Anomalous propagation Conditions under which the RADAR beam does not travel a
straight line.
Approach lighting systems Installed in areas extending outward from the threshold
of the instrument runway, these are usually pilots first visual contact with the ground
under extremely low-visibility conditions.
ARA-63 receiver/decoder Used by the pilot in the aircraft and in conjunction with the
SPN-41 system to obtain carrier line-up prior to entering the SPN-46 acquisition gate.
ATCoach Advanced, multipurpose, real-time Air Traffic Control Simulator system
used with the STARS.
Atmosphere A thin blanket of gases, mostly nitrogen and oxygen, that surrounds the
earth and is held in place by the earth s gravity.
Automated Air Facilities Intelligence File (AAFIF) Text file that contains evaluated
information on airport movement surfaces, facilities, support equipment, services,
operations, NAVAID/communications, transportation, and other aspects of airfields
worldwide.
Automatic Direction Finder (ADF) Aircraft radio navigation system that senses and
indicates direction to an NDB ground transmitter.
Cirrocumulus clouds Clouds that appear as fleecy flakes or small white cotton balls.
Cirrostratus clouds Smooth, thin-layered clouds that cover all or most of the sky,
giving it a milky appearance, and that produce a halo around the sun or moon.
Cirrus clouds Appear fibrous and delicate, like white wisps against the sky.
Code of Federal Regulations CFR, Part 91 Prescribes the basic flight regulations
governing the operation of aircraft within the United States.
Cold front Occurs when cold air invades a region occupied by warm air.
Compass Heading (CH) Heading determined in relation to compass north.
Continuous wave (CW) A continuous series of Hertzian waves of congruent
characteristics.
Controlled airspace Clearly delineated airspace within which instrument flight rules
(IFR) flights and to visual flight rules (VFR) flights receive air traffic control services in
accordance with the airspace classification.
Controlled firing area (CFA) Airspace designated to contain activities that would be
hazardous to nonparticipating aircraft if not conducted in a controlled environment.
Coordinated Universal Time (UTC) Time based upon the relationship of the mean
sun to the prime meridian. It is also referred to as ZULU time.
Cumulonimbus clouds Clouds that develop vertically and resemble mountains or
towers; tops may extend higher than 60,000 feet and resemble an anvil.
Cumulonimbus Mammatus clouds Large, baggish clouds with protuberances--like
udders or pouches--on the undersurface.
AI-2
