(a) Airport control tower stations (control towers) and control tower remote communications outlet stations (RCOs) must limit their communications to the necessities of safe and expeditious operations of aircraft operating on or in the vicinity of the airport. Control towers and RCOs provide air traffic control services to aircraft landing, taking off and taxing on the airport as well as aircraft transiting the airport traffic area. Additionally, control towers and RCOs can provide air traffic control services to vehicles operating on airport movement areas (see subpart L of this part). Control towers and RCOs must serve all aircraft without discrimination. An RCO must be remotely operated from a control tower or other FAA control facility located at a nearby airport.
(b) A control tower must maintain a continuous watch on the following frequencies during the hours of operation:
121.500 MHz
3023.0 kHz (Alaska only)
5680.0 kHz (Alaska only)
The Commission may exempt from these watch requirements the licensee of an airport control tower station if a satisfactory showing has been made that such an exemption will not adversely affect life and property in the air.
[53 FR 28940, Aug. 1, 1988, as amended at 54 FR 11721, Mar. 22, 1989; 55 FR 30464, July 26, 1990]
Only one control tower or RCO will be licensed at an airport.
[64 FR 27476, May 20, 1999]
The Commission will assign VHF frequencies after coordination with the FAA. Frequencies in the following bands are available to control towers and RCOs. Channel spacing is 25 kHz.
118.000-121.400 MHz
121.600-121.925 MHz
123.600-128.800 MHz
132.025-135.975 MHz
(a) The frequency 123.100 MHz is available for use by control towers and RCOs at special aeronautical events on the condition that no harmful interference is caused to search and rescue operations in the locale involved.
(b) Frequencies in the bands 200.0-285.0 and 325.0-405.0 kHz will normally be assigned only to control towers and RCOs authorized to operate on at least one VHF frequency. The Commission may assign frequencies in these bands to entities that do not provide VHF service in cases where granting such an application will not adversely affect life and property in the air.
(c) Frequencies listed in the introductory paragraph of this section are available to control towers and RCOs for communications with ground vehicles and aircraft on the ground. The antenna heights shall be restricted to the minimum necessary to achieve the required coverage. Channel spacing is 25 kHz.
(d) 121.500 MHz: emergency and distress only.
[53 FR 28940, Aug. 1, 1988, as amended at 55 FR 30464, July 26, 1990; 63 FR 68958, Dec. 14, 1998; 69 FR 32886, June 14, 2004; 71 FR 70680, Dec. 6, 2006]
The control tower must render a communications service 24 hours a day unless the Commission determines, in coordination with the NTIA IRAC, that reduced hours of service will not adversely affect life and property in the air.
[63 FR 68958, Dec. 14, 1998]
Control towers and RCOs must not cause harmful interference to control towers or RCOs at adjacent airports. If interference between adjacent control towers or RCOs exists, the Commission will direct the licensees how to eliminate the interference.
[55 FR 30465, July 26, 1990]