§ 87.431

Frequencies available.

The frequencies 121.60, 121.65, 121.70, 121.75, 121.80, 121.85, and 121.90 megacycles are available for use by aeronautical utility mobile stations. The frequency 121.60 Mc/s is available to aeronautical utility mobile stations for airport utility communications on the condition that no harmful interference is caused to search and rescue communications during any period of search and rescue operations in the locale involved. [28 F.R. 14095, Dec. 21, 1963, as amended at 33 F.R. 14298, Sept. 21, 1968]

§ 87.433 Scope of service.

Communications by a utility station shall be limited to the necessities of ground traffic control at an airdrome and may be used for essential communications with the control towers, ground vehicles and aircraft on the ground.

Power and antenna height shall be restricted to the minimum to achieve the required service.

§ 87.437 Supervision by airdrome control operator.

At any airdrome at which an airdrome control tower is in operation, transmission by the utility station shall be subject to the control of the airdrome control station and shall be discontinued immediately when so requested by the control station. The utility station shall guard the utility frequency during periods of operation.

Subpart K-Aeronautical Search and Rescue Mobile Stations

§ 87.441 Frequencies available.

(a) The frequency 123.1 megacycles is available for use by aeronautical search and rescue mobile stations.

NOTE: Prior to Jan. 1, 1969, the primary frequency for aeronautical search and rescue mobile operations is 121.6 Mc/s.

(b) 121.5 megacycles: This is a universal simplex emergency and distress frequency for air-ground communications and will not be assigned unless (1) a showing is made establishing a need for such services and (2) the regular search and rescue mobile frequency is assigned and available for use to accommodate normal communications needs. [31 F.R. 8629, June 22, 1966, as amended at 33 F.R. 14298, Sept. 21, 1968]

§ 87.443 Scope of service.

Aeronautical search and rescue mobile stations shall be used only for communications with aircraft engaged in search and rescue operations.

[28 FR. 14096, Dec. 21, 1963]

Subpart L-Aeronautical Fixed
Stations

SOURCE: The provisions of this Subpart L appear at 28 F.R. 14096, Dec. 21, 1963, unless otherwise noted.

§ 87.451 Eligibility.

Authorization to operate an aeronautical fixed station will be issued only to the licensee of an aeronautical en route station with which the aeronautical fixed station will be associated. Aeronautical fixed station authorizations will not be issued where land line facilities adequate for the service required are available.

§ 87.453 Scope of service.

Aeronautical fixed stations shall provide all necessary non-public point-topoint communications service pertaining to safety, regularity and economy of fight Such stations shall transmit, without discrimination, messages originated by aircraft radio station licensees who have entered into equitable, cost sharing arrangements governing the operation and maintenance of such sations: Provided, however, That aeronaumeat fixed station licensees are required to transmit, without charge or discriminamon, all necessary messages in time of public emergency which involve the safety of life and property.

87.455 Assignment of frequencies.

(a) United States (excluding Alaska). Only those frequencies which are in accordance with 2.106 of this chapter may be authorized for me by aeronautical fixed stations The applicant shall request specific frequencies within such bands when making an application for an aeronautical fixed station The avadability for assignment of such frequencies will be determined in the CommisSon F Sudy of the probabilines of interference to and from existing services assigned on the same or adjacent frequencies, and if necessary by appropriate coordination with other agen

(2) The frequency 4645 kc ́s is avalliable for assignment to aeronautical fixed stations in Alaska. This frequency wil only be authorized in conjunction with authorizations for use of the aeronautocal enroute frequencies specified f $87.297(a).

Subpart M-Operational Stations 87.461 Service authorized.

Operational stations in the Aviation Services are authorized for link or control circuits or other aeronautical operations.

130 F.R. 2801, Mar. 4, 1965]

§ 87.463 Frequencies available to fixed stations.

Operational fixed stations in the aeronautical fixed service will share the frequency bands allocated to operational fixed stations with other services as follows:

(a) The frequencies listed in this paragraph may be assigned under the conditions set forth in subparagraphs (1) through (6 of this paragraph. Stations authorized to operate in the band 73-74.6 Mes as of December 1, 1961, may continue to operate in this band and are not required to afford protection to the radio astronomy service.)

cies. All new assignments of frequencies will be subject to such conditions as may

b. Alaska. In the authorization of frequencies for me by aeronautical fixed stations in Alaska the following conditions in addition to those in paragraph a of this section, shall apply:

(1) Except as provided in subparagraph (2, of this paragraph, frequencies will be authorized to aeronautical £xed stations in Alaska, only when such stations serve scheduled certificated air carrers as defined by the Civil Aeronautica Board When filing applications for such frequencies. the applicant st show that the station will provide communications only along the routes served by the scheduled operations of such carA copy of the contractual arrangements made with each of the air carrers to be served must be submitted with the application.

(1) In any area in the contineu United States (excluding Alaska maxmum of four of the frequencies tated in this paragraph may be assigned to aeronautical operational fixed

tions.

2. All authorizations are subject to the condition that no harmful interference will be caused to television re ception on Channels 4 and 5.

(3) The applicant agrees to eliminate any harmful interference caused by his operation to TV reception on either Channel 4 or 5 that might develop by whatever means are found necessary within 90 days of the time knowledge of said interference is first brought to his attention by the Commission. If said interference is not cleared up within the 90-day period, operation of the fixed station will be discontinued.

(4) Vertical polarization is used.

(5) Whenever it is proposed to locate a 72-76 Mc/s fixed station less than 80, but more than 10 miles from the site of a TV transmitter operating on either Channel 4 or 5, or from the post office of a community in which such channels are assigned but are not in operation, the fixed station shall be authorized only if there are fewer than 100 family dwelling units, as defined by the U.S. Bureau of Census, located within a circle centered at the location of the proposed fixed station (family dwelling units 70 or more miles distant from the TV antenna site are not to be counted), the radius of which shall be determined by use of the appropriate chart entitled, "Chart for Determining Radius From Fixed Station in 72-76 Mc/s Band to Interference Contour Along Which 10 Percent of Service From Adjacent Channel Television Station Would Be Destroyed"; two charts are provided, one for Channel 4 and one for Channel 5. The Commission may, however, in a particular case, authorize the location of a fixed station within a circle as determined above containing 100 or more family dwelling units upon a showing that:

1 Available for assignment in accordance with the frequency pairing plan as contained in paragraph (c) of this section.

2 Subject to no protection from interference due to the operation of industrial, scientific, and medical devices in this band.

Limited to developmental operation only with the assigned frequency and particulars of operation specified in each authorization. Available on a developmental basis only for omnidirectional operation.

"Operational fixed stations in this band must utilize transmitting equipment which meets the technical requirements for Instructional Television Fixed Stations as contained in Part 74 of this chapter.

(c) The frequencies between 952 and 960 Mc/s will be assigned as follows: Paired frequencies (Mc/s)

(i) The proposed site is the only suitable location.

(ii) It is not feasible, technically or otherwise, to use other available frequencies.

(iii) The applicant has a plan to control any interference that might develop to TV reception from his operations.

(iv) The applicant is financially able and agrees to make such adjustments in the TV receivers affected as may be necessary to eliminate interference caused by his operations.

(6) All applications seeking authority to operate with a separation of less than 10 miles will be returned without action.

FOR

4

CHART FOR DETERMINING RADIUS FROM FIXED STATION IN 78-76 M./ BAND TO INTERFERENCE CONTOUR ALONG WHICH ION OF SERVICE FROM ADJACENT TELEVISION STATION WOULD BE DESTROYED

CHART FOR DETERMINING RADIUS FROM FIXED STATION IN 72-76 Mc/s BAND TO INTERFERENCE CONTOUR ALONG WHICH 10% OF SERVICE FROM ADJACENT TELEVISION STATION WOULD BE DESTROYED

Effective Radiated Power of TV Station.......100 kw. Television Transmitting Antenna Height......500 ft.

h height in feet of the center of the transmitting antenna array of
the fixed 72-76 Mc/s station with respect to the average level of
the terrain between 2 and 10 miles from such antenna in the
direction of the TV station. (The method for determining this
height is explained in detail in the TV Broadcast Rules.)

s separation in miles between the television station antenna and
the 72-76 Mc/s fixed station antenna.

r distance in miles from the 72-76 Mc/s fixed station antenna to
the contour at which the TV service area is reduced by 10%.
This distance is measured from the 72-76 Mc/s antenna in the
direction of the TV antenna.

40

DIRECTIONS FOR USING THIS CHART: