INSTRUMENT FLIGHT RULES WORKBOOK
13. You should acknowledge all calls or clearances unless the controller or FSS specialist
advises otherwise. There are some occasions when controllers must issue time-critical
instructions to other aircraft and they may be in a position to observe your response, either
visually or on radar. If the situation demands your response, take the appropriate action or
advise the controller of any problem. Example:
"NAVY THREE ECHO TWO FOUR ONE, JACKSONVILLE
Take action; actuate the "ident" switch on your transponder.
"NAVY THREE ECHO TWO FOUR ONE, RADAR CONTACT.
" (The controller observed your ident on the radar.)
"NAVY THREE ECHO TWO FOUR ONE, ROGER." (The term
"radar contact" means no further position reports required.)
803. AIR TRAFFIC CONTROL
ATC is a service operated by appropriate authorities to promote the safe, orderly, and
expeditious flow of air traffic. ATC facilities can be contacted over radio frequencies and ATC
operational telephone lines (lines used for operational purposes such as controller instructions,
briefings, opening and closing flight plans, issuance of IFR clearances and amendments, etc.).
Air Traffic Control Towers
Towers have been established to provide for a safe, orderly, and expeditious flow of traffic on
and in the vicinity of an airport. Towers use air/ground communications, visual signaling, and
other devices to provide ATC services to aircraft operating in the vicinity of an airport or on the
runways, taxiways, and other areas of an airport/heliport that are utilized for taxiing/hover
taxiing, air taxiing, takeoff, and landing of aircraft, exclusive of loading ramps and parking areas.
Tower, Ground Control, and Clearance Delivery positions are all normally located in the control
tower within close proximity to one another. Although they perform three separate functions,
they work hand in hand to ensure the safe, orderly, and expeditious flow of arriving and
At those airports/heliports with a tower, specific approval for entry onto the movement area must
be obtained from ATC. The aircrew of departing aircraft should communicate with the control
tower on the appropriate ground control/clearance delivery frequency prior to taxi to receive taxi
clearance and/or IFR clearance information. Unless otherwise advised by the tower, the aircrew
should remain on that frequency during taxiing and runup, then change to tower frequency when
ready to request takeoff clearance.
INTRODUCTION TO GROUND, AIRBORNE, LOST COMMUNICATION, AND
EMERGENCY VOICE PROCEDURES 8-7