Larry Dighera wrote:
On Thu, 29 May 2008 10:21:17 -0500, Gig 601Xl Builder
wrote in
:

Larry Dighera wrote:

The Advisory Circular mentions notifying UNICOM stations of over
flight of uncontrolled fields, but I find no mention of
self-announcing over flight intention on CTAF:

AC No: 9042F

http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/c54e50252a7fa56d862569d8007804ba/$FILE/ac90-42F.pdf
10 . UNICOM COMMUNICATION PROCEDURES.
a. In communicating with a UNICOM station, the flowing practices
will help reduce frequency
congestion, facilitate a better understanding of pilot intentions,
help identify the location of aircraft in. the traffic pattern,
and enhance safety of flight:
-- (1) Select the correct CTAF frequency. --
(2) State the identification of the UNICOM station you are calling
in each transmission.
(3) Speak slowly and distinctly.
(4) Notify the UNICOM station approximately 10 miles from the
airport, reporting altitude, aircraft type, aircraft
identification, location relative to the airport, and whether
-- landing or overflight.
Request wind information and runway in use.
(5) Report on downwind, base, and final approach.
(6) Report leaving the runway.


What do you mean? It's mentioned in the step 1 of what you posted.


Indeed. I overlooked that.

I guess I didn't expect to see CTAF mentioned under UNICOM.


The AIM hast this definition of UNICOM stations:

e. Information Provided by Aeronautical Advisory Stations (UNICOM)

1. UNICOM is a nongovernment air/ground radio communication
station which may provide airport information at public use
airports where there is no tower or FSS.


And the Pilot/Controller Glossary provides this definition of CTAF:


http://www.faa.gov/airports_airtraff...pubs/PCG/C.HTM
COMMON TRAFFIC ADVISORY FREQUENCY (CTAF)- A frequency designed for
the purpose of carrying out airport advisory practices while
operating to or from an airport without an operating control
tower. The CTAF may be a UNICOM, Multicom, FSS, or tower frequency
and is identified in appropriate aeronautical publications.

(Refer to AC 90-42, Traffic Advisory Practices at Airports Without
Operating Control Towers.)

(neither CTAF nor UNICOM are mentioned in Part 1 definitions)

So while the CTAF _frequency_ may be a UNICOM frequency also, I always
considered UNICOM stations to be manned, while I apparently
erroneously considered radio operation on CTAF frequencies to be
limited to one-way self-announced position and intention broadcasts.
Obviously CTAF is only so limited when there is neither an operating
UNICOM nor FSS station at the field.

Despite my confusion over the nomenclature, these documents seem to be
the sole guidance concerning announcing overflight intentions provided
by FAA. Neither CTAF nor UNICOM are mentioned in Part 91.

I did some Googleing of CTAF/UNICOM on Arinav and there are 6100 hits
for that exact phrase. I've not flown to a huge number of airports in my
career of flying but most of them have been uncontrolled fields and I
can't remember a single one since the first big reduction of FSS that
didn't use the Unicom as the CTAF.