§  80.327   Urgency signals and messages.

   (a) The urgency signal indicates that the calling station has a very
   urgent message to transmit concerning the safety of a ship, aircraft,
   or other vehicle, or the safety of a person. The urgency signal must be
   sent only on the authority of the master or person responsible for the
   mobile station.

   (b) In radiotelegraphy, the urgency signal consists of three
   repetitions of the group XXX, sent with the individual letters of each
   group, and the successive groups clearly separated from each other. It
   must be transmitted before the call.

   (c) In radiotelephony, the urgency signal consists of three oral
   repetitions of the group of words PAN PAN transmitted before the call.

   (d) The urgency signal has priority over all other communications
   except distress. All mobile and land stations which hear it must not
   interfere with the transmission of the message which follows the
   urgency signal.

   (e) The urgency signal and call, and the message following it, must be
   sent on one of the international distress frequencies. Stations which
   cannot transmit on a distress frequency may use any other available
   frequency on which attention might be attracted.

   (f) Mobile stations which hear the urgency signal must continue to
   listen for at least three minutes. At the end of this period, if no
   urgency message has been heard, they may resume their normal service.
   However, land and mobile stations which are in communication on
   frequencies other than those used for the transmission of the urgency
   signal and of the call which follows it may continue their normal work
   without interruption provided the urgency message is not addressed “to
   all stations”.

   (g) When the urgency signal has been sent before transmitting a message
   “to all stations” which calls for action by the stations receiving the
   message, the station responsible for its transmission must cancel it as
   soon as it knows that action is no longer necessary. This message of
   cancellation must likewise be addressed “to all stations”.

   [ 51 FR 31213 , Sept. 2, 1986, as amended at  52 FR 35245 , Sept. 18, 1987;
    73 FR 4485 , Jan. 25, 2008]