Sec.  90.403   General operating requirements.

   (a) Licensees of radio stations in the private land mobile radio services
   shall be directly responsible for the proper operation and use of each
   transmitter for which they are licensed. In this connection, licensees shall
   exercise such direction and control as is necessary to assure that all
   authorized facilities are employed:

   (1) Only for permissible purposes;

   (2) Only in a permissible manner; and

   (3) Only by persons with authority to use and operate such equipment.

   (b) In carrying out their responsibilities under  Sec. 90.403(a), licensees shall
   be bound by the provisions of the Communications Act of 1934, as amended,
   and by the rules and regulations of the Commission governing the radio
   service in which their facilities are licensed; and licensees may not,
   through written or oral agreements or otherwise, relieve themselves of any
   duty or obligation imposed upon them, by law, as licensees.

   (c) Except for stations that have been granted exclusive channels under this
   part and that are classified as commercial mobile radio service providers
   pursuant  to  part 20 of this chapter, each licensee must restrict all
   transmissions to the minimum practical transmission time and must employ an
   efficient operating procedure designed to maximize the utilization of the
   spectrum.

   (d) Communications involving the imminent safety-of-life or property are to
   be afforded priority by all licensees.

   (e) Licensees shall take reasonable precautions to avoid causing harmful
   interference.  This includes monitoring the transmitting frequency for
   communications in progress and such other measures as may be necessary to
   minimize the potential for causing interference.

   (f)  Stations  licensed in this part shall not continuously radiate an
   unmodulated carrier except where required for tests as permitted in  Sec. 90.405,
   except  where  specifically permitted by this part, where specifically
   authorized in the station authorization, or on an as needed basis in the
   Radiolocation Radio Service.

   (g) The radiations of the transmitter shall be suspended immediately upon
   detection or notification of a deviation from the technical requirements of
   the  station  authorization and until such deviation is corrected. For
   transmissions  concerning the imminent safety-of-life or property, the
   transmissions shall be suspended as soon as the emergency is terminated.

   [ 43 FR 54791 , Nov. 22, 1978;  44 FR 32220 , June 5, 1979, as amended at  59 FR 59965 , Nov. 21, 1994]