On Monday, November 19, 2012 10:05:31 AM UTC-8, John Carlyle wrote:
Darryl,



Thanks for taking the time and trouble to write your last post - I found it extremely informative!



Out of curiosity I did a Google search for "DO-260A versus DO-260B" to see what was changed. I found something ( http://adsb.tc.faa.gov/WG3_Meetings/...es_1-09-09.doc ), but it was way to technical for me.



Is there anything in this DO-260A to B change that we glider pilots should understand, or is it mostly "inside baseball" stuff that's important (as you said) only if you implement ADS-B?



-John

John

There are important changes. But the high order message is DO-260B is the 1090ES spec required by the FAA and its likely at some time that DO-260A transmitters just won't receive the full suite of ground services (ATC, TIS-B, ADS-R) and certainly won't meet FAA 2020 carriage mandate (that gliders are exempt from anyhow).

DO-260B technically is important for the USA rollout of ADS-B. For example it changed the interpretation of capability class bits, that tell the ground infrastructure if your aircraft has 1090ES data-in and/or UAT data-in capabilities and that is used by the ground infrastructure to work out what ADS-R and TIS-B data to broadcast for to your aircraft. There were also changes in the GPS sensor quality data parameters transmitted (the SIL, NIC, NACp and NACv parameters).

There are better docs discussing changes than the one you found, here is one example..,

http://www.bangkok.icao.int/cns/meet...21&doc_id=2159

Regards


Darryl