What does ground control frequency primarily serve, and what is its typical MHz range?

4-3-14. Communications
a. Pilots of departing aircraft should communicate with the control tower on the appropriate ground
control/clearance delivery frequency prior to starting engines to receive engine start time, taxi and/or clearance
information. Unless otherwise advised by the tower, remain on that frequency during taxiing and runup, then
change to local control frequency when ready to request takeoff clearance.
NOTE-
Pilots are encouraged to monitor the local tower frequency as soon as practical consistent with other ATC requirements.
REFERENCE-
AIM, Para 4-1-13, Automatic Terminal Information Service (ATIS).
b. The tower controller will consider that pilots of turbine-powered aircraft are ready for takeoff when they
reach the runway or warm-up block unless advised otherwise.
c. The majority of ground control frequencies are in the 121.6 -121.9 MHz bandwidth. Ground control
frequencies are provided to eliminate frequency congestion on the tower (local control) frequency and are limited
to communications between the tower and aircraft on the ground and between the tower and utility vehicles on
the airport, provide a clear VHF channel for arriving and departing aircraft. They are used for issuance of taxi
4-3-20 Airport Operations

2/20/25 AIM
information, clearances, and other necessary contacts between the tower and aircraft or other vehicles operated
on the airport. A pilot who has just landed should not change from the tower frequency to the ground control
frequency until directed to do so by the controller. Normally, only one ground control frequency is assigned at
an airport; however, at locations where the amount of traffic so warrants, a second ground control frequency
and/or another frequency designated as a clearance delivery frequency, may be assigned.
d. A controller may omit the ground or local control frequency if the controller believes the pilot knows which
frequency is in use. If the ground control frequency is in the 121 MHz bandwidth the controller may omit the
numbers preceding the decimal point; e.g., 121.7, "CONTACT GROUND POINT SEVEN." However, if any
doubt exists as to what frequency is in use, the pilot should promptly request the controller to provide that
information.
e. Controllers will normally avoid issuing a radio frequency change to helicopters, known to be
single-piloted, which are hovering, air taxiing, or flying near the ground. At times, it may be necessary for pilots
to alert A TC regarding single pilot operations to minimize delay of essential ATC communications. Whenever
possible, A TC instructions will be relayed through the frequency being monitored until a frequency change can
be accomplished. You must promptly advise ATC if you are unable to comply with a frequency change. Also,
you should advise ATC if you must land to accomplish the frequency change unless it is clear the landing will
have no impact on other air traffic; e.g., on a taxiway or in a helicopter operating area.