PCG SAFETY ALERT -- SYSTEM STRATEGIC NAVIGATION
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
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
a. They are following the same track in the same direction;
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.
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.
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.
(See SIMPLIFIED DIRECTIONAL FACILITY.)
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.)
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 RESCUE COORDINATION CENTER.)
SECTOR LIST DROP INTERVAL- A parameter number of minutes after the meter
fix time when arrival aircraft will be deleted from the arrival sector
(See AERONAUTICAL CHART.)
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.
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.
(See ICAO term MISSED APPROACH PROCEDURE.)
SEPARATION- In air traffic control, the spacing of aircraft to achieve
their safe and orderly movement in flight and while landing and taking
SEPARATION [ICAO]- Spacing between aircraft, levels or tracks.
(See ICAO term SEPARATION.)
SEPARATION MINIMA- The minimum longitudinal, lateral, or vertical distances
by which aircraft are spaced through the application of air traffic control
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.
(See SINGLE FREQUENCY APPROACH.)
(See SIMULATED FLAMEOUT.)
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
(See SUPER HIGH FREQUENCY.)
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.)
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 STANDARD INSTRUMENT APPROACH PROCEDURE.)
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.
(See ICAO term SIGMET INFORMATION.)
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
SIMULTANEOUS MLS 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
(See SIMULTANEOUS ILS APPROACHES.)
(See PREFERRED IFR ROUTES.)
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.
(Refer to AIRPORT/FACILITY DIRECTORY.)
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.
SLASH- A radar beacon reply displayed as an elongated target.
(See SINGLE FREQUENCY APPROACH.)
(See SECTOR LIST DROP INTERVAL.)
SLOW TAXI- To taxi a float plane at low power or low RPM.
(See METER FIX TIME/SLOT TIME.)
SPEAK SLOWER- Used in verbal communications as a request
to reduce speech rate.
(See SYSTEM STRATEGIC NAVIGATION.)
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-
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
(See INSTRUMENT APPROACH PROCEDURE.)
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
(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.
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
(See SPECIAL VFR OPERATIONS.)
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.)
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.
(See ICAO term SPECIAL VFR FLIGHT.)
Examples of speed adjustments are:
1. "Increase/reduce speed to Mach point (number.)"
SPEED BRAKES- Moveable aerodynamic devices on aircraft that reduce airspeed
during descent and landing.
2. "Increase/reduce speed to (speed in knots)" or "Increase/reduce
speed (number of knots) knots."
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
SQUAWK (Mode, Code, Function)- Activate specific modes/codes/functions
on the aircraft transponder; e.g., "Squawk three/alpha, two one zero five,
STAGING/QUEUING- The placement, integration, and segregation of departure
aircraft in designated movement areas of an airport by departure fix, EDCT,
STANDARD INSTRUMENT APPROACH PROCEDURE-
STANDARD RATE TURN- A turn of three degrees per second.
(See INSTRUMENT APPROACH PROCEDURE.)
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
STANDARD TERMINAL ARRIVAL CHARTS-
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.
(See AERONAUTICAL CHART.)
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
(See STANDARD TERMINAL ARRIVAL.)
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.
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.
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.
(See SHORT TAKEOFF AND LANDING AIRCRAFT.)
STOP SQUAWK (Mode or Code)- Used by ATC to tell the pilot
to turn specified functions of the aircraft transponder off.
STOP STREAM- Used by ATC to request a pilot to suspend electronic
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.
(See STOP ALTITUDE SQUAWK.)
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.)
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 30°
of the final approach course following completion of an instrument approach.
(See STRAIGHT-IN APPROACH VFR.)
STRAIGHT-IN LANDING MINIMUMS-
(See STRAIGHT-IN APPROACH-IFR.)
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.
(See STRAIGHT-IN LANDING MINIMUMS.)
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.
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.)
(See FAA Order 7110.65, paragraph 10-6-4, INFLIGHT CONTINGENCIES.)
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.