Aviation and air traffic control terminology · MLC-0104

Aviation and air traffic control terms: S (105)

• SAA, see Sense and avoid (SAA); Special activity airspace (SAA)
• Safety alertA safety alert issued by ATC to aircraft under their control if ATC is aware the aircraft is at an altitude...
• Safety logic systemA software enhancement to ASDE-3, ASDE-X, and ASSC, that predicts the path of aircraft landing and/or...
• Safety logic system alertsa. ALERT-
• Sail backA maneuver during high wind conditions (usually with power off) where float plane movement is controlled by...
• Same direction aircraftAircraft are operating in the same direction when:
• SAR, see Search and rescue
• Satellite-based augmentation system (SBAS)A wide coverage augmentation system in which the user receives augmentation information from a...
• SAW, see Aviation watch notification message
• Say againUsed to request a repeat of the last transmission. Usually specifies transmission or portion thereof not...
• Say altitudeUsed by ATC to ascertain an aircraft's specific altitude/flight level. When the aircraft is climbing or...
• Say headingUsed by ATC to request an aircraft heading. The pilot should state the actual heading of the aircraft.
• Scheduled time of arrival (STA)A STA is the desired time that an aircraft should cross a certain point (landing or metering fix). It takes...
• SE SAR, see Surveillance enhanced search and rescue (SE SAR)
• Sea laneA designated portion of water outlined by visual surface markers for and intended to be used by aircraft...
• Search and rescueA service which seeks missing aircraft and assists those found to be in need of assistance. It is a...
• Search and rescue facilityA facility responsible for maintaining and operating a search and rescue (SAR) service to render aid to...
• SECNOT, see Security notice (SECNOT)
• Secondary radar targetA target derived from a transponder return presented on a radar display.
• Sectional aeronautical charts, see Aeronautical chart
• Sector list drop intervalA parameter number of minutes after the meter fix time when arrival aircraft will be deleted from the arrival...
• Security notice (SECNOT)A SECNOT is a request originated by the Air Traffic Security Coordinator (ATSC) for an extensive...
• Security services airspaceAreas established through the regulatory process or by NOTAM, issued by the Administrator under title 14...
• See and avoidWhen weather conditions permit, pilots operating IFR or VFR are required to observe and maneuver to avoid...
• Segmented circleA system of visual indicators designed to provide traffic pattern information at airports without operating...
• Segments of a SID/STARa. En Route Transition- The segment(s) of a SID/STAR that connect to/from en route flight. Not all SIDs/STARs...
• Segments of an instrument approach procedureAn instrument approach procedure may have as many as four separate segments depending on how the approach...
• Self-briefingA self-briefing is a review, using automated tools, of all meteorological and aeronautical information that...
• Sense and avoid (SAA)The capability of an unmanned aircraft to detect (sense) and avoid collisions with other aircraft and all...
• SeparationIn air traffic control, the spacing of aircraft to achieve their safe and orderly movement in flight and...
• Separation [ICAO]Spacing between aircraft, levels or tracks.
• Separation minimaThe minimum longitudinal, lateral, or vertical distances by which aircraft are spaced through the application...
• ServiceA generic term that designates functions or assistance available from or rendered by air traffic control. For...
• Severe weather avoidance plan (SWAP)An approved plan to minimize the affect of severe weather on traffic flows in impacted terminal and/or ARTCC...
• Severe weather forecast alertsPreliminary messages issued in order to alert users that a Severe Weather Watch Bulletin (WW) is being...
• SFA, see Single frequency approach
• SFO, see Simulated flameout
• SGI, see Special government interest (SGI)
• Short range clearanceA clearance issued to a departing IFR flight which authorizes IFR flight to a specific fix short of the...
• Short takeoff and landing aircraft (STOL)An aircraft which, at some weight within its approved operating weight, is capable of operating from a runway...
• SID, see Standard instrument departure (SID)
• Sidestep maneuverA visual maneuver accomplished by a pilot at the completion of an instrument approach to permit a straight-in...
• SIGMETA weather advisory issued concerning weather significant to the safety of all aircraft. SIGMET advisories...
• SIGMET information [ICAO]Information issued by a meteorological watch office concerning the occurrence or expected occurrence of...
• Significant meteorological information, see SIGMET
• Significant pointA point, whether a named intersection, a NAVAID, a fix derived from a NAVAID(s), or geographical coordinate...
• Simulated flameoutA practice approach by a jet aircraft (normally military) at idle thrust to a runway. The approach may start...
• Simultaneous close parallel approachesA simultaneous, independent approach operation permitting ILS/RNAV/GLS approaches to airports having parallel...
• Simultaneous (converging) dependent approachesAn approach operation permitting ILS/RNAV/GLS approaches to runways or missed approach courses that intersect...
• Simultaneous (converging) independent approachesAn approach operation permitting ILS/RNAV/GLS approaches to non-parallel runways where approach procedure...
• Simultaneous ILS approachesAn approach system permitting simultaneous ILS approaches to airports having parallel runways separated by at...
• Simultaneous offset instrument approach (SOIA)An instrument landing system comprised of an ILS PRM, RNAV PRM or GLS PRM approach to one runway and an...
• Simultaneous (parallel) dependent approachesAn approach operation permitting approaches to adjacent parallel runways where prescribed diagonal spacing...
• Single direction routesPreferred IFR Routes which are sometimes depicted on high altitude en route charts and which are normally...
• Single frequency approachA service provided under a letter of agreement to military single-piloted turbojet aircraft which permits use...
• Single-piloted aircraftA military turbojet aircraft possessing one set of flight controls, tandem cockpits, or two sets of flight...
• SkyspotterA pilot who has received specialized training in observing and reporting inflight weather phenomena.
• SlashA radar beacon reply displayed as an elongated target.
• SLDI, see Sector list drop interval
• Slow taxiTo taxi a float plane at low power or low RPM.
• Small unmanned aircraft system (sUAS)An unmanned aircraft weighing less than 55 pounds on takeoff, including everything that is on board or...
• SN, see System strategic navigation
• Space launch and reentry areaLocations where commercial space launch and/or reentry operations occur. For pilot awareness, a rocket-shaped...
• Space-based ADS-B (SBA)A constellation of satellites that receives ADS-B Out broadcasts and relays that information to the...
• Speak slowerUsed in verbal communications as a request to reduce speech rate.
• Special activity airspace (SAA)Airspace with defined dimensions within the National Airspace System wherein limitations may be imposed upon...
• Special air traffic rules (SATR)Rules that govern procedures for conducting flights in certain areas listed in 14 CFR part 93. The term...
• Special emergencyA condition of air piracy or other hostile act by a person(s) aboard an aircraft which threatens the safety...
• Special flight rules area (SFRA)An area in the NAS, described in 14 CFR part 93, wherein the flight of aircraft is subject to special traffic...
• Special government interest (SGI)A near real-time airspace authorization for part 91 or part 107 UAS, which supports activities that answer...
• Special instrument approach procedureSPECIAL MILITARY ACTIVITY ROUTE (SMAR) - A route, which may also be charted on the VFR Sectional Chart, that...
• Special use airspaceAirspace of defined dimensions identified by an area on the surface of the earth wherein activities must be...
• Special VFR conditionsMeteorological conditions that are less than those required for basic VFR flight in Class B, C, D, or E...
• Special VFR flight [ICAO]A VFR flight cleared by air traffic control to operate within Class B, C, D, and E surface areas in...
• Special VFR operationsAircraft operating in accordance with clearances within Class B, C, D, and E surface areas in weather...
• SpecialistPROVIDED SERVICES - Services delivered directly by a flight service specialist via ground/ground...
• Speed, see Airspeed; Ground speed
• Speed adjustmentAn ATC procedure used to request pilots to adjust aircraft speed to a specific value for the purpose of...
• Speed advisorySpeed advisories that are generated within Time-Based Flow Management to assist controllers to meet the...
• Speed brakesMoveable aerodynamic devices on aircraft that reduce airspeed during descent and landing.
• Speed segmentsPortions of the arrival route between the transition point and the vertex along the optimum flight path for...
• SpoofingDenotes emissions of GNSS-like signals that may be acquired and tracked in combination with or instead of the...
• Squawk (Mode, Code, Function)Used by ATC to instruct a pilot to activate the aircraft transponder and ADS-B Out with altitude reporting...
• STA, see Scheduled time of arrival (STA)
• Staging/queuingThe placement, integration, and segregation of departure aircraft in designated movement areas of an airport...
• Stand byMeans the controller or pilot must pause for a few seconds, usually to attend to other duties of a higher...
• Standard instrument approach procedure (SIAP), see Instrument approach procedure
• Standard instrument departure (SID)A preplanned instrument flight rule (IFR) air traffic control (ATC) departure procedure printed for...
• Standard rate turnA turn of three degrees per second.
• Standard terminal arrival charts, see Aeronautical chart
• Standard terminal arrival (STAR)A preplanned instrument flight rule (IFR) air traffic control arrival procedure published for pilot use in...
• STAR, see Standard terminal arrival (STAR)
• State aircraftAircraft used in military, customs and police service, in the exclusive service of any government or of any...
• Static restrictionsThose restrictions that are usually not subject to change, fixed, in place, and/or published.
• Stationary airspace reservationThe term used in oceanic ATC for airspace that encompasses activities in a fixed volume of airspace to be...
• Stationary altitude reservation (stationary ALTRV)An altitude reservation which encompasses activities in a fixed volume of airspace to be occupied for a...
• Step taxiTo taxi a float plane at full power or high RPM.
• Step turnA maneuver used to put a float plane in a planing configuration prior to entering an active sea lane for...
• Stepdown fixA fix permitting additional descent within a segment of an instrument approach procedure by identifying a...
• Stereo routeA routinely used route of flight established by users and ARTCCs identified by a coded name; e.g., ALPHA 2...
• STNR alt reservationAn abbreviation for Stationary Altitude Reservation commonly used in NOTAMs.
• STOL aircraft, see Short takeoff and landing aircraft (STOL)
• Stop altitude squawkUsed by ATC to instruct a pilot to turn off the automatic altitude reporting feature of the aircraft...
• Stop and goA procedure wherein an aircraft will land, make a complete stop on the runway, and then commence a takeoff...
• Stop burst, see Stop stream
• Stop buzzer, see Stop stream
• Stop squawk (Mode or Code)Used by ATC to instruct a pilot to stop transponder and ADS-B transmissions, or to turn off only specified...
• Stop streamUsed by ATC to request a pilot to suspend electronic attack activity.
• Stopover flight planA flight plan format which permits in a single submission the filing of a sequence of flight plans through...
• StopwayAn area beyond the takeoff runway no less wide than the runway and centered upon the extended centerline of...
• Straight-in approach IFRAn instrument approach wherein final approach is begun without first having executed a procedure turn, not...
• Straight-in approach VFREntry into the traffic pattern by interception of the extended runway centerline (final approach course)...
• Straight-in landingA landing made on a runway aligned within 30° of the final approach course following completion of an...
• Straight-in landing minimums, see Landing minimums
• Strategic planningPlanning whereby solutions are sought to resolve potential conflicts.
• sUAS, see Small unmanned aircraft system (sUAS)
• Substitute routeA route assigned to pilots when any part of an airway or route is unusable because of NAVAID status. These...
• Sunset and sunriseThe mean solar times of sunset and sunrise as published in the Nautical Almanac, converted to local standard...
• Supplemental weather service locationAirport facilities staffed with contract personnel who take weather observations and provide current local...
• SUPPSRefers to ICAO Document 7030 Regional Supplementary Procedures. SUPPS contain procedures for each ICAO Region...
• Surface areaThe airspace contained by the lateral boundary of the Class B, C, D, or E airspace designated for an airport...
• Surface metering programA capability within Terminal Flight Data Manager that provides the user with the ability to tactically manage...
• Surface viewerA capability within the Traffic Flow Management System that provides situational awareness for a...
• SURPICA description of surface vessels in the area of a Search and Rescue incident including their predicted...
• Surveillance approachAn instrument approach wherein the air traffic controller issues instructions, for pilot compliance, based on...
• Surveillance enhanced search and rescue (SE SAR)An automated service used to enhance search and rescue operations that provides federal contract flight...
• Suspicious UASSuspicious UAS operations may include operating without authorization, loitering in the vicinity of sensitive...
• SWAP, see Severe weather avoidance plan (SWAP)
• SWSL, see Supplemental weather service location
• System strategic navigationMilitary activity accomplished by navigating along a preplanned route using internal aircraft systems to...

105 of 1,122 terms in Aviation and air traffic control terminology (MLC-0104). Request the full dataset.