandatory rule for flights at or above 18,000 MSL – ADS-B out must be transmitted on 1090 MHz ES even if it is also transmitted on 978 MHz. 

 

If you fly at or above FL18 and are thinking about replacing your transponder in the near future, consider one that transmits ES or is easily converted to such transmission at a later date.

 

Why UAT (Universal Access Transceiver) on a different frequency?  Uh, there are bandwidth, framing, rate and interrogation limitations on the transponder frequency.  

 

I hope that this is perfectly clear.  But, not to worry as these specific requirements are 8 years away.

 

OK, so there is nothing here you need to know now about ADS-B Out in 2020.  Ah, but there will be more about current ADS-B in a missive to follow – this is merely to whet your appetite or help you get to sleep.

 

See FAR 91.225, 91.227 and Appendix D if you are into self-abuse.

 

Grayhawk AKA Scott Krueger