Pilot/Controller Glossary

be based on airborne and ground transmitters in the
VHF/UHF frequency spectrum.
(See BEARING.)
(See NONDIRECTIONAL BEACON.)

AUTOMATIC FLIGHT INFORMATION SERVICE (AFIS) - ALASKA FSSs ONLY- The
continuous broadcast of recorded non-control
information at airports in Alaska where a FSS
provides local airport advisory service. The AFIS
broadcast automates the repetitive transmission of
essential but routine information such as weather,
wind, altimeter, favored runway, braking action,
airport NOTAMs, and other applicable information.
The information is continuously broadcast over a
discrete VHF radio frequency (usually the ASOS/
AWOS frequency).
AUTOMATIC TERMINAL INFORMATION SERVICE- The continuous broadcast of recorded
noncontrol information in selected terminal areas. Its
purpose is to improve controller effectiveness and to
relieve frequency congestion by automating the
repetitive transmission of essential but routine
information; e.g., "Los Angeles information Alfa.
One three zero zero Coordinated Universal Time.
Weather, measured ceiling two thousand overcast,
visibility three, haze, smoke, temperature seven one,
dew point five seven, wind two five zero at five,
altimeter two niner niner six. I-L-S Runway Two Five
Left approach in use, Runway Two Five Right closed,
advise you have Alfa."
(See ICAO term AUTOMATIC TERMINAL
INFORMATION SERVICE.)
(Refer to AIM.)

AUTOMATIC TERMINAL INFORMATION SERVICE [ICAO]- The provision of current, routine
information to arriving and departing aircraft by

means of continuous and repetitive broadcasts
throughout the day or a specified portion of the day.
AUTOROTATION- A rotorcraft flight condition in
which the lifting rotor is driven entirely by action of
the air when the rotorcraft is in motion.
a. Autorotative Landing/Touchdown Autorotation. Used by a pilot to indicate that the landing will
be made without applying power to the rotor.
b. Low Level Autorotation. Commences at an
altitude well below the traffic pattern, usually below
100 feet AGL and is used primarily for tactical
military training.
c. 180 degrees Autorotation. Initiated from a
downwind heading and is commenced well inside the
normal traffic pattern. "Go around" may not be
possible during the latter part of this maneuver.
AVAILABLE LANDING DISTANCE (ALD)- The
portion of a runway available for landing and roll-out
for aircraft cleared for LAHSO. This distance is
measured from the landing threshold to the
hold-short point.
AVIATION WEATHER SERVICE- A service
provided by the National Weather Service (NWS) and
FAA which collects and disseminates pertinent
weather information for pilots, aircraft operators, and
ATC. Available aviation weather reports and
forecasts are displayed at each NWS office and FAA
FSS.
(See TRANSCRIBED WEATHER BROADCAST.)
(See WEATHER ADVISORY.)
(Refer to AIM.)

AWW-
(See SEVERE WEATHER FORECAST
ALERTS.)