47 CFR 87.263 - Frequencies.
(a)Domestic VHF service.
(1) Frequencies in the 128.8125-132.125 MHz and 136.4875-137.00 MHz bands are available to serve domestic routes, except that the frequency 136.750 MHz is available only to aeronautical enroute stations located at least 288 kilometers (180 miles) from the Gulf of Mexico shoreline (outside the Gulf of Mexico region). The frequencies 136.900 MHz, 136.925 MHz, 136.950 MHz and 136.975 MHz are available to serve domestic and international routes. Frequency assignments may be based on either 8.33 kHz or 25 kHz spacing. Use of these frequencies must be compatible with existing operations and must be in accordance with pertinent international treaties and agreements.
(2) A system or network of interconnected enroute stations may employ offset carrier techniques on the frequencies listed in paragraph (a)(1). The carrier frequencies of the individual transmitters must not be offset by more than ±8kHz.
(3) The frequencies 122.825 and 122.875 MHz are available for assignment to enroute stations which provide local area service to aircraft approaching or departing a particular airport. These frequencies will be assigned without regard to the restrictions contained in § 87.261 (c) and (d). Only organizations operating aircraft with a maximum capacity of 56 passengers or 8,200 kg (18,000 lbs) cargo will be authorized use of these enroute frequencies.
(5) The frequency 136.750 MHz is available in the Gulf of Mexico Region to serve domestic routes over the Gulf of Mexico and adjacent coastal areas. Assignment of this frequency in the Gulf of Mexico Region shall be to licensees first licensed on this frequency in the Gulf of Mexico Region prior to January 1, 1994, their successors and assigns, and is not subject to the conditions in § 87.261(c) and paragraph (a)(2) of this section. For the purpose of this paragraph, the Gulf of Mexico Region is defined as an area bounded on the east, north, and west by a line 288 km (180 miles) from the Gulf of Mexico shore line. Inland stations must be located within forty-eight kilometers (30 miles) of the Gulf of Mexico shore line.
(b)Domestic HF service.
(1) Regular use of high frequencies for aeronautical enroute or any aeronautical mobile (R) communications in the domestic service within the continental United States (excluding Alaska) will not be authorized.
(2) These frequencies (carrier) are available for assignment to serve aircraft operating in support of offshore drilling operations in open sea areas beyond the range of VHF propagation:
(3) Alaska: The following frequencies (carrier) are available for assignment to serve domestic air routes in the Alaska area:
(i)Throughout Alaska: Shared with the FAA and assigned where an applicant shows the need for a service not provided by the FAA.
(ii)Alaska Aleutian chain and feeders.
(iii)Central and Southeast Alaska and feeders.
(iv) The following frequencies (carrier) are available to enroute stations in Alaska without regard to the restrictions contained in § 87.261 (c) or (d). These frequencies may also be used for communications between enroute stations concerning matters directly affecting aircraft with which they are engaged. Enroute stations located at an uncontrolled airport shall not transmit information concerning runway, wind or weather conditions during the operating hours of a unicom.
1 The frequency 5167.5 kHz is available to any station for emergency communications in Alaska. No airborne operations are permitted. Peak envelope power of stations operating on this frequency must not exceed 150 watts. This frequency may also be used by Alaska private fixed stations for calling purposes, but only for establishing communications.
(c)International VHF service. Frequencies in the 128.825-132.000 and 136.000-137.000 MHz bands are available to enroute stations serving international flight operations. Frequency assignments are based on either 8.33 kHz or 25 kHz channel spacing. Proposed operations must be compatible with existing operations in the band.
(d)International HF service. High frequencies (carrier) available to enroute stations serving international flight operations on the Major World Air Route Areas (MWARA's), as defined in the international Radio Regulations and the ICAO Assignment Plan, are:
(1) Central East Pacific (CEP):
(2) Central West Pacific (CWP):
(3) North Pacific (NP):
(4) South Pacific (SP):
(5) North Atlantic (NAT):
(6) Europe (EUR):
(7) South America (SAM):
(8) South Atlantic (SAT):
(9) Southeast Asia (SEA):
(10) East Asia (EA):
(11) Middle East (MID):
(12) Africa (AFI):
(13) Indian Ocean (INO):
(14) North Central Asia (NCA):
(15) Caribbean (CAR):
(e)Long distance operational control. Long distance operational control frequencies provide communications between aeronautical enroute stations and aircraft stations anywhere in the world for control of the regularity and efficiency of flight and safety of aircraft. World-wide frequencies are not assigned by administrations for MWARA and Regional and Domestic Air Route Area (RDARA).
(f)121.500 MHz: Emergency and distress only.