The attached picture shows the Rapid City Regional Airport, KRAP. If I arrive after KRAP's tower is closed, which frequency should I use: 125.85 or 122.95?

Sectional Snippet


1 Answer 1


You use the CTAF for announcing your position and intentions, i.e. 125.85. From the AIM 4-1-9(g):

If an airport has a tower and it is temporarily closed, or operated on a part-time basis and there is no FSS on the airport or the FSS is closed, use the CTAF to self-announce your position or intentions.

4-1-9(b) says:

The CTAF may be a UNICOM, MULTICOM, FSS, or tower frequency and is identified in appropriate aeronautical publications.

125.85 is marked as the CTAF on the sectional and listed in the Chart Supplement.

Note: The letter "C" in the dark circle next to the control tower ("CT") frequency indicates that the CT frequency is the CTAF frequency at that airport.

  • 1
    $\begingroup$ Understood, and I know the CTAF is 125.85 because the blue-circled C is next to 125.85, right? If the blue-circled C was next to 122.95, CTAF would be that frequency? $\endgroup$ Commented Jun 26, 2017 at 20:55
  • 3
    $\begingroup$ @GarrisonNeely Yes, the C indicates the CTAF frequency. You can check the VFR chart legend for a full breakdown of all the information shown there. $\endgroup$
    – Pondlife
    Commented Jun 26, 2017 at 21:02

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .