Cumulus clouds Dense clouds with vertical development; upper surfaces are dome
shaped and exhibit rounded protuberances, but their bases are nearly horizontal.
Digital Aeronautical Flight Information File (DAFIF) Incorporates US Military-
selected aeronautical data similar to data contained within FLIP products.
Digital Audio Legal Recorder (DALR) Provides legal recording capability between
air traffic controllers, pilots, towers, and ground-based air traffic control Terminal
RADAR Approach Controls (TRACON).
Direction The position of one point in space relative to another without reference to
the distance between them.
Distance The spatial separation between two points without regard to direction.
Enhanced Terminal Voice Switch (ETVS) Contains centralized communications
switching equipment (central switch).
Equator A great circle around the earth that divides the Northern and Southern
hemispheres and denotes the starting line for latitude.
FACSFAC Air Control Tracking System (FACTS) Provides air traffic control for the
Navy's operating areas.
Federal Aviation Administration (FAA) Responsible for the safe and efficient use of
airspace in the United States.
Frequency Number of cycles that occur per second, stated in hertz (Hz); thousands
of cycles per second, stated in kilohertz (kHz); the millions of cycles per second, stated
in megahertz (MHz); or the billions of cycles per seconds, stated in gigahertz (GHz).
Fog Collections of water droplets or ice crystals suspended in the air near the Earth s
surface.
Foreign Clearance Manual (FCM) Standards for requesting and approving DOD
foreign clearances for diplomatic and personal travel.
Gale (Warning) Condition I Indicates that non-thunderstorm winds sustained
between 34 to 47 knots are expected within 12 hours.
Gale (Warning) Condition II Indicates that non-thunderstorm winds sustained
between 34 to 47 knots are expected within 24 hours.
Global Positioning System (GPS) Space-based navigation system that relies on
multiple satellites to provide input to aircraft systems.
Hertzian wave Radiated electromagnetic energy suitable for radio communication.
High-Wind (Advisory) Condition I Indicates that non-thunderstorm winds sustained
between 18 and 33 knots, or numerous gusts equal to or greater than 24 knots are
expected within 12 hours.
High-Wind (Advisory) Condition II Indicates that non-thunderstorm winds sustained
between 18 and 33 knots, or numerous gusts equal to or greater than 24 knots are
expected within 24 hours.
Identification Friend or Foe (IFF) Electronically distinguishes between friendly and
hostile aircraft.
AI-3
