final authority as to, the operation of that aircraft."
THE PILOT IS RESPONSIBLE TO REQUEST AN
AMENDED CLEARANCE if ATC issues a
clearance that would cause a pilot to deviate from a
rule or regulation, or in the pilot"s opinion, would
place the aircraft in jeopardy.
(See ATC INSTRUCTIONS.)
(See ICAO term AIR TRAFFIC CONTROL
CLEARANCE.)

AIR TRAFFIC CONTROL- A service operated by
appropriate authority to promote the safe, orderly and
expeditious flow of air traffic.
(See ICAO term AIR TRAFFIC CONTROL
SERVICE.)

AIR TRAFFIC CONTROL CLEARANCE [ICAO]-
Authorization for an aircraft to proceed under
conditions specified by an air traffic control unit.
Note 1: For convenience, the term air traffic control
clearance is frequently abbreviated to clearance
when used in appropriate contexts.
Note 2: The abbreviated term clearance may be
prefixed by the words taxi, takeoff, departure, en
route, approach or landing to indicate the particular
portion of flight to which the air traffic control clearance relates.

AIR TRAFFIC CONTROL SERVICE-
(See AIR TRAFFIC CONTROL.)

AIR TRAFFIC CONTROL SERVICE [ICAO]- A
service provided for the purpose of:
a. Preventing collisions:
1. Between aircraft; and
2. On the maneuvering area between aircraft
and obstructions.
b. Expediting and maintaining an orderly flow of
air traffic.
AIR TRAFFIC CONTROL SPECIALIST- A person
authorized to provide air traffic control service.
(See AIR TRAFFIC CONTROL.)
(See FLIGHT SERVICE STATION.)
(See ICAO term CONTROLLER.)

AIR TRAFFIC CONTROL SYSTEM COMMAND
CENTER (ATCSCC)- An Air Traffic Tactical
Operations facility responsible for monitoring and
managing the flow of air traffic throughout the NAS,
producing a safe, orderly, and expeditious flow of
traffic while minimizing delays. The following
functions are located at the ATCSCC:

Pilot/Controller Glossary

a. Central Altitude Reservation Function
(CARF). Responsible for coordinating, planning,
and approving special user requirements under the
Altitude Reservation (ALTRV) concept.
(See ALTITUDE RESERVATION.)

b. Airport Reservation Office (ARO). Monitors
the operation and allocation of reservations for
unscheduled operations at airports designated by the
Administrator as High Density Airports. These
airports are generally known as slot controlled
airports. The ARO allocates reservations on a first
come, first served basis determined by the time the
request is received at the ARO.
(Refer to 14 CFR Part 93.)
(See CHART SUPPLEMENT U.S.)

c. U.S. Notice to Airmen (NOTAM) Office.
Responsible for collecting, maintaining, and distributing NOTAMs for the U.S. civilian and military, as
well as international aviation communities.
(See NOTICE TO AIRMEN.)

d. Weather Unit. Monitor all aspects of weather
for the U.S. that might affect aviation including cloud
cover, visibility, winds, precipitation, thunderstorms,
icing, turbulence, and more. Provide forecasts based
on observations and on discussions with meteorologists from various National Weather Service offices,
FAA facilities, airlines, and private weather services.
AIR TRAFFIC SERVICE- A generic term meaning:
a. Flight Information Service.
b. Alerting Service.
c. Air Traffic Advisory Service.
d. Air Traffic Control Service:
1. Area Control Service,
2. Approach Control Service, or
3. Airport Control Service.
AIR TRAFFIC SERVICE (ATS) ROUTES - The
term "ATS Route" is a generic term that includes
"VOR Federal airways," "colored Federal airways,"
"jet routes," and "RNAV routes." The term "ATS
route" does not replace these more familiar route
names, but serves only as an overall title when listing
the types of routes that comprise the United States
route structure.
AIRBORNE- An aircraft is considered airborne
when all parts of the aircraft are off the ground.
AIRBORNE DELAY- Amount of delay to be
encountered in airborne holding.