SAFETY ALERT -- SYSTEM STRATEGIC NAVIGATION
SAFETY ALERT- A safety alert issued by ATC to aircraft under their control if
ATC is aware the aircraft is at an altitude which, in the controller's judgment,
places the aircraft in unsafe proximity to terrain, obstructions, or other
aircraft. The controller may discontinue the issuance of further alerts if the
pilot advises he is taking action to correct the situation or has the other
aircraft in sight.
a. Terrain/Obstruction Alert- A safety alert issued by ATC to
aircraft under their control if ATC is aware the aircraft is at an altitude
which, in the controller's judgment, places the aircraft in unsafe proximity
to terrain/obstructions; e.g., "Low Altitude Alert, check your altitude
immediately."
b. Aircraft Conflict Alert- A safety alert issued by ATC to
aircraft under their control if ATC is aware of an aircraft that is not under
their control at an altitude which, in the controller's judgment, places both
aircraft in unsafe proximity to each other. With the alert, ATC will offer the
pilot an alternate course of action when feasible; e.g., "Traffic Alert,
advise you turn right heading zero niner zero or climb to eight thousand
immediately."
The issuance of a safety alert is contingent upon the
capability of the controller to have an awareness of an unsafe condition. The
course of action provided will be predicated on other traffic under ATC control.
Once the alert is issued, it is solely the pilot's prerogative to determine what
course of action, if any, he will take.
SAIL BACK- A maneuver during high wind conditions (usually with power off)
where float plane movement is controlled by water rudders/opening and closing
cabin doors.
SAME DIRECTION AIRCRAFT- Aircraft are operating in the same direction when:
a. They are following the same track in the same direction; or
b. Their tracks are parallel and the aircraft are flying in the
same direction; or
c. Their tracks intersect at an angle of less than 45
degrees.
SAR-
SAY AGAIN- Used to request a
repeat of the last transmission. Usually specifies transmission or portion
thereof not understood or received; e.g., "Say again all after ABRAM VOR."
SAY ALTITUDE- Used by ATC to ascertain an aircraft's specific
altitude/flight level. When the aircraft is climbing or descending, the pilot
should state the indicated altitude rounded to the nearest 100 feet.
SAY HEADING- Used by ATC to request an aircraft heading. The
pilot should state the actual heading of the aircraft.
SDF-
(See SIMPLIFIED DIRECTIONAL FACILITY.)
SEA LANE- A designated
portion of water outlined by visual surface markers for and intended to be used
by aircraft designed to operate on water.
SEARCH AND RESCUE- A service which seeks missing aircraft and assists those
found to be in need of assistance. It is a cooperative effort using the
facilities and services of available Federal, state and local agencies. The U.S.
Coast Guard is responsible for coordination of search and rescue for the
Maritime Region, and the U.S. Air Force is responsible for search and rescue for
the Inland Region. Information pertinent to search and rescue should be passed
through any air traffic facility or be transmitted directly to the Rescue
Coordination Center by telephone.
(See FLIGHT SERVICE STATION.)
(See RESCUE COORDINATION CENTER.)
SEARCH AND RESCUE FACILITY- A facility responsible
for maintaining and operating a search and rescue (SAR) service to render aid to
persons and property in distress. It is any SAR unit, station, NET, or other
operational activity which can be usefully employed during an SAR Mission; e.g.,
a Civil Air Patrol Wing, or a Coast Guard Station.
SECTIONAL AERONAUTICAL CHARTS-
(See AERONAUTICAL CHART.)
SECTOR LIST DROP INTERVAL- A parameter
number of minutes after the meter fix time when arrival aircraft will be deleted
from the arrival sector list.
SEE AND AVOID- When weather conditions permit, pilots operating IFR or VFR
are required to observe and maneuver to avoid other aircraft. Right-of-way rules
are contained in FAR Part 91.
SEGMENTED CIRCLE- A system of visual indicators designed to provide traffic
pattern information at airports without operating control towers.
SEGMENTS OF AN INSTRUMENT APPROACH PROCEDURE- An
instrument approach procedure may have as many as four separate segments
depending on how the approach procedure is structured.
a. Initial Approach- The segment between the initial approach fix
and the intermediate fix or the point where the aircraft is established on the
intermediate course or final approach course.
(See ICAO term INITIAL APPROACH SEGMENT.)
b. Intermediate Approach- The segment between the intermediate fix
or point and the final approach fix.
(See ICAO term INTERMEDIATE APPROACH SEGMENT.)
c. Final Approach- The segment between the final approach fix or
point and the runway, airport, or missed approach point.
(See ICAO term FINAL APPROACH SEGMENT.)
d. Missed Approach- The segment between the missed approach point
or the point of arrival at decision height and the missed approach fix at the
prescribed altitude.
(See ICAO term MISSED APPROACH PROCEDURE.)
SELECTED GROUND DELAYS-
A traffic management procedure whereby selected flights are issued ground delays
to better regulate traffic flows over a particular fix or area.
SEPARATION- In air traffic control, the spacing of aircraft to achieve their
safe and orderly movement in flight and while landing and taking off.
(See ICAO term SEPARATION.)
SEPARATION [ICAO]- Spacing between
aircraft, levels or tracks.
SEPARATION MINIMA- The minimum longitudinal, lateral, or vertical distances
by which aircraft are spaced through the application of air traffic control
procedures.
SERVICE- A generic term that designates functions
or assistance available from or rendered by air traffic control. For example,
Class C service would denote the ATC services provided within a Class C airspace
area.
SEVERE WEATHER AVOIDANCE PLAN- An approved plan to minimize the affect of
severe weather on traffic flows in impacted terminal and/or ARTCC areas. SWAP is
normally implemented to provide the least disruption to the ATC system when
flight through portions of airspace is difficult or impossible due to severe
weather.
SEVERE WEATHER FORECAST ALERTS- Preliminary messages issued in order to alert
users that a Severe Weather Watch Bulletin (WW) is being issued. These messages
define areas of possible severe thunderstorms or tornado activity. The messages
are unscheduled and issued as required by the National Severe Storm Forecast
Center at Kansas City, Missouri.
SFA-
(See SINGLE FREQUENCY APPROACH.)
SFO-
(See SIMULATED FLAMEOUT.)
SHF-
(See SUPER HIGH FREQUENCY.)
SHORT RANGE CLEARANCE- A clearance
issued to a departing IFR flight which authorizes IFR flight to a specific fix
short of the destination while air traffic control facilities are coordinating
and obtaining the complete clearance.
SHORT TAKEOFF AND LANDING AIRCRAFT AIRCRAFT- An aircraft which, at some
weight within its approved operating weight, is capable of operating from a STOL
runway in compliance with the applicable STOL characteristics, airworthiness,
operations, noise, and pollution standards.
(See VERTICAL TAKEOFF AND LANDING AIRCRAFT.)
SIAP-
(See STANDARD INSTRUMENT APPROACH PROCEDURE.)
SIDESTEP MANEUVER- A
visual maneuver accomplished by a pilot at the completion of an instrument
approach to permit a straight-in landing on a parallel runway not more than
1,200 feet to either side of the runway to which the instrument approach was
conducted.
SIGMET- A weather advisory issued
concerning weather significant to the safety of all aircraft. SIGMET advisories
cover severe and extreme turbulence, severe icing, and widespread dust or
sandstorms that reduce visibility to less than 3 miles.
(See ICAO term SIGMET INFORMATION.)
SIGMET INFORMATION [ICAO]- Information issued by a
meteorological watch office concerning the occurrence or expected occurrence of
specified en-route weather phenomena which may affect the safety of aircraft
operations.
SIGNIFICANT METEOROLOGICAL INFORMATION-
SIGNIFICANT POINT- A point, whether a named
intersection, a NAVAID, a fix derived from a NAVAID(s), or geographical
coordinate expressed in degrees of latitude and longitude, which is established
for the purpose of providing separation, as a reporting point, or to delineate a
route of flight.
SIMPLIFIED DIRECTIONAL FACILITY- A NAVAID used for nonprecision instrument
approaches. The final approach course is similar to that of an ILS localizer
except that the SDF course may be offset from the runway, generally not more
than 3 degrees, and the course may be wider than the localizer, resulting in a
lower degree of accuracy.
SIMULATED FLAMEOUT- A practice approach by a jet
aircraft (normally military) at idle thrust to a runway. The approach may start
at a runway (high key) and may continue on a relatively high and wide downwind
leg with a continuous turn to final. It terminates in landing or low approach.
The purpose of this approach is to simulate a flameout.
SIMULTANEOUS ILS APPROACHES- An approach system
permitting simultaneous ILS/MLS approaches to airports having parallel runways
separated by at least 4,300 feet between centerlines. Integral parts of a total
system are ILS/MLS, radar, communications, ATC procedures, and appropriate
airborne equipment.
SIMULTANEOUS MLS APPROACHES-
(See SIMULTANEOUS ILS APPROACHES.)
SINGLE DIRECTION ROUTES-
Preferred IFR Routes which are sometimes depicted on high altitude en route
charts and which are normally flown in one direction only.
(See PREFERRED IFR ROUTES.)
(Refer to AIRPORT/FACILITY DIRECTORY.)
SINGLE FREQUENCY APPROACH- A
service provided under a letter of agreement to military single-piloted turbojet
aircraft which permits use of a single UHF frequency during approach for
landing. Pilots will not normally be required to change frequency from the
beginning of the approach to touchdown except that pilots conducting an en route
descent are required to change frequency when control is transferred from the
air route traffic control center to the terminal facility. The abbreviation
"SFA" in the DOD FLIP IFR Supplement under "Communications" indicates this
service is available at an aerodrome.
SINGLE-PILOTED AIRCRAFT- A military turbojet aircraft possessing one set of
flight controls, tandem cockpits, or two sets of flight controls but operated by
one pilot is considered single-piloted by ATC when determining the appropriate
air traffic service to be applied.
(See SINGLE FREQUENCY APPROACH.)
SLASH- A radar beacon reply
displayed as an elongated target.
SLDI-
(See SECTOR LIST DROP INTERVAL.)
SLOT TIME-
(See METER FIX TIME/SLOT TIME.)
SLOW TAXI- To taxi a float plane at
low power or low RPM.
SN-
(See SYSTEM STRATEGIC NAVIGATION.)
SPEAK SLOWER- Used
in verbal communications as a request to reduce speech rate.
SPECIAL EMERGENCY- A condition of air piracy or other hostile act by a
person(s) aboard an aircraft which threatens the safety of the aircraft or its
passengers.
SPECIAL INSTRUMENT APPROACH PROCEDURE-
(See INSTRUMENT APPROACH PROCEDURE.)
SPECIAL USE AIRSPACE- Airspace
of defined dimensions identified by an area on the surface of the earth wherein
activities must be confined because of their nature and/or wherein limitations
may be imposed upon aircraft operations that are not a part of those activities.
Types of special use airspace are:
a. Alert Area- Airspace which may contain a high volume of pilot
training activities or an unusual type 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 Area
are conducted in accordance with Federal Aviation Regulations, and pilots of
participating aircraft as well as pilots transiting the area are 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)- A MOA is 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.
d. Prohibited Area- Airspace designated under part 73 within which
no person may operate an aircraft without the permission of the using
agency.
(Refer to En Route Charts, AIM.)
e. Restricted Area- Airspace designated under FAR 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. Restricted areas are depicted on
en route charts. Where joint use is authorized, the name of the ATC
controlling facility is also shown.
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.)
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.)
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:
1. "Increase/reduce speed to Mach point (number.)"
2. "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 transponder; e.g., "Squawk three/alpha,
two one zero five, low."
STAGING/QUEUING- The placement, integration, and
segregation of departure aircraft in designated movement areas of an airport by
departure fix, EDCT, and/or restriction.
STANDARD INSTRUMENT APPROACH PROCEDURE-
(See INSTRUMENT APPROACH PROCEDURE.)
STANDARD RATE TURN- A turn of
three degrees per second.
STANDARD TERMINAL ARRIVAL- A preplanned instrument flight rule (IFR) air
traffic control arrival procedure published for pilot use in graphic and/or
textual form. STAR's provide transition from the en route structure to an outer
fix or an instrument approach fix/arrival waypoint in the terminal area.
STANDARD TERMINAL ARRIVAL CHARTS-
(See AERONAUTICAL CHART.)
STAND BY- Means the
controller or pilot must pause for a few seconds, usually to attend to other
duties of a higher priority. Also means to wait as in "stand by for clearance."
The caller should reestablish contact if a delay is lengthy. "Stand by" is not
an approval or denial.
STAR-
(See STANDARD TERMINAL ARRIVAL.)
STATE AIRCRAFT- Aircraft used in
military, customs and police service, in the exclusive service of any
government, or of any political subdivision, thereof including the government of
any state, territory, or possession of the United States or the District of
Columbia, but not including any government-owned aircraft engaged in carrying
persons or property for commercial purposes.
STATIC RESTRICTIONS- Those restrictions that are usually not subject to
change, fixed, in place, and/or published.
STATIONARY RESERVATIONS- Altitude reservations which encompass activities in
a fixed area. Stationary reservations may include activities, such as special
tests of weapons systems or equipment, certain U.S. Navy carrier, fleet, and
anti-submarine operations, rocket, missile and drone operations, and certain
aerial refueling or similar operations.
STEPDOWN FIX- A fix permitting additional descent within a segment of an
instrument approach procedure by identifying a point at which a controlling
obstacle has been safely overflown.
STEP TAXI- To taxi a float plane at full power or high RPM.
STEP TURN- A maneuver used to put a float plane in a planing configuration
prior to entering an active sea lane for takeoff. The STEP TURN maneuver should
only be used upon pilot request.
STEREO ROUTE- A routinely used route of flight established by users and
ARTCC's identified by a coded name; e.g., ALPHA 2. These routes minimize flight
plan handling and communications.
STOL AIRCRAFT-
(See SHORT TAKEOFF AND LANDING AIRCRAFT.)
STOP ALTITUDE
SQUAWK- Used by ATC to inform an aircraft to turn-off the automatic
altitude reporting feature of its transponder. It is issued when the verbally
reported altitude varies 300 feet or more from the automatic altitude report.
STOP AND GO- A procedure wherein an aircraft
will land, make a complete stop on the runway, and then commence a takeoff from
that point.
STOP BURST-
STOP BUZZER-
STOPOVER FLIGHT PLAN- A flight plan format which
permits in a single submission the filing of a sequence of flight plans through
interim full-stop destinations to a final destination.
STOP SQUAWK (Mode or Code)- Used by ATC to tell the pilot to
turn specified functions of the aircraft transponder off.
(See STOP ALTITUDE SQUAWK.)
STOP STREAM- Used by ATC to
request a pilot to suspend electronic countermeasure activity.
STOPWAY- An area beyond the takeoff runway no less
wide than the runway and centered upon the extended centerline of the runway,
able to support the airplane during an aborted takeoff, without causing
structural damage to the airplane, and designated by the airport authorities for
use in decelerating the airplane during an aborted takeoff.
STRAIGHT-IN APPROACH IFR- An instrument approach wherein final approach is
begun without first having executed a procedure turn, not necessarily completed
with a straight-in landing or made to straight-in landing minimums.
(See STRAIGHT-IN LANDING.)
(See STRAIGHT-IN APPROACH VFR.)
STRAIGHT-IN APPROACH VFR- Entry
into the traffic pattern by interception of the extended runway centerline
(final approach course) without executing any other portion of the traffic
pattern.
STRAIGHT-IN LANDING- A landing made on a
runway aligned within 30ฐ of the final approach course following completion of
an instrument approach.
(See STRAIGHT-IN APPROACH-IFR.)
STRAIGHT-IN LANDING MINIMUMS-
STRAIGHT-IN MINIMUMS-
(See STRAIGHT-IN LANDING MINIMUMS.)
SUBSTITUTIONS- Users are
permitted to exchange CTA's. Normally, the airline dispatcher will contact the
ATCSCC with this request. The ATCSCC shall forward approved substitutions to the
TMU's who will notify the appropriate terminals. Permissible swapping must not
change the traffic load for any given hour of an EQF program.
SUBSTITUTE ROUTE- A route assigned to pilots when any part of an airway or
route is unusable because of NAVAID status. These routes consist of:
a. Substitute routes which are shown on U.S. Government charts.
b. Routes defined by ATC as specific NAVAID radials or courses.
c. Routes defined by ATC as direct to or between NAVAID's.
SUNSET
AND SUNRISE- The mean solar times of sunset and sunrise as published in the
Nautical Almanac, converted to local standard time for the locality concerned.
Within Alaska, the end of evening civil twilight and the beginning of morning
civil twilight, as defined for each locality.
SUPER HIGH FREQUENCY- The frequency band between 3 and 30 gigahertz (GHz).
The elevation and azimuth stations of the microwave landing system operate from
5031 MHz to 5091 MHz in this spectrum.
SUPPLEMENTAL WEATHER SERVICE LOCATION- Airport facilities staffed with
contract personnel who take weather observations and provide current local
weather to pilots via telephone or radio. (All other services are provided by
the parent FSS).
SUPPS- Refers to ICAO Document 7030 Regional Supplementary Procedures. SUPPS
contain procedures for each ICAO Region which are unique to that Region and are
not covered in the worldwide provisions identified in the ICAO Air Navigation
Plan. Procedures contained in chapter 8 are based in part on those published in
SUPPS.
SURFACE AREA- The airspace contained by the lateral boundary of the Class B,
C, D, or E airspace designated for an airport that begins at the surface and
extends upward.
SURPIC- A description of surface vessels in the area of a Search and Rescue
incident including their predicted positions and their characteristics.
(See FAA Order 7110.65, paragraph 10-6-4, INFLIGHT
CONTINGENCIES.)
SURVEILLANCE APPROACH- An instrument approach wherein
the air traffic controller issues instructions, for pilot compliance, based on
aircraft position in relation to the final approach course (azimuth), and the
distance (range) from the end of the runway as displayed on the controller's
radar scope. The controller will provide recommended altitudes on final approach
if requested by the pilot.
SWAP- (See SEVERE WEATHER AVOIDANCE PLAN.)
SWSL- (See SUPPLEMENTAL WEATHER SERVICE LOCATION.)
SYSTEM STRATEGIC NAVIGATION- Military activity accomplished by navigating
along a preplanned route using internal aircraft systems to maintain a desired
track. This activity normally requires a lateral route width of 10 NM and
altitude range of 1,000 feet to 6,000 feet AGL with some route segments that
permit terrain following.