FCC Regulation Document

Part: 
Topic: C

47 CFR Part 87 (up to date as of 2/20/2024)
                                                                          47 CFR Part 87 (Feb. 20, 2024)
Aviation Services

This content is from the eCFR and is authoritative but unofficial.

Title 47 —Telecommunication
Chapter I —Federal Communications Commission
Subchapter D —Safety and Special Radio Services

Part 87 Aviation Services
  Subpart A General Information
      § 87.1 Basis and purpose.
      § 87.3 Other applicable rule parts.
      § 87.5 Definitions.
  Subpart B Applications and Licenses
      § 87.17 Scope.
      § 87.18 Station license required.
      § 87.19 Basic eligibility.
      § 87.25 Filing of applications.
      § 87.27 License term.
      § 87.29 Partial grant of application.
      § 87.35 Cancellation of license.
      § 87.39 Equipment acceptable for licensing.
      § 87.41 Frequencies.
      § 87.43 Operation during emergency.
      § 87.45 Time in which station is placed in operation.
      § 87.47 Application for a portable aircraft station license.
      § 87.51 Aircraft earth station commissioning.
  Subpart C Operating Requirements and Procedures
      Operating Requirements
         § 87.69 Maintenance tests.
         § 87.71 Frequency measurements.
         § 87.73 Transmitter adjustments and tests.
         § 87.75 Maintenance of antenna structure marking and control equipment.
         § 87.77 Availability for inspections.
      Radio Operator Requirements
         § 87.87 Classification of operator licenses and endorsements.
         § 87.89 Minimum operator requirements.
         § 87.91 Operation of transmitter controls.
      Operating Procedures
         § 87.103 Posting station license.
         § 87.105 Availability of operator permit or license.

47 CFR Part 87 (Feb. 20, 2024) (enhanced display)                                           page 1 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                           47 CFR Part 87 (Feb. 20, 2024)
Aviation Services

        § 87.107 Station identification.
        § 87.109 Station logs.
        § 87.111 Suspension or discontinuance of operation.
   Subpart D Technical Requirements
     § 87.131 Power and emissions.
     § 87.133 Frequency stability.
     § 87.135 Bandwidth of emission.
     § 87.137 Types of emission.
     § 87.139 Emission limitations.
     § 87.141 Modulation requirements.
     § 87.143 Transmitter control requirements.
     § 87.145 Acceptability of transmitters for licensing.
     § 87.147 Authorization of equipment.
     § 87.149 Special requirements for automatic link establishment (ALE).
     § 87.151 Special requirements for differential GPS receivers.
   Subpart E Frequencies
     § 87.169 Scope.
     § 87.171 Class of station symbols.
     § 87.173 Frequencies.
   Subpart F Aircraft Stations
     § 87.185     Scope of service.
     § 87.187     Frequencies.
     § 87.189     Requirements for public correspondence equipment and operations.
     § 87.191     Foreign aircraft stations.
     Emergency Locator Transmitters
        § 87.193 Scope of service.
        § 87.195 121.5 MHz ELTs.
        § 87.197 ELT test procedures.
        § 87.199 Special requirements for 406.0–406.1 MHz ELTs.
   Subpart G Aeronautical Advisory Stations (Unicoms)
     § 87.213 Scope of service.
     § 87.215 Supplemental eligibility.
     § 87.217 Frequencies.
     § 87.219 Automatic operations.
   Subpart H Aeronautical Multicom Stations
     § 87.237 Scope of service.
     § 87.239 Supplemental eligibility.
     § 87.241 Frequencies.
   Subpart I Aeronautical Enroute Stations, Aeronautical Fixed Stations, and Aircraft

47 CFR Part 87 (Feb. 20, 2024) (enhanced display)                                            page 2 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                47 CFR Part 87 (Feb. 20, 2024)
Aviation Services

               Data Link Land Test Stations
     Aeronautical Enroute Stations
        § 87.261 Scope of service.
        § 87.263 Frequencies.
        § 87.265 Administrative communications.
     Aeronautical Fixed Stations
        § 87.275 Scope of service.
        § 87.277 Supplemental eligibility.
        § 87.279 Frequencies.
     Aircraft Data Link Land Test Stations
        § 87.285 Scope of service.
        § 87.287 Frequencies.
   Subpart J Flight Test Stations
     § 87.299 Scope of service.
     § 87.301 Supplemental eligibility.
     § 87.303 Frequencies.
     § 87.305 Frequency coordination.
     § 87.307 Cooperative use of facilities.
   Subpart K Aviation Support Stations
     § 87.319 Scope of service.
     § 87.321 Supplemental eligibility.
     § 87.323 Frequencies.
   Subpart L Aeronautical Utility Mobile Stations
     § 87.345 Scope of service.
     § 87.347 Supplemental eligibility.
     § 87.349 Frequencies.
     § 87.351 Frequency changes.
   Subpart M Aeronautical Search and Rescue Stations
     § 87.371 Scope of service.
     § 87.373 Supplemental eligibility.
     § 87.375 Frequencies.
   Subpart N Emergency Communications
     § 87.393 Scope of service.
     § 87.395 Plan for the Security Control of Air Traffic and Air Navigation Aids (Short Title:
               SCATANA).
     § 87.397 Emergency operations.
   Subpart O Airport Control Tower Stations
     § 87.417 Scope of service.
     § 87.419 Supplemental eligibility.
47 CFR Part 87 (Feb. 20, 2024) (enhanced display)                                                 page 3 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                          47 CFR Part 87 (Feb. 20, 2024)
Aviation Services

     § 87.421 Frequencies.
     § 87.423 Hours of operation.
     § 87.425 Interference.
   Subpart P Operational Fixed Stations
     § 87.445 Scope of service.
     § 87.447 Supplemental eligibility.
     § 87.449 Frequencies.
     § 87.451 Licensing limitations.
   Subpart Q Stations in the Radiodetermination Service
     § 87.471 Scope of service.
     § 87.473 Supplemental eligibility.
     § 87.475 Frequencies.
     § 87.477 Condition of grant for radionavigation land stations.
     § 87.479 Harmful interference to radionavigation land stations.
     § 87.481 Unattended operation of domestic radiobeacon stations.
     § 87.483 Audio visual warning systems.
   Subpart R [Reserved]
   Subpart S Automatic Weather Stations (AWOS/ASOS)
     § 87.525 Scope of service.
     § 87.527 Supplemental eligibility.
     § 87.529 Frequencies.

PART 87—AVIATION SERVICES
Authority: 47 U.S.C. 154, 303 and 307(e), unless otherwise noted.

Source: 53 FR 28940, Aug. 1, 1988, unless otherwise noted.

Subpart A—General Information
§ 87.1 Basis and purpose.
This section contains the statutory basis and provides the purpose for which this part is issued.

     (a) Basis. The rules for the aviation services in this part are promulgated under the provisions of the
         Communications Act of 1934, as amended, which vests authority in the Federal Communications
         Commission (Commission) to regulate radio transmission and to issue licenses for radio stations. These
         rules conform with applicable statutes and international treaties, agreements and recommendations to
         which the United States is a party. The most significant of these documents are listed with the short title
         appearing in parentheses:

           (1) Communications Act of 1934, as amended—(Communications Act).

47 CFR 87.1(a)(1) (enhanced display)                                                                       page 4 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                       47 CFR 87.1(a)(2)
Aviation Services

           (2) International Telecommunication Union Radio Regulations, in force for the United States—(Radio
               Regulations).

           (3) The Convention on International Civil Aviation—(ICAO Convention).

     (b) Purpose. This part states the conditions under which radio stations may be licensed and used in the
         aviation services. These rules do not govern U.S. Government radio stations.

§ 87.3 Other applicable rule parts.
Other applicable CFR title 47 parts include:

     (a) Part 0 contains the Commission's organizations and delegations of authority. Part 0 also lists
         Commission publications, standards and procedures for access to Commission records and location of
         Commission monitoring stations.

     (b) Part 1 contains rules of practice and procedure for license applications, adjudicatory proceedings, rule
         making proceedings, procedures for reconsideration and review of the Commission's actions; provisions
         concerning violation notices and forfeiture proceedings; and the environmental processing requirements
         that, together with the procedures specified in § 17.4(c) of this chapter, if applicable, must be complied
         with prior to the initiation of construction.

     (c) Part 2 contains the Table of Frequency Allocations and special requirements in international regulations,
         recommendations, agreements, and treaties. This part also contains standards and procedures
         concerning marketing of radio frequency devices, and for obtaining equipment authorization.

     (d) Part 13 contains information and rules for the licensing of commercial radio operators.

     (e) Part 17 contains requirements for construction, marking and lighting of antenna towers, and the
         environmental notification process that must be completed before filing certain antenna structure
         registration applications.

     (f) Part 80 contains rules for the maritime services. Certain maritime frequencies are available for use by
         aircraft stations for distress and safety, public correspondence and operational communications.

[53 FR 28940, Aug. 1, 1988, as amended at 77 FR 3955, Jan. 26, 2012]

§ 87.5 Definitions.
    Aeronautical advisory station (unicom). An aeronautical station used for advisory and civil defense
         communications primarily with private aircraft stations.

    Aeronautical enroute station. An aeronautical station which communicates with aircraft stations in flight status
         or with other aeronautical enroute stations.

    Aeronautical fixed service. A radiocommunication service between specified fixed points provided primarily for
         the safety of air navigation and for the regular, efficient and economical operation of air transport. A
         station in this service is an aeronautical fixed station.

    Aeronautical Mobile Off-Route (OR) Service. An aeronautical mobile service intended for communications,
         including those relating to flight coordination, primarily outside national or international civil air
         routes.(RR)

47 CFR 87.5 “Aeronautical Mobile Off-Route (OR) Service” (enhanced display)                                page 5 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                        47 CFR 87.5 “Aeronautical Mobile Route (R) Service”
Aviation Services

    Aeronautical Mobile Route (R) Service. An aeronautical mobile service reserved for communications relating to
         safety and regularity of flight, primarily along national or international civil air routes.(RR)

    Aeronautical Mobile-Satellite Off-Route (OR) Service. An aeronautical mobile-satellite service intended for
         communications, including those relating to flight coordination, primarily outside national and
         international civil air routes.(RR)

    Aeronautical Mobile-Satellite Route (R) Service. An aeronautical mobile-satellite service reserved for
         communications relating to safety and regularity of flights, primarily along national or international civil air
         routes.(RR)

    Aeronautical Mobile-Satellite Service. A mobile-satellite service in which mobile earth stations are located on
         board aircraft.

    Aeronautical mobile service. A mobile service between aeronautical stations and aircraft stations, or between
         aircraft stations, in which survival craft stations may also participate; emergency position-indicating
         radiobeacon stations may also participate in this service on designated distress and emergency
         frequencies.

    Aeronautical multicom station. An aeronautical station used to provide communications to conduct the activities
         being performed by, or directed from, private aircraft.

    Aeronautical radionavigation service. A radionavigation service intended for the benefit and for the safe
         operation of aircraft.

    Aeronautical search and rescue station. An aeronautical station for communication with aircraft and other
         aeronautical search and rescue stations pertaining to search and rescue activities with aircraft.

    Aeronautical station. A land station in the aeronautical mobile service. In certain instances an aeronautical
         station may be located, for example, on board ship or on a platform at sea.

    Aeronautical utility mobile station. A mobile station used on airports for communications relating to vehicular
         ground traffic.

    Air carrier aircraft station. A mobile station on board an aircraft which is engaged in, or essential to, the
           transportation of passengers or cargo for hire.

    Aircraft data link system. A system used to provide data communications between the aircraft and ground
           personnel necessary for the safe, efficient and economic operation of the aircraft.

    Aircraft data link land test station. A station which is used to test and calibrate aircraft data link system
           communications equipment.

    Aircraft earth station (AES). A mobile earth station in the aeronautical mobile-satellite service located on board
           an aircraft.

    Aircraft station. A mobile station in the aeronautical mobile service other than a survival craft station, located on
           board an aircraft.

    Air operations area. All airport areas where aircraft can operate, either under their own power or while in tow. The
          airport operations area includes runways, taxiways, apron areas, and all unpaved surfaces within the
          airport's perimeter fence. An apron area is a surface in the air operations area where aircraft park and are
          serviced (refueled, loaded with cargo, and/or boarded by passengers).

47 CFR 87.5 “Air operations area” (enhanced display)                                                            page 6 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                       47 CFR 87.5 “Airport”
Aviation Services

    Airport. An area of land or water that is used or intended to be used for the landing and takeoff of aircraft, and
          includes its buildings and facilities, if any.

    Airport control tower (control tower) station. An aeronautical station providing communication between a control
          tower and aircraft.

    Automatic dependent surveillance—broadcast (ADS–B) Service. Broadcast transmissions from aircraft,
         supporting aircraft-to-aircraft or aircraft-to-ground surveillance applications, including position reports,
         velocity vector, intent and other relevant information about the aircraft.

    Automatic terminal information service-broadcast (ATIS-B). The automatic provision of current, routine
         information to arriving and departing aircraft throughout a 24-hour period or a specified portion thereof.

    Automatic weather observation station (AWOS) or automatic surface observation station (ASOS). A land station
         located at an airport and used to automatically transmit weather information to aircraft.

    Aviation service organization. Any business firm which maintains facilities at an airport for the purposes of one
           or more of the following general aviation activities:

           (a) Aircraft fueling;

           (b) Aircraft services (e.g. parking, storage, tie-downs);

           (c) Aircraft maintenance or sales;

           (d) Electronics equipment maintenance or sales;

           (e) Aircraft rental, air taxi service or flight instructions; and

           (f) Baggage and cargo handling, and other passenger or freight services.

    Aviation services. Radio-communication services for the operation of aircraft. These services include
           aeronautical fixed service, aeronautical mobile service, aeronautical radiodetermination service, and
           secondarily, the handling of public correspondence on frequencies in the maritime mobile and maritime
           mobile satellite services to and from aircraft.

    Aviation support station. An aeronautical station used to coordinate aviation services with aircraft and to
           communicate with aircraft engaged in unique or specialized activities. (See subpart K)

    Differential GPS (DGPS). A system which transmits corrections to the GPS derived position.

    Emergency locator transmitter (ELT). A transmitter of an aircraft or a survival craft actuated manually or
         automatically that is used as an alerting and locating aid for survival purposes.

    Emergency locator transmitter (ELT) test station. A land station used for testing ELTs or for training in the use of
         ELTs.

    Expendable Launch Vehicle (ELV). A booster rocket that can be used only once to launch a payload, such as a
         missile or space vehicle.

    Flight Information Service-Broadcast (FIS-B). A broadcast service provided for the purpose of giving advice and
           information useful for the safe and efficient conduct of flights.

    Flight telemetering mobile station. A telemetering mobile station used for transmitting data from an airborne
           vehicle, excluding data related to airborne testing of the vehicle itself (or major components thereof).

    Flight test aircraft station. An aircraft station used in the testing of aircraft or their major components.

47 CFR 87.5 “Flight test aircraft station” (enhanced display)                                                      page 7 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                      47 CFR 87.5 “Flight test land station”
Aviation Services

    Flight test land station. An aeronautical station used in the testing of aircraft or their major components.

    Glide path station. A radionavigation land station which provides vertical guidance to aircraft during approach to
           landing.

    Instrument landing system (ILS). A radionavigation system which provides aircraft with horizontal and vertical
          guidance just before and during landing and, at certain fixed points, indicates the distance to the
          reference point of landing.

    Instrument landing system glide path. A system of vertical guidance embodied in the instrument landing system
          which indicates the vertical deviation of the aircraft from its optimum path of descent.

    Instrument landing system localizer. A system of horizontal guidance embodied in the instrument landing
          system which indicates the horizontal deviation of the aircraft from its optimum path of descent along the
          axis of the runway or along some other path when used as an offset.

    Land station. A station in the mobile service not intended to be used while in motion.

    Localizer station. A radionavigation land station which provides horizontal guidance to aircraft with respect to a
          runway center line.

    Marker beacon station. A radionavigation land station in the aeronautical radionavigation service which employs
         a marker beacon. A marker beacon is a transmitter which radiates vertically a distinctive pattern for
         providing position information to aircraft.

    Mean power (of a radio transmitter). The average power supplied to the antenna transmission line by a
         transmitter during an interval of time sufficiently long compared with the lowest frequency encountered in
         the modulation taken under normal operating conditions.

    Microwave landing system. An instrument landing system operating in the microwave spectrum that provides
         lateral and vertical guidance to aircraft having compatible avionics equipment.

    Mobile service. A radiocommunication service between mobile and land stations, or between mobile stations. A
          mobile station is intended to be used while in motion or during halts at unspecified points.

    Operational fixed station. A fixed station, not open to public correspondence, operated by and for the sole use of
          persons operating their own radiocommunication facilities in the public safety, industrial, land
          transportation, marine, or aviation services.

    Peak envelope power (of a radio transmitter). The average power supplied to the antenna transmission line by a
          transmitter during one radio frequency cycle at the crest of the modulation envelope taken under normal
          operating conditions.

    Private aircraft station. A mobile station on board an aircraft not operated as an air carrier. A station on board an
           air carrier aircraft weighing less than 12,500 pounds maximum certified takeoff gross weight may be
           licensed as a private aircraft station.

    Racon station. A radionavigation land station which employs a racon. A racon (radar beacon) is a transmitter-
         receiver associated with a fixed navigational mark, which when triggered by a radar, automatically returns
         a distinctive signal which can appear on the display of the triggering radar, providing range, bearing and
         identification information.

    Radar. A radiodetermination system based upon the comparison of reference signals with radio signals
          reflected, or re-transmitted, from the position to be determined.

47 CFR 87.5 “Radar” (enhanced display)                                                                         page 8 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                 47 CFR 87.5 “Radio altimeter”
Aviation Services

    Radio altimeter. Radionavigation equipment, on board an aircraft or spacecraft, used to determine the height of
          the aircraft or spacecraft above the Earth's surface or another surface.

    Radiobeacon station. A station in the radionavigation service the emissions of which are intended to enable a
          mobile station to determine its bearing or direction in relation to the radiobeacon station.

    Radiodetermination service. A radiocommuncation service which uses radiodetermination. Radiodetermination
          is the determination of the position, velocity and/or other characteristics of an object, or the obtaining of
          information relating to these parameters, by means of the propagation of radio waves. A station in this
          service is called a radiodetermination station.

    Radiolocation service. A radiodetermination service for the purpose of radiolocation. Radiolocation is the use of
          radiodetermination for purposes other than those of radionavigation.

    Radionavigation land test stations. A radionavigation land station which is used to transmit information essential
          to the testing and calibration of aircraft navigational aids, receiving equipment, and interrogators at
          predetermined surface locations. The Maintenance Test Facility (MTF) is used primarily to permit
          maintenance testing by aircraft radio service personnel. The Operational Test Facility (OTF) is used
          primarily to permit the pilot to check a radionavigation system aboard the aircraft prior to takeoff.

    Radionavigation service. A radiodetermination service for the purpose of radionavigation. Radionavigation is the
          use of radiodetermination for the purpose of navigation, including obstruction warning.

    Re-usable launch vehicle (RLV). A booster rocket that can be recovered after launch, refurbished and re-
          launched.

    Surveillance radar station. A radionavigation land station in the aeronautical radionavigation service employing
          radar to detect the presence of aircraft within its range.

    Survival craft station. A mobile station in the maritime or aeronautical mobile service intended solely for survival
          purposes and located on any lifeboat, life raft or other survival equipment.

    Traffic information services—broadcast (TIS–B). Traffic information broadcasts derived from ground-based radar
           systems.

    Universal access transceiver (UAT). A radio datalink system authorized to operate on the frequency 978 MHz to
          support Automatic Dependent Surveillance—Broadcast (ADS–B) Service, Traffic Information
          Services—Broadcast (TIS–B) and Flight Information Service—Broadcast (FIS–B).

    VHF Omni directional range station (VOR). A radionavigation land station in the aeronautical radionavigation
         service providing direct indication of the bearing (omni-bearing) of that station from an aircraft.

[53 FR 28940, Aug. 1, 1988, as amended at 54 FR 11719, Mar. 22, 1989; 54 FR 49995, Dec. 4, 1989; 55 FR 4175, Feb. 7, 1990; 57
FR 45749, Oct. 5, 1992; 64 FR 27474, May 20, 1999; 69 FR 32879, June 14, 2004; 71 FR 70676, Dec. 6, 2006; 78 FR 45074, July 26,
2013; 78 FR 61205, Oct. 3, 2013; 80 FR 38909, July 7, 2015]

Subpart B—Applications and Licenses
§ 87.17 Scope.
Part 1 of the Commission's rules contains the general rules of practice and procedure applicable to proceedings
before the Commission and for the filing of applications for radio station licenses in the aviation services. Specific
guidance for each type of radio service license in aviation services is set forth in this part.

47 CFR 87.17 (enhanced display)                                                                                    page 9 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                             47 CFR 87.18
Aviation Services

[63 FR 68957, Dec. 14, 1998]

§ 87.18 Station license required.
     (a) Except as noted in paragraph (b) of this section, stations in the aviation service must be licensed by the
         FCC either individually or by fleet.

     (b) An aircraft station is licensed by rule and does not need an individual license issued by the FCC if the
         aircraft station is not required by statute, treaty, or agreement to which the United States is signatory to
         carry a radio, and the aircraft station does not make international flights or communications. Even though
         an individual license is not required, an aircraft station licensed by rule must be operated in accordance
         with all applicable operating requirements, procedures, and technical specifications found in this part.

[61 FR 58011, Nov. 12, 1996]

§ 87.19 Basic eligibility.
     (a) General. Foreign governments or their representatives cannot hold station licenses.

     (b) Aeronautical enroute and aeronautical fixed stations. The following persons cannot hold an aeronautical
         enroute or an aeronautical fixed station license.

           (1) Any alien or the representative of any alien;

           (2) Any corporation organized under the laws of any foreign government;

           (3) Any corporation of which more than one-fifth of the capital stock is owned of record or voted by
               aliens or their representatives or by a foreign government or its representative, or by a corporation
               organized under the laws of a foreign country; or

           (4) Any corporation directly or indirectly controlled by any other corporation of which more than one-
               fourth of the capital stock is owned of record or voted by aliens, their representatives, or by a foreign
               government or its representatives, or by any corporation organized under the laws of a foreign
               country, if the Commission finds that the public interest will be served by the refusal or revocation of
               such license.

[53 FR 28940, Aug. 1, 1988, as amended at 61 FR 55581, Oct. 28, 1996]

§ 87.25 Filing of applications.
     (a) [Reserved]

     (b) An application must be filed with the Commission in accordance with part 1, subpart F of this chapter.
         Applications requiring fees as set forth at part 1, subpart G of this chapter must be filed in accordance
         with § 0.401(b) of the rules.

     (c) One application may be submitted for the total number of aircraft stations in the fleet (fleet license).

     (d) One application for aeronautical land station license may be submitted for the total number of stations in
         the fleet.

47 CFR 87.25(d) (enhanced display)                                                                          page 10 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                               47 CFR 87.25(e)
Aviation Services

     (e) One application for modification or transfer of control may be submitted for two or more stations when
         the individual stations are clearly identified and the following elements are the same for all existing or
         requested station licenses involved:

           (1) Applicant;

           (2) Specific details of request;

           (3) Rule part.

[53 FR 28940, Aug. 1, 1988, as amended at 56 FR 64715, Dec. 12, 1991; 63 FR 68957, Dec. 14, 1998; 64 FR 53241, Oct. 1, 1999; 69
FR 32879, June 14, 2004]

§ 87.27 License term.
Licenses for stations in the aviation services will normally be issued for a term of ten years from the date of original
issuance, or renewal.

[78 FR 25175, Apr. 29, 2013]

§ 87.29 Partial grant of application.
Whenever the Commission, without a hearing, grants an application in part or with any privileges, terms, or
conditions other than those requested, the action will be considered as a grant of the application unless the
applicant, within 30 days from the date on which such grant is made, or from its effective date if a later day is
specified, files with the Commission a written protest, rejecting the grant as made. Upon receipt of such protest, the
Commission will vacate its original action upon the application and, if necessary, set the application for hearing.

§ 87.35 Cancellation of license.
When a station permanently discontinues operation the station license must be canceled in accordance with the
procedures set forth in part 1 of this chapter.

[63 FR 68957, Dec. 14, 1998]

§ 87.39 Equipment acceptable for licensing.
Transmitters listed in this part must be certificated for a particular use by the Commission based upon technical
requirements contained in subpart D of this part.

[53 FR 28940, Aug. 1, 1988, as amended at 63 FR 36607, July 7, 1998]

§ 87.41 Frequencies.
     (a) Applicant responsibilities. The applicant must propose frequencies to be used by the station consistent
         with the applicant's eligibility, the proposed operation and the frequencies available for assignment.
         Applicants must cooperate in the selection and use of frequencies in order to minimize interference and
         obtain the most effective use of stations. See subpart E and the appropriate subpart applicable to the
         class of station being considered.

47 CFR 87.41(a) (enhanced display)                                                                                page 11 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                        47 CFR 87.41(b)
Aviation Services

     (b) Licensing limitations. Frequencies are available for assignment to stations on a shared basis only and will
         not be assigned for the exclusive use of any licensee. The use of any assigned frequency may be
         restricted to one or more geographical areas.

     (c) Government frequencies. Frequencies allocated exclusively to federal government radio stations may be
         licensed. The applicant for a government frequency must provide a satisfactory showing that such
         assignment is required for inter-communication with government stations or required for coordination
         with activities of the federal government. The Commission will coordinate with the appropriate
         government agency before a government frequency is assigned.

     (d) Assigned frequency. The frequency coinciding with the center of an authorized bandwidth of emission
         must be specified as the assigned frequency. For single sideband emission, the carrier frequency must
         also be specified.

§ 87.43 Operation during emergency.
A station may be used for emergency communications in a manner other than that specified in the station license
or in the operating rules when normal communication facilities are disrupted. The Commission may order the
discontinuance f any such emergency service.

§ 87.45 Time in which station is placed in operation.
This section applies only to unicom stations and radionavigation land stations, excluding radionavigation land test
stations. When a new license has been issued or additional operating frequencies have been authorized, the station
or frequencies must be placed in operation no later than one year from the date of the grant. The licensee must
notify the Commission in accordance with § 1.946 of this chapter that the station or frequencies have been placed
in operation.

[69 FR 32879, June 14, 2004]

§ 87.47 Application for a portable aircraft station license.
A person may apply for a portable aircraft radio station license if the need exists to operate the same station on
more than one U.S. aircraft.

§ 87.51 Aircraft earth station commissioning.
     (a) [Reserved]

     (b) Aircraft earth stations authorized to operate in the Inmarsat space segment must display the Commission
         license together with the commissioning certificate issued by Inmarsat. Notwithstanding the
         requirements of this paragraph, aircraft earth stations may operate in the Inmarsat space segment
         without an Inmarsat-issued commissioning certificate if written approval is obtained from Inmarsat in
         addition to the license from the Commission.

[57 FR 45749, Oct. 5, 1992, as amended at 63 FR 68957, Dec. 14, 1998]

Subpart C—Operating Requirements and Procedures

                                               OPERATING REQUIREMENTS

47 CFR 87.51(b) (enhanced display)                                                                         page 12 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                          47 CFR 87.69
Aviation Services

§ 87.69 Maintenance tests.
The licensee may make routine maintenance tests on equipment other than emergency locator transmitters if there
is no interference with the communications of any other station. Procedures for conducting tests on emergency
locator transmitters are contained in subpart F.

§ 87.71 Frequency measurements.
A licensed operator must measure the operating frequencies of all land-based transmitters at the following times:

     (a) When the transmitter is originally installed;

     (b) When any change or adjustment is made in the transmitter which may affect an operating frequency; or

     (c) When an operating frequency has shifted beyond tolerance.

§ 87.73 Transmitter adjustments and tests.
A general radiotelephone operator must directly supervise and be responsible for all transmitter adjustments or
tests during installation, servicing or maintenance of a radio station. A general radiotelephone operator must be
responsible for the proper functioning of the station equipment.

§ 87.75 Maintenance of antenna structure marking and control equipment.
The owner of each antenna structure required to be painted and/or illuminated under the provisions of Section
303(q) of the Communications Act of 1934, as amended, shall operate and maintain the antenna structure painting
and lighting in accordance with part 17 of this chapter. In the event of default by the owner, each licensee or
permittee shall be individually responsible for conforming to the requirements pertaining to antenna structure
painting and lighting.

[61 FR 4368, Feb. 6, 1996]

§ 87.77 Availability for inspections.
The licensee must make the station and its records available for inspection upon request.

                                              RADIO OPERATOR REQUIREMENTS

§ 87.87 Classification of operator licenses and endorsements.
     (a) Commercial radio operator licenses issued by the Commission are classified in accordance with the Radio
         Regulations of the International Telecommunication Union.

     (b) The following licenses are issued by the Commission. International classification, if different from the
         license name, is given in parentheses. The licenses and their alphanumeric designator are listed in
         descending order.

           (1) T–1. First Class Radiotelegraph Operator's Certificate. Beginning May 20, 2013, no applications for
               new First Class Radiotelegraph Operator's Certificates will be accepted for filing.

           (2) T–2. Second Class Radiotelegraph Operator's Certificate. Beginning May 20, 2013, no applications for
               new Second Class Radiotelegraph Operator's Certificates will be accepted for filing.

47 CFR 87.87(b)(2) (enhanced display)                                                                     page 13 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                      47 CFR 87.87(b)(3)
Aviation Services

           (3) T–3. Third Class Radiotelegraph Operator's Certificate (radiotelegraph operator's special certificate).
               Beginning May 20, 2013, no applications for new Third Class Radiotelegraph Operator's Certificates
               will be accepted for filing.

           (4) T. Radiotelegraph Operator License.

           (5) G General Radiotelephone Operator Licenes (radiotelephone operator's general certificate)

           (6) MP Marine Radio Operator Permit (radiotelephone operator's restricted certificate)

           (7) RP Restricted Radiotelephone Operator Permit (radiotelephone operator's restricted certificate)

[53 FR 28940, Aug. 1, 1988, as amended at 78 FR 23158, Apr. 18, 2013]

§ 87.89 Minimum operator requirements.
     (a) A station operator must hold a commercial radio operator license or permit, except as listed in paragraph
         (d).

     (b) The minimum operator license or permit required for operation of each specific classification is:

     Minimum Operator License or Permit

     Land stations, all classes

     —All frequencies except VHF telephony transmitters providing domestic service                                          RP

     Aircraft stations, all classes

     —Frequencies below 30 MHz allocated exclusively to aeronautical mobile services                                        RP

     —Frequencies below 30 MHz not allocated exclusively to aeronautical mobile services                          MP or higher

     —Frequencies above 30 MHz not allocated exclusively to aeronautical mobile services and assigned for         MP or higher
     international use

     —Frequencies above 30 MHz not assigned for international use                                                          none

     —Frequencies not used solely for telephone or exceeding 250 watts carrier power or 1000 watts peak             G or higher
     envelope power

     (c) The operator of a telephony station must directly supervise and be responsible for any other person who
         transmits from the station, and must ensure that such communications are in accordance with the station
         license.

     (d) No operator license is required to:

           (1) Operate an aircraft radar set, radio altimeter, transponder or other aircraft automatic radionavigation
               transmitter by flight personnel;

47 CFR 87.89(d)(1) (enhanced display)                                                                      page 14 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                         47 CFR 87.89(d)(2)
Aviation Services

           (2) Test an emergency locator transmitter or a survival craft station used solely for survival purposes;

           (3) Operate an aeronautical enroute station which automatically transmits digital communications to
               aircraft stations;

           (4) Operate a VHF telephony transmitter providing domestic service or used on domestic flights.

§ 87.91 Operation of transmitter controls.
The holder of a marine radio operator permit or a restricted radiotelephone operator permit must perform only
transmitter operations which are controlled by external switches. These operators must not perform any internal
adjustment of transmitter frequency determining elements. Further, the stability of the transmitter frequencies at a
station operated by these operators must be maintained by the transmitter itself. When using an aircraft radio
station on maritime mobile service frequencies the carrier power of the transmitter must not exceed 250 watts
(emission A3E) or 1000 watts (emission R3E, H3E, or J3E).

                                                OPERATING PROCEDURES

§ 87.103 Posting station license.
     (a) Stations at fixed locations. The license or a photocopy must be posted or retained in the station's
         permanent records.

     (b) Aircraft radio stations. The license must be either posted in the aircraft or kept with the aircraft
         registration certificate. If a single authorization covers a fleet of aircraft, a copy of the license must be
         either posted in each aircraft or kept with each aircraft registration certificate.

     (c) Aeronautical mobile stations. The license must be retained as a permanent part of the station records.

[53 FR 28940, Aug. 1, 1988, as amended at 54 FR 11720, Mar. 22, 1989]

§ 87.105 Availability of operator permit or license.
All operator permits or licenses must be readily available for inspection.

§ 87.107 Station identification.
     (a) Aircraft station. Identify by one of the following means:

           (1) Aircraft radio station call sign.

           (2) The type of aircraft followed by the characters of the registration marking (“N” number) of the
               aircraft, omitting the prefix letter “N.” When communication is initiated by a ground station, an
               aircraft station may use the type of aircraft followed by the last three characters of the registration
               marking. Notwithstanding any other provision of this section, an aircraft being moved by
               maintenance personnel from one location in an airport to another location in that airport may be
               identified by a station identification consisting of the name of the company owning or operating the
               aircraft, followed by the word “Maintenance” and additional alphanumeric characters of the
               licensee's choosing.

           (3) The FAA assigned radiotelephony designator of the aircraft operating organization followed by the
               flight identification number.

47 CFR 87.107(a)(3) (enhanced display)                                                                        page 15 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                         47 CFR 87.107(a)(4)
Aviation Services

           (4) An aircraft identification approved by the FAA for use by aircraft stations participating in an
               organized flying activity of short duration.

     (b) Land and fixed stations. Identify by means of radio station call sign, its location, its assigned FAA identifier,
         the name of the city area or airport which it serves, or any additional identification required. An
         aeronautical enroute station which is part of a multistation network may also be identified by the location
         of its control point.

     (c) Survival craft station. Identify by transmitting a reference to its parent aircraft. No identification is required
         when distress signals are transmitted automatically. Transmissions other than distress or emergency
         signals, such as equipment testing or adjustment, must be identified by the call sign or by the registration
         marking of the parent aircraft followed by a single digit other than 0 or 1.

     (d) Exempted station. The following types of stations are exempted from the use of a call sign: Airborne
         weather radar, radio altimeter, air traffic control transponder, distance measuring equipment, collision
         avoidance equipment, racon, radio relay, radionavigation land test station (MTF), and automatically
         controlled aeronautical enroute stations.

[53 FR 28940, Aug. 1, 1988, as amended at 71 FR 70676, Dec. 6, 2006]

§ 87.109 Station logs.
     (a) A station at a fixed location in the international aeronautical mobile service must maintain a log in
         accordance with Annex 10 of the ICAO Convention.

     (b) A station log must contain the following information:

           (1) The name of the agency operating the station.

           (2) The identification of the station.

           (3) The date.

           (4) The time of opening and closing the station.

           (5) The frequencies being guarded and the type of watch (continuous or scheduled) being maintained
               on each frequency.

           (6) Except at intermediate mechanical relay stations where the provisions of this paragraph need not be
               complied with, a record of each communication showing text of communication, time
               communications completed, station(s) communicated with, and frequency used.

           (7) All distress communications and action thereon.

           (8) A brief description of communications conditions and difficulties, including harmful interference.
               Such entries should include, whenever practicable, the time at which interference was experienced,
               the character, radio frequency and identification of the interfering signal.

           (9) A brief description of interruption to communications due to equipment failure or other troubles,
               giving the duration of the interruption and action taken.

          (10) Such additional information as may be considered by the operator to be of value as part of the record
               of the stations operations.

47 CFR 87.109(b)(10) (enhanced display)                                                                        page 16 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                        47 CFR 87.109(c)
Aviation Services

     (c) Stations maintaining written logs must also enter the signature of each operator, with the time the
         operator assumes and relinquishes a watch.

[69 FR 32879, June 14, 2004]

§ 87.111 Suspension or discontinuance of operation.
The licensee of any airport control tower station or radionavigation land station must notify the nearest FAA regional
office upon the temporary suspension or permanent discontinuance of the station. The FAA regional office must be
notified again when service resumes.

[69 FR 32880, June 14, 2004]

Subpart D—Technical Requirements
§ 87.131 Power and emissions.
The following table lists authorized emissions and maximum power. Power must be determined by direct
measurement.

                                                                          Authorized     Maximum
      Class of station              Frequency band/frequency
                                                                         emission(s)9     power1
 Aeronautical advisory      VHF                                    A3E                   10 watts.10
 Aeronautical multicom      VHF                                    A3E                   10 watts.
 Aeronautical enroute and HF                                       R3E, H3E, J3E, J7B,   6 kw.
 aeronautical fixed                                                H2B, J2D
                            HF                                     A1A, F1B, J2A, J2B    1.5 kw.
                            VHF                                    A3E, A9W G1D, A2D
 Aeronautical search and    VHF                                    A3E                   10 watts.
 rescue                     HF                                     R3E, H3E, J3E         100 watts.
 Operational fixed          VHF                                    G3E, F2D              30 watts.
 Flight test land           VHF                                    A3E                   200 watts.
                            UHF                                    F2D, F9D, F7D         25 watts.3
                            HF                                     H2B, J3E, J7D, J9W    6.0 kw.
 Aviation support           VHF                                    A3E                   50 watts.
 Airport control tower      VHF                                    A3E, G1D, G7D         50 watts.
                            Below 400 kHz                          A3E                   15 watts.
 Aeronautical utility       VHF                                    A3E                   10 watts.
 mobile
                            1090 MHz                               M1D                   20 watts.
 Aircraft data link land    131.450 MHz, 131.550 MHz, 131.725      A2D                   100
 test                       MHz, 131.825 MHz, 136.850 MHz                                microwatts.
                            136.900 MHz, 136.925 MHz, 136.950      G1D                   100
                            MHz, 136.975 MHz                                             microwatts.
 Radionavigation land test 108.150 MHz                             A9W                   1 milliwatt.
                            334.550 MHz                            A1N                   1 milliwatt.

47 CFR 87.131 (enhanced display)                                                                           page 17 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                         47 CFR 87.131
Aviation Services

                                                                            Authorized     Maximum
      Class of station              Frequency band/frequency
                                                                           emission(s)9     power1
                            Other VHF                                M1A, XXA, A1A, A1N, 1 watt.
                                                                     A2A, A2D, A9W
                            Other UHF                                M1A, XXA, A1A, A1N, 1 watt.
                                                                     A2A, A2D, A9W
                            5031.0 MHz                               F7D                   1 watt.
                                      4                                        4
 Radionavigation land       Various                                  Various               Various.4
                                                     Aeronautical Frequencies
 Aircraft                   UHF                                      F2D, F9D, F7D         25 watts.
 (Communication)
                            VHF                                      A3E, A9W, G1D, G7D,   55 watts.
                                                                     A2D
                            HF                                       R3E, H3E, J3E, J7B,   400 watts.
                                                                     H2B, J7D, J9W
                            HF                                       A1A, F1B, J2A, J2B    100 watts.
                                                       Marine Frequencies5
                            156.300 MHz                              G3E                   5 watts.
                            156.375 MHz                              G3E                   5 watts.
                            156.400 MHz                              G3E                   5 watts.
                            156.425 MHz                              G3E                   5 watts.
                            156.450 MHz                              G3E                   5 watts.
                            156.625 MHz                              G3E                   5 watts.
                            156.800 MHz                              G3E                   5 watts.
                            156.900 MHz                              G3E                   5 watts.
                            157.425 MHz                              G3E                   5 watts.
                            HF6                                      R3E, H3E, J3E, J2B,   1000 watts.
                                                                     F1B, A3E              250 watts.
                            MF6                                      R3E, H3E, J3E, J2B,   1000 watts.
                                                                     F1B
                            HF6                                      A3E                   250 watts.
 (Radionavigation)          Various7                                 Various7              Various.7
 Aircraft earth             UHF                                      G1D, G1E, G1W         60 watts.8
 Differential GPS           VHF                                      G7D                   Various.2

1The power is measured at the transmitter output terminals and the type of power is determined
according to the emission designator as follows:

(i) Mean power (pY) for amplitude modulated emissions and transmitting both sidebands using
unmodulated full carrier.

(ii) Peak envelope power (pX) for all emission designators other than those referred to in paragraph
(i) of this note.

47 CFR 87.131 (enhanced display)                                                                         page 18 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                                  47 CFR 87.133
Aviation Services

2Power and antenna height are restricted to the minimum necessary to achieve the required
service.

3Transmitter power may be increased to overcome line and duplexer losses but must not exceed
25 watts delivered to the antenna.

4Frequency, emission, and maximum power will be determined after coordination with appropriate
Government agencies.

5To be used with airborne marine equipment certificated for part 80 (ship) and used in accordance
with part 87.

6   Applicable onIy to marine frequencies used for public correspondence.

7Frequency, emission, and maximum power will be determined by appropriate standards during the
certification process.

8 Power may not exceed 60 watts per carrier, as measured at the input of the antenna subsystem,
including any installed diplexer. The maximum EIRP may not exceed 2000 watts per carrier.

9   Excludes automatic link establishment.

10Power is limited to 0.5 watt, but may not exceed 2 watts when station is used in an automatic
unattended mode.

[54 FR 11720, Mar. 22, 1989, as amended at 57 FR 45749, Oct. 5, 1992; 62 FR 40308, July 28, 1997; 63 FR 36607, July 7, 1998; 64
FR 27474, May 20, 1999; 66 FR 26798, May 15, 2001; 69 FR 32880, June 14, 2004; 78 FR 61205, Oct. 3, 2013]

§ 87.133 Frequency stability.
       (a) Except as provided in paragraphs (c), (d), (f), and (g) of this section, the carrier frequency of each station
           must be maintained within these tolerances:

             Frequency band (lower limit exclusive, upper limit inclusive), and categories of
                                                                                                Tolerance1 Tolerance2
                                                stations
             (1) Band-9 to 535 kHz:
              Aeronautical stations                                                                   100 100
              Aircraft stations                                                                       200 100
              Survival craft stations on 500 kHz                                                     5,000 20 Hz3
              Radionavigation stations                                                                100 100
             (2) Band-1605 to 4000 kHz:
              Aeronautical fixed stations:
                Power 200 W or less                                                                   100 1008
                Power above 200 W                                                                       50 508
              Aeronautical stations:
                Power 200 W or less                                                                  1007 1007 8

47 CFR 87.133(a) (enhanced display)                                                                                page 19 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                                     47 CFR 87.133(a)
Aviation Services

            Frequency band (lower limit exclusive, upper limit inclusive), and categories of
                                                                                               Tolerance1 Tolerance2
                                               stations
               Power above 200 W                                                                       507 507 8
             Aircraft stations                                                                      1007 1007
             Survival craft stations on 2182 kHz                                                       200 20 Hz3
            (3) Band-4 to 29.7 MHz:
             Aeronautical fixed stations:
               Power 500 W or less                                                                         50
               Power above 500 W                                                                           15
             Single-sideband and Independent-sideband emission:
               Power 500 W or less                                                                              50 Hz
               Power above 500 W                                                                                20 Hz
             Class F1B emissions                                                                                10 Hz
             Other classes of emission:
               Power 500 W or less                                                                              20
               Power above 500 W                                                                                10
             Aeronautical stations:
                                                                                                   7
               Power 500 W or less                                                                     100 1007
                                                                                                       7
               Power above 500 W                                                                           50 507
             Aircraft stations                                                                     7   100 1007
             Survival craft stations on 8364 kHz                                                       200 50 Hz3
            (4) Band-29.7 to 100 MHz:
             Aeronautical fixed stations:
               Power 200 W or less                                                                         50
               Power above 200 W                                                                           30
               Power 50 W or less                                                                               30
               Power above 50 W                                                                                 20
             Operational fixed stations:
               73–74.6 MHz (Power 50 W or less)                                                            50 30
               73–74.6 MHz (Power above 50 W)                                                              20 20
               72–73.0 MHz and 75.4–76.0 MHz                                                                5 5
             Radionavigation stations                                                                  100 50
            (5) Band-108 to 137 MHz:
                                                                                                       4        12
               Aeronautical stations                                                                       50        20
             Emergency locator transmitter test stations                                                   50 50
             Survival craft stations on 121.5 MHz                                                          50 50
             Emergency locator stations                                                                    50 50
               Aircraft and other mobile stations in the Aviation Services                             5   50   13   30
             Radionavigation stations                                                                      20 20
             Differential GPS                                                                                   2
            (6) Band-137 to 470MHz:

47 CFR 87.133(a) (enhanced display)                                                                                       page 20 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                                   47 CFR 87.133(a)
Aviation Services

               Frequency band (lower limit exclusive, upper limit inclusive), and categories of
                                                                                                  Tolerance1 Tolerance2
                                                  stations
               Aeronautical stations                                                                       50 20
               Survival craft stations on 243 MHz                                                          50 50
               Aircraft stations                                                                          505 3010
               Radionavigation stations                                                                    50 50
               Emergency locator transmitters on 406 MHz                                                 N/A 5
            (7) Band-470 to 2450 MHz:
               Aeronautical stations                                                                      100 20
               Aircraft stations                                                                          100 20
               Aircraft earth station                                                                         320 Hz11
            Aeronautical utility mobile stations on 1090 MHz                                             1000 1000
               Radionavigation stations:
                 470–960 MHz                                                                              500 500
                 960–1215 MHz                                                                              20 20
                 1215–2450 MHz                                                                            500 500
            (8) Band-2450 to 10500 MHz:
                                                                                                    69
               Radionavigation stations                                                                  1250 12506 9
            (9) Band-10.5 GHz to 40 GHz:
               Radionavigation stations                                                                  5000 5000

           1
            This tolerance is the maximum permitted until January 1, 1990, for transmitters installed before
           January 2, 1985, and used at the same installation. Tolerance is indicated in parts in 106 unless
           shown as Hertz (Hz).

           2 This tolerance is the maximum permitted after January 1, 1985 for new and replacement
           transmitters and to all transmitters after January 1, 1990. Tolerance is indicated in parts in 106
           unless shown as Hertz (Hz).

           3   For transmitters first approved after November 30, 1977.

           4The tolerance for transmitters approved between January 1, 1966, and January 1, 1974, is 30
           parts in 106. The tolerance for transmitters approved after January 1, 1974, and stations using
           offset carrier techniques is 20 parts in 106.

           5   The tolerance for transmitters approved after January 1, 1974, is 30 parts in 106.

           6In the 5000 to 5250 MHz band, the FAA requires a tolerance of ±10 kHz for Microwave Landing
           System stations which are to be a part of the National Airspace System (FAR 171).

           7For single-sideband transmitters operating in the frequency bands 1605–4000 kHz and 4–29.7
           MHz which are allocated exclusively to the Aeronautical Mobile (R) Service, the tolerance is:
           Aeronautical stations, 10 Hz; aircraft stations, 20 Hz.

47 CFR 87.133(a) (enhanced display)                                                                                   page 21 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                              47 CFR 87.133(b)
Aviation Services

           8 For single-sideband radiotelephone transmitters the tolerance is: In the bands 1605–4000 kHz
           and 4–29.7 MHz for peak envelope powers of 200 W or less and 500 W or less, respectively, 50 Hz;
           in the bands 1605–4000 kHz and 4–29.7 MHz for peak envelope powers above 200 W and 500 W,
           respectively, 20 Hz.

           9 Where specific frequencies are not assigned to radar stations, the bandwidth occupied by the
           emissions of such stations must be maintained within the band allocated to the service and the
           indicated tolerance does not apply.

           10Until January 1, 1997, the maximum frequency tolerance for transmitters with 50 kHz channel
           spacing installed before January 2, 1985, is 50 parts in 106.

           11 For purposes of certification, a tolerance of 160 Hz applies to the reference oscillator of the AES
           transmitter. This is a bench test.

           12   For emissions G1D and G7D, the tolerance is 2 parts per 106.

           13   For emissions G1D and G7D, the tolerance is 5 parts per 106.

     (b) The power shown in paragraph (a) of this section is the peak envelope power for single-sideband
         transmitters and the mean power for all other transmitters.

     (c) For single-sideband transmitters, the tolerance is:

           (1) All aeronautical stations on land—10 Hz.

           (2) All aircraft stations—20 Hz.

     (d) For radar transmitters, except non-pulse signal radio altimeters, the frequency at which maximum
         emission occurs must be within the authorized frequency band and must not be closer than 1.5/T MHz to
         the upper and lower limits of the authorized bandwidth, where T is the pulse duration in microseconds.

     (e) The Commission may authorize tolerances other than those specified in this section upon a satisfactory
         showing of need.

     (f) The carrier frequency tolerance of all transmitters that operate in the 1435–1525 MHz or 2345–2395 MHz
         band is 0.002 percent. The carrier frequency tolerance of all transmitters that operate in the 5091–5150
         MHz band is 0.005 percent.

     (g) Any aeronautical enroute service transmitter operating in U.S. controlled airspace with 8.33 kHz channel
         spacing (except equipment being tested by avionics equipment manufacturers and flight test stations
         prior to delivery to their customers for use outside U.S. controlled airspace) must achieve 0.0005%
         frequency stability when operating in that mode.

[53 FR 28940, Aug. 1, 1988, as amended at 56 FR 38084, Aug. 12, 1991; 57 FR 45749, Oct. 5, 1992; 58 FR 31027, May 26, 1993; 63
FR 36607, July 7, 1998; 64 FR 27474, May 20, 1999; 66 FR 26799, May 15, 2001; 69 FR 32880, June 14, 2004; 76 FR 17350, Mar.
29, 2011; 78 FR 61205, Oct. 3, 2013; 80 FR 38909, July 7, 2015]

47 CFR 87.133(g) (enhanced display)                                                                              page 22 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                           47 CFR 87.135
Aviation Services

§ 87.135 Bandwidth of emission.
     (a) Occupied bandwidth is the width of a frequency band such that, below the lower and above the upper
         frequency limits, the mean powers emitted are each equal to 0.5 percent of the total mean power of a
         given emission.

     (b) The authorized bandwidth is the maximum occupied bandwidth authorized to be used by a station.

     (c) The necessary bandwidth for a given class of emission is the width of the frequency band which is just
         sufficient to ensure the transmission of information at the rate and with the quality required under
         specified conditions.

§ 87.137 Types of emission.
     (a) The assignable emissions, corresponding emission designators and authorized bandwidths are as
         follows:

                                                                   Authorized bandwidth (kilohertz)
             Class of emission     Emission designator
                                                         Below 50 MHz    Above 50 MHz       Frequency deviation
            A1A1                  100HA1A                         0.25
            A1N                   300HA1N                                          0.75
            A2A                   2K04A2A                         2.74               50
            A2D                   6K0A2D                                             50
            A2D5                  13K0A2D                                            50
               A3E2               6K00A3E                                           503
               A3E                5K6A3E                                     8.33 kHz17
            A3X4                  3K20A3X                                            25
            A9W5                  13K0A9W                                            25
            F1B1                  1K70F1B                          1.7
            F1B1                  2K40F1B                          2.5
            F1D18                 1M30F1D                                     1300 kHz                312.5 kHz
            F2D                   5M0F2D                                             ( 9)
            F3E6                  16K0F3E                                            20                       5
            F3E7                  36K0F3E                                            40                      15
            F7D8                  5M0F7D                                               9

                                                                                       9
            F9D                   5M0F9D
            G1D                   16K0G1D                                        20 kHz
            G1D16                 21K0G1D                                            25
            G1D                   14K0G1D                                            25
                                                                                       9
            F9D                   5M0F9D
            G1D                   16K0G1D                                        20 kHz
            G3E6                  16K0G3E                                            20                       5
            G7D                   14K0G7D                                            25
            H2B10 11              2K80H2B                          3.0
            H3E11 12              2K80H3E                          3.0

47 CFR 87.137(a) (enhanced display)                                                                        page 23 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                          47 CFR 87.137(a)
Aviation Services

                                                                       Authorized bandwidth (kilohertz)
               Class of emission       Emission designator
                                                             Below 50 MHz    Above 50 MHz     Frequency deviation
                  1
            J2A                    100HJ2A                            0.25
                  1
            J2B                    1K70J2B                             1.7
                                   2K40J2B                             2.5
            J3E11 12               2K80J3E                             3.0
                  11
            J7B                    2K80J7B                             3.0
                                                                                          9
            J7D                    5M0J7D
            J9W11                  2K80J9W                             3.0
            M1A                    620HM1A
            M1D                    14M0M1D                            14.0
            NON                    NON                                              None15
            PON13                  9                                                      9

            R3E11 12               2K80R3E                             3.0
            XXA14                  1K12XXA                            2.74

           NOTES:

           1A1A, F1B, J2A and J2B are permitted provided they do not cause harmful interference to H2B,
           J3E, J7B and J9W.

           2
            For use with an authorized bandwidth of 8.0 kilohertz at radiobeacon stations. A3E will not be
           authorized:

           (i) At existing radiobeacon stations that are not authorized to use A3 and at new radiobeacon
           stations unless specifically recommended by the FAA for safety purposes.

           (ii) At existing radiobeacon stations currently authorized to use A3, subsequent to January 1, 1990,
           unless specifically recommended by the FAA for safety purposes.

           3In the band 117.975–136 MHz, the authorized bandwidth is 25 kHz for transmitters approved
           after January 1, 1974.

           4Applicable only to Survival Craft Stations and to the emergency locator transmitters and
           emergency locator transmitter test stations employing modulation in accordance with that
           specified in § 87.141 of the Rules. The specified bandwidth and modulation requirements shall
           apply to emergency locator transmitters for which approval is granted after October 21, 1973.

           5This emission may be authorized for audio frequency shift keying and phase shift keying for
           digital data links on any frequency listed in § 87.263(a)(1), § 87.263(a)(3) or § 87.263(a)(5).
           13K0A2D emission may be authorized on frequencies not used for voice communications. If the
           channel is used for voice communications, 13K0A9W emission may be authorized, provided the
           data is multiplexed on the voice carrier without derogating voice communications.

47 CFR 87.137(a) (enhanced display)                                                                          page 24 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                              47 CFR 87.137(b)
Aviation Services

           6Applicable to operational fixed stations in the bands 72.0–73.0 MHz and 75.4–76.0 MHz and to
           CAP stations using F3 on 143.900 MHz and 148.150 MHz.

           7   Applicable to operational fixed stations presently authorized in the band 73.0–74.6 MHz.

           8 The authorized bandwidth is equal to the necessary bandwidth for frequency or digitally
           modulated transmitters used in aeronautical telemetering and associated aeronautical telemetry or
           telecommand stations that operate in the 1435–1525 MHz, 2345–2395 MHz, or 5091–5150 MHz
           band. The necessary bandwidth must be computed in accordance with part 2 of this chapter.

           9   To be specified on license.

           10   H2B must be used by stations employing digital selective calling.

           11For A1A, F1B and single sideband emissions, except H2B, the assigned frequency must be 1400
           Hz above the carrier frequency.

           12R3E, H3E, and J3E will be authorized only below 25000 kHz. Only H2B, J3E, J7B, and J9W are
           authorized, except that A3E and H3E may be used only on 3023 kHz and 5680 kHz for search and
           rescue operations.

           13   The letters “K, L, M, Q, V, W, and X” may also be used in place of the letter “P” for pulsed radars.

           14   Authorized for use at radiobeacon stations.

           15Applicable only to transmitters of survival craft stations, emergency locator transmitter stations
           and emergency locator transmitter test stations approved after October 21, 1973.

           16Authorized for use by aircraft earth stations. Lower values of necessary and authorized
           bandwidth are permitted.

           17 In the band 117.975–137 MHz, the Commission will not authorize any 8.33 kHz channel spaced
           transmissions or the use of their associated emission designator within the U.S. National Airspace
           System, except, on an optional basis, by Aeronautical Enroute Stations and Flight Test Stations, or
           by avionics equipment manufacturers which are required to perform installation and checkout of
           such radio systems prior to delivery to their customers. For transmitters certificated to tune to 8.33
           kHz channel spacing as well as 25 kHz channel spacing, the authorized bandwidth is 8.33 kHz
           when tuned to an 8.33 kHz channel.

           18   Authorized only for Universal Access Transceiver use at 978 MHz.

     (b) For other emissions, an applicant must determine the emission designator by using part 2 of this chapter.

     (c) A license to use radiotelephony includes the use of tone signals or signaling devices whose sole function
         is to establish or maintain voice communications.

47 CFR 87.137(c) (enhanced display)                                                                              page 25 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                           47 CFR 87.139
Aviation Services

[53 FR 28940, Aug. 1, 1988]

Editorial Note: For FEDERAL REGISTER citations affecting § 87.137, see the List of CFR Sections Affected, which
appears in the Finding Aids section of the printed volume and at www.govinfo.gov.

§ 87.139 Emission limitations.
     (a) Except for ELTs and when using single sideband (R3E, H3E, J3E), or frequency modulation (F9) or digital
         modulation (F9Y) for telemetry or telecommand in the 1435–1525 MHz, 2345–2395 MHz, or 5091–5150
         MHz band or digital modulation (G7D) for differential GPS, the mean power of any emissions must be
         attenuated below the mean power of the transmitter (pY) as follows:

           (1) When the frequency is removed from the assigned frequency by more than 50 percent up to and
               including 100 percent of the authorized bandwidth the attenuation must be at least 25 dB;

           (2) When the frequency is removed from the assigned frequency by more than 100 percent up to and
               including 250 percent of the authorized bandwidth the attenuation must be at least 35 dB.

           (3) When the frequency is removed from the assigned frequency by more than 250 percent of the
               authorized bandwidth the attenuation for aircraft station transmitters must be at least 40 dB; and the
               attenuation for aeronautical station transmitters must be at least 43 + 10 log10 pY dB.

     (b) For aircraft station transmitters and for aeronautical station transmitters first installed before February 1,
         1983, and using H2B, H3E, J3E, J7B or J9W, the mean power of any emissions must be attenuated below
         the mean power of the transmitter (pY) as follows:

           (1) When the frequency is removed from the assigned frequency by more than 50 percent up to and
               including 150 percent of the authorized bandwidth of 4.0 kHz, the attenuation must be at least 25
               dB.

           (2) When the frequency is removed from the assigned frequency by more than 150 percent up to and
               including 250 percent of the authorized bandwidth of 4.0 kHz, the attenuation must be at least 35
               dB.

           (3) When the frequency is removed from the assigned frequency by more than 250 percent of the
               authorized bandwidth of 4.0 kHz for aircraft station transmitters the attenuation must be at least 40
               dB; and for aeronautical station transmitters the attenuation must be at least 43 + 10 log10 pY dB.

     (c) For aircraft station transmitters first installed after February 1, 1983, and for aeronautical station
         transmitters in use after February 1, 1983, and using H2B, H3E, J3E, J7B or J9W, the peak envelope power
         of any emissions must be attenuated below the peak envelope power of the transmitter (pX) as follows:

           (1) When the frequency is removed from the assigned frequency by more than 50 percent up to and
               including 150 percent of the authorized bandwidth of 3.0 kHz, the attenuation must be at least 30
               dB.

           (2) When the frequency is removed from the assigned frequency by more than 150 percent up to and
               including 250 percent of the authorized bandwidth of 3.0 kHz, the attenuation must be at least 38
               dB.

47 CFR 87.139(c)(2) (enhanced display)                                                                      page 26 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                      47 CFR 87.139(c)(3)
Aviation Services

            (3) When the frequency is removed from the assigned frequency by more than 250 percent of the
                authorized bandwidth of 3.0 kHz for aircraft transmitters the attenuation must be at least 43 dB. For
                aeronautical station transmitters with transmitter power up to and including 50 watts the attenuation
                must be at least 43 + 10 log10 pX dB and with transmitter power more than 50 watts the attenuation
                must be at least 60 dB.

     (d) Except for telemetry in the 1435–1525 MHz band, when the frequency is removed from the assigned
         frequency by more than 250 percent of the authorized bandwidth for aircraft stations above 30 MHz and
         all ground stations the attenuation must be at least 43 + 10 log10pY dB.

     (e) When using frequency modulation or digital modulation for telemetry or telecommand in the 1435–1525
         MHz, 2345–2395 MHz, or 5091–5150 MHz band with an authorized bandwidth equal to or less than 1
         MHz the emissions must be attenuated as follows:

            (1) On any frequency removed from the assigned frequency by more than 100 percent of the authorized
                bandwidth up to and including 100 percent plus 0.5 MHz, the attenuation must be at least 60 dB,
                when measured in a 3.0 kHz bandwidth. This signal need not be attenuated more than 25 dB below 1
                milliwatt.

            (2) On any frequency removed from the assigned frequency by more than 100 percent of the authorized
                bandwidth plus 0.5 MHz, the attenuation must be at least 55 + 10 log10 pY dB when measured in a
                3.0 kHz bandwidth.

     (f) When using frequency modulation or digital modulation for telemetry or telecommand in the 1435–1525
         MHz, 2345–2395 MHz, or 5091–5150 MHz band with an authorized bandwidth greater than 1 MHz, the
         emissions must be attenuated as follows:

            (1) On any frequency removed from the assigned frequency by more than 50 percent of the authorized
                bandwidth plus 0.5 MHz up to and including 50 percent of the authorized bandwidth plus 1.0 MHz,
                the attenuation must be 60 dB, when measured in a 3.0 kHz bandwidth. The signal need not be
                attenuated more than 25 dB below 1 milliwatt.

            (2) On any frequency removed from the assigned frequency by more than 50 percent of the authorized
                bandwidth plus 1.0 MHz, the attenuation must be at least 55 + 10 log10 pY dB, when measured in a
                3.0 kHz bandwidth.

     (g) The requirements of paragraphs (e) and (f) of this section apply to transmitters approved after January 1,
         1977, and to all transmitters first installed after January 1, 1983.

     (h) For ELTs operating on 121.500 MHz, 243.000 MHz and 406.0–406.1 MHz the mean power of any
         emission must be attenuated below the mean power of the transmitter (pY) as follows:

            (1) When the frequency is moved from the assigned frequency by more than 50 percent up to and
                including 100 percent of the authorized bandwidth the attenuation must be at least 25 dB;

            (2) When the frequency is removed from the assigned frequency by more than 100 percent of the
                authorized bandwidth the attenuation must be at least 30 dB.

      (i)   In case of conflict with other provisions of § 87.139, the provisions of this paragraph shall govern for
            aircraft earth stations. When using G1D, G1E, or G1W emissions in the 1646.5–1660.5 MHz frequency
            band, the emissions must be attenuated as shown below.

47 CFR 87.139(i) (enhanced display)                                                                         page 27 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                          47 CFR 87.139(i)(1)
Aviation Services

           (1) At rated output power, while transmitting a modulated single carrier, the composite spurious and
               noise output shall be attenuated by at least:

                                Frequency (MHz)                                      Attenuation (dB)1
                 0.01 to 1525                                    −135 dB/4 kHz
                 1525 to 1559                                    −203 dB/4 kHz
                 1559 to 1585                                    −155 dB/MHz
                 1585 to 1605                                    −143 dB/MHz
                 1605 to 1610                                    −117 dB/MHz
                 1610 to 1610.6                                  −95 dB/MHz
                 1610.6 to 1613.8                                −80 dBW/MHz3
                 1613.8 to 1614                                  −95 dB/MHz
                 1614 to 1626.5                                  −70 dB/4 kHz
                 1626.5 to 1660                                  −70 dB/4 kHz2 3 4
                 1660 to 1670                                    −49.5 dBW/20 kHz2 3 4
                 1670 to 1735                                    −60 dB/4 kHz
                 1735 to 12000                                   −105 dB/4 kHz
                 12000 to 18000                                  −70 dB/4 kHz

                1 These values are expressed in dB referenced to the carrier for the bandwidth indicated, and
                relative to the maximum emission envelope level, except where the attenuation is shown in dBW,
                the attenuation is expressed in terms of absolute power referenced to the bandwidth indicated.

                2 Attenuation measured within the transmit band excludes the band ±35 kHz of the carrier
                frequency.

                3   This level is not applicable for intermodulation products.

                4 The upper limit for the excess power for any narrow-band spurious emission (excluding
                intermodulation products within a 30 kHz measurement bandwidth) shall be 10 dB above the
                power limit in this table.

           (2) The transmitter emission limit is a function of the modulation type and symbol rate (SR). Symbol
               Rate is expressed in symbols per second.

           (3) While transmitting a single modulated signal at the rated output power of the transmitter, the
               emissions must be attenuated below the maximum emission level by at least:

                                    Frequency Offset (normalized to SR)                          Attenuation (dB)
                 ±0.75 × SR                                                                                             0
                 ±1.40 × SR                                                                                            20
                 ±2.95 × SR                                                                                            40

     Where:

47 CFR 87.139(i)(3) (enhanced display)                                                                         page 28 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                        47 CFR 87.139(j)
Aviation Services

     SR = Symbol Rate,

     SR = 1 × channel rate for BPSK,

     SR = 0.5 × channel rate for QPSK.

                 The mask shall be defined by drawing straight lines through the above points.

      (j)   When using G7D for differential GPS in the 112–118 MHz band, the amount of power during transmission
            under all operating conditions when measured over a 25 kHz bandwidth centered on either of the second
            adjacent channels shall not exceed −25 dBm and shall decrease 5 dB per octave until −52 dBm.

     (k) For VHF aeronautical stations and aircraft stations operating with G1D or G7D emissions:

            (1) The amount of power measured across either first adjacent 25 kHz channel shall not exceed 2 dBm.

            (2) For stations first installed before January 1, 2002, the amount of power measured across either
                second adjacent channel shall be less than −25 dBm and the power measured in any other adjacent
                25 kHz channels shall monotonically decrease at a rate of at least 5 dB per octave to a maximum
                value of −52 dBm. For stations first installed on or after January 1, 2002,

                 (i)    The amount of power measured across either second adjacent 25 kHz channel shall be less
                        than −28 dBm;

                 (ii) The amount of power measured across either fourth adjacent 25 kHz channel shall be less than
                      −38 dBm; and

                 (iii) From thereon the power measured in any other adjacent 25 kHz channel shall monotonically
                       decrease at a rate of at least 5 dB per octave to a maximum value of −53 dBm.

            (3) The amount of power measured over a 16 kHz channel bandwidth centered on the first adjacent 25
                kHz channel shall not exceed −18 dBm.

      (l)

            (1) For Universal Access Transceiver transmitters, the average emissions measured in a 100 kHz
                bandwidth must be attenuated below the maximum emission level contained within the authorized
                bandwidth by at least:

                                                                                          Attenuation
                                         Frequency (MHz)
                                                                                              (dB)
                 ±0.5                                                                                               0
                 ±1.0                                                                                             18
                 ±2.25                                                                                            50
                 ±3.25                                                                                            60

            (2) Universal Access Transceiver transmitters with an output power of 5 Watts or more must limit their
                emissions by at least 43 + 10 log (P) dB on any frequency removed from the assigned frequency by
                more than 250% of the authorized bandwidth. Those emissions shall be measured with a bandwidth
                of 100 kHz. P in the above equation is the average transmitter power measured within the occupied
                bandwidth in Watts.

47 CFR 87.139(l)(2) (enhanced display)                                                                    page 29 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                             47 CFR 87.139(l)(3)
Aviation Services

           (3) Universal Access Transceiver transmitters with less than 5 Watts of output power must limit their
               emissions by at least 40 dB relative to the carrier peak on any frequency removed from the assigned
               frequency by more than 250% of the authorized bandwidth. Those emissions shall be measured with
               a bandwidth of 100 kHz.

     (m) In the 1435–1452 MHz band, operators of aeronautical telemetry stations are encouraged to take all
         reasonable steps to ensure that unwanted emissions power does not exceed −28 dBW/27 MHz in the
         1400–1427 MHz band. Operators of aeronautical telemetry stations that do not meet this limit shall first
         attempt to operate in the 1452–1525 MHz band prior to operating in the 1435–1452 MHz band.

[53 FR 28940, Aug. 1, 1988]

Editorial Note: For FEDERAL REGISTER citations affecting § 87.139, see the List of CFR Sections Affected, which
appears in the Finding Aids section of the printed volume and at www.govinfo.gov.

§ 87.141 Modulation requirements.
     (a) When A3E emission is used, the modulation percentage must not exceed 100 percent. This requirement
         does not apply to emergency locator transmitters or survival craft transmitters.

     (b) A double sideband full carrier amplitude modulated radiotelephone transmitter with rated carrier power
         output exceeding 10 watts must be capable of automatically preventing modulation in excess of 100
         percent.

     (c) If any licensed radiotelephone transmitter causes harmful interference to any authorized radio service
         because of excessive modulation, the Commission will require the use of the transmitter to be
         discontinued until it is rendered capable of automatically preventing modulation in excess of 100 percent.

     (d) Single sideband transmitters must be able to operate in the following modes:

                    Carrier mode                    Level N(dB) of the carrier with respect to peak envelope power
            Full carrier (H3E)                O>N>−6.
            Suppressed carrier (J3E)          Aircraft stations N<−26;
                                              Aeronautical stations N<−40.

     (e) Each frequency modulated transmitter operating in the band 72.0–76.0 MHz must have a modulation
         limiter.

     (f) Each frequency modulated transmitter equipped with a modulation limiter must have a low pass filter
         between the modulation limiter and the modulated stage. At audio frequencies between 3 kHz and 15
         kHz, the filter must have an attenuation greater than the attenuation at 1 kHz by at least 40 log10 (f/3) db
         where “f” is the frequency in kilohertz. Above 15 kHz, the attenuation must be at least 28 db greater than
         the attenuation at 1 kHz.

     (g) Except that symmetric side bands are not required, the modulation characteristics for ELTs must be in
         accordance with specifications contained in the Federal Aviation Administration (FAA) Technical Standard
         Order (TSO) Document TSO-C91a titled “Emergency Locator Transmitter (ELT) Equipment” dated April 29,
         1985. TSO-C91a is incorporated by reference in accordance with 5 U.S.C. 552(a). TSO-C91a may be
         obtained from the Department of Transportation, Federal Aviation Administration, Office of Airworthiness,
         800 Independence Avenue SW., Washington DC 20591.
47 CFR 87.141(g) (enhanced display)                                                                                  page 30 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                               47 CFR 87.141(h)
Aviation Services

     (h) ELTs must use A3X emission and may use A3E or NON emissions on an optional basis while transmitting.
         Each transmission of a synthesized or recorded voice message from an ELT must be preceded by the
         words “this is a recording”; transmission of A3E or NON emission must not exceed 90 seconds; and any
         transmission of A3E or NON emissions must be followed by at least three minutes of A3X emission.

      (i)   ELTs manufactured on or after October 1, 1988, must have a clearly defined carrier frequency distinct from
            the modulation sidebands for the mandatory emission, A3X, and, if used, the A3E or NON emissions. On
            121.500 MHz at least thirty per cent of the total power emitted during any transmission cycle with or
            without modulation must be contained within plus or minus 30 Hz of the carrier frequency. On 243.000
            MHz at least thirty percent of the total power emitted during any transmission cycle with or without
            modulation must be contained within plus or minus 60 Hz of the carrier frequency. Additionally, if the type
            of emission is changed during transmission, the carrier frequency must not shift more than plus or minus
            30 Hz on 121.500 MHz and not more than plus or minus 60Hz on 243.000 MHz. The long term stability of
            the carrier frequency must comply with the requirements in § 87.133 of this part.

      (j)   Transmitters used at Aircraft earth stations must employ BPSK for transmission rates up to and including
            2400 bits per second, and QPSK for higher rates.

     (k) Universal Access Transceiver transmitters must use F1D modulation without phase discontinuities.

[53 FR 28940, Aug. 1, 1988, as amended at 54 FR 11721, Mar. 22, 1989; 56 FR 11518, Mar. 19, 1991; 57 FR 45749, Oct. 5, 1992; 71
FR 70676, Dec. 6, 2006]

§ 87.143 Transmitter control requirements.
     (a) Each transmitter must be installed so that it is not accessible to, or capable of being operated by persons
         other than those authorized by the licensee.

     (b) Each station must be provided with a control point at the location of the transmitting equipment, unless
         otherwise specifically authorized. Except for aeronautical enroute stations governed by paragraph (e) of
         this section, a control point is the location at which the radio operator is stationed. It is the position at
         which the transmitter(s) can immediately be turned off.

     (c) Applicants for additional control points at aeronautical advisory (unicom) stations must specify the
         location of each proposed control point.

     (d) Except for aeronautical enroute stations governed by paragraph (f) of this section, the control point must
         have the following facilities installed:

            (1) A device that indicates when the transmitter is radiating or when the transmitter control circuits have
                been switched on. This requirement does not apply to aircraft stations;

            (2) Aurally monitoring of all transmissions originating at dispatch points;

            (3) A way to disconnect dispatch points from the transmitter; and

            (4) A way to turn off the transmitter.

     (e) A dispatch point is an operating position subordinate to the control point. Dispatch points may be
         installed without authorization from the Commission, and dispatch point operators are not required to be
         licensed.

47 CFR 87.143(e) (enhanced display)                                                                               page 31 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                        47 CFR 87.143(f)
Aviation Services

     (f) In the aeronautical enroute service, the control point for an automatically controlled enroute station is the
         computer facility which controls the transmitter. Any computer controlled transmitter must be equipped to
         automatically shut down after 3 minutes of continuous transmission of an unmodulated carrier.

§ 87.145 Acceptability of transmitters for licensing.
     (a) Each transmitter must be certificated for use in these services, except as listed in paragraph (c) of this
         section. However, aircraft stations which transmit on maritime mobile frequencies must use transmitters
         certificated for use in ship stations in accordance with part 80 of this chapter. Certification under part 80
         is not required for aircraft earth stations transmitting on maritime mobile-satellite frequencies. Such
         stations must be certificated under part 87.

     (b) Some radio equipment installed on air carrier aircraft must meet the requirements of the Commission and
         the requirements of the FAA. The FAA requirements may be obtained from the FAA, Aircraft Maintenance
         Division, 800 Independence Ave., SW., Washington, DC 20591.

     (c) The equipment listed below is exempted from certification. The operation of transmitters which have not
         been certificated must not result in harmful interference due to the failure of those transmitters to comply
         with technical standards of this subpart.

           (1) Flight test station transmitters for limited periods where justified.

           (2) U.S. Government transmitters furnished in the performance of a U.S. Government contract if the use
               of certificated equipment would increase the cost of the contract or if the transmitter will be
               incorporated in the finished product. However, such equipment must meet the technical standards
               contained in this subpart.

           (3) ELTs verified in accordance with § 87.147(e).

           (4) Signal generators when used as radionavigation land test stations (MTF).

     (d) Aircraft earth stations must correct their transmit frequencies for Doppler effect relative to the satellite.
         The transmitted signal may not deviate more than 335 Hz from the desired transmit frequency. (This is a
         root sum square error which assumes zero error for the received ground earth station signal and includes
         the AES transmit/receive frequency reference error and the AES automatic frequency control residual
         errors.) The applicant must attest that the equipment provides adequate Doppler effect compensation
         and where applicable, that measurements have been made that demonstrate compliance. Submission of
         data demonstrating compliance is not required unless requested by the Commission.

[63 FR 36607, July 7, 1998, as amended at 69 FR 32881, June 14, 2004]

§ 87.147 Authorization of equipment.
     (a) Certification may be requested by following the procedures in part 2 of this chapter. Aircraft transmitters
         must meet the requirements over an ambient temperature range of −20 degrees to + 50 degrees Celsius.

     (b) ELTs manufactured after October 1, 1988, must meet the output power characteristics contained in §
         87.141(i). A report of the measurements must be submitted with each application for certification. ELTs
         that meet the output power characteristics of the section must have a permanent label prominently
         displayed on the outer casing state, “Meets FCC Rule for improved satellite detection.” This label, however,
         must not be placed on the equipment without authorization to do so by the Commission. Application for
         such authorization may be made either by submission of a new application for certification accompanied
         by the required fee and all information and test data required by parts 2 and 87 of this chapter or, for ELTs
47 CFR 87.147(b) (enhanced display)                                                                        page 32 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                          47 CFR 87.147(c)
Aviation Services

           approved prior to October 1, 1988, a letter requesting such authorization, including appropriate test data
           and a showing that all units produced under the original equipment authorization comply with the
           requirements of this paragraph without change to the original circuitry.

     (c) An applicant for a station license may request certification for an individual transmitter by following the
         procedure in part 2 of this chapter. Such a transmitter will be individually certified and so noted on the
         station license.

     (d) An applicant for certification of equipment intended for transmission in any of the frequency bands listed
         in paragraph (d)(3) of this section must notify the FAA of the filing of a certification application. The letter
         of notification must be mailed to: FAA, Office of Spectrum Policy and Management, ASR–1, 800
         Independence Ave., SW., Washington, DC 20591 prior to the filing of the application with the Commission.

           (1) The notification must describe the equipment, give the manufacturer's identification, antenna
               characteristics, rated output power, emission type and characteristics, the frequency or frequencies
               of operation, and essential receiver characteristics if protection is required.

           (2) The certification application must include a copy of the notification letter to the FAA. The
               Commission will not act until it receives the FAA's determination regarding whether it objects to the
               application for equipment authorization. The FAA should mail its determination to: Office of
               Engineering and Technology Laboratory, Authorization and Evaluation Division, 7435 Oakland Mills
               Rd., Columbia, MD 21046. The Commission will consider the FAA determination before taking final
               action on the application.

           (3) The frequency bands are as follows:

          90–110 kHz

          190–285 kHz

          325–435 kHz

          74.800 MHz to 75.200 MHz

          108.000 MHz to 137.000 MHz

          328.600 MHz to 335.400 MHz

          960.000 MHz to 1215.000 MHz

          1545.000 MHz to 1626.500 MHz

          1646.500 MHz to 1660.500 MHz

          5000.000 MHz to 5250.000 MHz

          14.000 GHz to 14.400 GHz

          15.400 GHz to 15.700 GHz

47 CFR 87.147(d)(3) (enhanced display)                                                                       page 33 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                              47 CFR 87.147(e)
Aviation Services

          24.250 GHz to 25.250 GHz

          31.800 GHz to 33.400 GHz

     (e) Supplier's Declaration of Conformity for ELTs capable of operating on the frequency 406.0–406.1 MHz
         must include sufficient documentation to show that the ELT meets the requirements of § 87.199(a). A
         letter notifying the FAA of the ELT Supplier's Declaration of Conformity must be mailed to: FAA, Office of
         Spectrum Policy and Management, ASR–1, 800 Independence Avenue SW., Washington, DC 20591.

           Note 1 to paragraph (e): The verification procedure has been replaced by Supplier's Declaration of
           Conformity. Equipment previously authorized under subpart J of part 2 of this chapter may remain
           in use. See § 2.950 of this chapter.

     (f) Certification may be requested for equipment that has the capability to transmit in the 138–144 MHz,
         148–149.9 MHz, or 150.5–150.8 MHz bands as well as frequency bands set forth in § 87.173. The
         Commission will only certify this equipment for use in the bands regulated by this part.

[53 FR 28940, Aug. 1, 1988, as amended at 54 FR 11721, Mar. 22, 1989; 56 FR 11518, Mar. 19, 1991; 57 FR 45750, Oct. 5, 1992; 58
FR 30127, May 26, 1993; 58 FR 67696, Dec. 22, 1993; 63 FR 36608, July 7, 1998; 69 FR 32881, June 14, 2004; 82 FR 50837, Nov. 2,
2017; 83 FR 63812, Dec. 12, 2018]

§ 87.149 Special requirements for automatic link establishment (ALE).
Brief signalling for the purposes of measuring the quality of a radio channel and thereafter establishing
communication shall be permitted within the 2 MHz–30 MHz band. Public coast stations licensed under part 80 of
this chapter providing high seas service are authorized by rule to use such signalling under the following conditions:

     (a) The transmitter power shall not exceed 100 W ERP;

     (b) Transmissions must sweep linearly in frequency at a rate of at least 60 kHz per second, occupying any 3
         kHz bandwidth for less than 50 milliseconds;

     (c) The transmitter shall scan the band no more than four times per hour;

     (d) Transmissions within 6 kHz of the following protected frequencies and frequency bands must not exceed
         10 µW peak ERP:

47 CFR 87.149(d) (enhanced display)                                                                              page 34 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                      47 CFR 87.149(d)(1)
Aviation Services

           (1) Protected frequencies (kHz)

                 2091.0               4188.0          6312.0                12290.0               16420.0
                 2174.5               4207.5          8257.0                12392.0               16522.0
                 2182.0               5000.0          8291.0                12520.0               16695.0
                 2187.5               5167.5          8357.5                12563.0               16750.0
                 2500.0               5680.0          8364.0                12577.0               16804.5
                 3023.0               6215.0          8375.0                15000.0               20000.0
                 4000.0               6268.0          8414.5                16000.0               25000.0
                 4177.5               6282.0          10000.0

           (2) Protected bands (kHz)

          4125.0–4128.0

          8376.25–8386.75

          13360.0–13410.0

          25500.0–25670.0

     (e) The instantaneous signal, which refers to the peak power that would be measured with the frequency
         sweep stopped, along with spurious emissions generated from the sweeping signal, must be attenuated
         below the peak carrier power (in watts) as follows:

           (1) On any frequency more than 5 Hz from the instantaneous carrier frequency, at least 3 dB;

           (2) On any frequency more than 250 Hz from the instantaneous carrier frequency, at least 40 dB; and

           (3) On any frequency more than 7.5 kHz from the instantaneous carrier frequency, at least 43 + 10log10
               (peak power in watts) db.

[62 FR 40308, July 28, 1997]

§ 87.151 Special requirements for differential GPS receivers.
     (a) The receiver shall achieve a message failure rate less than or equal to one failed message per 1000 full-
         length (222 bytes) application data messages, while operating over a range from −87 dBm to −1 dBm,
         provided that the variation in the average received signal power between successive bursts in a given time
         slot shall not exceed 40 dB. Failed messages include those lost by the VHF data receiver system or which
         do not pass the cyclic redundancy check (CRC) after application of the forward error correction (FEC).

     (b) The aircraft receiving antenna can be horizontally or vertically polarized. Due to the difference in the signal
         strength of horizontally and vertically polarized components of the broadcast signal, the total aircraft
         implementation loss is limited to 15 dB for horizontally polarized receiving antennas and 11 dB for
         vertically polarized receiving antennas.

     (c) Desensitization. The receiver shall meet the requirements specified in paragraph (a) of this section in the
         presence of VHF-FM broadcast signals in accord with following tables.

47 CFR 87.151(c) (enhanced display)                                                                         page 35 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                         47 CFR 87.151(c)(1)
Aviation Services

           (1) Maximum levels of undesired signals.

                              Frequency1                Maximum level of undesired signal at the receiver input (dBm)
                 50 kHz up to 88 MHz                 −13
                 88 MHz–107.900 MHz                  [see paragraph (c)(2)]
                 108.000 MHz–117.975 MHz             excluded
                 118MHz                              −44
                 118.025 MHz                         −41
                 118.050 MHz up to 1660.5 MHz        −13

                1   The relationship is linear between single adjacent points designated by the above frequencies.

           (2) Desensitization frequency and power requirements for the frequencies 108.025 MHz to 111.975
               MHz.

                          Frequency1                Maximum level of undesired signal at the receiver input (dBm)
                 88 MHz ≤f ≤102 MHz                                                                                     15
                 104 MHz                                                                                                10
                 106 MHz                                                                                                 5
                 107.9 MHz                                                                                           −10

                1
                    The relationship is linear between single adjacent points designated by the above frequencies.

           (3) Desensitization frequency and power requirements for the frequencies 112.00 MHz to 117.975 MHz.

                          Frequency1                Maximum level of undesired signal at the receiver input (dBm)
                 88 MHz ≤f ≤104 MHz                                                                                     15
                 106 MHz                                                                                                10
                 107 MHz                                                                                                 5
                 107.9 MHz                                                                                               0

                1   The relationship is linear between single adjacent points designated by the above frequencies.

     (d) Intermodulation immunity. The receiver shall meet the requirements specified in paragraph (a) of this
         section in the presence of interference from two-signal, third order intermodulation products of two VHF-
         FM broadcast signals having levels in accordance with the following:

           (1) 2N1 + N2 + 72 ≤0 for VHF-FM sound broadcasting signals in the range 107.7–108 MHz; and

           (2) 2N1 + N2 + 3 (24 −20log delta f/0.4) ≤0 for VHF-FM sound broadcasting signals below 107.7 MHz,
               where the frequencies of the two VHF-FM sound broadcasting signals produce, within the receiver, a
               two signal, third-order intermodulation product on the desired VDB frequency.

47 CFR 87.151(d)(2) (enhanced display)                                                                        page 36 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                        47 CFR 87.151(d)(3)
Aviation Services

           (3) In the formulas in paragraphs (d)(1) and (d)(2) of this section, N1 and N2 are the levels (dBm) of the
               two VHF FM sound broadcasting signals at the VHF data broadcast (VDB) receiver input. Neither
               level shall exceed the desensitization criteria set forth in paragraph (c) of this section. Delta f = 108.1
               − f1, where f1 is the frequency of N1, the VHF FM sound broadcasting signal closer to 108.1 MHz.

[69 FR 32881, June 14, 2004]

Subpart E—Frequencies
§ 87.169 Scope.
This subpart contains class of station symbols and a frequency table which lists assignable frequencies.
Frequencies in the Aviation Services will transmit communications for the safe, expeditious, and economic
operation of aircraft and the protection of life and property in the air. Each class of land station may communicate in
accordance with the particular sections of this part which govern these classes. Land stations in the Aviation
Services in Alaska may transmit messages concerning sickness, death, weather, ice conditions or other matters
relating to safety of life and property if there is no other established means of communications between the points
in question and no charge is made for the communications service.

[69 FR 32882, June 14, 2004]

§ 87.171 Class of station symbols.
The two or three letter symbols for the classes of station in the aviation services are:

Symbol and class of station
     AX—Aeronautical fixed

     AVW—Audio visual warning systems

     AXO—Aeronautical operational fixed

     DGP—Differential GPS

     DLT—Aircraft data link land test

     FA—Aeronautical land (unspecified)

     FAC—Airport control tower

     FAE—Aeronautical enroute

     FAM—Aeronautical multicom

     FAR—Aeronautical search and rescue

     FAS—Aviation support

47 CFR 87.171 (enhanced display)                                                                             page 37 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                              47 CFR 87.171
Aviation Services

     FAT—Flight test

     FAU—Aeronautical advisory (unicom)

     FAW—Automatic weather observation

     GCO—Ground Communication Outlet

     MA—Aircraft (Air carrier and Private)

     MA1—Air carrier aircraft only

     MA2—Private aircraft only

     MOU—Aeronautical utility mobile

     MRT—ELT test

     RCO—Remote Communications Outlet

     RL—Radionavigation land (unspecified)

     RLA—Marker beacon

     RLB—Radiobeacon

     RLD—RADAR/TEST

     RLG—Glide path

     RLL—Localizer

     RLO—VHF omni-range

     RLS—Surveillance radar

     RLT—Radionavigation land test

     RLW—Microwave landing system

     RNV—Radio Navigation Land/DME

     RPC—Ramp Control

     TJ—Aircraft earth station in the Aeronautical Mobile-Satellite Service

47 CFR 87.171 (enhanced display)                                              page 38 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                                47 CFR 87.173
Aviation Services

     UAT—Universal Access Transceiver

[53 FR 28940, Aug. 1, 1988, as amended at 57 FR 45750, Oct. 5, 1992; 64 FR 27475, May 20, 1999; 69 FR 32882, June 14, 2004;
71 FR 70676, Dec. 6, 2006; 76 FR 17351, Mar. 29, 2011; 78 FR 61206, Oct. 3, 2013]

§ 87.173 Frequencies.
     (a) The table in paragraph (b) of this section lists assignable carrier frequencies or frequency bands.

             (1) The single letter symbol appearing in the “Subpart” column indicates the subpart of this part which
                 contains additional applicable regulations.

             (2) The two or three letter symbol appearing in the “Class of Station” column indicates the class of
                 station to which the frequency is assignable.

     (b) Frequency table:

    Frequency or                    Class of
                     Subpart                                              Remarks
  frequency band                    station
 90–110 kHz          Q         RL              LORAN “C”.
 190–285 kHz         Q         RLB             Radiobeacons.
 200–285 kHz         O         FAC             Air traffic control.
 325–405 kHz         O         FAC             Air traffic control.
 325–435 kHz         Q         RLB             Radiobeacons.
 410.0 kHz           F         MA              International direction-finding for use outside of United
                                               States.
 457.0 kHz           F         MA              Working frequency for aircraft on over-water flights.
 500.0 kHz           F         MA              International calling and distress frequency for ships and
                                               aircraft on over-water flights.
 510–535 kHz         Q         RLB             Radiobeacons.
 2182.0 kHz          F         MA              International distress and calling.
 2648.0 kHz          I         AX              Alaska station.
 2850.0–3025.0       I         MA, FAE         International HF.
 kHz
 2851.0 kHz          I, J      MA, FAE, FAT    International HF; Flight Test.
 2866.0 kHz          I         MA, FAE         Domestic HF; (Alaska).
 2875.0 kHz          I         MA, FAE         Domestic HF.
 2878.0 kHz          I         MA1, FAE        Domestic HF; International HF.
 2911.0 kHz          I         MA, FAE         Domestic HF.
 2956.0 kHz          I         MA, FAE         Domestic HF.
 3004.0 kHz          I, J      MA, FAE, FAT    International HF; Flight Test.
 3019.0 kHz          I         MA1, FAE        Domestic HF; International HF.
 3023.0 kHz          F, M, O   MA1, FAR, FAC Search and rescue communications.
 3281.0 kHz          K         MA, FAS         Lighter-than-air craft and aeronautical stations serving
                                               lighter-than-air craft.
 3400.0–3500.0       I         MA, FAE         International HF.

47 CFR 87.173(b) (enhanced display)                                                                              page 39 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                    47 CFR 87.173(b)
Aviation Services

    Frequency or                    Class of
                    Subpart                                             Remarks
  frequency band                    station
 kHz
 3434.0 kHz         I          MA1, FAE        Domestic HF.
 3443.0 kHz         J          MA, FAT         Flight Test.
 3449.0 kHz         I          MA, FAE         Domestic HF.
 3470.0 kHz         I          MA, FAE         Domestic HF; International HF.
 4125.0 kHz         F          MA              Distress and safety with ships and coast stations.
 4550.0 kHz         I          AX              Gulf of Mexico.
 4645.0 kHz         I          AX              Alaska.
 4650.0–4700.0      I          MA, FAE         International HF.
 kHz
 4672.0 kHz         I          MA1, FAE        Domestic HF.
 4947.5 kHz         I          AX              Alaska.
 5036.0 kHz         I          AX              Gulf of Mexico.
 5122.5 kHz         I          AX              Alaska.
 5167.5 kHz         I          FA              Alaska emergency.
 5310.0 kHz         I          AX              Alaska.
 5450.0–5680.0      I          MA, FAE         International HF.
 kHz
 5451.0 kHz         J          MA, FAT         Flight Test.
 5463.0 kHz         I          MA1, FAE        Domestic HF.
 5469.0 kHz         J          MA, FAT         Flight Test.
 5472.0 kHz         I          MA, FAE         Domestic HF.
 5484.0 kHz         I          MA, FAE         Domestic HF.
 5490.0 kHz         I          MA, FAE         Domestic HF.
 5496.0 kHz         I          MA, FAE         Domestic HF.
 5508.0 kHz         I          MA1, FAE        Domestic HF.
 5571.0 kHz         J          MA, FAT         Flight Test.
 5631.0 kHz         I          MA, FAE         Domestic HF.
 5680.0 kHz         F, M, O    MA1, FAC, FAR Search and rescue communications.
 5887.5 kHz         I          AX              Alaska.
 6525.0–6685.0      I          MA, FAE         International HF.
 kHz
 6550.0 kHz         J          MA, FAT         Flight Test.
 6580.0 kHz         I          MA, FAE         Domestic HF.
 6604.0 kHz         I          MA, FAE         Domestic HF.
 8015.0 kHz         I          AX              Alaska.
 8364.0 kHz         F          MA              Search and rescue communications.
 8815.0–8965.0      I          MA, FAE         International HF.
 kHz
 8822.0 kHz         J          MA, FAT         Flight Test.

47 CFR 87.173(b) (enhanced display)                                                                   page 40 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                     47 CFR 87.173(b)
Aviation Services

    Frequency or                  Class of
                    Subpart                                                Remarks
  frequency band                  station
 8855.0 kHz         I          MA, FAE          Domestic HF; international HF.
 8876.0 kHz         I          MA, FAE          Domestic HF.
 10005.0–10100.0 I             MA, FAE          International HF.
 kHz
 10045.0 kHz        J          MA, FAT          Flight Test.
 10066.0 kHz        I          MA, FAE          Domestic HF; international HF.
 11275.0–11400.0 I             MA, FAE          International HF.
 kHz
 11288.0 kHz        J          MA, FAT          Flight Test.
 11306.0 kHz        J          MA, FAT          Flight Test.
 11357.0 kHz        I          MA, FAE          Domestic HF.
 11363.0 kHz        I          MA, FAE          Domestic HF.
 13260.0–13360.0 I             MA, FAE          International HF.
 kHz
 13312.0 kHz        I, J       MA, FAE, FAT     International HF; Flight Test.
 17900.0–17970.0 I             MA, FAE          International HF.
 kHz
 17964.0 kHz        J          MA, FAT          Flight Test.
 21924.0–22000.0 I             MA, FAE          International HF.
 kHz
 21931.0 kHz        J          MA, FAT          Flight Test.
 72.02–72.98        P          FA, AXO          Operational fixed.
 MHz
 75.000 MHz         Q          RLA              Marker beacon.
 75.42–75.98        P          FA, AXO          Operational fixed.
 MHz
 108.000 MHz        Q          RLT
 108.000–117.950 Q             RLO              VHF omni-range.
 MHz
 108.000–117.975 Q             DGP              Differential GPS.
 MHz
 108.050 MHz        Q          RLT
 108.100–111.950 Q             RLL              ILS Localizer.
 MHz
 108.100 MHz        Q          RLT
 108.150 MHz        Q          RLT
 118.000–121.400 O, S          MA, FAC, FAW,    25 kHz channel spacing
 MHz                           GCO
                               RCO, RPC
 121.500 MHz        G, H, I,   MA, FAU, FAE,    Emergency and distress.
                    J, K, M,   FAT, FAS, FAC,
                    O          FAM

47 CFR 87.173(b) (enhanced display)                                                     page 41 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                                  47 CFR 87.173(b)
Aviation Services

    Frequency or                  Class of
                    Subpart                                               Remarks
  frequency band                  station
 121.600–121.925 O, L, Q       MA, FAC,        25 kHz channel spacing.
 MHz                           MOU, RLT,
                               GCO, RCO,
                               RPC
 121.950 MHz        K          FAS
 121.975 MHz        F, S       MA2, FAW,       Air traffic control operations.
                               FAC, MOU
 122.000 MHz        F          MA, FAC, MOU    Air carrier and private aircraft enroute flight advisory service
                                               provided by FAA.
 122.025 MHz        F, S       MA2, FAW,       Air traffic control operations.
                               FAC, MOU
 122.050 MHz        F          MA, FAC, MOU    Air traffic control operations.
 122.075 MHz        F, S       MA2, FAW,       Air traffic control operations.
                               FAC, MOU
 122.100 MHz        F, O       MA, FAC, MOU    Air traffic control operations.
 122.125–122.675 F             MA2, FAC,       Air traffic control operations; 25 kHz spacing.
 MHz                           MOU
 122.700 MHz        G, L, Q    MA, FAU,        Unicom at airports with no control tower; Aeronautical utility
                               MOU, AVW        stations.
 122.725 MHz        G, L, Q    MA, FAU,        Unicom at airports with no control tower; Aeronautical utility
                               MOU, AVW        stations.
 122.750 MHz        F, Q       MA2, AVW        Private fixed wing aircraft air-to-air communications.
 122.775 MHz        K          MA, FAS
 122.800 MHz        G, L, Q    MA, FAU,        Unicom at airports with no control tower; Aeronautical utility
                               MOU, AVW        stations.
 122.825 MHz        I          MA, FAE         Domestic VHF.
 122.850 MHz        H, K, Q    MA, FAM, FAS,
                               AVW.
 122.875 MHz        I          MA, FAE         Domestic VHF.
 122.900 MHz        F, H, L,   MA, FAR, FAM,
                    M, Q       MOU, AVW
 122.925 MHz        H          MA2, FAM
 122.950 MHz        G, L, Q    MA, FAU,        Unicom at airports with control tower; Aeronautical utility
                               MOU, AVW        stations.
 122.975 MHz        G, L, Q    MA, FAU,        Unicom at airports with no control tower; Aeronautical utility
                               MOU, AVW        stations.
 123.000 MHz        G, L, Q    MA, FAU,        Unicom at airports with no control tower; Aeronautical utility
                               MOU, AVW        stations.
 123.025 MHz        F, Q       MA2, AVW        Helicopter air-to-air communications; Air traffic control
                                               operations.
 123.050 MHz        G, L, Q    MA, FAU,        Unicom at airports with no control tower; Aeronautical utility
                               MOU, AVW        stations.

47 CFR 87.173(b) (enhanced display)                                                                                  page 42 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                                47 CFR 87.173(b)
Aviation Services

    Frequency or                  Class of
                    Subpart                                               Remarks
  frequency band                  station
 123.075 MHz        G, L, Q    MA, FAU,        Unicom at airports with no control tower; Aeronautical utility
                               MOU, AVW        stations.
 123.100 MHz        M, O       MA, FAC, FAR
 123.125 MHz        J          MA, FAT         Itinerant.
 123.150 MHz        J          MA, FAT         Itinerant.
 123.175 MHz        J          MA, FAT         Itinerant.
 123.200 MHz        J          MA, FAT
 123.225 MHz        J          MA, FAT
 123.250 MHz        J          MA, FAT
 123.275 MHz        J          MA, FAT
 123.300 MHz        K, Q       MA, FAS, AVW.
 123.325 MHz        J          MA, FAT
 123.350 MHz        J          MA, FAT
 123.375 MHz        J          MA, FAT
 123.400 MHz        J          MA, FAT         Itinerant.
 123.425 MHz        J          MA, FAT
 123.450 MHz        J          MA, FAT
 123.475 MHz        J          MA, FAT
 123.500 MHz        K, Q       MA, FAS, AVW.
 123.525 MHz        J          MA, FAT
 123.550 MHz        J          MA, FAT
 123.575 MHz        J          MA, FAT
 123.6–128.8        O, S       MA, FAC, FAW,   25 kHz channel spacing.
 MHz                           GCO, RCO,
                               RPC
 128.825–132.000 I             MA, FAE         Domestic VHF.
 MHz
 131.450 MHz        I          DLT.
 131.550 MHz        I          DLT.
 131.725 MHz        I          DLT.
 131.825 MHz        I          DLT.
 132.025–135.975 O, S          MA, FAC, FAW,   25 kHz channel spacing.
 MHz                           GCO RCO RPC
 136.000–136.400 O, S          MA, FAC, FAW,   Air traffic control operations; 25 kHz channel spacing.
 MHz                           GCO, RCO,
                               RPC
 136.425 MHz        O, S       MA, FAC, FAW,   Air traffic control operations.
                               GCO, RCO,
                               RPC
 136.450 MHz        O, S       MA, FAC, FAW,   Air traffic control operations.
                               GCO, RCO,

47 CFR 87.173(b) (enhanced display)                                                                                page 43 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                             47 CFR 87.173(b)
Aviation Services

    Frequency or                  Class of
                    Subpart                                                Remarks
  frequency band                  station
                               RPC
 136.475 MHz        O, S       MA, FAC, FAW,    Air traffic control operations.
                               GCO, RCO,
                               RPC
 136.500–136.875 I             MA, FAE          Domestic VHF; 25 kHz channel spacing.
 MHz
 136.850 MHz        I          DLT.
 136.900 MHz        I          MA, FAE, DLT     International and Domestic VHF.
 136.925 MHz        I          MA, FAE, DLT     International and Domestic VHF.
 136.950 MHz        I          MA, FAE, DLT     International and Domestic VHF.
 136.975 MHz        I          MA, FAE, DLT     International and Domestic VHF.
 156.300 MHz        F          MA               For communications with ship stations under specific
                                                conditions.
 156.375 MHz        F          MA               For communications with ship stations under specific
                                                conditions; Not authorized in New Orleans Vessel traffic
                                                service area.
 156.400 MHz        F          MA               For communications with ship stations under specific
                                                conditions.
 156.425 MHz        F          MA               For communications with ship stations under specific
                                                conditions.
 156.450 MHz        F          MA               For communications with ship stations under specific
                                                conditions.
 156.625 MHz        F          MA               For communications with ship stations under specific
                                                conditions.
 156.800 MHz        F          MA               Distress, safety and calling frequency; For communications
                                                with ship stations under specific conditions.
 156.900 MHz        F          MA               For communications with ship stations under specific
                                                conditions.
 157.425 MHz        F          MA               For communications with commercial fishing vessels under
                                                specific conditions except in Great Lakes and St. Lawrence
                                                Seaway Areas.
 243.000 MHz        F          MA               Emergency and distress frequency for use of survival craft
                                                and emergency locator transmitters.
 328.600–335.400 Q             RLG              ILS glide path.
 MHz
 334.550 MHz        Q          RLT
 334.700 MHz        Q          RLT
 406.0–406.1        F, G, H,   MA, FAU, FAE,    Emergency and distress.
 MHz                I, J, K,   FAT, FAS, FAC,
                    M, O       FAM
 960–1215 MHz       F, Q       MA, RL, RNV      Electronic aids to air navigation.
 978.000 MHz        F, L, Q    MA, MOU, UAT Universal Access Transceivers.

47 CFR 87.173(b) (enhanced display)                                                                            page 44 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                    47 CFR 87.173(b)
Aviation Services

    Frequency or                    Class of
                    Subpart                                              Remarks
  frequency band                    station
                    UAT
                    Q          RLT
 979.000 MHz        Q          RLT
 1030.000 MHz       Q          RLT.
 1090.000 MHz       L          MOU, RLT        Vehicle Squitter.
 1104.000 MHz       Q          RLT
 1300–1350 MHz      F, Q       MA, RLS         Surveillance radars and transponders.
 1435–1525 MHz      F, J       MA, FAT         Aeronautical telemetry and telecommand operations.
 1559–1610 MHz      Q          DGP             Differential GPS.
 1559–1626.5        F, Q       MA, RL          Aeronautical radionavigation.
 MHz
 1646.5–1660.5      F          TJ              Aeronautical Mobile-Satellite (R).
 MHz
 2345–2395 MHz      J          MA, FAT         Aeronautical telemetry and telecommand operations.
 2700–2900 MHz      Q          RLS, RLD        Airport surveillance and weather radar.
 4200–4400 MHz      F          MA              Radio altimeters.
 5030–5150 MHz      Q          MA, RLW         Microwave landing systems.
 5031.000 MHz       Q          RLT
 5091–5150 MHz      J          MA, FAT         Aeronautical telemetry.
 5350–5470 MHz      F          MA              Airborne radars and associated airborne beacons.
 8750–8850 MHz      F          MA              Airborne doppler radar.
 9000–9200 MHz      Q          RLS, RLD        Land-based radar.
 9300–9500 MHz      F, Q       MA              Airborne radars and associated airborne beacons.
 13250–13400        F          MA              Airborne doppler radar.
 MHz
 15400–15700        Q          RL              Aeronautical radionavigation.
 MHz
 24450–24650        F, Q       MA, RL          Aeronautical radionavigation.
 MHz
 32300–33400        F, Q       MA, RL          Aeronautical radionavigation.
 MHz

[53 FR 28940, Aug. 1, 1988]

Editorial Note: For FEDERAL REGISTER citations affecting § 87.183, see the List of CFR Sections Affected, which
appears in the Finding Aids section of the printed volume and at www.govinfo.gov.

Subpart F—Aircraft Stations

47 CFR 87.173(b) (enhanced display)                                                                    page 45 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                          47 CFR 87.185
Aviation Services

§ 87.185 Scope of service.
     (a) Aircraft stations must limit their communications to the necessities of safe, efficient, and economic
         operation of aircraft and the protection of life and property in the air, except as otherwise specifically
         provided in this part. Contact with an aeronautical land station must only be attempted when the aircraft
         is within the serivce area of the land station. however, aircraft stations may transmit advisory information
         on air traffic control, unicom or aeronautical multicom frequencies for the benefit and use of other
         stations monitoring these frequencies in accordance with FAA recommended traffic advisory practices.

     (b) Aircraft public correspondence service must be made available to all persons without discrimination and
         on reasonable demand, and must communicate without discrimination with any public coast station or
         mobile-satellite earth station authorized to provide aircraft public correspondence service.

     (c) Aircraft public correspondence service on maritime mobile frequencies may only be carried by aircraft
         stations licensed to use maritime mobile frequencies and must follow the rules for public correspondence
         in part 80.

     (d) Aircraft public correspondence service on Aeronautical Mobile-Satellite (R) Service frequencies may only
         be carried on aircraft earth stations licensed to use Aeronautical Mobile-Satellite (R) frequencies and are
         subject to the rules for public correspondence in this part. Aircraft public correspondence service on
         Maritime Mobile-Satellite Service frequencies may only be carried by aircraft earth stations licensed to
         use Maritime Mobile-Satellite frequencies and are subject to the rules for public correspondence in part
         80.

[53 FR 28940, Aug. 1, 1988, as amended at 57 FR 45750, Oct. 5, 1992]

§ 87.187 Frequencies.
     (a) Frequencies used for air-ground Communications are listed in subpart E. Aircraft stations may use
         frequencies assigned to Government or non-Government aeronautical stations or radionavigation land
         stations if the communications are within the aeronautical or radionavigation land station scope of
         service.

     (b) 410 kHz is the international direction-finding frequency for use outside the continental United States.

     (c) 457 kHz is an authorized working frequency for flights over the high seas.

     (d) 500 kHz an international calling and distress frequency for aircraft on flights over the high seas. Except for
         distress, urgency or safety messages an aircraft station must not transmit on 500 kHz during the silence
         periods for three minutes twice each hour beginning at x h. 15 and x h.45 Coordinated Universal Time
         (u.t.c.).

     (e) The frequency 2182 khz is an international distress and calling frequency for use by ship, aircraft and
         survival craft stations. Aircraft stations must use J3E emission when operating on 2182 kHz and
         communicating with domestic public and private coast stations. The emission H3E may be used when
         communicating with foreign coast and ship stations.

     (f) The frequencies 3023 kHz, 5680 kHz, 122.900 MHz and 123.100 MHz are authorized for use by aircraft
         engaged in seach and rescue activities in accordance with subpart M. These frequencies may be used for
         air-air and air-ground communications.

     (g) The frequency 4125 kHz may be used for distress and safety communications between aircraft and ship
         and coast maritime mobile stations.
47 CFR 87.187(g) (enhanced display)                                                                       page 46 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                          47 CFR 87.187(h)
Aviation Services

     (h) The frequency 8364.0 kHz is authorized for use of survival craft for search and rescue communications
         with stations in the maritime mobile service.

      (i)   The frequencies in the band 121.975–122.675 MHz are authorized for use by private aircraft of air traffic
            control operations.

            (1) The frequencies 122.00 and 122.050 MHz are authorized for use by air carrier and private aircraft
                stations for enroute flight advisory service (EFAS) provided by the FAA;

            (2) The frequency 122.100 MHz is authorized for use by air carrier aircraft stations for air traffic control
                operations at locations in Alaska where other frequencies are not available for air traffic control.

      (j)   The frequency 122.750 MHz is authoried for use by private fixed wing aircraft for air-air communications.
            The frequency 123.025 MHz is authorized for use by helicopters for air-air Communications.

     (k) The frequencies 121.500 MHz and 243.000 MHz are emergency and distress frequences available for use
         by survival craft stations, emergency locator transmitters and equipment used for survival pruposes. Use
         of 121.500 MHz and 243.00 MHz shall be limited to transmission of signals and communications for
         survival purposes. Type A2A, A3E or A3N emission may be employed, except in the case of emergency
         locator transmitters where A3E, A3X and NON are permitted.

      (l)   The frequencies 156.300, 156.375, 156,400, 156,425, 156.450, 156.625, 156.800 156.900 and 157.425
            MHz may be used by aircraft stations to communicate with ship stations in accordance with part 80 and
            the following conditions:

            (1) The altitude of aircraft stations must not exceed 300 meters (1,000 feet), except for reconnaissance
                aircraft participating in icebreaking operations where an altitude of 450 meters (1,500 feet) is
                allowed;

            (2) Aircraft station transmitter power must not exceed five watts;

            (3) The frequency 156.300 MHz may be used for safety purposes only. The frequency 156.800 MHz may
                be used for distress, safety and calling purposes only.

            (4) Except in the Great Lakes and along the St. Lawrence Seaway the frequency 157.425 MHz is
                available for communications with commerical fishing vessels.

            (5) The frequency 156.375 MHz cannot be used in the New Orleans, LA, VTS protection area. No harmful
                interference shall be caused to the VTS.

     (m) The frequency 406.0–406.1 MHz is an emergency and distress frequency available for use by emergency
         locator transmitters. Use of this frequency must be limited to transmission of distress and safety
         communications.

     (n) The frequency band 960–1215 MHz is for the use of airborne electronic aids to air navigation and directly
         associated land stations.

     (o) The frequency band 1300-1350 MHz is for surveillance radar stations and associated airborne
         transponders.

     (p) The 1435–1525 MHz and 2360–2395 MHz bands are available on a primary basis, and the 2345–2360
         MHz band is available on a secondary basis (the latter band only until January 1, 2020), for telemetry and
         telecommand associated with the flight testing of aircraft, missiles, or related major components. This
         includes launching into space, reentry into the Earth's atmosphere and incidental orbiting prior to reentry.
         In the 1435–1525 MHz band, the following frequencies are shared on a co-equal basis with flight

47 CFR 87.187(p) (enhanced display)                                                                          page 47 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                       47 CFR 87.187(q)
Aviation Services

           telemetering mobile stations: 1444.5, 1453.5, 1501.5, 1515.5, and 1524.5 MHz. In the 2360–2395 MHz
           band, the following frequencies may be assigned for telemetry and associated telecommand operations
           of expendable and re-usable launch vehicles, whether or not such operations involve flight testing: 2364.5,
           2370.5 and 2382.5 MHz. See § 87.303(d).

           Note to paragraph (p): Aeronautical telemetry operations must protect Miscellaneous Wireless
           Communications Services operating in the 2345–2360 MHz band.

     (q) The frequencies in the band 1545.000–1559.000 MHz and 1646.500–1660.500 MHz are authorized for
         use by the Aeronautical Mobile-Satellite (R) Service. The use of the bands 1544.000–1545.000 MHz
         (space-to-Earth) and 1645.500–1646.500 MHz (Earth-to-space) by the Mobile-Satellite Service is limited
         to distress and safety operations. In the frequency bands 1549.500–1558.500 MHz and
         1651.000–1660.000 MHz, the Aeronautical Mobile-Satellite (R) requirements that cannot be
         accommodated in the 1545.000–1549.500 MHz, 1558.500–1559.000 MHz, 1646.500–1651.000 MHz,
         and 1660.000–1660.500 MHz bands shall have priority access with real-time preemptive capability for
         communications in the Mobile-Satellite Service. Systems not interoperable with the Aeronautical Mobile-
         Satellite (R) Service shall operate on a secondary basis. Account shall be taken of the priority of safety-
         related communications in the Mobile-Satellite Service.

     (r) The frequency band 1559–1626.5 MHz is available for airborne electronic aids to air navigation and any
         associated land station.

     (s) The frequency band 4200–4400 MHz is reserved exclusively for radio altimeters.

     (t) The frequency band 5350–5470 MHz in the aeronautical radionavigation service is limited to airborne
         radars and associated airborne beacons.

     (u) The frequency band 8750–8850 MHz is available for use by airborne doppler radars in the aeronautical
         radionavigation service only on the condition that they must accept any interference which may be
         experienced from stations in the radiolocation service in the band 8500–10,000 MHz.

     (v) The frequency band 9300–9500 MHz is limited to airborne radars and associated airborne beacons.

     (w) The frequency band 13250–13400 MHz available for airborne doppler radar use.

     (x) The frequency bands 24450–24650 MHz and 32300–33400 MHz are available for airborne
         radionavigation devices.

     (y) Brief keyed RF signals (keying the transmitter by momentarily depressing the microphone “push-to-talk”
         button) may be transmitted from aircraft for the control of automated unicoms on the unicom frequencies
         listed in paragraph (y)(3) of this section, or for the control of airport lights on the following frequencies:

           (1) Any air traffic control frequency listed in § 87.421.

           (2) FAA Flight Service Station frequencies 121.975–122.675 MHz.

           (3) The unicom frequencies 122.700, 122.725, 122.800, 122.950, 122.975, 123.000, 123.050 and
               123.075 MHz.

           (4) Aviation support station frequencies listed in § 87.323(b): 121.950, 123.300 and 123.500 MHz if the
               frequency is assigned to a station at the airport and no harmful interference is caused to voice
               communications. If no such station is located at the concerned airport, aircraft may use one of the
               aviation support station frequencies for the control of airport lights.

47 CFR 87.187(y)(4) (enhanced display)                                                                    page 48 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                        47 CFR 87.187(y)(5)
Aviation Services

              (5) The frequency 122.9 MHz when it is used as the common traffic advisory frequency at the concerned
                  airport.

         (z) Frequencies for public correspondence between ships and public coast stations in the maritime mobile
             service (except frequencies in the 156–174 MHz band) and coast earth stations in the maritime mobile-
             satellite service are available for public correspondence between aircraft and public coast stations and
             coast earth stations, respectively. The transmission of public correspondence from aircraft must not
             cause interference to maritime communications.

     (aa) Frequencies in the 454.675–459.975 MHz band are available in the Public Mobile Radio Service (part 22)
          for use on board aircraft for communications with land mobile stations which are interconnected to the
          nationwide public telephone system.

     (bb) The frequencies 121.950 MHz, 122.850 MHz and 127.050[1] MHz are authorized for air-to-air use for
          aircraft up to and including 3 km (10,000 ft) mean sea level in the vicinity of Grand Canyon National Park
          in Arizona within the area bounded by the following coordinates (all coordinates are referenced to North
          American Datum 1983 (NAD83)):

         36–27–59.9 N. Lat; 112–47–2.7 W. Long.

         36–27–59.9 N. Lat; 112–48–2.7 W. Long.

         35–50–00.0 N. Lat; 112–48–2.7 W. Long.

         35–43–00.0 N. Lat; 112–47–2.7 W. Long.

     (cc) The frequency 120.650 MHz1 is authorized for air-to-air use for aircraft up to and including 3 km (10,000
          ft) mean sea level within the area bounded by the following coordinates (all coordinates are referenced to
          North American Datum 1983 (NAD83)):

             35–59–44.9 N. Lat; 114–51–48.0 W. Long.

             36–09–29.9 N. Lat; 114–50–3.0 W. Long.

             36–09–29.9 N. Lat; 114–02–57.9 W. Long.

             35–54–45.0 N. Lat; 113–48–47.8 W. Long.
     (dd) The frequencies 136.425, 136.450, and 136.475 MHz are designated for flight information
          services—broadcast (FIS–B) and may not be used by aircraft for transmission.

     (ee) The frequency 121.95 MHz is authorized for air-to-ground and air-to-air communications for aircraft up to
          13000 feet above mean sea level (AMSL) within the area bounded by the following coordinates (all
          coordinates are referenced to North American Datum 1983 (NAD83)):

             32–35–00 N. Lat.; 117–12–00 W. Long.

   [1]
     Until further notice this frequency is available for air-to-air use as described in the Grand Canyon vicinity.
   Availability is a result of the FAA's assignment of this frequency. If the FAA reassigns this frequency the
   Commission may require air-to-air use to cease.

47 CFR 87.187(ee) (enhanced display)                                                                         page 49 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                       47 CFR 87.187(ff)
Aviation Services

           32–42–00 N. Lat.; 116–56–00 W. Long.

           32–41–00 N. Lat.; 116–41–00 W. Long.

           32–35–00 N. Lat.; 116–38–00 W. Long.

           32–31–00 N. Lat.; 117–11–00 W. Long.
     (ff) The frequency 978 MHz is authorized for Universal Access Transceiver data transmission.

    (gg)

           (1) The frequency 120.650 MHz is authorized for air-to-air communications for aircraft over and within
               five nautical miles of the shoreline of the Hawaiian Island of Maui.

           (2) The frequency 121.950 MHz is authorized for air-to-air use for aircraft over and within five nautical
               miles of the shoreline of the Hawaiian Island of Molokai.

           (3) The frequency 122.850 MHz is authorized for air-to-air use for aircraft over and within five nautical
               miles of the shoreline of the Hawaiian Island of Oahu.

           (4) The frequency 122.850 MHz is authorized for aircraft over and within five nautical miles of the
               shoreline of the Hawaiian Island of Hawaii when aircraft are south and east of the 215 degree radial
               of very high frequency omni-directional radio range of Hilo International Airport.

           (5) The frequency 127.050 MHz is authorized for air-to-air use for aircraft over and within five nautical
               miles of the shoreline of the Hawaiian Island of Hawaii when aircraft are north and west of the 215
               degree radial of very high frequency omni-directional radio range of Hilo International Airport.

           (6) The frequency 127.050 MHz is authorized for air-to-air use for aircraft over and within five nautical
               miles of the Hawaiian Island of Kauai.

    (hh)

           (1) The frequency 121.95 MHz is authorized for air-to-air communications for aircraft within the area
               bounded by the following coordinates (all coordinates are referenced to North American Datum 1983
               (NAD83)):

                33–46–00 N. Lat.; 118–27–00 W. Long.

                33–47–00 N. Lat.; 118–12–00 W. Long.

                33–40–00 N. Lat.; 118–00–00 W. Long.

                33–35–00 N. Lat.; 118–08–00 W. Long.

                34–00–00 N. Lat.; 118–26–00 W. Long.
           (2) The frequency 122.775 MHz is authorized for air-to-air communications for aircraft within the area
               bounded by the following coordinates (all coordinates are referenced to North American Datum 1983
               (NAD83)):

                34–22–00 N. Lat.; 118–30–00 W. Long.

47 CFR 87.187(hh)(2) (enhanced display)                                                                    page 50 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                              47 CFR 87.187(hh)(3)
Aviation Services

                34–35–00 N. Lat.; 118–15–00 W. Long.

                34–27–00 N. Lat.; 118–15–00 W. Long.

                34–16–00 N. Lat.; 118–35–00 W. Long.

                34–06–00 N. Lat.; 118–35–00 W. Long.

                34–05–00 N. Lat.; 118–50–00 W. Long.
           (3) The frequency 123.30 MHz is authorized for air-to-air communications for aircraft within the area
               bounded by the following coordinates (all coordinates are referenced to North American Datum 1983
               (NAD83)):

                34–08–00 N. Lat.; 118–00–00 W. Long.

                34–10–00 N. Lat.; 117–08–00 W. Long.

                34–00–00 N. Lat.; 117–08–00 W. Long.

                33–53–00 N. Lat.; 117–42–00 W. Long.

                33–58–00 N. Lat.; 118–00–00 W. Long.
           (4) The frequency 123.50 MHz is authorized for air-to-air communications for aircraft within the area
               bounded by the following coordinates (all coordinates are referenced to North American Datum 1983
               (NAD83)):

                33–53–00 N. Lat.; 117–37–00 W. Long.

                34–00–00 N. Lat.; 117–15–00 W. Long.

                34–00–00 N. Lat.; 117–07–00 W. Long.

                33–28–00 N. Lat.; 116–55–00 W. Long.

                33–27–00 N. Lat.; 117–12–00 W. Long.
           (5) The frequency 123.50 MHz is authorized for air-to-air communications for aircraft within the area
               bounded by the following coordinates (all coordinates are referenced to North American Datum 1983
               (NAD83)):

33–50–00 N. Lat.; 117–48–00 W. Long.

33–51–00 N. Lat.; 117–41–00 W. Long.

33–38–00 N. Lat.; 117–30–00 W. Long.

33–30–00 N. Lat.; 117–30–00 W. Long.

47 CFR 87.187(hh)(5) (enhanced display)                                                              page 51 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                                 47 CFR 87.189
Aviation Services

33–30–00 N. Lat.; 117–49–00 W. Long.

[53 FR 28940, Aug. 1, 1988]

Editorial Note: For FEDERAL REGISTER citations affecting § 87.187, see the List of CFR Sections Affected, which
appears in the Finding Aids section of the printed volume and at www.govinfo.gov.

§ 87.189 Requirements for public correspondence equipment and operations.
     (a) Transmitters used for public correspondence by aircraft stations in the maritime mobile frequency bands
         must be authorized by the Commission in conformity with part 80 of this chapter.

     (b) Transmitters used for public correspondence by aircraft stations in the Aeronautical Mobile-Satellite (R) or
         Maritime Mobile-Satellite frequencies must be certificated by the Commission in conformity with part 87.
         Aircraft earth stations that are required to be commissioned to use a privately owned satellite system also
         must meet the provisions of § 87.51.

     (c) A continuous watch must be maintained on the frequencies used for safety and regularity of flight while
         public correspondence communications are being handled. For aircraft earth stations, this requirement is
         satisfied by compliance with the priority and preemptive access requirements of § 87.187(q).

     (d) All communications in the Aeronautical Mobile Service and the Aeronautical Mobile-Satellite (R) Service
         have priority over public correspondence.

     (e) Transmission of public correspondence must be suspended when such operation will delay or interfere
         with message pertaining to safety of life and property or regularity of flight, or when ordered by the
         captain of the aircraft.

[53 FR 28940, Aug. 1, 1988, as amended at 57 FR 45750, Oct. 5, 1992; 63 FR 36608, July 7, 1998; 69 FR 32884, June 14, 2004]

§ 87.191 Foreign aircraft stations.
     (a) Aircraft of member States of the International Civil Aviation Organization may carry and operate radio
         transmitters in the United States airspace only if a license has been issued by the State in which the
         aircraft is registered and the flight crew is provided with a radio operator license of the proper class,
         issued or recognized by the State in which the aircraft is registered. The use of radio transmitters in the
         United States airspace must comply with these rules and regulations.

     (b) Notwithstanding paragraph (a) of this section where an agreement with a foreign government has been
         entered into with respect to aircraft registered in the United States but operated by an aircraft operator
         who is subject to regulation by that foreign government, the aircraft radio station license and aircraft radio
         operator license may be issued by such foreign government.

                                          EMERGENCY LOCATOR TRANSMITTERS

§ 87.193 Scope of service.
Transmissions by emergency locator transmitters (ELTs) are intended to be actuated manually or automatically and
operated automatically as part of an aircraft or a survival craft station as a locating aid for survival purposes.

47 CFR 87.193 (enhanced display)                                                                                  page 52 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                        47 CFR 87.195
Aviation Services

§ 87.195 121.5 MHz ELTs.
ELTs that operate only on frequency 121.5 MHz will no longer be certified. The manufacture, importation, and sale of
ELTs that operate only on frequency 121.5 MHz is prohibited beginning July 10, 2019. Existing ELTs that operate
only on frequency 121.5 MHz must be operated as certified.

[83 FR 63812, Dec. 12, 2018]

§ 87.197 ELT test procedures.
ELT testing must avoid outside radiation. Bench and ground tests conducted outside of an RF-shielded enclosure
must be conducted with the ELT terminated into a dummy load.

§ 87.199 Special requirements for 406.0–406.1 MHz ELTs.
     (a) 406.0–406.1 MHz ELTs use G1D emission. Except for the spurious emission limits specified in §
         87.139(h), 406.0–406.1 MHz ELTs must meet all the technical and performance standards contained in
         the Radio Technical Commission for Aeronautics document titled “Minimum Operational Performance
         Standards 406 MHz Emergency Locator Transmitters (ELT)” Document No. RTCA/DO–204 dated
         September 29, 1989. Document No. RTCA/DO–204 is incorporated by reference into this the section with
         the approval of the Director of the Federal Register in accordance with 5 U.S.C 552(a) and 1 CFR part 51.
         This incorporation by reference (IBR) material is available for inspection at the FCC and at the National
         Archives and Records Administration (NARA). Contact the FCC through the Federal Communications
         Commission's Reference Information Center, phone: (202) 418–0270. For information on the availability
         of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations.html or email
         fr.inspection@nara.gov. The material may be obtained from the Radio Technical Commission for
         Aeronautics (RTCA), Inc., 1150 18th Street NW, Suite 910, Washington, DC 20036; phone: (202) 833–9339;
         email: info@rtca.org; website: www.rtca.org.

     (b) The 406.0–406.1 MHz ELT must contain as an integral part a homing beacon operating only on 121.500
         MHz that meets all the requirements described in the RTCA Recommended Standards document
         described in paragraph (a) of this section. The 121.500 MHz homing beacon must have a continuous duty
         cycle that may be interrupted during the transmission of the 406.0–406.1 MHz signal only.

     (c) As part of its Supplier's Declaration of Conformity a 406.0–406.1 MHz ELT, the ELT must be certified by a
         test facility recognized by one of the COSPAS/SARSAT Partners that the equipment satisfies the design
         characteristics associated with the COSPAS/SARSAT document COSPAS/SARSAT 406 MHz Distress
         Beacon Type Approval Standard (C/S T.007). Additionally, an independent test facility must certify that the
         ELT complies with the electrical and environmental standards associated with the RTCA Recommended
         Standards.

           Note 1 to paragraph (c): The verification procedure has been replaced by Supplier's Declaration of
           Conformity. Equipment previously authorized under subpart J of part 2 of this chapter may remain
           in use. See § 2.950 of this chapter.

     (d) The procedures for Supplier's Declaration of Conformity are contained in subpart J of part 2 of this
         chapter.

47 CFR 87.199(d) (enhanced display)                                                                      page 53 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                              47 CFR 87.199(e)
Aviation Services

     (e) An identification code, issued by the National Oceanic and Atmospheric Administration (NOAA), the
         United States Program Manager for the 406.0–406.1 MHz COSPAS/SARSAT satellite system, must be
         programmed in each ELT unit to establish a unique identification for each ELT station. With each
         marketable ELT unit the manufacturer or grantee must include a postage pre-paid registration card printed
         with the ELT identification code addressed to: NOAA/SARSAT Beacon Registration, NSOF, E/SPO53, 1315
         East West Hwy, Silver Spring, MD 20910–9684. The registration card must request the owner's name,
         address, telephone, type of aircraft, alternate emergency contact, and other information as required by
         NOAA. The registration card must also contain information regarding the availability to register the ELT at
         NOAA's online Web-based registration database at: http://www.beaconregistration.noaa.gov. Further, the
         following statement must be included: “WARNING—failure to register this ELT with NOAA before
         installation could result in a monetary forfeiture being issued to the owner.”

     (f) To enhance protection of life and property, it is mandatory that each 406.0–406.1 MHz ELT must be
         registered with NOAA before installation and that information be kept up-to-date. In addition to the
         identification plate or label requirements contained in §§ 2.925 and 2.926 of this chapter, each
         406.0–406.1 MHz ELT must be provided on the outside with a clearly discernable permanent plate or label
         containing the following statement: “The owner of this 406.0–406.1 MHz ELT must register the NOAA
         identification code contained on this label with the National Oceanic and Atmospheric Administration
         (NOAA), whose address is: NOAA/SARSAT Beacon Registration, NSOF, E/SPO53, 1315 East West Hwy,
         Silver Spring, MD 20910–9684.” Aircraft owners shall advise NOAA in writing upon change of aircraft or
         ELT ownership, or any other change in registration information. Fleet operators must notify NOAA upon
         transfer of ELT to another aircraft outside of the owner's control, or any other change in registration
         information. NOAA will provide registrants with proof of registration and change of registration postcards.

     (g) For 406.0–406.1 MHz ELTs whose identification code can be changed after manufacture, the
         identification code shown on the plant or label must be easily replaceable using commonly available
         tools.

[69 FR 32885, June 14, 2004, as amended at 76 FR 17352, Mar. 29, 2011; 79 FR 77918, Dec. 29, 2014; 82 FR 50838, Nov. 2, 2017;
85 FR 64410, Oct. 13, 2020; 88 FR 21449, Apr. 10, 2023]

Subpart G—Aeronautical Advisory Stations (Unicoms)
§ 87.213 Scope of service.
     (a) An aeronautical advisory station (unicom) must provide service to any aircraft station upon request and
         without discrimination. A unicom must provide impartial information concerning available ground
         services.

     (b)

           (1) Unicom transmissions must be limited to the necessities of safe and expeditious operation of
               aircraft such as condition of runways, types of fuel available, wind conditions, weather information,
               dispatching, or other necessary information. At any airport at which a control tower, control tower
               remote communications outlet station (RCO) or FAA flight service station is located, unicoms must
               not transmit information pertaining to the conditions of runways, wind conditions, or weather
               information during the hours of operation of the control tower, RCO or FAA service station.

           (2) On a secondary basis, unicoms may transmit communications which pertain to the efficient portal-
               to-portal transit of an aircraft, such as requests for ground transportation, food or lodging.

47 CFR 87.213(b)(2) (enhanced display)                                                                           page 54 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                    47 CFR 87.213(b)(3)
Aviation Services

           (3) Communications between unicoms and air carrier must be limited to the necessities of safety of life
               and property.

           (4) Unicoms may communicate with aeronautical utility stations and ground vehicles concerning runway
               conditions and safety hazards on the airport when neither a control tower nor FAA flight service
               station is in operation.

     (c) Unicoms must not be used for air traffic control (ATC) purposes other than to relay ATC information
         between the pilot and air traffic controller. Relaying of ATC information is limited to the following:

           (1) Revisions of proposed departure time;

           (2) Takeoff, arrival or flight plan cancellation time;

           (3) ATC clearances, provided a letter of agreement is obtained from the FAA by the licensee of the
               unicom.

[53 FR 28940, Aug. 1, 1988, as amended at 55 FR 30464, July 26, 1990]

§ 87.215 Supplemental eligibility.
     (a) A unicom and any associated dispatch or control points must be located on the airport to be served.

     (b) Only one unicom will be authorized to operate at an airport which does not have a control tower, RCO or
         FAA flight service station that operates on the published common traffic advisory frequency. At any other
         airport, the one unicom limitation does not apply, and the airport operator and all aviation services
         organizations may be licensed to operate a unicom on the assigned frequency.

     (c) At an airport where only one unicom may be licensed, eligibility for new unicom licenses is restricted to
         State or local government entities, and to nongovernmental organizations (NGOs) that are authorized to
         apply for the license by a State or local government entity whose primary mission is the provision of
         public safety services. All applications submitted by NGOs must be accompanied by a new, written
         certification of support (for the NGO applicant to operate the applied for station) by the state or local
         government entity. Applications for a unicom license at the same airport, where only one unicom may be
         licensed, that are filed by two or more applicants meeting these eligibility criteria must be resolved
         through settlement or technical amendment.

     (d) At an airport where only one unicom may be licensed, the license may be assigned or transferred only to
         an entity meeting the requirements of paragraph (c) of this section.

     (e) An applicant for renewal of a unicom license shall be granted a presumptive renewal expectancy
         regardless of whether the applicant is eligible for a new unicom license under paragraph (c) of this
         section. Unless the renewal expectancy is defeated, applications that are mutually exclusive with the
         renewal application will not be accepted. The renewal expectancy may be defeated only upon a
         determination, following a hearing duly designated on the basis of a petition to deny or on the
         Commission's own motion, that the renewal applicant has not provided substantial service. For purposes
         of this paragraph, substantial service means service which is sound, favorable, and substantially above a
         level of mediocre service during the applicant's past license term. If the renewal expectancy is defeated,
         the renewal application will be dismissed unless the renewal applicant is eligible for a new unicom license
         pursuant to paragraph (c) of this section.

47 CFR 87.215(e) (enhanced display)                                                                       page 55 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                              47 CFR 87.215(f)
Aviation Services

     (f) At an airport where only one unicom may be licensed, when the Commission believes that the unicom has
         been abandoned or has ceased operation, another unicom may be licensed on an interim basis pending
         final determination of the status of the original unicom. An applicant for an interim license must notify the
         present licensee and must comply with the notice requirements of paragraph (g) of this section.

     (g) An applicant for a unicom license, renewal or modification of frequency assignment at an airport which
         does not have a control tower, RCO or FAA flight service station must notify in writing the owner of the
         airport and all aviation service organizations located at the airport. The notice must include the
         applicant's name and address, the name of the airport and a statement that the applicant intends to file
         an application with the Commission for a unicom. The notice must be given within the ten days preceding
         the filing of the application with the Commission. Each applicant must certify upon application that either
         notice has been given and include the date of notification, or notice is not required because the applicant
         owns the airport and there are no organizations that should be notified.

[53 FR 28940, Aug. 1, 1988, as amended at 55 FR 30464, July 26, 1990; 63 FR 68957, Dec. 14, 1998; 69 FR 32885, June 14, 2004;
76 FR 17352, Mar. 29, 2011]

§ 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]

§ 87.219 Automatic operations.
     (a) A station operator need not be present when an automated unicom is in operation.

     (b) Unicoms operating in an automated mode must comply with the requirements of paragraphs (1)–(5) of
         this section, in addition to the requirements applicable to non-automated unicom operations.

           (1) An automated unicom must transmit only in response to interrogating signals from aircraft, including
               but not limited to the brief keyed RF signals specified in § 87.187(y).

           (2) An automated unicom must monitor the unicom frequency prior to transmission, and provide a brief
               delay between the aircraft's interrogating signal and the automatic unicom's response.

           (3) Automated advisory transmissions must be as brief as possible, and must never exceed one minute
               in length.

           (4) An automated unicom may not provide weather information at an airport that has an operational,
               FAA-certified, automatic weather facility, unless the unicom itself is certified by the FAA.

           (5) If weather information is provided by an automated unicom:

                 (i)   Weather sensors must be placed in order to adequately represent the weather conditions at the
                       airport(s) to be served;
47 CFR 87.219(b)(5)(i) (enhanced display)                                                                        page 56 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                  47 CFR 87.219(b)(5)(ii)
Aviation Services

                 (ii) The weather information must be proceeded by the word “advisory;”

                (iii) The phrase “automated advisory” must be included when the weather information was gathered
                      by real-time sensors or within the last minute; and,

                (iv) The time and date of the last update must be included when the weather information was not
                     gathered within the last minute.

     (c) Only one automated unicom may be operated at an uncontrolled airport. Prior to the operation of an
         automated unicom at an airport with more than one unicom licensee, all of the licensees at that airport
         must sign a letter of agreement stating which licensee(s) control the automated unicom operations, and,
         if control is to be shared among several operators, how that control will be divided or scheduled. The
         original or a copy of the letter of agreement must be kept with each licensees' station records. Within 90
         days of the date upon which a new unicom operator is licensed at an airport where more than one unicom
         is authorized, and an automated unicom is being operated, an amended letter of agreement that includes
         the new licensee's signature must be signed or automated unicom operations must cease.

[64 FR 27475, May 20, 1999]

Subpart H—Aeronautical Multicom Stations
§ 87.237 Scope of service.
     (a) The communications of an aeronautical multicom station (multicom) must pertain to activities of a
         temporary, seasonal or emergency nature involving aircraft in flight. Communications are limited to
         directing or coordinating ground activities from the air or aerial activities from the ground. Air-to-air
         communications will be authorized if the communications are directly connected with the air-to-ground or
         ground-to-air activities described above. Multicom communications must not include those air/ground
         communications provided for elsewhere in this part.

     (b) If there is not unicom and an applicant is unable to meet the requirements for a unicom license, the
         applicant will be eligible for a multicom license.

           (1) The multicom license becomes invalid when a unicom is established at the landing area.

           (2) Multicoms must not be used for ATC purposes other than the relay of ATC information between the
               pilot and air traffic controller. Relaying of ATC information is limited to the following:

                 (i)   Revisions of proposed departure time;

                 (ii) Takeoff, arrival flight plan cancellation time;

                (iii) ATC clearances, provided a letter of agreement is obtained from the FAA by the licensee of the
                      multicom.

           (3) Communications by a multicom must be limited to the safe and expeditious operation of private
               aircraft, pertaining to the conditions of runways, types of fuel available, wind conditions, weather
               information, dispatching or other information. On a secondary basis, multicoms may transmit
               communictions which pertain to efficient portal-to-portal transit of an aircraft such as requests for
               ground transportation, food or lodging.

47 CFR 87.237(b)(3) (enhanced display)                                                                     page 57 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                          47 CFR 87.239
Aviation Services

§ 87.239 Supplemental eligibility.
Each applicant for a multicom may be required to demonstrate why such a station is necessary, based on the scope
of service defined above.

[63 FR 68957, Dec. 14, 1998]

§ 87.241 Frequencies.
     (a) 121.500 MHz: emergency and distress only;

     (b) 122.850 or 122.900 MHz;

     (c) 122.925 MHz: available for assignment to communicate with aircraft when coordinating foresty
         management and fire suppression, fish and game management and protection, and environmental
         monitoring and protection.

Subpart I—Aeronautical Enroute Stations, Aeronautical Fixed Stations, and Aircraft Data Link
Land Test Stations

                                              AERONAUTICAL ENROUTE STATIONS

§ 87.261 Scope of service.
     (a) Aeronautical enroute stations provide operational control communications to aircraft along domestic or
         international air routes. Operational control communications include the safe, efficient and economical
         operation of aircraft, such as fuel, weather, position reports, aircraft performance, and essential services
         and supplies. Public correspondence is prohibited.

     (b) Service must be provided to any aircraft station licensee who makes cooperative arrangements for the
         operation, maintenance and liability of the stations which are to furnish enroute service. In emergency or
         distress situations service must be provided without prior arrangements.

     (c) Except in Alaska, only one aeronautical enroute station licensee will be authorized at any one location. In
         Alaska, only one aeronautical enroute station licensee in the domestic service and one aeronautical
         enroute station licensee in the international service will be authorized at any one location. (Because
         enroute stations may provide service over a large area containing a number of air routes or only provide
         communications in the local area of an airport, location here means the area which can be adequately
         served by the particular station.)

     (d) In Alaska, only stations which serve scheduled air carriers will be licensed to operate aeronautical enroute
         stations. Applicants must show that the station will provide communications only along routes served by
         scheduled air carriers.

     (e) Mobile units may be operated under an aeronautical enroute station authorization so long as the units are
         limited to use at an airport and are only used to communicate with aircraft on the ground or the
         associated aeronautical enroute station. Mobile units are further limited to operation on the VHF
         frequencies listed in 87.263(a)(1).

     (f) Mobile units licensed under paragraph (e) of this section shall not be operated on air traffic control
         frequencies, nor cause harmful interference to, communications on air traffic control frequencies.

47 CFR 87.261(f) (enhanced display)                                                                        page 58 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                         47 CFR 87.263
Aviation Services

[53 FR 28940, Aug. 1, 1988, as amended at 64 FR 27476, May 20, 1999]

§ 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.

           (4) In Alaska, the frequencies 131.500, 131.600, 131.800 and 131.900 MHz may be assigned to
               aeronautical enroute stations without regard to the restrictions contained in § 87.261 (c) and (d).

           (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:

          kHz
           (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.

47 CFR 87.263(b)(3)(i) (enhanced display)                                                                 page 59 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                  47 CFR 87.263(b)(3)(ii)
Aviation Services

                                                                   kHz

                       2866.0                                          5631.0

                 (ii) Alaska Aleutian chain and feeders.

                                                                   kHz

                       2911.0                                       8855.0
                       2956.0                                       10066.0
                       5496.0                                       11363.0
                       6580.0

                (iii) Central and Southeast Alaska and feeders.

                                                                   kHz

                       2875.0                                       6580.0
                       2911.0                                       6604.0
                       3470.0                                       8876.0
                       5484.0                                       11357.0

                (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.

                                                                   kHz

                       3449.0                                             5472.0
                       5167.51                                            5490.0

                      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.

47 CFR 87.263(c) (enhanced display)                                                                        page 60 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                        47 CFR 87.263(d)
Aviation Services

     (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:

47 CFR 87.263(d) (enhanced display)                                                                         page 61 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                        47 CFR 87.263(d)(1)
Aviation Services

           (1) Central East Pacific (CEP):

                                              kHz

                 2869.0                       8843.0
                 3413.0                       10057.0
                 4657.0                       11282.0
                 5547.0                       13300.0
                 5574.0                       17904.0
                 6673.0

           (2) Central West Pacific (CWP):

                                              kHz

                 2998.0                       6562.0
                 3455.0                       8903.0
                 4666.0                       10081.0
                 5652.0                       11384.0
                 5661.0                       13300.0
                 6532.0                       17904.0

           (3) North Pacific (NP):

                                              kHz

                 2932.0                       10048.0
                 5628.0                       11330.0
                 6655.0                       13300.0
                 6661.0                       17904.0

           (4) South Pacific (SP):

                                              kHz

                 3467.0                       10084.0
                 5559.0                       11327.0
                 5643.0                       13300.0
                 8867.0                       17904.0

           (5) North Atlantic (NAT):

47 CFR 87.263(d)(5) (enhanced display)                        page 62 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                        47 CFR 87.263(d)(6)
Aviation Services

                                              kHz

                 2872.0                       8825.0
                 2899.0                       8831.0
                 2962.0                       8864.0
                 2971.0                       8879.0
                 3016.0                       8891.0
                 3476.0                       8906.0
                 4675.0                       11279.0
                 5598.0                       11309.0
                 5616.0                       11336.0
                 5649.0                       13291.0
                 6622.0                       13306.0
                 6628.0                       17946.0

           (6) Europe (EUR):

                                              kHz

                 3479.0                       10084.0
                 5661.0                       13288.0
                 6598.0                       17961.0

           (7) South America (SAM):

                                              kHz

                 2944.0                       10024.0
                 3479.0                       10096.0
                 4669.0                       11360.0
                 5526.0                       13297.0
                 6649.0                       17907.0
                 8855.0

           (8) South Atlantic (SAT):

                                              kHz

                 2854.0                       8861.0
                 2935.0                       11291.0
                 3452.0                       13315.0
                 5565.0                       13357.0

47 CFR 87.263(d)(8) (enhanced display)                        page 63 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                        47 CFR 87.263(d)(9)
Aviation Services

                 6535.0                       17955.0

           (9) Southeast Asia (SEA):

                                              kHz

                 3470.0                       10066.0
                 3485.0                       11396.0
                 5649.0                       13309.0
                 5655.0                       13318.0
                 6556.0                       17907.0
                 8942.0

          (10) East Asia (EA):

                                              kHz

                 3016.0                       10042.0
                 3485.0                       11396.0
                 3491.0                       13297.0
                 5655.0                       13303.0
                 5670.0                       13309.0
                 6571.0                       17907.0
                 8897.0

          (11) Middle East (MID):

                                              kHz

                 2944.0                       6631.0
                 2992.0                       8918.0
                 3467.0                       8951.0
                 3473.0                       10018.0
                 4669.0                       11375.0
                 5658.0                       13288.0
                 5667.0                       13312.0
                 6625.0                       17961.0

          (12) Africa (AFI):

47 CFR 87.263(d)(12) (enhanced display)                       page 64 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                        47 CFR 87.263(d)(13)
Aviation Services

                                              kHz

                 2851.0                       6673.0
                 2878.0                       8894.0
                 3419.0                       8903.0
                 3425.0                       8894.0
                 3467.0                       11300.0
                 4657.0                       11330.0
                 5493.0                       13273.0
                 5652.0                       13288.0
                 5658.0                       13294.0
                 6559.0                       17961.0
                 6574.0

          (13) Indian Ocean (INO):

                                              kHz

                 3476.0                       13306.0
                 5634.0                       17961.0
                 8879.0

          (14) North Central Asia (NCA):

                                              kHz

                 3004.0                       6592.0
                 3019.0                       10096.0
                 4678.0                       13303.0
                 5646.0                       13315.0
                 5664.0                       17958.0

          (15) Caribbean (CAR):

                                              kHz

                 2887.0                       8846.0
                 3455.0                       8918.0
                 5520.0                       11387.0
                 5550.0                       11396.0
                 6577.0                       13297.0
                 6586.0                       17907.0

47 CFR 87.263(d)(15) (enhanced display)                        page 65 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                             47 CFR 87.263(e)
Aviation Services

     (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).

                                                              kHz

            3013.0                                                10075.0
            3494.0                                                11342.0
            5529.0                                                11348.0
            5538.0                                                13330.0
            6637.0                                                13348.0
            6640.0                                                17925.0
            8933.0                                                21964.0
            10033.0

     (f) 121.500 MHz: Emergency and distress only.

[53 FR 28940, Aug. 1, 1988, as amended at 54 FR 11721, Mar. 22, 1989; 55 FR 28628, July 12, 1990; 56 FR 21084, May 7, 1991; 58
FR 44954, Aug. 25, 1993; 66 FR 26800, May 15, 2001; 76 FR 17352, Mar. 29, 2011]

§ 87.265 Administrative communications.
Domestic VHF aeronautical enroute stations authorized to use A9W emission on any frequency listed in §
87.263(a)(1) or § 87.263(a)(3) may transmit digital administrative communications on a secondary basis, in
addition to the operational and control communications routinely permitted under § 87.261(a) above. Such
secondary administrative communications must directly relate to the business of a participating aircraft operator in
providing travel and transportation services to the flying public or to the travel, transportation or scheduling
activities of the aircraft operator itself. Stations transmitting administrative communications must provide absolute
priority for operational control and other safety communications by means of an automatic priority control system.

[54 FR 11721, Mar. 22, 1989]

                                              AERONAUTICAL FIXED STATIONS

§ 87.275 Scope of service.
Aeronautical fixed stations provide non-public point-to-point communications service pertaining to safety, regularity
and economy of flight. These stations must transmit, without discrimination, messages from aircraft which have
entered into cooperative arrangements governing the operation and maintenance of such stations. Aeronautical
fixed station licensees are required to transmit, without charge or discrimination, all emergency communications.

§ 87.277 Supplemental eligibility.
Aeronautical fixed station licenses will only be issued to the licensees of associated aeronautical enroute stations.
Aeronautical fixed station licenses will not be issued where adequate land line facilities are available.

47 CFR 87.277 (enhanced display)                                                                                 page 66 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                         47 CFR 87.279
Aviation Services

§ 87.279 Frequencies.
     (a) United States (except Alaska). The applicant must request specific frequencies in accordance with §
         2.106 of this chapter. The Commission will determine the suitability of the applicant's selection based on
         the probability of interference to and from existing services assigned on the same or adjacent
         frequencies. All new assignments of frequencies will be subject to such conditions as may be required to
         minimize the possibility of harmful interference to existing services.

     (b) Alaska.

           (1) Only stations which serve scheduled air carriers will be licensed. Applicants must show that the
               station will provide communications only along routes served by the scheduled operations of such
               carriers.

           (2) The following frequencies are available in Alaska. These frequencies will only be licensed in
               conjunction with licenses for use of the aeronautical enroute frequencies specified in § 87.263(c).

                                                                kHz

                 2648.0                                             5310.0
                 4645.0                                             5887.5
                 4947.5                                             8015.0
                 5122.5

     (c) Gulf of Mexico. In addition to the provisions of paragraph (a) of this section, the frequencies 4550.0 and
         5036.0 kHz are available in the Gulf of Mexico.

                                       AIRCRAFT DATA LINK LAND TEST STATIONS

§ 87.285 Scope of service.
     (a) Frequencies. The frequencies indicated in § 87.287 may be used to test aircraft data link systems on a
         secondary basis to other licensed stations. Equipment must be designed so that it will engage in data link
         exchange only with the aircraft whose identification has been programmed into the device, and must
         comply with the applicable specifications for VDL Mode 2 operation set forth in the ICAO “Manual on VHF
         Digital Link (VDL) Mode 2” and RTCA DO–281A.

     (b) Incorporation by reference. The material listed in this paragraph (b) is incorporated by reference into this
         section with the approval of the Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51.
         This incorporation by reference (IBR) material is available for inspection at the FCC and at the National
         Archives and Records Administration (NARA). Contact the FCC through the Federal Communications
         Commission's Reference Information Center, phone: (202) 418–0270. For information on the availability
         of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations.html or email
         fr.inspection@nara.gov. The material may be obtained from the following sources in this paragraph (b):

           (1) ICAO, Customer Services Unit, 999 University Street, Montréal, Quebec H3C 5H7, Canada; email:
               icaohq@icao.int; website: www.ICAO.int.

                 (i)   ICAO “Manual on VHF Digital Link (VDL) Mode 2” First Edition-2001.

47 CFR 87.285(b)(1)(i) (enhanced display)                                                                 page 67 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                    47 CFR 87.285(b)(1)(ii)
Aviation Services

                 (ii) [Reserved]

           (2) Radio Technical Commission for Aeronautics (RTCA), Inc., 1150 18th Street NW, Suite 910,
               Washington, DC 20036; phone: (202) 833–9339; email: info@rtca.org; website: www.rtca.org.

                 (i)   RTCA DO–281A, “Minimum Operational Performance Standards for Aircraft VDL Mode 2
                       Physical, Link and Network Layer”, November 8, 2005.

                 (ii) [Reserved]

[88 FR 21449, Apr. 10, 2023]

§ 87.287 Frequencies.
     (a) The frequencies assignable to aircraft data link land test stations are 131.450 MHz, 131.550 MHz,
         131.725 MHz, 131.825 MHz, 136.850 MHz, 136.900 MHz, 136.925 MHz, 136.950 MHz, and 136.975 MHz.
         Interstitial frequencies separated by 8.33 kilohertz from these frequencies may also be assigned.

     (b) Before submitting an application for an aircraft data link land test station, an applicant must obtain written
         permission from the licensee of the aeronautical enroute stations serving the areas in which the aircraft
         data link land test station will operate on a co-channel basis. The Commission may request an applicant
         to provide documentation as to this fact.

[78 FR 61207, Oct. 3, 2013]

Subpart J—Flight Test Stations
§ 87.299 Scope of service.
The use of flight test stations is restricted to the transmission of necessary information or instructions relating
directly to tests of aircraft or components thereof.

§ 87.301 Supplemental eligibility.
     (a) The following entities are eligible for flight test station licenses:

           (1) Manufacturers of aircraft or major aircraft components;

           (2) A parent corporation or its subsidiary if either corporation is a manufacturer of aircraft or major
               aircraft components; or

           (3) Educational institutions and persons primarily engaged in the design, development, modification, and
               flight test evaluation of aircraft or major aircraft components.

     (b) Each application must include a certification sufficient to establish the applicant's eligibility under the
         criteria in paragraph (a) of this section.

[53 FR 28940, Aug. 1, 1988, as amended at 63 FR 68957, Dec. 14, 1998]

47 CFR 87.301(b) (enhanced display)                                                                          page 68 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                            47 CFR 87.303
Aviation Services

§ 87.303 Frequencies.
     (a) These frequencies are available for assignment to flight test land and aircraft stations:

                      kHz                     MHz                        MHz                       MHz
                            3281.01                 123.1752                    123.2253                 123.4002
                                                    123.2003                    123.3753                 123.4503

     (b) These additional frequencies are available for assignment only to flight test stations of aircraft
         manufacturers:

                      MHz                      MHz                        MHz                      MHz
                               2                        3                          3
                     123.125                  123.275                    123.425                 123.5503
                     123.1502                 123.3253                   123.4753                123.5752
                     123.2503                 123.3503                   123.5253

           1When R3E, H3E or J3E emission is used, the assigned frequency will be 3282.4 kHz (3281.0 kHz
           carrier frequency).

           2 This frequency is available only to itinerant stations that have a requirement to be periodically
           transferred to various locations.

           3Mobile station operations on these frequencies are limited to an area within 320 km (200 mi) of
           an associated flight test land station.

     (c) These frequencies are available for equipment test, emergency and backup use with aircraft beyond the
         range of VHF propagation. Either H2B, J3E, J7B or J9W emission may be used.

           Frequencies (carrier) available kHz:

                                                            kHz

            2851.0                                             8822.0
            3004.0                                             10045.0
            3443.0                                             11288.0
            5451.0                                             11306.0
            5469.0                                             13312.0
            5571.0                                             17964.0
            6550.0                                             21931.0

     (d) Aeronautical mobile telemetry (AMT) operations are conducted in the 1435–1525 MHz, 2345–2395 MHz,
         and 5091–5150 MHz bands on a co-equal basis with U.S. Government stations.

           (1) Frequencies in the 1435–1525 MHz and 2360–2395 MHz bands are assigned in the mobile service
               primarily for aeronautical telemetry and associated telecommand operations for flight testing of
               aircraft and missiles, or their major components. Until January 1, 2020, the 2345–2360 MHz band is

47 CFR 87.303(d)(1) (enhanced display)                                                                        page 69 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                           47 CFR 87.303(d)(2)
Aviation Services

                also available to licensees holding a valid authorization on April 23, 2015 for these purposes on a
                secondary basis. Permissible uses of these bands include telemetry and associated telecommand
                operations associated with the launching and reentry into the Earth's atmosphere, as well as any
                incidental orbiting prior to reentry, of objects undergoing flight tests. In the 1435–1525 MHz band,
                the following frequencies are shared on a co-equal basis with flight telemetering mobile stations:
                1444.5, 1453.5, 1501.5, 1515.5, and 1524.5 MHz. In the 2360–2395 MHz band, the following
                frequencies may be assigned for telemetry and associated telecommand operations of expendable
                and re-usable launch vehicles, whether or not such operations involve flight testing: 2364.5, 2370.5
                and 2382.5 MHz. All other mobile telemetry uses of the 2360–2395 MHz band shall be on a non-
                interfering and unprotected basis to the above uses.

           (2) Frequencies in the 5091–5150 MHz band are assigned in the aeronautical mobile service on a
               primary basis for flight testing of aircraft. AMT use of these frequencies is restricted to aircraft
               stations transmitting to aeronautical stations (AMT ground stations) in the flight test areas listed in
               47 CFR 2.106, footnote US111.

           (3) The authorized bandwidths for stations that operate in the 1435–1525 MHz, 2345–2395 MHz, or
               5091–5150 MHz bands are normally 1, 3 or 5 MHz. Applications for greater bandwidths will be
               considered in accordance with the provisions of § 87.135. Each assignment will be centered on a
               frequency between 1435.5 MHz and 1524.5 MHz, between 2345.5 MHz and 2394.5 MHz, or between
               5091.5 MHz and 5149.5 MHz, with 1 MHz channel spacing.

           (4) Frequencies in the bands 1435–1525 MHz are also available for low power auxiliary station use on a
               secondary basis.

     (e) 121.500 MHz: Emergency and distress only.

     (f) Frequency assignments for Flight Test VHF Stations may be based on either 8.33 kHz or 25 kHz spacing.
         Assignable frequencies include the interstitial frequencies 8.33 kHz from the VHF frequencies listed in
         paragraphs (a) and (b) of this section. Each 8.33 kHz interstitial frequency is subject to the same eligibility
         criteria and limitations as the nearest frequency listed in paragraphs (a) and (b) of this section.

[53 FR 28940, Aug. 1, 1988, as amended at 55 FR 4175, Feb. 7, 1990; 58 FR 44954, Aug. 25, 1993; 58 FR 67696, Dec. 22, 1993; 60
FR 37829, July 24, 1995; 62 FR 11107, Mar. 11, 1997; 68 FR 74388, Dec. 23, 2003; 69 FR 77950, Dec. 29, 2004; 71 FR 29818, May
24, 2006; 76 FR 17352, Mar. 29, 2011; 80 FR 38910, July 7, 2015; 80 FR 71731, Nov. 17, 2015; 82 FR 41562, Sept. 1, 2017]

§ 87.305 Frequency coordination.
     (a)

           (1) Each application for a new station license, renewal or modification of an existing license concerning
               flight test frequencies, except as provided in paragraph (b) of this section, must be accompanied by
               a statement from a frequency advisory committee. The committee must comment on the
               frequencies requested or the proposed changes in the authorized station and the probable
               interference to existing stations. The committee must consider all stations operating on the
               frequencies requested or assigned within 320 km (200 mi) of the proposed area of operation and all
               prior coordinations and assignments on the proposed frequency(ies). The committee must also
               recommend frequencies resulting in the minimum interference. The committee must coordinate in
               writing all requests for frequencies or proposed operating changes in the 1435–1525 MHz,
               2345–2360 MHz (only until January 1, 2020), 2360–2395 MHz, and 5091–5150 MHz bands with the
               responsible Government Area Frequency Coordinators listed in the NTIA “Manual of Regulations and

47 CFR 87.305(a)(1) (enhanced display)                                                                            page 70 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                           47 CFR 87.305(a)(2)
Aviation Services

                Procedures for Federal Radio Frequency Management.” In addition, committee recommendations
                may include comments on other technical factors and may contain recommended restrictions which
                it believes should appear on the license.

           (2) The frequency advisory committee must be organized to represent all persons who are eligible for
               non-Government radio flight test stations. A statement of organization service area and composition
               of the committee must be submitted to the Commission for approval. The functions of any advisory
               committee are purely advisory to the applicant and the Commission, and its recommendations are
               not binding upon either the applicant or the Commission.

     (b) These applications need not be accompanied by evidence of frequency coordination:

           (1) Any application for modification not involving change in frequency(ies), power, emission, antenna
               height, antenna location or area of operation.

           (2) Any application for 121.5 MHz.

[53 FR 28940, Aug. 1, 1988, as amended at 54 FR 11721, Mar. 22, 1989; 58 FR 44954, Aug. 25, 1993; 80 FR 38910, July 7, 2015]

§ 87.307 Cooperative use of facilities.
     (a) The Commission will license only one flight test land station per airport, except as provided in paragraph
         (d) of this section.

     (b) Flight test land stations located at an airport are required to provide service without discrimination, on a
         cooperative maintenance basis, to anyone eligible for a flight test station license.

     (c) When the licensee of a flight test land station intends to conduct flight tests at an area served by another
         flight test land station, which may result in interference, the licensees must coordinate their schedules in
         advance. If no agreement is reached, the Commission will determine the time division upon request by
         either licensee.

     (d) Applicants for an additional flight test land station at an airport where such a station is already authorized
         may be required to submit a factual showing to include the following:

           (1) Reasons why shared use of the currently licensed flight test land station is not possible; and

           (2) Results of coordination with the current licensee of the flight test station at the airport demonstrating
               that an additional station can be accommodated without significant degradation of the reliability of
               existing facilities.

[53 FR 28940, Aug. 1, 1988, as amended at 63 FR 68958, Dec. 14, 1998]

Subpart K—Aviation Support Stations
§ 87.319 Scope of service.
Aviation support stations are used for the following types of operations:

     (a) Pilot training;

     (b) Coordination of soaring activities between gliders, tow aircraft and land stations;

     (c) Coordination of activities between free balloons or lighter-than-air aircraft and ground stations;

47 CFR 87.319(c) (enhanced display)                                                                               page 71 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                        47 CFR 87.319(d)
Aviation Services

     (d) Coordination between aircraft and aviation service organizations located on an airport concerning the
         safe and efficient portal-to-portal transit of the aircraft, such as the types of fuel and ground services
         available; and

     (e) Promotion of safety of life and property.

§ 87.321 Supplemental eligibility.
Each applicant must certify as to its eligibility under the scope of service described above.

[63 FR 68958, Dec. 14, 1998]

§ 87.323 Frequencies.
     (a) 121.500 MHz: Emergency and distress only.

     (b) The frequencies 121.950, 123.300 and 123.500 MHz are available for assignment to aviation support
         stations used for pilot training, coordination of lighter-than-air aircraft operations, or coordination of
         soaring or free ballooning activities. Applicants for 121.950 MHz must coordinate their proposal with the
         appropriate FAA Regional Spectrum Management Office. The application must specify the FAA Region
         notified and the date notified. Applicants for aviation support land stations may request frequency(ies)
         based upon their eligibility although the Commission reserves the right to specify the frequency of
         assignment. Aviation support mobile stations will be assigned 123.300 and 123.500 MHz. However,
         aviation support mobile stations must operate only on a noninterference basis to communications
         between aircraft and aviation support land stations.

     (c) The frequency 122.775 MHz and, secondary to aeronautical multicom stations, the frequency 122.850
         MHz are available for assignment to aviation support stations. These frequencies may be used for
         communications between aviation service organizations and aircraft in the airport area. These
         frequencies must not be used for air traffic control purposes or to transmit information pertaining to
         runway, wind or weather conditions.

     (d) The frequency 3281.0 kHz is available for assignment to aviation support stations used for coordination
         of lighter-than-air aircraft operations.

[53 FR 28940, Aug. 1, 1988, as amended at 63 FR 68958, Dec. 14, 1998]

Subpart L—Aeronautical Utility Mobile Stations
§ 87.345 Scope of service.
Aeronautical utility mobile stations provide communications for vehicles operating on an airport movement area. An
airport movement area is defined as the runways, taxiways and other areas utilized for taxiing, takeoff and landing
of aircraft, exclusive of loading ramp and parking areas.

     (a) An aeronautical utility mobile station must monitor its assigned frequency during periods of operation.

     (b) At an airport which has a control tower, control tower remote communications outlet station (RCO) or FAA
         flight service station in operation, communications by an aeronautical utility mobile station are limited to
         the management of ground vehicular traffic.

47 CFR 87.345(b) (enhanced display)                                                                        page 72 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                               47 CFR 87.345(c)
Aviation Services

     (c) Aeronautical utility mobile stations which operate on the airport's unicom frequency or the frequency
         122.900 MHz are authorized only to transmit information relating to safety, such as runway conditions
         and hazards on the airport. These stations are authorized primarily for monitoring communications from
         and to aircraft approaching or departing the airport.

     (d) Transmissions by an aeronautical utility mobile station are subject to the control of the control tower, the
         FAA flight service station or the unicom, as appropriate. When requested by the control tower, the flight
         service station or the unicom, an aeronautical utility station must discontinue transmitting immediately.

     (e) Communications between aeronautical utility mobile stations are not authorized.

     (f) Transmissions by aeronautical utility mobile stations for Universal Access Transceiver service are
         authorized.

[53 FR 28940, Aug. 1, 1988, as amended at 55 FR 7333, Mar. 1, 1990; 55 FR 30464, July 26, 1990; 71 FR 70680, Dec. 6, 2006]

§ 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.

[53 FR 28940, Aug. 1, 1988, as amended at 55 FR 30464, July 26, 1990; 55 FR 30908, July 30, 1990; 63 FR 68958, Dec. 14, 1998]

§ 87.349 Frequencies.
     (a) The frequency assigned to an aeronautical utility station at an airport served by a control tower, RCO or
         FAA flight service station is the frequency used by the control tower for ground traffic control or by the
         flight service station for communications with vehicles. In addition to the ground control frequency, an
         aeronautical utility station at an airport served by a control tower or RCO may be assigned the tower or
         RCO frequency if the assignment is specifically approved by the FAA as provided for in § 87.347(c). The
         frequencies assigned are normally from the band 121.600–121.925 MHz.

     (b) The frequency assigned to the unicom is available to aeronautical utility stations on a noninterference
         basis at airports which have a part-time control tower, part-time RCO or part-time FAA flight service
         station and a unicom.

47 CFR 87.349(b) (enhanced display)                                                                               page 73 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                               47 CFR 87.349(c)
Aviation Services

     (c) At airports which have a unicom but no control tower, RCO or FAA flight service station, the frequency
         assigned to the unicom is available to aeronautical utility stations on a noninterference basis. The
         frequencies available for assignment to unicoms are described in subpart G of this part.

     (d) At airports which have no control tower, RCO, flight service station or unicom, the frequency 122.900 MHz
         is available for assignment to aeronautical utility stations.

     (e) The frequency 978.0 MHz is authorized for Universal Access Transceiver data transmission.

     (f) The Commission will assign frequency 1090 MHz for use by aeronautical utility mobile stations for ground
         vehicle identification and collision avoidance after coordination with the FAA, subject to the following
         conditions:

           (1) The applicant must notify the appropriate Regional Office of the FAA prior to submission to the
               Commission of an application for a new station or for modification of an existing station. Each
               application must include the FAA Regional Office notified and date of notification.

           (2) Eligibility is restricted to airport operators holding an FAA Airport Operating Certificate, and other
               entities approved by the FAA on a case-by-case basis to use frequency 1090 MHz for use by
               aeronautical utility mobile stations for ground vehicle identification and collision avoidance;

           (3) No more than two hundred 1090 MHz aeronautical utility mobile stations will be authorized at one
               airport;

           (4) Licenses are limited to only those locations that are within the vicinity of an FAA ASDE–X
               multilateration system or ADS–B equipment, and/or where the primary purpose for seeking transmit
               authorization is to provide surface data to aircraft and air traffic control authorities.

           (5) Message transmission rates are limited as indicated in the table below:

                ADS–B Message                         Rate when moving             Rate when stationary
 Surface Position Message (Types 5, 6, 7, 8)      Every 0.4 to 0.6 seconds     Every 4.8 to 5.2 seconds.
 Aircraft Operational Status (Type 31)            Every 4.8 to 5.2 seconds     Every 4.8 to 5.2 seconds.
 Aircraft Identification and Type (Type 2)        Every 4.8 to 5.2 seconds     Every 9.8 to 10.2 seconds.

[55 FR 30464, July 26, 1990, as amended at 55 FR 30908, July 30, 1990; 71 FR 70680, Dec. 6, 2006; 78 FR 61207, Oct. 3, 2013]

§ 87.351 Frequency changes.
When the aeronautical utility frequency is required to be changed because of an action by the FAA or the
Commission (such as a change in the ground control of unicom frequency) the licensee must submit an application
for modification to specify the new frequency within 10 days from the date the station begins operation on the new
frequency. The licensee has temporary authority to use the new frequency from the date of the change pending
receipt of the modified license.

Subpart M—Aeronautical Search and Rescue Stations

47 CFR 87.351 (enhanced display)                                                                                  page 74 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                          47 CFR 87.371
Aviation Services

§ 87.371 Scope of service.
Aeronautical search and rescue land and mobile stations must be used only for communications with aircraft and
other aeronautical search and rescue stations engaged in search and rescue activities. Aeronautical land search
and rescue stations can be moved for temporary periods from a specified location to an area where actual or
practice search and rescue operations are being conducted.

§ 87.373 Supplemental eligibility.
Licenses for aeronautical search and rescue stations will be granted only to governmental entities or private
organizations chartered to perform aeronautical search and rescue functions.

§ 87.375 Frequencies.
     (a) The frequency 123.100 MHz is available for assignment to aeronautical search and rescue stations for
         actual search and rescue missions. Each search and rescue station must be equipped to operate on this
         frequency.

     (b) The frequency 122.900 MHz is available for assignment to aeronautical search and rescue stations for
         organized search and rescue training and for practice search and rescue missions.

     (c) The frequencies 3023.0 kHz and 5680.0 kHz are available for assignment to aircraft and ship stations for
         search and rescue scene-of-action coordination, including communications with participating land
         stations. Ship stations communicating with aircraft stations must employ 2K80J3E emission.

     (d) 121.500 MHz: Emergency and distress only.

Subpart N—Emergency Communications
§ 87.393 Scope of service.
This subpart provides the rules governing operation of stations in the Aviation Services during any national or local
emergency situation constituting a threat to national security or safety of life and property. This subpart is
consistent with the Aeronautical Emergency Communications System Plan for all Aviation Services licensees of the
Commission which was developed pursuant to sections 1, 4(o), 301 and 303 of the Communications Act, and
Executive Order 11490, as amended. This Plan provides for emergency communications to meet the requirements
of the Plan for the Security Control of Air Traffic and Air Navigation Aids (SCATANA), Civil Reserve Air Fleet (CRAF),
War Air Service Program (WASP) and, where applicable, State and Regional Disaster Airlift Planning (SARDA).

§ 87.395 Plan for the Security Control of Air Traffic and Air Navigation Aids (Short Title:
SCATANA).
     (a) The Plan for the Security Control of Air Traffic and Air Navigation Aids (SCATANA) is promulgated in
         furtherance of the Federal Aviation Act of 1958, as amended, the Communications Act and Executive
         Order 11490, as amended. SCATANA defines the responsibilities of the Commission for the security
         control of non-Federal air navigation aids.

     (b) Under the responsibilities defined in SCATANA, an FCC Support Plan for the Security Control of Non-
         Federal Air Navigation Aids has been developed by the Commission. The FCC Support Plan defines
         responsibilities, procedures, and instructions in consonance with SCATANA which will effect control of
         non-Federal air navigation aids when SCATANA is implemented. It permits the use of such navigation aids

47 CFR 87.395(b) (enhanced display)                                                                       page 75 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                      47 CFR 87.395(b)(1)
Aviation Services

           by aircraft of military and civil agencies when SCATANA is implemented. The FCC Support Plan highlights
           those parts of SCATANA which deal specifically with non-Federal air navigation aids. SCATANA and the
           FCC Support Plan apply to radionavigation stations authorized by the Commission in the following
           manner:

           (1) All licensees are subject to restrictions imposed by appropriate military authorities pursuant to
               SCATANA and the FCC Support Plan when an Air Defense Emergency or Defense Emergency exists
               or is imminent. The restrictions will be imposed through FAA Air Route Traffic Control Centers
               (ARTCCs).

           (2) All licensees of aeronautical radionavigation (VOR/DME, ILS, MLS, LF and MF non-directional
               beacons) stations will comply with SCATANA implementation instructions from FAA ARTCCs as
               follows:

                 (i)   Shut down the above navigation aids as directed. These instructions will permit time to land or
                       disperse airborne aircraft, and will permit extension of time when the air traffic situation
                       dictates.

                 (ii) Shut down as soon as possible stations which require more than five minutes control time,
                      unless directed otherwise or unless such stations are essential for the handling of existing air
                      traffic.

                (iii) Operate aeronautical radionavigation stations to ensure that required stations, as indicated in
                      flight plans, will be available for authorized aircraft flights.

           (3) Licensees of aeronautical radionavigation stations will be notified of the reduction or removal of
               SCATANA restrictions by FAA ARTCCs when notice of the termination is issued.

           (4) Licensees of aeronautical radionavigation stations may voluntarily participate in SCATANA tests as
               requested by an ARTCC. SCATANA testing must not interrupt the normal service of non-Federal air
               navigation aids.

§ 87.397 Emergency operations.
     (a) The licensee of any land station in the Aviation services, during a local emergency involving the safety of
         life and property may communicate in a manner other than that specified in the license (See § 87.395).
         Such emergency operations may include operation at other locations or with equipment not specified in
         the license or by unlicensed personnel provided that:

           (1) Such operations are under the control and supervision of the station licensee,

           (2) The emergency use is discontinued as soon as practicable upon termination of the emergency,

           (3) In no event shall any station transmit on frequencies other than or with power in excess of that
               specified in the license,

           (4) The details of the emergency must be retained with the station license, and

           (5) At a controlled airport these communications must be coordinated with the FAA.

     (b) The unicom frequencies listed in subpart G may also be used for communications with private aircraft
         engaged in organized civil defense activities in preparation for, during an enemy attack or immediately
         after an enemy attack. When used for these purposes, unicoms may be moved from place to place or
         operated at unspecified locations, except at landing areas served by other unicoms or control towers.

47 CFR 87.397(b) (enhanced display)                                                                         page 76 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                         47 CFR 87.397(c)
Aviation Services

     (c) In any case in which a license for unattended operation has been granted, the Commission may at any
         time, for national defense, modify the license.

Subpart O—Airport Control Tower Stations
§ 87.417 Scope of service.
     (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]

§ 87.419 Supplemental eligibility.
Only one control tower or RCO will be licensed at an airport.

[64 FR 27476, May 20, 1999]

§ 87.421 Frequencies.
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

47 CFR 87.421 (enhanced display)                                                                            page 77 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                              47 CFR 87.421(a)
Aviation Services

     (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]

§ 87.423 Hours of operation.
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]

§ 87.425 Interference.
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]

Subpart P—Operational Fixed Stations
§ 87.445 Scope of service.
An operational fixed station provides control, repeater or relay functions for its associated aeronautical station.

§ 87.447 Supplemental eligibility.
An applicant for an operational fixed station must certify that:

     (a) The applicant is the licensee of an aeronautical land station in the aeronautical mobile service; and

     (b) Common carrier facilities are not available to satisfy the aeronautical station's requirements.

[53 FR 28940, Aug. 1, 1988, as amended at 63 FR 68958, Dec. 14, 1998]

47 CFR 87.447(b) (enhanced display)                                                                              page 78 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                             47 CFR 87.449
Aviation Services

§ 87.449 Frequencies.
The following frequencies in the 72–76 MHz band are assignable to operational fixed stations using vertical
polarization, if no harmful interference is caused to TV reception on Channels 4 and 5. These frequencies are
shared with the Land Mobile and the Maritime Mobile Services.

         Operational frequencies in the 72–76 MHz band

         Carrier frequency in MHz

§ 87.451 Licensing limitations.
Operational fixed stations are subject to the following licensing limitations:

         (a) A maximum of four frequencies will be assigned.

         (b) Stations will not be authorized when applications indicate less than 16 km (10 miles) separation between
             a proposed station and a TV transmitter operating on either Channel 4 or 5, or from the post office of a
             community in which either channel is assigned but not in operation.

         (c) Stations located between 16 km (10 miles) and 128 km (80 miles) of a TV transmitter operating on either
             Channel 4 or 5, or from the post office of a community in which either channel is assigned but not in
             operation, are secondary to TV operations within the Grade B service contour.[1]

Subpart Q—Stations in the Radiodetermination Service
§ 87.471 Scope of service.
Stations in the aeronautical radiodetermination service provide radionavigation and radiolocation services.

         (a) Transmission by radionavigation land stations must be limited to aeronautical navigation, including
             obstruction warning.

         (b) Radionavigation land test stations are used for the testing and calibration of aircraft navigational aids and
             associated equipment. When used as radionavigation land test stations (MTF) signal generators must be
             licensed as radionavigation land test stations (MTF). Transmission must be limited to cases when
             radiation is necessary and there is no alternative.

         (c) Transmissions by emergency locator transmitter (ELT) test stations must be limited to necessary testing
             of ELTs and to training operations related to the use of such transmitters.

   [1]
     OET Bulletin No. 67, March 1988, entitled “Potential Interference from Operational Fixed Stations in the
   72–76 MHz Band to Television Channels 4 and 5” describes an analytical model that can be used to calculate
   the potential interference that might result from a given fixed station operation. Copies of the bulletin may be
   obtained from the Commission's current duplication contractor. Information concerning the current duplication
   contractor may be obtained from the Office of Public Affairs, Consumer Assistance and Small Business
   Division, Telephone (202) 632–5050.

47 CFR 87.471(c) (enhanced display)                                                                           page 79 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                         47 CFR 87.473
Aviation Services

[53 FR 28940, Aug. 1, 1988, as amended at 58 FR 67696, Dec. 22, 1993]

§ 87.473 Supplemental eligibility.
     (a) Licenses for radionavigation land test stations (MTF) will be granted only to applicants engaged in the
         development, manufacture or maintenance of aircraft radionavigation equipment. Licenses for
         radionavigation land test stations (OTF) will be granted only to applicants who agree to establish the
         facility at an airport for the use of the public.

     (b) Licenses for ELT test stations will be granted only to applicants to train personnel in the operation and
         location of ELTs, or for testing related to the manufacture or design of ELTs.

[53 FR 28940, Aug. 1, 1988, as amended at 63 FR 68958, Dec. 14, 1998]

§ 87.475 Frequencies.
     (a) Frequency coordination. The Commission will assign frequencies to radionavigation land stations and
         radionavigation land test stations after coordination with the FAA. The applicant must notify the
         appropriate Regional Office of the FAA prior to submission to the Commission of an application for a new
         station or for modification of an existing station to change frequency, power, location or emission. Each
         application must include the FAA Regional Office notified and date of notification.

     (b) Frequencies available for radionavigation land stations.

           (1) LORAN-C is a long range navigation system which operates in the 90–110 kHz band.

           (2) Radiobeacon stations enable an aircraft station to determine bearing or direction in relation to the
               radiobeacon station. Radiobeacons operate in the bands 190–285 kHz; 325–435 kHz; 510–525 kHz;
               and 525–535 kHz. Radiobeacons may be authorized, primarily for off-shore use, in the band
               525–535 kHz on a non-interference basis to travelers information stations.

           (3) Aeronautical marker beacon stations radiate a vertical distinctive pattern on 75 MHz which provides
               position information to aircraft.

           (4) The following table lists the specific frequencies in the 108.100–111.950 MHz band which are
               assignable to localizer stations with simultaneous radiotelephone channels and their associated
               glide path station frequency from the 328.600–335.400 MHz band.

                                   Localizer (MHz)                                 Glide path (MHz)
                                                           108.100                                          334.700
                                                           108.150                                          334.550
                                                           108.300                                          334.100
                                                           108.350                                          333.950
                                                           108.500                                          329.900
                                                           108.550                                          329.750
                                                           108.700                                          330.500
                                                           108.750                                          330.350
                                                           108.900                                          329.300
                                                           108.950                                          329.150

47 CFR 87.475(b)(4) (enhanced display)                                                                    page 80 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                   47 CFR 87.475(b)(5)
Aviation Services

                                   Localizer (MHz)                              Glide path (MHz)
                                                      109.100                                              331.400
                                                      109.150                                              331.250
                                                      109.300                                              332.000
                                                      109.350                                              331.850
                                                      109.500                                              332.600
                                                      109.550                                              332.450
                                                      109.700                                              333.200
                                                      109.750                                              333.050
                                                      109.900                                              333.800
                                                      109.950                                              333.650
                                                      110.100                                              334.400
                                                      110.150                                              334.250
                                                      110.300                                              335.000
                                                      110.350                                              334.850
                                                      110.500                                              329.600
                                                      110.550                                              329.450
                                                      110.700                                              330.200
                                                      110.750                                              330.050
                                                      110.900                                              330.800
                                                      110.950                                              330.650
                                                      111.100                                              331.700
                                                      111.150                                              331.550
                                                      111.300                                              332.300
                                                      111.350                                              332.150
                                                      111.500                                              332.900
                                                      111.550                                              332.750
                                                      111.700                                              333.500
                                                      111.750                                              333.350
                                                      111.900                                              331.100
                                                      111.950                                              330.950

           (5) VHF omni-range (VOR) stations are to be assigned frequencies in the 112.050–117.950 MHz band
               (50 kHz channel spacing) and the following frequencies in the 108–112 MHz band:

           (6) The band 960–1215 MHz is available for the use of land stations and associated airborne electronic
               aids to air navigation. When distance measuring equipment (DME) is intended to operate with a
               single VHF navigation station in the 108–117.975 MHz band, the DME operating channel must be
               paired with the VHF channel as shown in the following table:

47 CFR 87.475(b)(6) (enhanced display)                                                                   page 81 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                  47 CFR 87.475(b)(6)
Aviation Services

                                                  DME Channeling and Pairing

                [MHz]

                    VHF channel               Airborne interrogating frequency         Ground reply frequency
                            108.000                                         1041.000                      978.000
                            108.050                                         1041.000                     1104.000
                            108.100                                         1042.000                      979.000
                            108.150                                         1042.000                     1105.000
                            108.200                                         1043.000                      980.000
                            108.250                                         1043.000                     1106.000
                            108.300                                         1044.000                      981.000
                            108.350                                         1044.000                     1107.000
                            108.400                                         1045.000                      982.000
                            108.450                                         1045.000                     1108.000
                            108.500                                         1046.000                      983.000
                            108.550                                         1046.000                     1109.000
                            108.600                                         1047.000                      984.000
                            108.650                                         1047.000                     1110.000
                            108.700                                         1048.000                      985.000
                            108.750                                         1048.000                     1111.000
                            108.800                                         1049.000                      986.000
                            108.850                                         1049.000                     1112.000
                            108.900                                         1050.000                      987.000
                            108.950                                         1050.000                     1113.000
                            109.000                                         1051.000                      988.000
                            109.050                                         1051.000                     1114.000
                            109.100                                         1052.000                      989.000
                            109.150                                         1052.000                     1115.000
                            109.200                                         1053.000                      990.000
                            109.250                                         1053.000                     1116.000
                            109.300                                         1054.000                      991.000
                            109.350                                         1054.000                     1117.000
                            109.400                                         1055.000                      992.000
                            109.450                                         1055.000                     1118.000
                            109.500                                         1056.000                      993.000
                            109.550                                         1056.000                     1119.000
                            109.600                                         1057.000                      994.000
                            109.650                                         1057.000                     1120.000
                            109.700                                         1058.000                      995.000
                            109.750                                         1058.000                     1121.000

47 CFR 87.475(b)(6) (enhanced display)                                                                  page 82 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                  47 CFR 87.475(b)(6)
Aviation Services

                    VHF channel               Airborne interrogating frequency         Ground reply frequency
                            109.800                                         1059.000                      996.000
                            109.850                                         1059.000                     1122.000
                            109.900                                         1060.000                      997.000
                            109.950                                         1060.000                     1123.000
                            110.000                                         1061.000                      998.000
                            110.050                                         1061.000                     1124.000
                            110.100                                         1062.000                      999.000
                            110.150                                         1062.000                     1125.000
                            110.200                                         1063.000                     1000.000
                            110.250                                         1063.000                     1126.000
                            110.300                                         1064.000                     1001.000
                            110.350                                         1064.000                     1127.000
                            110.400                                         1065.000                     1002.000
                            110.450                                         1065.000                     1128.000
                            110.500                                         1066.000                     1003.000
                            110.550                                         1066.000                     1129.000
                            110.600                                         1067.000                     1004.000
                            110.650                                         1067.000                     1130.000
                            110.700                                         1068.000                     1005.000
                            110.750                                         1068.000                     1131.000
                            110.800                                         1069.000                     1006.000
                            110.850                                         1069.000                     1132.000
                            110.900                                         1070.000                     1007.000
                            110.950                                         1070.000                     1133.000
                            111.000                                         1071.000                     1008.000
                            111.050                                         1071.000                     1134.000
                            111.100                                         1072.000                     1009.000
                            111.150                                         1072.000                     1135.000
                            111.200                                         1073.000                     1010.000
                            111.250                                         1073.000                     1136.000
                            111.300                                         1074.000                     1011.000
                            111.350                                         1074.000                     1137.000
                            111.400                                         1075.000                     1012.000
                            111.450                                         1075.000                     1138.000
                            111.500                                         1076.000                     1013.000
                            111.550                                         1076.000                     1139.000
                            111.600                                         1077.000                     1014.000
                            111.650                                         1077.000                     1140.000
                            111.700                                         1078.000                     1015.000
                            111.750                                         1078.000                     1141.000

47 CFR 87.475(b)(6) (enhanced display)                                                                  page 83 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                  47 CFR 87.475(b)(6)
Aviation Services

                    VHF channel               Airborne interrogating frequency         Ground reply frequency
                            111.800                                         1079.000                     1016.000
                            111.850                                         1079.000                     1142.000
                            111.900                                         1080.000                     1017.000
                            111.950                                         1080.000                     1143.000
                            112.000                                         1081.000                     1018.000
                            112.050                                         1081.000                     1144.000
                            112.100                                         1082.000                     1019.000
                            112.150                                         1082.000                     1145.000
                            112.200                                         1083.000                     1020.000
                            112.250                                         1083.000                     1146.000
                            112.300                                         1094.000                     1157.000
                            112.350                                         1094.000                     1031.000
                            112.400                                         1095.000                     1158.000
                            112.450                                         1095.000                     1032.000
                            112.500                                         1096.000                     1159.000
                            112.550                                         1096.000                     1033.000
                            112.600                                         1097.000                     1160.000
                            112.650                                         1097.000                     1034.000
                            112.700                                         1098.000                     1161.000
                            112.750                                         1098.000                     1035.000
                            112.800                                         1099.000                     1162.000
                            112.850                                         1099.000                     1036.000
                            112.900                                         1100.000                     1163.000
                            112.950                                         1100.000                     1037.000
                            113.000                                         1101.000                     1164.000
                            113.050                                         1101.000                     1038.000
                            113.100                                         1102.000                     1165.000
                            113.150                                         1102.000                     1039.000
                            113.200                                         1103.000                     1166.000
                            113.250                                         1103.000                     1040.000
                            113.300                                         1104.000                     1167.000
                            113.350                                         1104.000                     1041.000
                            113.400                                         1105.000                     1168.000
                            113.450                                         1105.000                     1042.000
                            113.500                                         1106.000                     1169.000
                            113.550                                         1106.000                     1043.000
                            113.600                                         1107.000                     1170.000
                            113.650                                         1107.000                     1044.000
                            113.700                                         1108.000                     1171.000
                            113.750                                         1108.000                     1045.000

47 CFR 87.475(b)(6) (enhanced display)                                                                  page 84 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                  47 CFR 87.475(b)(6)
Aviation Services

                    VHF channel               Airborne interrogating frequency         Ground reply frequency
                            113.800                                         1109.000                     1172.000
                            113.850                                         1109.000                     1046.000
                            113.900                                         1110.000                     1173.000
                            113.950                                         1110.000                     1047.000
                            114.000                                         1111.000                     1174.000
                            114.050                                         1111.000                     1048.000
                            114.100                                         1112.000                     1175.000
                            114.150                                         1112.000                     1049.000
                            114.200                                         1113.000                     1176.000
                            114.250                                         1113.000                     1050.000
                            114.300                                         1114.000                     1177.000
                            114.350                                         1114.000                     1051.000
                            114.400                                         1115.000                     1178.000
                            114.450                                         1115.000                     1052.000
                            114.500                                         1116.000                     1179.000
                            114.550                                         1116.000                     1053.000
                            114.600                                         1117.000                     1180.000
                            114.650                                         1117.000                     1054.000
                            114.700                                         1118.000                     1181.000
                            114.750                                         1118.000                     1055.000
                            114.800                                         1119.000                     1182.000
                            114.850                                         1119.000                     1056.000
                            114.900                                         1120.000                     1183.000
                            114.950                                         1120.000                     1057.000
                            115.000                                         1121.000                     1184.000
                            115.050                                         1121.000                     1058.000
                            115.100                                         1122.000                     1185.000
                            115.150                                         1122.000                     1059.000
                            115.200                                         1123.000                     1186.000
                            115.250                                         1123.000                     1060.000
                            115.300                                         1124.000                     1187.000
                            115.350                                         1124.000                     1061.000
                            115.400                                         1125.000                     1188.000
                            115.450                                         1125.000                     1062.000
                            115.500                                         1126.000                     1189.000
                            115.550                                         1126.000                     1063.000
                            115.600                                         1127.000                     1190.000
                            115.650                                         1127.000                     1064.000
                            115.700                                         1128.000                     1191.000
                            115.750                                         1128.000                     1065.000

47 CFR 87.475(b)(6) (enhanced display)                                                                  page 85 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                  47 CFR 87.475(b)(6)
Aviation Services

                    VHF channel               Airborne interrogating frequency         Ground reply frequency
                            115.800                                         1129.000                     1192.000
                            115.850                                         1129.000                     1066.000
                            115.900                                         1130.000                     1193.000
                            115.950                                         1130.000                     1067.000
                            116.000                                         1131.000                     1194.000
                            116.050                                         1131.000                     1068.000
                            116.100                                         1132.000                     1195.000
                            116.150                                         1132.000                     1069.000
                            116.200                                         1133.000                     1196.000
                            116.250                                         1133.000                     1070.000
                            116.300                                         1134.000                     1197.000
                            116.350                                         1134.000                     1071.000
                            116.400                                         1135.000                     1198.000
                            116.450                                         1135.000                     1072.000
                            116.500                                         1136.000                     1199.000
                            116.550                                         1136.000                     1073.000
                            116.600                                         1137.000                     1200.000
                            116.650                                         1137.000                     1074.000
                            116.700                                         1138.000                     1201.000
                            116.750                                         1138.000                     1075.000
                            116.800                                         1139.000                     1202.000
                            116.850                                         1139.000                     1076.000
                            116.900                                         1140.000                     1203.000
                            116.950                                         1140.000                     1077.000
                            117.000                                         1141.000                     1204.000
                            117.050                                         1141.000                     1078.000
                            117.100                                         1142.000                     1205.000
                            117.150                                         1142.000                     1079.000
                            117.200                                         1143.000                     1206.000
                            117.250                                         1143.000                     1080.000
                            117.300                                         1144.000                     1207.000
                            117.350                                         1144.000                     1081.000
                            117.400                                         1145.000                     1208.000
                            117.450                                         1145.000                     1082.000
                            117.500                                         1146.000                     1209.000
                            117.550                                         1146.000                     1083.000
                            117.600                                         1147.000                     1210.000
                            117.650                                         1147.000                     1084.000
                            117.700                                         1148.000                     1211.000
                            117.750                                         1148.000                     1085.000

47 CFR 87.475(b)(6) (enhanced display)                                                                  page 86 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                       47 CFR 87.475(b)(7)
Aviation Services

                       VHF channel            Airborne interrogating frequency            Ground reply frequency
                             117.800                                        1149.000                         1212.000
                             117.850                                        1149.000                         1086.000
                             117.900                                        1150.000                         1213.000
                             117.950                                        1150.000                         1087.000

           (7) 978.0 MHz is authorized for Universal Access Transceiver service.

           (8) 1300–1350 MHz: The use of this band is restricted to surveillance radar stations and associated
               airborne transponders.

           (9) 1559–1626.5 MHz: The use of this band is limited to airborne electronic aids to air navigation and
               any associated land stations.

          (10) 2700–2900 MHz: Non-Government land-based radars may be licensed. U.S. Government
               coordination is required. Applicants must demonstrate a need for the service which the Government
               is not prepared to render.

          (11) 5000–5250 MHz: This band is to be used for the operation of the international standard system
               (microwave landing system).

          (12) 9000–9200 MHz: This band is available to land-based radars. Stations operating in this band may
               receive interference from stations operating in the radiolocation service.

          (13) 15,400–15,700 MHz: This band is available for use of land stations associated with airborne
               electronic aids to air navigation.

          (14) 24,250–25,250, 32,300–33,400 MHz: In these bands, land-based radionavigation aids are permitted
               where they operate with airborne radionavigation devices.

     (c) Frequencies available for radionavigation land test stations.

           (1) The frequencies set forth in §§ 87.187(c), (e) through (j), (r), (t), and (ff); and 87.475(b)(6) through
               (b)(11) may be assigned to radionavigation land test stations for the testing of aircraft transmitting
               equipment that normally operate on these frequencies and for the testing of land-based receiving
               equipment that operate with airborne radionavigation equipment.

           (2) The frequencies available for assignment to radionavigation land test stations for the testing of
               airborne receiving equipment are 108.000 and 108.050 MHz for VHF omni-range; 108.100 and
               108.150 MHz for localizer; 334.550 and 334.700 MHz for glide slope; 978 and 979 MHz (X
               channel)/1104 MHz (Y channel) for DME; 978 MHz for Universal Access Transceiver; 1030 MHz for
               air traffic control radar beacon transponders; 1090 MHz for Traffic Alert and Collision Avoidance
               Systems (TCAS); and 5031.0 MHz for microwave landing systems. Additionally, the frequencies in
               paragraph (b) of this section may be assigned to radionavigation land test stations after
               coordination with the FAA. The following conditions apply:after coordination with the FAA. The
               following conditions apply:

                 (i)    The maximum power authorized on the frequencies 108.150 and 334.550 MHz is 1 milliwatt.
                        The maximum power authorized on all other frequencies is one watt.

                 (ii) The pulse repetition rate (PRR) of the 1030 MHz ATC radar beacon test set will be 235 pulses
                      per second (pps) ±5pps.

47 CFR 87.475(c)(2)(ii) (enhanced display)                                                                   page 87 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                       47 CFR 87.475(c)(2)(iii)
Aviation Services

                (iii) The assignment of 108.000 MHz is subject to the condition that no interference will be caused
                      to the reception of FM broadcasting stations and stations using the frequency are not
                      protected against interference from FM broadcasting stations.

     (d) Frequencies available for ELT test stations. The frequencies available for assignment to ELT test stations
         are 121.600, 121.650, 121.700, 121.750, 121.800, 121.850, and 121.900 MHz. Licensees must:

           (1) Not cause harmful interference to voice communications on these frequencies or any harmonically
               related frequency.

           (2) Coordinate with the appropriate FAA Regional Spectrum Management Office prior to each activation
               of the transmitter.

     (e) Frequencies available for differential GPS stations. Frequencies in the 112–118 MHz band may be
         assigned to Special Category I (SCAT-I) ground stations for differential GPS data links.

           (1) The frequencies available are on 25 kHz centers with the lowest assignable frequency being
               centered at 112.000 MHz and the highest assignable frequency being centered at 117.950 MHz.

           (2) Applicants must coordinate a frequency, time slot assignment, and three-letter identifier with the FAA
               and provide this information to the Commission upon application.

[53 FR 28940, Aug. 1, 1988, as amended at 54 FR 11721, Mar. 22, 1989; 63 FR 68958, Dec. 14, 1998; 64 FR 27476, May 20, 1999;
69 FR 32886, June 14, 2004; 71 FR 70680, Dec. 6, 2006; 78 FR 61207, Oct. 3, 2013]

Editorial Note: At 80 FR 38911, July 7, 2015, § 87.475 was amended by adding paragraphs (b)(11) and (14),
however these paragraphs already existed, and the amendment could not be incorporated.

§ 87.477 Condition of grant for radionavigation land stations.
Radionavigation land stations may be designated by the FAA as part of the National Airspace System. Stations so
designated will be required to serve the public under IFT conditions. This condition of grant is applicable to all
radionavigation land stations.

§ 87.479 Harmful interference to radionavigation land stations.
     (a) Military or other Government stations have been authorized to establish wide-band systems using
         frequency-hopping spread spectrum techniques in the 960–1215 MHz band. Authorization for a Joint
         Tactical Information Distribution Systems (JTIDS) has been permitted on the basis of non-interference to
         the established aeronautical radionavigation service in this band. In order to accommodate the
         requirements for the system within the band, restrictions are imposed. Transmissions will be
         automatically prevented if:

           (1) The frequency-hopping mode fails to distribute the JTIDS spectrum uniformly across the band;

           (2) The radiated pulse varies from the specified width of 6.4 microseconds ±5%;

           (3) The energy radiated within ±7 MHz of 1030 and 1090 MHz exceeds a level of 60 dB below the peak
               of the JTIDS spectrum as measured in a 300 kHz bandwidth. The JTIDS will be prohibited from
               transmitting if the time slot duty factor exceeds a 20 percent duty factor for any single user and a 40
               percent composite duty factor for all JTIDS emitters in a geographic area.

47 CFR 87.479(a)(3) (enhanced display)                                                                          page 88 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                      47 CFR 87.479(b)
Aviation Services

     (b) If radionavigation systems operating in the 960–1215 MHz band experience interference or unexplained
         loss of equipment performance, the situation must be reported immediately to the nearest office of the
         FAA, the National Telecommunications and Information Administration, Washington, DC 20504, or the
         nearest Federal Communications Commission field office. The following information must be provided to
         the extent available:

           (1) Name, call sign and category of station experiencing the interference;

           (2) Date and time of occurrence;

           (3) Geographical location at time of occurrence;

           (4) Frequency interfered with;

           (5) Nature of interference; and

           (6) Other particulars.

§ 87.481 Unattended operation of domestic radiobeacon stations.
     (a) Radiobeacons may be licensed for unattended operation. An applicant must comply with the following:

           (1) The transmitter is crystal controlled and specifically designed for radiobeacon service and capable of
               transmitting by self-actuating means;

           (2) The emissions of the transmitter must be continuously monitored by a licensed operator, or by a
               direct positive automatic monitor, supplemented by aural monitoring at suitable intervals;

           (3) If as a result of aural monitoring it is determined that a deviation from the terms of the station
               license has occurred, the transmitters must be disabled immediately by a properly authorized
               person. If automatic monitoring is used, the monitor must insure that the operation of the transmitter
               meets the license terms or is disabled;

           (4) A properly authorized person must be able to reach the transmitter and disable it in a reasonable
               amount of time, so as not to adversely affect life or property in the air;

           (5) The equipment must be inspected at least every 180 days. Results of inspections must be kept in the
               station maintenance records;

           (6) The transmitter is not operable by or accessible to, other than authorized persons;

           (7) The transmitter is in a remote location.

     (b) Authority for unattended operation must be expressly stated in the station license.

[53 FR 28940, Aug. 1, 1988, as amended at 63 FR 68958, Dec. 14, 1998]

§ 87.483 Audio visual warning systems.
An audio visual warning system (AVWS) is a radar-based obstacle avoidance system. AVWS activates obstruction
lighting and transmits VHF audible warnings to alert pilots of potential collisions with land-based obstructions. The
AVWS operations are limited to locations where natural and man-made obstructions exist. The continuously
operating radar calculates the location, direction and groundspeed of nearby aircraft that enter one of two warning

47 CFR 87.483 (enhanced display)                                                                          page 89 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                       47 CFR 87.483(a)
Aviation Services

zones reasonably established by the licensee. As aircraft enter the first warning zone, the AVWS activates
obstruction lighting. If the aircraft continues toward the obstacle and enters the second warning zone, the VHF radio
transmits an audible warning describing the obstacle.

     (a) Radiodetermination (radar) frequencies. Frequencies authorized under § 87.475(b)(8) of this chapter are
         available for use by an AVWS. The frequency coordination requirements in § 87.475(a) of this chapter
         apply.

     (b) VHF audible warning frequencies. Frequencies authorized under § 87.187(j), § 87.217(a), § 87.241(b), and
         § 87.323(b) (excluding 121.950 MHz) of this chapter are available for use by an AVWS. Multiple
         frequencies may be authorized for an individual station, depending on need and the use of frequencies
         assigned in the vicinity of a proposed AVWS facility. Use of these frequencies is subject to the following
         limitations:

           (1) The output power shall not exceed −3 dBm watts for each frequency authorized.

           (2) The antenna used in transmitting the audible warnings must be omnidirectional with a maximum
               gain equal to or lower than a half-wave centerfed dipole above 30 degrees elevation, and a maximum
               gain of + 5 dBi from horizontal up to 30 degrees elevation.

           (3) The audible warning shall not exceed two seconds in duration. No more than six audible warnings
               may be transmitted in a single transmit cycle, which shall not exceed 12 seconds in duration. An
               interval of at least twenty seconds must occur between transmit cycles.

[78 FR 61207, Oct. 3, 2013]

Subpart R [Reserved]

Subpart S—Automatic Weather Stations (AWOS/ASOS)
§ 87.525 Scope of service.
Automatic weather observation stations (AWOS) and automatic surface observation stations (ASOS) must provide
up-to-date weather information including the time of the latest weather sequence, altimeter setting, wind speed and
direction, dew point, temperature, visibility and other pertinent data needed at airports having neither a full-time
control tower nor a full-time FAA Flight Service Station. When a licensee has entered into an agreement with the
FAA, an AWOS or an ASOS may also operate as an automatic terminal information station (ATIS) during the control
tower's operating hours.

[64 FR 27476, May 20, 1999]

§ 87.527 Supplemental eligibility.
     (a) Licenses will be granted only upon FAA approval.

     (b) Eligibility for an AWOS, an ASOS, or an ATIS is limited to the owner or operator of an airport or to a person
         who has entered into a written agreement with the owner or operator for exclusive rights to operate and
         maintain the station. Where applicable a copy of the agreement between the applicant and owner or
         operator of the airport must be submitted with an application.

     (c) Only one AWOS, ASOS, or ATIS will be licensed at an airport.

47 CFR 87.527(c) (enhanced display)                                                                       page 90 of 91
47 CFR Part 87 (up to date as of 2/20/2024)
                                                                                                    47 CFR 87.529
Aviation Services

[53 FR 28940, Aug. 1, 1988, as amended at 64 FR 27476, May 20, 1999]

§ 87.529 Frequencies.
Prior to submitting an application, each applicant must notify the applicable FAA Regional Frequency Management
Office. Each application must be accompanied by a statement showing the name of the FAA Regional Office and
date notified. The Commission will assign the frequency. Normally, frequencies available for air traffic control
operations set forth in subpart E will be assigned to an AWOS, ASOS, or to an ATIS. When a licensee has entered
into an agreement with the FAA to operate the same station as both an AWOS and as an ATIS, or as an ASOS and an
ATIS, the same frequency will be used in both modes of operation.

[69 FR 52886, June 14, 2004]

47 CFR 87.529 (enhanced display)                                                                     page 91 of 91