Sec. 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 type-accepted 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 
Sec. 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 Sec. 87.187(p).
    (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]