Larry Dighera wrote:
I would expect to
see data-link equipment (ACARS* or more likely ATN** or NEXCOM***)
available for GA aircraft soon.

* http://en.wikipedia.org/wiki/ACARS
** http://www.tc.faa.gov/act300/act350/
*** http://www.faa.gov/nextgen/nexcom/Publib/aboutnc2.htm

Ah - thanks for the links. The last one states:

"Through the RTCA forum and the FAA's Investment Analysis process, the Time
Division Multiple Access (TDMA) system was selected for implementation. The
TDMA system will use multi channels to operate on one 25 kHz frequency
assignment. The system will utilize Differential (D8PSK) Phase Shift Keying
(D8PSK) and will require a 4.8 KB VOCODER for voice operation. While
current planning calls for operating the system in a 2 -Voice/2 -Data
configuration, other combinations could also be used. Standards for the
system, termed VHF Digital Link Mode Three or VDL-3, are close to
completion and are expected to be validated. In the fully operational
state, the system will accommodate both voice and data."

That would definitely be a great solution, but that page was last updated
January 4, 2000. Do you or anyone else know if any further progress been
made or have the efforts died? (The links I could find all seemed to dead-
end.)