Similar to the problem experienced by the poster at Why do so many airports have the same CTAF frequency?, I have noticed that my CTAF is crowded. Not with local pilots, but with operations as much as 100nm away. There's little benefit to knowing that there are skydivers jumping in the mountains when I am an hour away in the plains. Likewise, hearing someone on downwind for an identically named-runway but on an island out in the ocean is, well, distracting.

I asked the airport manager what it would take and he chortled out, "An act of Congress." And he might well be right!

Does anyone know the procedure for getting a frequency changed? And can the 25kHz spacing be used or is that reserved for ATC and ATIS/AWOS/ASOS channels, which are, respectively, redundant or non-critical?


If your CTAF is a Unicom frequency, from AOPA:

the operator of the Unicom can change the frequency by submitting an application for modification on FCC forms 601 and 159 along with the $95 application fee. The current time for approval is typically 30 to 60 days from filing.

Frequencies are allocated by FCC, and rules are found at 4-1-11 of this document:

CTAF/Unicom/Multicom/FSS frequency allocation

CTAF/Unicom/Multicom/FSS frequency allocation

Under this table there is a note which deals with both of your concerns, requesting a new frequency and usign the 25 kHz spacing:

In some areas of the country, frequency interference may be encountered from nearby airports using the same UNICOM frequency. Where there is a problem, UNICOM operators are encouraged to develop a “least interference” frequency assignment plan for airports concerned using the frequencies designated for airports without operating control towers. UNICOM licensees are encouraged to apply for UNICOM 25 kHz spaced channel frequencies. Due to the extremely limited number of frequencies with 50 kHz channel spacing, 25 kHz channel spacing should be implemented. UNICOM licensees may then request FCC to assign frequencies in accordance with the plan, which FCC will review and consider for approval.


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