2. The provision of traffic advisories is not mentioned, or even high on the list of services that Unicom operators are authorised to provide
eCFR ? Code of Federal Regulations
Interesting reading.
So, although it would appear that many Unicom operators in the US are providing traffic advisories on pilot request, the question we should all be trying to find out is whether they are operating legally and what is their (or the airport's) legal liability exposure if something should go wrong?
The reason I asked the question is that a rumour is going around that when recently CASA asked the FAA what sort of traffic information UNICOMs in the U.S. were permitted to give aircraft, the FAA expressed interest and asked what locations were giving such info.