Darryl,

Many thanks for your easy to understand version of DO-260B. I get it...

I had seen the link you provided, but it wouldn't open. I persevered once I understood it was important, and was finally successful. You're right, it was a much better document - and almost understandable! grin

Best regards,
John

On Monday, November 19, 2012 3:34:10 PM UTC-5, Darryl Ramm wrote:
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