Section 87.217 - Frequencies(a) Only one unicom frequency will be assigned at any one airport. Applicants must request a particular frequency, which will be taken into consideration when the assignment is made. The frequencies assignable to unicoms are:(1) 122.950 MHz at airports which have a full-time control tower or full-time FAA flight service station.(2) 122.700, 122.725, 122.800, 122.975, 123.000, 123.050 or 123.075 MHz at all other airports.(b) 121.500 MHz: emergency and distress only.53 FR 28940, Aug. 1, 1988, as amended at 55 FR 30464, July 26, 1990; 58 FR 67696, Dec. 22, 1993; 69 FR 32885 , June 14, 2004