Sec.  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]