Pilot/Controller Glossary

of aerial activity, neither of which is hazardous to
aircraft. Alert Areas are depicted on aeronautical
charts for the information of nonparticipating pilots.
All activities within an Alert Arere conducted in
accordance with Federal Aviation Regulations, and
pilots of participating aircraft as well as pilots
transiting the arere equally responsible for
collision avoidance.
b. Controlled Firing Area- Airspace wherein
activities are conducted under conditions so
controlled as to eliminate hazards to nonparticipating
aircraft and to ensure the safety of persons and
property on the ground.
c. Military Operations Area (MOA)- Permanent
and temporary MOAs are airspace established
outside of Class A airspace area to separate or
segregate certain nonhazardous military activities
from IFR traffic and to identify for VFR traffic where
these activities are conducted. Permanent MOAs are
depicted on Sectional Aeronautical, VFR Terminal
Area, and applicable En Route Low Altitude Charts.
Note: Temporary MOAs are not charted.
(Refer to AIM.)

d. Prohibited Area- Airspace designated under
14 CFR Part 73 within which no person may operate
an aircraft without the permission of the using
agency.
(Refer to AIM.)
(Refer to En Route Charts.)

e. Restricted Area- Permanent and temporary
restricted areas are airspace designated under 14 CFR
Part 73, within which the flight of aircraft, while not
wholly prohibited, is subject to restriction. Most
restricted areas are designated joint use and IFR/VFR
operations in the area may be authorized by the
controlling ATC facility when it is not being utilized
by the using agency. Permanent restricted areas are
depicted on Sectional Aeronautical, VFR Terminal
Area, and applicable En Route charts. Where joint
use is authorized, the name of the ATC controlling
facility is also shown.
Note: Temporary restricted areas are not charted.
(Refer to 14 CFR Part 73.)
(Refer to AIM.)

f. Warning Area- A warning area is airspace of
defined dimensions extending from 3 nautical miles
outward from the coast of the United States, that
contains activity that may be hazardous to

nonparticipating aircraft. The purpose of such
warning area is to warn nonparticipating pilots of the
potential danger. A warning area may be located over
domestic or international waters or both.
SPECIAL VFR CONDITIONS- Meteorological
conditions that are less than those required for basic
VFR flight in Class B, C, D, or E surface areas and
in which some aircraft are permitted flight under
visual flight rules.
(See SPECIAL VFR OPERATIONS.)
(Refer to 14 CFR Part 91.)

SPECIAL VFR FLIGHT [ICAO]- A VFR flight
cleared by air traffic control to operate within Class
B, C, D, and E surface areas in metrological
conditions below VMC.
SPECIAL VFR OPERATIONS- Aircraft operating
in accordance with clearances within Class B, C, D,
and E surface areas in weather conditions less than the
basic VFR weather minima. Such operations must be
requested by the pilot and approved by ATC.
(See SPECIAL VFR CONDITIONS.)
(See ICAO term SPECIAL VFR FLIGHT.)

SPEED-
(See AIRSPEED.)
(See GROUND SPEED.)

SPEED ADJUSTMENT- An ATC procedure used to
request pilots to adjust aircraft speed to a specific
value for the purpose of providing desired spacing.
Pilots are expected to maintain a speed of plus or
minus 10 knots or 0.02 Mach number of the specified
speed. Examples of speed adjustments are:
a. "Increase/reduce speed to Mach point
(number)."
b. "Increase/reduce speed to (speed in knots)" or
"Increase/reduce speed (number of knots) knots."
SPEED BRAKES- Moveable aerodynamic devices
on aircraft that reduce airspeed during descent and
landing.
SPEED SEGMENTS- Portions of the arrival route
between the transition point and the vertex along the
optimum flight path for which speeds and altitudes
are specified. There is one set of arrival speed
segments adapted from each transition point to each
vertex. Each set may contain up to six segments.
SQUAWK (Mode, Code, Function)- Activate
specific modes/codes/functions on the aircraft