Sec. 87.107  Station identification.

    (a) Aircraft station. Identify by one of the following means:
    (1) Aircraft radio station call sign.
    (2) Assigned FCC control number (assigned to ultralight aircraft).
    (3) The type of aircraft followed by the characters of the 
registration marking (``N'' number) of the aircraft, omitting the prefix 
letter ``N''. When communication is initiated by a ground station, an 
aircraft station may use the type of aircraft followed by the last three 
characters of the registration marking.
    (4) The FAA assigned radiotelephony designator of the aircraft 
operating organization followed by the flight identification number.
    (5) An aircraft identification approved by the FAA for use by 
aircraft stations participating in an organized flying activity of short 
duration.
    (b) Land and fixed stations. Identify by means of radio station call 
sign, its location, its assigned FAA identifier, the name of the city 
area or airport which it serves, or any additional identification 
required. An aeronautical enroute station which is part of a 
multistation network may also be identified by the location of its 
control point.
    (c) Survival craft station. Identify by transmitting a reference to 
its parent aircraft. No identification is required when distress signals 
are transmitted automatically. Transmissions other than distress or 
emergency signals, such as equipment testing or adjustment, must be 
identified by the call sign or by the registration marking of the parent 
aircraft followed by a single digit other than 0 or 1.
    (d) Exempted station. The following types of stations are exempted 
from the use of a call sign: Airborne weather radar, radio altimeter, 
air traffic control transponder, distance measuring equipment, collision 
avoidance equipment, racon, radio relay, radionavigation land test 
station (MTF), and automatically controlled aeronautical enroute 
stations.