47 CFR 87.347: Supplemental eligibility.

(a) Aeronautical utility stations may transmit on unicom frequencies only at airports which have a unicom and a part-time or no control tower, an RCO or an FAA flight service station.

(b) An applicant for an aeronautical utility station operating on a unicom frequency or the frequency 122.900 MHz must:

(1) Have a need to routinely operate a ground vehicle on the airport movement area;

(2) Maintain a list of the vehicle(s) in which the station is to be located;

(3) Certify on the application that either the applicant is the airport owner or operator, or a state or local government aeronautical agency, or that the airport owner or operator has granted permission to operate the vehicle(s) on the airport movement area.

(c) An applicant for an aeronautical utility station requesting authority to transmit on the local control (tower) frequency or on the control tower remote communications outlet (RCO) frequency must certify that the Air Traffic Manager of the airport control tower approves the requested use of the tower or RCO frequency.